WorldWideScience

Sample records for roll mill grinding

  1. Control of grinding the mandrel working surface of cold-rolling mills

    OpenAIRE

    Петраков, Юрій Володимирович; Чамата, Сергій Миколайович

    2015-01-01

    It was found that for maximum performance of grinding the mandrel working surface of cold rolling mills at fulfilling all quality requirements for the machined surface, a graph of the material removal rate (MaterialRemovalRate) throughout the grinding cycle must be located in the region of acceptability, which is limited by the marginal algorithm as close to the boundaries of this region as possible. A problem of determining the material removal rate in grinding the curved surface of the mand...

  2. Grinding arrangement for ball nose milling cutters

    Science.gov (United States)

    Burch, C. F. (inventor)

    1974-01-01

    A grinding arrangement for spiral fluted ball nose end mills and like tools includes a tool holder for positioning the tool relative to a grinding wheel. The tool is mounted in a spindle within the tool holder for rotation about its centerline and the tool holder is pivotably mounted for angular movement about an axis which intersects that centerline. A follower arm of a cam follower secured to the spindle cooperates with a specially shaped cam to provide rotation of the tool during the angular movement of the tool holder during the grinding cycle, by an amount determined by the cam profile. In this way the surface of the cutting edge in contact with the grinding wheel is maintained at the same height on the grinding wheel throughout the angular movement of the tool holder during the grinding cycle.

  3. Continuous grinding mill simulation using Austin's model

    Directory of Open Access Journals (Sweden)

    André Carlos Silva

    2012-01-01

    Full Text Available Comminution is a frequently-required step in mineral processing and is responsible for almost 90% of all energy consumption in a mineral processing plant. Tumbling mill design has been studied since the middle of the XIX century. There are many comminution models in the literature, with preponderance, however, of Austin’s model (2002 for mineral impact breakage. In this paper, Austin’s model was applied to tubular tumbling mills. Once Austin's model was proposed for batch processing of narrowly-distributed fraction sizes, an artifice has allowed it to be used in continuous grinding mill processes with widely-distributed fraction sizes. Interesting results were obtained with errors less than 0.005 for mills with sharp residence time distributions.

  4. Evaluation of Recycle Grinding Performance in Flour Milling

    OpenAIRE

    Siti Mazlina Mustapa Kamal; Colin Webb

    2007-01-01

    A typical flour milling process is a very linear operation that is almost entirely void of recycled streams where separate fractions from each operation go ahead as new streams to the next operation. In some cases, there are opportunities for combining some streams, for recycling particles that have been insufficiently broken to go back to the same roller mill. This study introduces this recycle concept in flour milling process at second break system. The recycle grinding assessment was made ...

  5. NUMERICAL EVALUATION OF TEMPERATURE DISTRIBUTION IN THE ROLLING MILL ROLLS

    Directory of Open Access Journals (Sweden)

    José Claudino de Lira Júnior

    2013-06-01

    Full Text Available In hot rolling processes occur changes in the profile of the rolling mill rolls (expansion and contraction and constant wear due to mechanical stress and continuous thermal cycles of heating/cooling caused by contact rolled material- working roll and the cooling system by water jets in their surface, decreasing their lifetime. This paper presents a computational model to simulate the thermal performance of rolling mill rolls. The model was developed using the finite volume method for a transient two-dimensional system and allows calculating the temperature distribution of the rolling mill rolls under various conditions of service. Here it is investigated the influence of flow rate and temperature of the cooling water on the temperature distribution. The results show that the water temperature has greater influence than the water flow to control the surface temperature of the cylinders.

  6. Research on roll wear of 2050mm hot strip finishing train (CVC Mill) of Baosteel

    International Nuclear Information System (INIS)

    In this paper, the general characteristics and affecting factors of work and backup rolls wear of finishing train were analyzed. Taking the CVC finishing mills of 2050mm hot strip mill of Baosteel as an example, the roll wear magnitude and contour were calculated in theory, and measured by the present grinding machine in experiment. The calculated results agree well with the measured data in distribution, and also in general characteristics. Based on the calculated and measured results, an on-line prediction model by which the roll wear distribution characteristics of a CVC mill can be revealed more accurately was proposed. (author)

  7. Evaluation of Recycle Grinding Performance in Flour Milling

    Directory of Open Access Journals (Sweden)

    Siti Mazlina Mustapa Kamal

    2007-01-01

    Full Text Available A typical flour milling process is a very linear operation that is almost entirely void of recycled streams where separate fractions from each operation go ahead as new streams to the next operation. In some cases, there are opportunities for combining some streams, for recycling particles that have been insufficiently broken to go back to the same roller mill. This study introduces this recycle concept in flour milling process at second break system. The recycle grinding assessment was made using a Satake STR-100 test roller mill. The recycle process was started after the second break system and the number of recycle grinding was up to 7 regrinds. The particle size distribution and ash analysis were produced to describe the behaviour of the recycle grinding performance. The material release was sifted on a range of sieves and the ash content was analysed using a laboratory furnace. The performance for each recycle stage was investigated. It was determined that it is possible for some coarse particles that contain only bran to keep being recycled in the recycle circuit. A purging operation was recommended to be included in the recycle system, to separate the unwanted particles.

  8. ELECTRO-RESISTANCE METHOD OF CHECK A PROCESS GRINDING THE ROLLING BEARINGS

    Directory of Open Access Journals (Sweden)

    K. V. Podmasteryev

    2015-08-01

    Full Text Available Base a possibility of monitoring processes of grinding the rolling bearings with use electroresistance method of check. Is write of essence this method, are analyses his peculiarities, which are provide objective information on the condition a object by his grinding. Are consider the results of experimental researches the effective different diagnostically parameters, which are confirm a possibility of realization objective check of grinding the rolling bearings with use electro-resistance method.

  9. Energy efficiency definition of a grinding process in a ball mill

    OpenAIRE

    Кузнецова, Мария Максимовна; Ведь, Валерий Евгеньевич; Вамболь, Сергей Александрович

    2014-01-01

    Theoretical, analytical and experimental studies of the solid materials grinding process in the ball mill have shown that it is possible to improve the energy efficiency of the grinding process by implementing the direct blow effect, ensuring rational grinding mode and correlation of destructive loads during dispersion of specific material with the prescribed physical and mechanical properties. A phenomenological model of energy efficiency of grinding solid materials in the ball mill was deve...

  10. Tribology; Cold rolling mill roll; Hard chrome; Surface texturing.

    Directory of Open Access Journals (Sweden)

    Jos Lucio Gonalves Junior

    2012-12-01

    Full Text Available The present work analyzes the tribological behavior of surface modifications often used in cold rolling mill rolls. Different surface modifications were carried out on samples produced from a fragment of the rolling mill roll: i texturing; ii chromium plating; iii texturing with subsequent hard chrome plating; iv and hard chrome plating with subsequent texturing. Before the surface modifications the samples were heat treated and ground on both faces. Wear tests were performed using a reciprocating movement of a ball over flat configuration under a load of 9.8 N. It is observed that there is no significant change in the coefficient of friction as a function of surface modification. Surface texturing increases the wear of the counter body, while the hard chromium coating reduces it. The addition of hard chromium coating promotes the formation of a tribolayer on the counter body consisting of chromium and oxygen. On the other hand, for the samples without hard chrome coating, the tribolayer consists of iron and oxygen

  11. Metallurgical analysis of spalled work roll of hot strip mill

    International Nuclear Information System (INIS)

    In this study failure analysis of four work roll of the Hot Strip Mill is carried out. The microstructure is correlated with the chemical composition of shell and roll-life. It was concluded that for the longer service of the roll, cementite, graphite and martensite should be balanced (as per working requirement of the mill). (author)

  12. Grinding Kinetics of Vanadium-Titanium Magnetite Concentrate in a Damp Mill and Its Properties

    Science.gov (United States)

    Long, Hongming; Chun, Tiejun; Wang, Ping; Meng, Qingmin; Di, Zhanxia; Li, Jiaxin

    2016-03-01

    The grinding behavior of the as-received (5 pct moisture) vanadium-titanium magnetite concentrates in a damp mill was investigated in this paper. A grinding kinetics equation was established based on a population balance model using size distribution data obtained from a laser diffraction technique. X-ray diffraction results show that a loss in crystallinity occurs when the grinding time is increased. The crystallite size of the materials decreased, whereas their structural microstrain increased with increasing grinding time. The wettability increased because the surface roughness increases with increasing grinding time. The moisture capacity of the solids increased during the first 3 minutes of grinding and then remained roughly constant with further increases in grinding time. The water transfer coefficient of the particles increased at grinding times of 3 and 6 minutes and then decreased at grinding times of 9 and 12 minutes. The compressive strength of oxidized pellets increased with increasing grinding time; longer grinding times can compensate for the effects of lower roasting temperature or shorter roasting time on the strength of the pellets. Lowering the roasting temperature and shortening the roasting time by grinding appeared to be possible.

  13. 7th Hungarian conference of rolling mill engineers

    Energy Technology Data Exchange (ETDEWEB)

    Krautmacher, H.

    1981-12-17

    Six main subjects were discussed at the 7th Hungarian Conference of Rolling Mill Operators on September 29 to October 1, 1981, in Eger/Hungary. The article comments on each of these fields. One of the fields was 'energy economy in rolling mills', of which the contribution by S. Farkas, 'energy-saving furnaces for rolling mills' is presented.

  14. The Adaptive Control of Accuracy at Centerless Grinding of Rolling Bearings

    Science.gov (United States)

    Yalovoy, O. A.; Zakharov, O. V.; Kochetkov, A. V.

    2015-10-01

    The method of adaptive control of accuracy at centerless grinding is developed. This method is based on statistical modeling of Monte Carlo and considers basic data of measurement of roundness of details. Results of application of the method for control of the accuracy of processing of rings of rolling bearings are given.

  15. A Kinetic Study of Micronization Grinding of Dry Mica in a Planetary Ball Mill

    OpenAIRE

    Ljubica Pavlović; Milan Petrov; Milan Trumić; Zagorka Aćimović-Pavlović; Ljubiša Andrić; Anja Terzić

    2013-01-01

    This paper presents results of the research of micronization grinding of dry mica in a planetary ball mill. Investigation was conducted in order to improve the quality and to obtain clearly defined properties and characteristics of mica powder. The micronization grinding of dry mica was performed in four time periods: 30, 60, 120, and 360 minutes. The micronized powder was investigated by means of differential thermal and thermogravimetric analyses, analysis of the degree of micronization, th...

  16. Structural investigations of HSS rolls for hot strip mill

    OpenAIRE

    Lecomte-Beckers, Jacqueline; Tchuindjang, Jérôme Tchoufack; Ernst, R.; Breyer, J.-P.

    2004-01-01

    High Speed Steel (HSS) cast rolls are used in front finishing stands of hot strip mills (HSM). Good wear resistance and hardness at high temperatures, are defining features of HSS. Previous experience has shown that HSS rolls containing mainly hard MC carbides have a high friction coefficient, which is detrimental for the rolling power consumption and for the strip surface quality. On the other hand, HSS rolls containing eutectic rod shaped carbides are brittle and more susc...

  17. EXTREME MANAGEMENT OF PERFORMANCE GRINDING OF LIMESTONE INTO TWO-CHAMBER BALL MILLS

    Directory of Open Access Journals (Sweden)

    UZHELOVSKY V. A.

    2016-02-01

    Full Text Available Problem statement. The productivity of ball mills is an important process parameter. Optimization of loading of the mill will get the maximum efficiency of grinding limestone. Analysis of theresent research. In the scientific work on the process control of grinding in ball mills, particularly interesting are the work of Alekseev B. V., Maksimenko A. A., Uteush E. V., Bapat D. D., Kaminsky A. D. It is proved that the assessment of management effectiveness limestone grinding in a ball mill is a multiobjective and must provide to achieve the highest possible performance and the required fineness of electricity at the lowest cost. A significant factor affecting the performance of the mill is utilization level of limestone. Purpose. Performance of two-chamber ball mill increased by maintaining an optimal level of loading of the drum limestone. Conclusions. 1. In Matlab package developed and investigated simulation model of extreme performance management of a ball mill by optimizing the filling level of the drum limestone. 2. Simulation model allows you to study the influence of various factors on the performance of the mill and determine the previous settings establish extreme regulator to obtain the desired transition process with a given accuracy at the stage of design work.

  18. Structural causes of defects in a cast iron mill roll

    Directory of Open Access Journals (Sweden)

    J. Krawczyk

    2008-07-01

    Full Text Available This paper describes an analysis of a defective microstructure of a mill roll. For this purpose, a piece of a broken roll was collected. That roll was made of mottled cast iron. Its microstructure consisted of modular graphite, transformed ledeburite and a matrix composed of bainite and martensite. Metallographic investigations were performed nearby the fracture in the roll. Observations were conducted on polished sections, first not etched, and then etched, which allowed us to trace carefully the propagation of the fracture. There was found a strict correlation between the microstructure of the roll and the progress occurring in the crack. It was ascertained that the basic reason for the damage to the roll was banded precipitations of ledeburitic cementite. In addition, cementite formed a continuous network. Another microstructure defects of that roll are also precipitations of secondary carbides on the boundaries of former grain of austenite as well as the occurrence of upper bainite in its matrix. The results obtained hereunder allow broadening the data base relative to the genesis of damages to mill rolls, which in future will permit one to design a proper microstructure of cast iron mill rolls. Proper microstructure of cast iron mill roll should be shaped at the stage of designing the chemical composition, conditions of crystallization or heat treatment if any.

  19. Influence of pin and hammer mill on grinding characteristics, thermal and antioxidant properties of coriander powder.

    Science.gov (United States)

    Barnwal, P; Singh, K K; Sharma, Alka; Choudhary, A K; Saxena, S N

    2015-12-01

    In present study, influence of grinding (hammer and pin mills) and moisture content (range: 6.4-13.6 % dry basis) on the quality traits of coriander powder were investigated. These include grinding parameters, colour parameters, specific heat, thermal conductivity, thermal diffusivity, glass transition temperature, essential oil, total phenolic content, total flavonoid content and DPPH scavenging (%) of coriander powder. For coriander seed, the geometric properties such as major, medium, minor dimensions, geometric mean diameter, arithmetic mean diameter, sphericity, surface area and volume of coriander seeds increased significantly with increasing moisture (6.4-13.6 % db). For coriander powder, the grinding parameters such as average particle size, volume surface mean diameter and volume mean diameter increased significantly with increasing moisture (6.4-13.6 % db). With the grinding method, the colour attributes of coriander powder such as L-value, a-value, b-value, hue angle and browning index varied significantly. It was observed that the specific heat followed second order polynomial relationship with temperature and moisture whereas thermal conductivity varied linearly with temperature and moisture content. The variation of glass transition temperature with moisture can be best represented in quadratic manner. Total flavonoid content (mg QE/g crude seed extract) and DPPH scavenging % activity of coriander powder is significantly affected by grinding methods. A lower value of specific heat was observed for hammer ground coriander powder as compared to pin mill ground coriander powder. The thermal conductivity of hammer mill ground coriander powder was higher as compared to pin mill ground coriander. It was observed that hammer mill yields more fine coriander powder in comparison to pin mill. The browning index was more in hammer mill ground coriander powder. PMID:26604351

  20. THEORETICAL AND EXPERIMENTAL STUDIES OF ENERGY-EFFICIENT GRINDING PROCESS OF CEMENT CLINKER IN A BALL MILL

    Directory of Open Access Journals (Sweden)

    Kuznetsova M.M.

    2014-08-01

    Full Text Available The article presents results of theoretical and experimental research of grinding process of bulk materials in a ball mill. The new method of determination of energy efficiently mode of operation of ball mills in a process of a cement clinker grinding is proposed and experimentally tested.

  1. Technological design for rolling uranium rod by Y-type rolling mill with three rollers

    International Nuclear Information System (INIS)

    The fundamental characteristics of Y-type rolling mill with three rollers and the methods for designing and calculating the grooves are described. The feasibility of producing metallic uranium rod is substantiated by the experiment in continuous rolling. The advantage of this process in rolling metallic uranium rod is analysed

  2. Optimum condition determination of Rirang uranium ores grinding using ball mill

    International Nuclear Information System (INIS)

    The grinding experiment on Rirang Uranium ore has been carried out with the aim is to find out the optimum condition of wet grinding using ball mill to produce particle size -325, -200 and -100 mesh. This will be used for decomposition feed the test was done by examine the parameters comparison of ore's weight against ball's weight and time of grinding. The test shown that the product of particle size -325 meshes was achieved optimum condition at the comparison ore's weight: ball = 1:3, grinding time 150 minutes, % solid 60, speed rotation of ball mill 60 rpm and recovery of grinding was 93.51 % of -325 mesh. The product of particle size -200 mesh was achieved optimum condition at comparison ore's weight: ball = 1:2, time of grinding 60 minutes, the fraction of + 200 mesh was regrind, the recovery of grinding 6.82% at particle size of (-200 + 250) mesh, 5.75 % at (-250 + 325)m mesh and, 47.93 % -325 mesh. The product of particle size -100 mesh was achieved the optimum condition at comparison ore's weight: ball = 1:2, time of grinding at 30 minutes particle size +100 mesh regrinding using mortar grinder, recovery of grinding 30.10% at particle size (-100 + 150) m, 12.28 % at (-150 + 200) mesh, 15.92 % at (-200 + 250) mesh, 12.44 % at (-250 + 325) mesh and 29.26 % -325 mesh. The determination of specific gravity of Rirang uranium ore was between 4.15 - 4.55 g/cm3

  3. Grinding and cooking dry-mill germ to optimize aqueous enzymatic oil extraction

    Science.gov (United States)

    The many recent dry grind plants that convert corn to ethanol are potential sources of substantial amounts of corn oil. This report describes an aqueous enzymatic extraction (AEE) method to separate oil from dry-mill corn germ (DMG). The method is an extension of AEE previously developed for wet...

  4. Failure analysis of work rolls of a thin hot strip mill

    OpenAIRE

    Piyas Palit; Hrishikesh R. Jugade; Arvind Kumar Jha; Souvik Das; Goutam Mukhopadhyay

    2015-01-01

    In hot rolling mills, premature failure of rolls is a major concern as it adversely affects the mill operation as well as production. Analysis of failed roll materials and actual rolling conditions in service are therefore necessary to understand the roll failure mechanism and thereby improve the wear resistance and extend the service life of rolls. The hot strip mill referred here consists of six stands wherein high chromium (Hi-Cr) iron rolls and Indefinite Chilled Double Poured (ICDP) c...

  5. Corrosion of Cast Iron Mill Plates in Wet Grinding

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    Anthony ANDREWS

    2010-12-01

    Full Text Available Corrosion studies were carried out on two different maize grinding plates. Maize was soaked in water for three days and the water decanted and used as electrolyte. Mass loss and pH measurements were carried out every 3 days for 15-day period. Results show that, for each plate, mass loss and pH increased with exposure time. Corrosion rates determined from mass loss data was found to be strongly dependent on pH. The observed behaviour may be explained in terms of the chemical composition and/or microstructures of the plates. Results are briefly discussed in terms of the contribution of corrosion to wear.

  6. Corrosion of Cast Iron Mill Plates in Wet Grinding

    OpenAIRE

    Anthony ANDREWS; Samuel KWOFIE

    2010-01-01

    Corrosion studies were carried out on two different maize grinding plates. Maize was soaked in water for three days and the water decanted and used as electrolyte. Mass loss and pH measurements were carried out every 3 days for 15-day period. Results show that, for each plate, mass loss and pH increased with exposure time. Corrosion rates determined from mass loss data was found to be strongly dependent on pH. The observed behaviour may be explained in terms of the chemical composition and/or...

  7. ALSTOM Schusselmuhle fur die feinvermahlung von anhydrit ALSTOM bowl mill for anhydrite fine grinding

    CERN Document Server

    Angleys, M

    2003-01-01

    After the ALSTOM bowl mill had proved a success during numerous laboratory tests using different industrial minerals, for the first time a mill, type SM 20/12 was commissioned for ATLAS s.c. at Lodz /Poland for anhydrite grinding. Based on corresponding laboratory tests with anhydrite, it was possible to adapt the equipment to the requirements of the material with modified properties. Due to the project preparation together with the customer, the mill could be installed and commissioned according to schedule by a joint team of engineers for erection and commissioning.

  8. DESIGN OF INTELLIGENT CONTROL SYSTEM USING ACOUSTIC PARAMETERS FOR GRINDING MILL OPERATION

    Directory of Open Access Journals (Sweden)

    Sonali Sen

    2013-02-01

    Full Text Available This paper utilizes acoustic parameters such as FS,NC, N, P, INC, FL, FH, W for acoustic signals S of different running conditions of a ballmill to deriveout the acoustic signatures and hence control signals, which is to be used for designing the control systems of the mill. The parameters FS, NC, N, P, INC, FL, FH and W are represented by sample rate in Hz, number of cepstral coefficients, length of frame in samples, number of filters in filter bank, frame increment, low end of the lowest filter, high end of highest filter and the window over which the analysis is to be performed respectively. The work establishes an appropriate theoretical background that helps to predict dynamic breakage characteristics with respect to particle size distribution of materials, adequately supported by experimental data. The signatures of different running conditions of grinding mill have been extracted from the captured signal in time frame these have been used as feedback signal to monitor the grinding operation. Condenser based microphones have been used for capturing acoustic signals in time domain directly in computers and stored for further analysis. Matlab R2010b has been used for different analysis of the experiment. On analyzing the signatures, it has been observed whether the fines are produced progressively to attain the desired size range or the mill producing undesired products. Thus, the approach has been used in this paper has the ability to arrive in the stage of optimum grinding by tuning parameters of the mill in real time, and also it can prevent the mill to enter into an erroneous state. Moreover, on study it has found that the present scheme can be used more accurately in comparison to the earlier work of the author. This paper presents an implementation scheme to use acoustic signal as the control signal to regulate the operation of a grinding mill.

  9. Performance characteristics of mill rolls from graphite chromium cast iron

    OpenAIRE

    Lecomte-Beckers, Jacqueline; Terziev, L.; Breyer, J. P.

    2000-01-01

    The main requirements for the development of a new grade for the later finishing section of the mill are : good oxidation and thermal behaviour, high wear resistance, good resistance to rolling incidents. The approach of Marichal Ketin to improve the rolling performances in the last finishing stands is presented. The Hi-Cr cast iron possesses excellent wear resistance due to the presence of hard chromium carbides, but its thermal conductivity and sticking properties are fairly low. A graphite...

  10. Theoretical And Experimental Analysis Of Aluminium Bars Rolling Process In Three-High Skew Rolling Mill

    Directory of Open Access Journals (Sweden)

    Stefanik A.

    2015-06-01

    Full Text Available Technology of round bars rolling on a three-high skew rolling mills allows rolling of standard materials such as steel and aluminum, as well as new materials, especially hard deformable materials. The paper presents the results of theoretical and experimental rolling process of aluminum bars with a diameter of 20 mm. As the stock round bars with a diameter of 25 mm made of aluminum grade 1050A and aluminum alloy grade 2017A were used. The rolling process of aluminum bars has been carried out in a single pass. The numerical analysis was carried out by using computer program Forge2011. On the basis of theoretical research it has been determined the state of deformation, stress and temperature distribution during rolling of aluminum bars. In addition, the results of theoretical research allowed to determine the schema of the metal plastic flow in the roll gap. Verification of the theoretical research was carried out during the rolling of aluminum bars on the RSP 40/14 laboratory three-high skew rolling mill. From the finished bars were taken the samples to set the shape and compared with the results of theoretical research. Finished aluminum round bars were characterized by low ovality and good surface quality.

  11. IMPROVEMENT PROCESS FOR ROLLING MILL THROUGH THE DMAIC SIX SIGMA APPROACH

    OpenAIRE

    Kunal Ganguly

    2012-01-01

    This project aims to address the problems that are facing a large aluminum company in a) Developing Hot Rolling Mill Capabilities for Wider Widths Hard Alloys Rolling and b) Eliminate down time due to strip /coil slippage during hard alloys 5xxx rolling at Hot Mill. The challenge for the company was to cater the fast changing export demand for Flat Rolled products with its existing resources. By applying Six Sigma principles, the team identified the current situation that the rolling mills op...

  12. Digital technology for radiometric thickness gages in rolling mills

    International Nuclear Information System (INIS)

    In this paper a nuclear (Am-241, Sr-90) computer-controlled thicknessgerge is described, utilizing the digital technologies additionally for transmission and filtration of signals of the receiver for automatic computation of the calibration curves, automatic standardization over the gauge range and on-line digital diagnosis. This device works without contact and can be used in cold and hot rolling mills. (orig.)

  13. Service behaviour of high speed steel rolling rolls used in hot strip mills

    International Nuclear Information System (INIS)

    Work rolls used in hot strip mills may be able to carry out severe actions: very high thermal stresses and wear, along with mechanical stresses due to normal rolling loads, which develop in the presence of cracks, produced by the former actions. The microstructure and the mechanical behaviour (strength and toughness) of high speed steels, which recently have been introduced in this applications, were studied in this work in comparison with high chromium cast irons. (Author) 7 refs

  14. Dimensional ranges and rolling efficiency in a tandem cold rolling mill

    Energy Technology Data Exchange (ETDEWEB)

    Larkiola, J.

    1997-12-31

    In this work, physical models and a neural network theory have been combined in order to predict the properties of a steel strip and to optimise the process parameters in cold rolling. The prediction of the deformation resistance of the material and the friction parameter is based on the physical model presented by Bland, Ford and Ellis and artificial neural network computing (ANN). The accuracy of these models has been tested and proved by using a large amount of the measured data. With the aid of these models it has been shown that (a) the small change to the relative reduction distribution can have a clear effect upon the rolling efficiency, (b) the dimensional ranges of the tandem cold roll mill can be determined and optimised and (c) the possibility to cold roll a new product of new width, strength or thickness can be determined and the parameters of the tandem cold rolling process can be optimised. (orig.) 43 refs.

  15. Inprovement in rolling procedure and steel plates finishing on the rolling mill 2800

    International Nuclear Information System (INIS)

    Technology directed towards the increase of metal output and quality of production in the process of rolling and finishing of steel plates on the rolling mill 2800 has been elaborated. The slab end deformation in vertical stand with angular gauge of 60 deg has been applied. Minimal uneven gauge is established by work roll contouring. Special cuts of optimal form on the surface of roller breaking-down stand are used for removal of mill scale together with hydrocleaning at increasing pressure. Methods of line slitting of sheet edges are analyzed. The sheets of all types of steel with the thickness up to 40 mm may be successfully cut in plastic state at 600-900 deg C

  16. Work Roll Materials For Hot Strip Milling and Casting Methods of Rolling Roll

    Directory of Open Access Journals (Sweden)

    Şadi KARAGÖZ

    2009-03-01

    Full Text Available The selection of materials for rolling, which is one of the powerful manufacturing process and the influence of these materials on the roll properties is an important factor. Also, the use of suitable material and various manufacturing technologies affect these characteristics. To understand that which roll grade is needed for which application, the rolling conditions, the roll grades and their properties should be known. In this work the evolution of roll materials from classical materials up to recently developed materials are presented and bimetallic roll technologies are investigated. Furthermore, experimentally cast pearlitic and martensitic roll microstructures were examined. The influence of microstructural phases on the roll properties were analyzed with the results of mechanical and microstructural observations.

  17. Optimization of a Heavy Continuous Rolling Mill System Via Simulation

    OpenAIRE

    Ali Azadeh; Farid Ghaderi

    2006-01-01

    The objective of this study was to develop an integrated simulation model, which generates a set of optimizing alternatives for a heavy continuous rolling mill system in a full-scale steelmaking factory. The simulation approach enabled us to evaluate the performance of the existing system and pinpointed existing bottlenecks in workstations and production flow. Consequently, it generated a set of optimum production alternatives. Data related to process and operation times, repairs, maintenance...

  18. Development of rolling mill for rectangular orthodontic wires production

    OpenAIRE

    Totten, G.E.; A.I. Filho; C.A.R. Gouva; Neto, A.; L.C. Casteletti

    2007-01-01

    Purpose: In orthodontic treatments, wires of different metallic alloys are used for alignment, leveling, correction of the molar position, space closing, finish and retention. The purpose of the paper is the characteristics of austenitic stainless steel wires, with a square traverse section, which were produced using a rolling mill built for this purpose, are presented hereDesign/methodology/approach: With respect to finish and retention, these wires are responsible for adequate positioning o...

  19. Application of mechano-chemical synthesis for protective coating on steel grinding media prior to ball milling of copper

    Indian Academy of Sciences (India)

    Indranil Lahiri; K Balasubramanian

    2007-04-01

    One of the major sources of contamination during mechanical milling/alloying is from the surface erosion of the container and the grinding medium. This can either be prevented by using grinding medium and container of same material of the milled material or by adding a coating of the milled material on them. The paper describes the observations made during a mechano-chemical reaction, being used for coating the balls and vials in a planetary ball mill. Visual observation, XRD, optical micrography and EDS analysis were used to understand the progress of the reaction. Copper was successfully coated on the steel balls and vials. The method can easily be adopted in daily production purposes, prior to mechanical milling of a Cu-based powder for prevention of Fe contamination.

  20. Development of rolling mill for rectangular orthodontic wires production

    Directory of Open Access Journals (Sweden)

    G.E. Totten

    2007-09-01

    Full Text Available Purpose: In orthodontic treatments, wires of different metallic alloys are used for alignment, leveling, correction of the molar position, space closing, finish and retention. The purpose of the paper is the characteristics of austenitic stainless steel wires, with a square traverse section, which were produced using a rolling mill built for this purpose, are presented hereDesign/methodology/approach: With respect to finish and retention, these wires are responsible for adequate positioning of the upper teeth on the lower teeth. Wires that are subjected to incisor torque require high resistance and stiffness. For this, wires of rectangular austenitic stainless steel are used due to high modulus of elasticity and good corrosion resistance in the oral environment. Because of the rectangular geometry, wire production requires process development suitable for industrial scale manufacture with geometric characteristics and mechanical properties better adapted to the use conditions.Findings: To obtain wires with such characteristics, a rolling mill was developed for the production of rectangular wires by a rolling process with the objective of reducing cost of the cold drawing process that is currently used which utilize complex and expensive wire-drawing dies. In addition to the rolling process itself, wire deformation, microhardness, tension and bend tests were also performed.Research limitations/implications: A rolling-mill was built that successfully produced dental wires within acceptable tolerances and physical/mechanical properties.These wires exhibited excellent hardness and tensile strength, although slightly less than analogous commercial wires. It is expected that this problem are corrected by using initial wires with a higher hardness, since this property is directly related with the tensile strength.Originality/value: In these tests, wire geometry, surface finish and mechanical properties were successfully adapted for use in orthodontic treatments.

  1. The grinding behavior of ground copper powder for Cu/CNT nanocomposite fabrication by using the dry grinding process with a high-speed planetary ball mill

    Science.gov (United States)

    Choi, Heekyu; Bor, Amgalan; Sakuragi, Shiori; Lee, Jehyun; Lim, Hyung-Tae

    2016-01-01

    The behavior of ground copper powder for copper-carbon nanotube (copper-CNT) nanocomposite fabrication during high-speed planetary ball milling was investigated because the study of the behavior characteristics of copper powder has recently gained scientific interest. Also, studies of Cu/CNT composites have widely been done due to their useful applications to enhanced, advanced nano materials and components, which would significantly improve the properties of new mechatronics-integrated materials and components. This study varied experimental conditions such as the rotation speed and the grinding time with and without CNTs, and the particle size distribution, median diameter, crystal structure and size, and particle morphology were monitored for a given grinding time. We observed that pure copper powders agglomerated and that the morphology changed with changing rotation speed. The particle agglomerations were observed with maximum experiment conditions (700 rpm, 60 min) in this study of the grinding process for mechanical alloys in the case of pure copper powders because the grinding behavior of Cu/CNT agglomerations was affected by the addition of CNTs. Indeed, the powder morphology and the crystal size of the composite powder could be changed by increasing the grinding time and the rotation speed.

  2. Bayesian model mixing for cold rolling mills: Test results

    Czech Academy of Sciences Publication Activity Database

    Ettler, P.; Puchr, I.; Dedecius, Kamil

    Slovensko : Slovak University of Technology, 2013, s. 359-364. ISBN 978-1-4799-0926-1. [19th International Conference on Process Control . Štrbské Pleso (SK), 18.06.2013-21.06.2013] R&D Projects: GA MŠk(CZ) 7D09008; GA MŠk 7D12004 Keywords : Bayesian statistics * model mixing * process control Subject RIV: BC - Control Systems Theory http://library.utia.cas.cz/separaty/2013/AS/dedecius-bayesian model mixing for cold rolling mills test results.pdf

  3. Optimization of a Heavy Continuous Rolling Mill System Via Simulation

    Directory of Open Access Journals (Sweden)

    Ali Azadeh

    2006-01-01

    Full Text Available The objective of this study was to develop an integrated simulation model, which generates a set of optimizing alternatives for a heavy continuous rolling mill system in a full-scale steelmaking factory. The simulation approach enabled us to evaluate the performance of the existing system and pinpointed existing bottlenecks in workstations and production flow. Consequently, it generated a set of optimum production alternatives. Data related to process and operation times, repairs, maintenance and quality control were collected and analyzed systematically. The simulation model was modeled by Visual SLAM and Awesim simulation language. The results and structure of the computer simulation model were validated and verified against the actual system. Also, the results of the models were discussed and approved by the production managers. The distinct feature of the simulation model is three fold. First, it is integrated and considers detailed operations and activities of the Rolling Mill system. Furthermore, it is designed to be integrated with other workshops of the factory. Second, it locates the optimum solutions by a rule-based methodology. Finally, the model considers the Just-in-Time configuration of the line and is capable of answering all production and inventory issues.

  4. The effect of cryogenic grinding and hammer milling on the flavour quality of ground pepper (Piper nigrum L.).

    Science.gov (United States)

    Liu, Hong; Zeng, Fankui; Wang, Qinghuang; Ou, Shiyi; Tan, Lehe; Gu, Fenglin

    2013-12-15

    In this study, we compared the effects of cryogenic grinding and hammer milling on the flavour attributes of black, white, and green pepper. The flavour attributes were analysed using headspace solid-phase micro-extraction (HS-SPME) and gas chromatography-mass spectrometry (GC/MS), sensory evaluation and electronic nose (e-nose) analysis. Cryogenic grinding resulted in minimal damage to the colour, flavour, and sensory attributes of the spices. Cryogenic grinding was also better than hammer milling at preserving the main potent aroma constituents, but the concentrations of the main aroma constituents were dramatically reduced after storing the samples at 4 °C for 6 months. Pattern matching performed by the e-nose further supported our sensory and instrumental findings. Overall, cryogenic grinding was superior to hammer milling for preserving the sensory properties and flavour attributes of pepper without significantly affecting its quality. However, we found that the flavour quality of ground pepper was reduced during storage. PMID:23993499

  5. PENELITIAN OPTIMASI TEMPERATUR YANG MEMPENGARUHI KEKERASAN PADA PEMBUATAN GRINDING BALL DENGAN CARA HOT ROLLING

    Directory of Open Access Journals (Sweden)

    Amelia Amelia

    2000-01-01

    Full Text Available Hardness is one of the mechanical properties needed in a grinding ball. The hardness of grinding ball produced up to now is gained by trial and error to those parameters which are presumed influencing the hardness. Research is done to get parameter influence the hardness of grinding ball and optimum level. Three parameters presumed influencing the hardness are temperature of raw material (Tm, the initial temperature of quenching (Tq, and the final temperature of quenching (Tt. Design of experiment is used to analysis which parameter influence the hardness. A 23 factorial design is chosen, each parameter has two level. According to experiment and data analysis, the influencing parameter are Tq, Tt and interaction between Tq and Tt. The optimum value of Tq and Tt are 905 ± 10°C and 133 ± 3°C, value of Tm is 1110 ± 10°C. Abstract in Bahasa Indonesia : Kekerasan merupakan salah satu sifat yang dibutuhkan oleh grinding ball. Untuk mendapatkan sifat tersebut hingga saat ini masih dilakukan dengan cara trial and error sehingga sangatlah tidak efektif. Maka dari itu dilakukan suatu penelitian untuk mengetahui parameter-parameter yang mempengaruhi kekerasan grinding ball dan level yang optimal. Ada tiga parameter yang diduga mempengaruhi kekerasan grinding ball, yaitu temperatur raw material (Tm, temperatur awal proses quenching (Tq dan temperatur akhir proses quenching (Tt. Untuk menganalisa parameter-parameter yang berpengaruh digunakan desain eksperimen. Desain eksperimen yang digunakan adalah rancangan faktorial 23, masing-masing terdiri atas 2 level. Dari percobaan dan analisa data, tampak bahwa parameter yang berpengaruh adalah Tq, Tt serta interaksi antara Tq dan Tt. Nilai Tq dan Tt yang optimum adalah 905 ± 10°C dan 133 ± 3°C, sedang nilai Tm yang dianjurkan 1110 ± 10°C. Kata kunci: Desain eksperimen, grinding ball, temperatur quenching

  6. Numerical And Experimental Study On Producing Aluminum Alloy 6061 Shafts By Cross Wedge Rolling Using A Universal Rolling Mill

    Directory of Open Access Journals (Sweden)

    Tofil A.

    2015-06-01

    Full Text Available The paper presents a selection of numerical and theoretical results of the cross wedge rolling process for producing stepped shafts made of aluminum alloy 6061. The numerical modeling was performed using the FEM-based Simufact Forming simulation software. In the simulations, we examined the kinematics of metal flow and determined the distribution patterns of effective strains, temperatures, axial stresses and the Cockroft-Latham damage criterion. Variations in the rolling forces were determined, too. The numerical results were verified experimentally using a universal rolling mill designed and constructed by the present authors. This machine can be used to perform such processes as cross wedge rolling, longitudinal rolling and round bar cropping. During the experiments, we examined process stability and finished product geometry and recorded the torques. The experimental results confirm that axisymmetric aluminum alloy shafts can be produced by cross wedge rolling with two rolls. Last but not least, the experiments served to evaluate the technological potential of the rolling mill used.

  7. Crush Grinding

    International Nuclear Information System (INIS)

    Crush Grinding is a special process used at the Kansas City Plant to finish stem sections of reservoir products. In this process, a precise profile of the desired product is formed on a tungsten carbide roll. This roll slowly transfers a mirror image of the profile onto the grinding surface of a wheel. The transfer rate of the profile is between 0.001 and 0.010 inches per minute. Crush grinding is desirable since it provides consistent surface finishes and thin walls at a high production rate. In addition, it generates very sharp fillet radii. However, crush grinding is a complex process since many variables affect the final product. Therefore, the process requires more attention and knowledge beyond basic metal removal practices. While the Kansas City Plant began using these machines in 1995, a formal study regarding crush grinding has not been conducted there. In addition, very little literature is available in the grinding industry regarding this process. As a result, new engineers at the Kansas City Plant must learn the process through trial and error. The purpose of this document is to address this literature deficit while specifically promoting a better understanding of the stem crush grinding process at the Kansas City Plant.

  8. IMPROVEMENT PROCESS FOR ROLLING MILL THROUGH THE DMAIC SIX SIGMA APPROACH

    Directory of Open Access Journals (Sweden)

    Kunal Ganguly

    2012-09-01

    Full Text Available This project aims to address the problems that are facing a large aluminum company in a Developing Hot Rolling Mill Capabilities for Wider Widths Hard Alloys Rolling and b Eliminate down time due to strip /coil slippage during hard alloys 5xxx rolling at Hot Mill. The challenge for the company was to cater the fast changing export demand for Flat Rolled products with its existing resources. By applying Six Sigma principles, the team identified the current situation that the rolling mills operations were in. Si x Sigma DMAIC methodologies were use d in the project to determine the project's CTQ characteristics, defining the possible causes, Identifying the variation sources, establishing variable relationships and Implementing Control Plans. The project can be useful for any company that needs to fi nd the most cost efficient way to improve and utilize its resources.

  9. Drop deformation in two-roll mills considering wall effects

    International Nuclear Information System (INIS)

    Experimental, theoretical and numerical results of dynamics of drop deformation in strong flows generated by a co-rotating two-roll mill and considering the influence of near rigid walls are presented. The drop dynamics is altered, with respect to a drop free of wall effects, by the proximity of the rigid boundaries as well as caused by a non-linear and non-uniform flow due to gradients of flow-type parameter and shear rate. Simulations were carried out using the Boundary Element Method (BEM). Since the inclusion of the whole boundaries (drop and rollers surfaces) is not an easy and trivial task, bi-dimensional numerical simulations was performed as a first approach. The experimental and numerical results were obtained for a flow type of ? = 0.03 and two values of viscosity ratio ? = 0.012 and 16. In general, numerical results for the stationary deformation parameters, up to intermediate confinements, are in agreement with the experiments, with and without wall effects. Since the case of drops with a high viscosity ratio did not match existing theoretical models, the wall-effect theory of Shapira and Haber was modified, considering Cox's second-order theory as the converging theory without wall effects. From low to intermediate confinements, the new Cox-Shapira-Haber model fitted the observed experimental deformations

  10. INVESTIGATION OF THE MAINTENANCE ORGANISATION FOR HOT ROLLING MILLS

    Directory of Open Access Journals (Sweden)

    P.K. Pretorius

    2012-01-01

    Full Text Available

    ENGLISH ABSTRACT: Production systems have undergone dramatic changes in recent years. Many companies have implemented new technologies such as flexible manufacturing systems. There is therefore a shift in focus to maintenance and the effective management thereof. Maintenance is a dynamic activity and is comprised of a large number of interacting variables. An effective maintenance organisation is required to control these variables .
    This paper discusses the building of a maintenance organisation and the aspects that should be considered during the design. The way in which five companies that operate hot rolling mills apptoached the problem of building an effective maintenance organisation was investigated.

    AFRIKAANSE OPSOMMING: y eryaardigingstelsels het drastiese veranderinge ondergaan die afgelope aantal jaar. Verskeie Il1~atskappyemaak nou gebruik van nuwe tegnologiee, soas byvoorbeeld aanpasbare vervaardigingstelsels. Daar is gevolglik 'n verskuiwing in fokus na instandhouding en die effektiewe bestuur daarvan. lnstandhouding is 'n dinamiese aktiwiteit en behels 'n groot aantal ' gekoppelde veranderlikes. 'n Effektiewe instandhoudingsorganisasie word benodig om hierdie v'eranderlikes te beheer.
    Hierdie artikel bespreek die daarstelling van die instandhoudingsorganisasie en die parameters V~toorweeg moet word tydens die ontwerp. Die wyse waarop vyf maatskappye wat }V~rIl1walse bedryf die ontwikkeling van 'neffektiewe organisasie vir instandhouding benader hc(is ondersoek .

  11. Drop deformation in two-roll mills considering wall effects

    Science.gov (United States)

    Escalante-Velzquez, C. A.; Huesca-Reyes, M. A.; Yescas Rosas, I.; Geffroy, E.

    2015-01-01

    Experimental, theoretical and numerical results of dynamics of drop deformation in strong flows generated by a co-rotating two-roll mill and considering the influence of near rigid walls are presented. The drop dynamics is altered, with respect to a drop free of wall effects, by the proximity of the rigid boundaries as well as caused by a non-linear and non-uniform flow due to gradients of flow-type parameter and shear rate. Simulations were carried out using the Boundary Element Method (BEM). Since the inclusion of the whole boundaries (drop and rollers surfaces) is not an easy and trivial task, bi-dimensional numerical simulations was performed as a first approach. The experimental and numerical results were obtained for a flow type of ? = 0.03 and two values of viscosity ratio ? = 0.012 and 16. In general, numerical results for the stationary deformation parameters, up to intermediate confinements, are in agreement with the experiments, with and without wall effects. Since the case of drops with a high viscosity ratio did not match existing theoretical models, the wall-effect theory of Shapira and Haber was modified, considering Cox's second-order theory as the converging theory without wall effects. From low to intermediate confinements, the new Cox-Shapira-Haber model fitted the observed experimental deformations.

  12. Hot sheet rolling on continuous mill under plastic fluid friction conditions

    International Nuclear Information System (INIS)

    A technique for hot sheet rolling in plastic fluid friction conditions of sheets of the 12Kh18N10T and carbon 10 sp steels is developed and tested. A new lubricant ''Silicatherm'' constitutes the basis of the technique. The advantages of the given technique as compared to the rolling with liquid lubricants of mineral and vegetative origin as well as the prospects of its introduction during hot rolling on continuous mills are shown

  13. Premature failure analysis of forged cold back-up roll in a continuous tandem mill

    International Nuclear Information System (INIS)

    Highlights: → Metal wrapping and strip welding in work/back-up rolls contact zone caused spalling. → MnS inclusion and pore initiated crack which propagated in milling led to spalling. → Retained austenite conversion to α'-martensite accelerated spalling failure. → Needle shaped carbide (Fe,Mo,Cr)7C3, may cause poor service life of back-up roll. -- Abstract: In this paper, premature failure of a forged back-up roll from a continuous tandem mill was investigated. Microstructural evolutions of the spalled specimen and surface of the roll were characterized by optical microscopy, X-ray diffraction, scanning electron microscopy and ferritscopy, while hardness value of the specimen was measured by Vickers hardness testing. The results revealed that the presence of pore and MnS inclusion with spherical and oval morphologies were the main contributing factors responsible for the poor life of the back-up roll. In addition, metal pick up and subsequently strip welding on the surface of the work roll were found as the major causes of failure in work roll which led to spalling occurrence in the back-up roll. Furthermore, relatively high percentage of retained austenite, say 9%, in outer surface of the back-up roll contributed spalling due to conversion of this meta-stable phase to martensite and creation of volume expansion on the outer surface through work hardening during mill campaign.

  14. Genera use of CBN in tool grinding: Technology and economics

    Science.gov (United States)

    Meyer, H. R.; Wiemann, H. J.

    A long term test program in which all the grinding processes technically capable of being converted from conventional abrasives to crystalline boron nitrides (CBN) was carried out in close cooperation with an abrasives manufacturer and a tool manufacturer whose production included all types of cutters; notably, hobs, profile cutters, side melting cutters, and face milling cutters, as well as crushing rolls for profiling grinding wheels. The material mainly used was EM05C05 confirming to S 6-5-2-5.

  15. Predictive 3D roll grinding method for reducing paper quality variations in coating machines

    OpenAIRE

    Kuosmanen, Petri

    2004-01-01

    The predominant trend in paper machines is towards an increased running speed. At the same time, the paper produced must have a higher and more even quality. In printing papers the main end-use properties and quality components are runnability, printability, and print quality. These coexistent requirements create new demands for the behaviour of rolls under production conditions. High quality printing paper grades are coated. In blade coating the thickness of the coating film on the paper sur...

  16. Rolling process simulation of a pair-crossed hot strip mill

    International Nuclear Information System (INIS)

    Process simulation can help optimize the operating parameters aiming to improve the quality of rolled products. In this paper, software in Visual Basic language is developed to simulate the hot rolling process of a pair-crossed mill. The strip temperature is calculated by considering air cooling, water cooling, heat generation and conduction.The production parameters including rolling speeds, resistance to deformation, rolling forces, drive torques and powers are evaluated by mathematical models and their parameter identification support tools. The deformation of roll stack is calculated by influential function method. The roll temperature and expansion are calculated by finite differential method, and the roll wear is described by empirical formula. Based on these calculations as well as the effect of heredity is taken into account, the strip crown and flatness then can be obtained. The results show that the simulation software has friendly user interface, high accuracy and practicability. It can be served as a basis for the mill design and optimization of process parameters to acquire high quality of hot rolled strip. (author)

  17. Wireless Remote Monitoring System for the Agc Svibration Fault of Rolling Mill

    OpenAIRE

    Yan Gao; Baoquan Jin; Hongjuan Zhang

    2013-01-01

    The rolling mill screw down AGC system sets several subsystems of machinery, electronics, hydraulics, controls in one. Under the action of responding extreme frequency or external disturbances, the non design objective coupling between the subsystems may be excited, and causing the most serious vibration, seriously impact product quality or even cause great destruction. Aiming at the defects in fault diagnosis and control system of the traditional rolling m...

  18. Extended Kalman Filter Based Neural Networks Controller For Hot Strip Rolling mill

    International Nuclear Information System (INIS)

    The present paper deals with the application of an Extended Kalman filter based adaptive Neural-Network control scheme to improve the performance of a hot strip rolling mill. The suggested Neural Network model was implemented using Bayesian Evidence based training algorithm. The control input was estimated iteratively by an on-line extended Kalman filter updating scheme basing on the inversion of the learned neural networks model. The performance of the controller is evaluated using an accurate model estimated from real rolling mill input/output data, and the usefulness of the suggested method is proved

  19. Advanced Soft Sensor Technology to be Used for Cold Rolling Mills

    Czech Academy of Sciences Publication Activity Database

    Ettler, P.; Dedecius, Kamil; Juričič, D.; Preglej, A.

    Toulouse : IEEE, 2011, s. 1-4. ISBN 978-1-4577-0016-3. [16th IEEE International Conference on Emerging Technologies and Factory Automation ETFA'2011. Toulouse (FR), 05.09.2011-09.09.2011] R&D Projects: GA MŠk(CZ) 7D09008 Institutional research plan: CEZ:AV0Z10750506 Keywords : soft sensor * rolling mill Subject RIV: IN - Informatics, Computer Science http://library.utia.cas.cz/separaty/2011/AS/dedecius-advanced soft sensor technology to be used for cold rolling mills.pdf

  20. Force prediction in cold rolling mills by polynomial methods

    Directory of Open Access Journals (Sweden)

    Nicu ROMAN

    2007-12-01

    Full Text Available A method for steel and aluminium strip thickness control is provided including a new technique for predictive rolling force estimation method by statistic model based on polynomial techniques.

  1. Tribological Testing of Anti-Adhesive coatings for Cold Rolling Mill Rolls--Application to TiN-Coated Rolls

    International Nuclear Information System (INIS)

    Roll life is a major issue in cold strip rolling. Roll wear may result either in too low roll roughness, bringing friction below the minimum requested for strip entrainment; or it may degrade strip surface quality. On the contrary, adhesive wear and transfer (''roll coating'', ''pick up'') may form a thick metallic deposits on the roll which increases friction excessively and degrades strip surface again [1]. The roll surface, with the help of a materials-adapted lubricant, must therefore possess anti-wear and anti-adhesive properties. Thus, High Speed Steeel (HSS) rolls show superior properties compared with standard Cr-steel rolls due to their high carbide surface coverage. Another way to improve wear and adhesion properties of surfaces is to apply hard metallic (hard-Cr) or ceramic coatings. Chromium is renowned for its excellent anti-wear and anti-adhesive properties and may serve as a reference. Here, as a first step towards alternative, optimised coatings, a PVD TiN coating has been deposited on tool steels, as previous attempts have proved TiN to be rather successful in cold rolling experiments [2,3]. Different tribological tests are reported here, giving insight in both anti-adhesive properties and fatigue life improvement.

  2. Fuzzy-Neural Control of Hot-Rolling Mill

    Directory of Open Access Journals (Sweden)

    Khearia Mohamad

    2010-12-01

    Full Text Available This paper deals with the application of Fuzzy-Neural Networks (FNNs in multi-machine system control applied on hot steel rolling. The electrical drives that used in rolling system are a set of three-phase induction motors (IM controlled by indirect field-oriented control (IFO. The fundamental goal of this type of control is to eliminate the coupling influence though the coordinate transformation in order to make the AC motor behaves like a separately excited DC motor. Then use Fuzzy-Neural Network in control the IM speed and the rolling plant. In this work MATLAB/SIMULINK models are proposed and implemented for the entire structures. Simulation results are presented to verify the effectiveness of the proposed control schemes. It is found that the proposed system is robust in that it eliminates the disturbances considerably.

  3. Soft Starting Arrangements Availables for Hot Rolling Mills for Energy Conservation

    Science.gov (United States)

    Bisen, A. M.; Bapat, P. M.; Gagnuly, S. K.

    2012-07-01

    The conventional rolling mills in India are producing a major part of structural steel requirement of the country. The energy conservation in these rolling mills can be achieved mainly by reducing the size of the prime mover i.e. main electric motor. The power consumption per ton can be considerably decreased through proper selection of electric motor since it has been an observation by many surveyors[1] that the selection of electric motor of the rolling mill has been almost five to ten times on the higher side which can be easily verified from the power consumption and motor working data.Flywheel is a mechanical storage device. Largest size of flywheels are frequently recommended for smooth running of rolling mills. The main difficulty encountered in selecting large capacity flywheel or flywheel gear box system is the starting of the mill with smaller capacity electric motor. The starting characteristic of electric motor is not suitable for starting such rolling mill with very high inertia flywheel. In such condition it becomes very essential to introduce the soft starting arrangement for the electric motor so that considerably small size motor can start the flywheel effectively.Soft starters are used for the smooth start-up control of three-phase induction motors. The soft starter is functionally located between the Flywheel and the electric motor. In selecting the correct soft starter to suit the application the peculiarities of the soft start should be considered. In the prevailing conditions we use the motor of high horse power due to the fact that the flywheel requires high torque to be driven initially. For the same reason the efficiency of the flywheel is very low initially. Once the flywheel stores sufficient power which is required at the start up, the flywheel then requires less power than given initially. If we somehow are able to increase the efficiency of the flywheel using a flexible electrical, mechanical, hydraulic or flexible drives with different combinations (Electrical, Mechanical, Hydraulic) then the motor of less horse power can thus be installed to run the flywheel.This paper gives an idea of available type of the soft starting arrangement for a rolling mill so that horse power of motor can be reduced without affecting the working of the mill. Hence optimum selection of the soft starting arrangement is to be done so that initial and billing cost will be less.

  4. Design of Rolling State Observers for Application to Control of Thickness and Tension in Rolling Mills

    Directory of Open Access Journals (Sweden)

    Hamid R. Koofigar

    2011-09-01

    Full Text Available This study focuses on the necessity of designing state observers to be used in controller synthesis for rolling processes. This is motivated by the fact that using several kinds of sensors for measuring all of process variables is technically and economically avoided. On the other hand, using exact measurement in feedback control systems could considerably improve the quality of products. In other word, there is a trade-off between high quality and the implementation limitations, managed here by developing rolling state observers. The proposed observers estimate the states not measured directly by the installed sensors. This technique is applicable to both hot rolling and cold rolling processes. Simulation results demonstrate the performance of the proposed estimation algorithm.

  5. Influence of a matrix on properties of mottled cast iron applied for mill rolls

    Directory of Open Access Journals (Sweden)

    J. Krawczyk

    2010-07-01

    Full Text Available Mill rolls are ones of the most expensive tools applied in plastic working processes and have to satisfy several criteria, which allow them to be used. Cast iron mill rolls, due to their fracture toughness and tribological properties, are the most often applied at hot-rolling in the last rolling stands. This results from the smallest dynamic loads of such rolling stands and the decisive influence of the surface quality of these tools on the surface quality of the rolled product. An improper microstructure of rolls can lead to their premature wearing, e.g. broken flanges, pivots twisting off etc. By means of the heat treatment the matrix microstructure and morphology of carbide precipitationscan be modified and this in-turn can influence cast iron properties.Determination of the influence of microstructure changes, caused by the heat treatment, on the properties of EN-GJN-HV300 low-alloycast iron, after its modification and spheroidization – is the aim of the present paper. Those changes are based on the formation pearlitic or bainitic matrices at the similar morphology of graphite and ledeburitic cementite precipitations. The performed investigations should enable designing the heat treatment of cast iron metallurgical rolls in such a way as to obtain the optimal microstructures for functional parameters of these type of tools. The influence of changing the pearlitic matrix into the bainitic one on such properties as: hardness, impact strength, tensile strength, creep limit, bending strength and a stress intensity factor KIc was investigated in this study. Samples for testing, the listed above mechanical properties, were taken from an industrial casting with care to have pieces of very similar crystallization conditions.

  6. Optimized simulation of vortex jet mill in waste rubber grinding technology by LNG

    Science.gov (United States)

    Han, Yuemei

    2015-07-01

    Frozen rubber powder has excellent qualities and application value, and it can be achieved from waste rubber after being crushed at low temperature used liquefied natural gas (LNG) as cryogen. Vortex jet mill was the key equipment to further crush the rubber particles which the pressure-air was jet into in the basic LNG technological process. After confirming the structure and size of the jet nozzle, the Height (H) between the nozzle and the bottom of the mill, the incident angle α and the initial size of the rubber particles were changed then the continuous phase and the track of single particle were optimized in order to gain more excellent crushing effect. The results showed: the jetting gas were spiral rising in the mill and the speed of it was reduced, so the particle was graded by the gas. The impact and collision could reduce the particle diameter and crush them but the result was influenced by the initial size of the particle. The size of the original rubber particles must not be more than 110μm. The simulation was helpful and leading for the experiment.

  7. Strip/Foil Rolling Mill Stochastic Excitation Model and Its Stability

    Directory of Open Access Journals (Sweden)

    Baoyu Xu

    2012-06-01

    Full Text Available Based on the stochastic rolling force data from aluminum hot strip tandem mill, the ARMA time series model and the stochastic excitation power spectral density (PSD model are established, and the stochastic rolling forces excitation model is established by utilizing Levenberg-Marquardt combined with generalized global planning algorithm. A two dimensional stochastic nonlinear dynamical model of rolls is presented considering the stochastic factor of the rolling force. The Hamilton function is also described as one dimension diffusion process by using stochastic average method, the singular boundary theory was taken for analyzing the global stochastic stability of the system, and the system’s stochastic stability was researched by solving the Fokker-Planck-Kolmogorov (FPK equation. The results show that the stochastic excitation model obtained has significance for analyzing and researching stochastic dynamics characteristics to the system, and also generalized energy H in the range of 0.02 to 0.4, the system’s response has the minimum transition probability density, and the system state is not easy to change, therefore the system generalized energy H should be to limit in this range in the design and operation of the rolling mill.

  8. Influence of the Radiation Shield on the Temperature of Rails Rolled in the Reversing Mill

    Directory of Open Access Journals (Sweden)

    Gołdasz A.

    2015-04-01

    Full Text Available The paper presents a mathematical model of heat transfer during cooling of hot-rolled rails in the reversing mill. The influence of the radiation shield on the temperature of rolled rails has been analyzed. The heat transfer model for cooling a strip covered by the thermal shield has been presented. The two types of shields build of steel and aluminum sheets separated with insulating layer have been studded. Calculations have been performed with self developed software which utilizes the finite element method.

  9. Milling dynamics. I - Attritor dynamics: Results of a cinematographic study

    Science.gov (United States)

    Rydin, R. W.; Maurice, D.; Courtney, T. H.

    1993-01-01

    The motions of grinding media and powder in an attritor canister were studied by means of filming the agitated charge and frame-by-frame scrutiny of the footage. In conjunction with auxiliary experiments, this permitted semiquantitative analysis of the milling action. In particular, the mill can be divided into several regions characterized by different balances between direct impacts and rolling/sliding of the grinding media. Simple calculations suggest that impacts are more capable of effecting mechanical alloying (MA) than are rolling or sliding events in an attritor. Powder circulation within an operating mill was also investigated. Based on the results and the accompanying analysis, concepts for improved attritor design are presented.

  10. Online Prediction under Model Uncertainty Via Dynamic Model Averaging: Application to a Cold Rolling Mill

    Czech Academy of Sciences Publication Activity Database

    Raftery, A. E.; Kárný, Miroslav; Ettler, P.

    Volume 52, Number 1 (2010), s. 52-66. ISSN 0040-1706 R&D Projects: GA MŠk 1M0572; GA MŠk(CZ) 7D09008 Institutional research plan: CEZ:AV0Z10750506 Keywords : prediction * rolling mills * Bayesian Dynamic Averaging Subject RIV: BC - Control Systems Theory Impact factor: 1.560, year: 2010 http://library.utia.cas.cz/separaty/2010/AS/karny-0342595.pdf

  11. Effect of powder milling on mechanical properties of hot-pressed and hot-rolled Cu–Cr–Nb alloy

    International Nuclear Information System (INIS)

    Highlights: •Milled powder enhances sintering and mechanical properties after hot pressing. •Hot-rolling of hot-pressed samples made from milled powder enhances ductility. •Pore size and number of pores decreases after hot-rolling. -- Abstract: The present study is on the effect of mechanical milling of gas-atomized powders on mechanical properties of the hot-pressed and subsequently hot-rolled Cu–8 at% Cr–4 at% Nb alloy with a microstructure consisting of pure copper matrix hardened by intermetallic Cr2Nb precipitates. The mechanically milled powders result in lower sintering temperature during hot pressing compared to the atomized powders. The hot-pressed samples made from the milled powder exhibit significantly higher hardness and tensile strength, but lower ductility and electrical conductivity compared to that made from the un-milled gas-atomized powders. The hot rolling results in marginal increase in strength, but significant increase in ductility compared to the hot-pressed alloy for both the milled and atomized powders and it is attributed to the decrease in size of the pores and amount of porosities after hot rolling

  12. Simulation of accelerated strip cooling on the hot rolling mill run-out roller table

    International Nuclear Information System (INIS)

    Full text: A mathematical model of the thermal state of the metal on the run-out roller table of a continuous wide hot-strip mill is presented. The mathematical model takes into account the heat generation during the polymorphic γ → α transformation of super cooled austenite phase and the influence of chemical composition on the physical properties of the steel. The model allows the calculation of modes of accelerated cooling of strips on the run-out roller table of a continuous wide hot strip mill. Winding temperature calculation error does not exceed 20 °C for 98.5 % of the strips from low-carbon and low-alloyed steels. key words: hot rolled, wide-strip, accelerated cooling, run-out roller table, polymorphic transformation, mathematical modeling

  13. Customized maximal-overlap multiwavelet denoising with data-driven group threshold for condition monitoring of rolling mill drivetrain

    Science.gov (United States)

    Chen, Jinglong; Wan, Zhiguo; Pan, Jun; Zi, Yanyang; Wang, Yu; Chen, Binqiang; Sun, Hailiang; Yuan, Jing; He, Zhengjia

    2016-02-01

    Fault identification timely of rolling mill drivetrain is significant for guaranteeing product quality and realizing long-term safe operation. So, condition monitoring system of rolling mill drivetrain is designed and developed. However, because compound fault and weak fault feature information is usually sub-merged in heavy background noise, this task still faces challenge. This paper provides a possibility for fault identification of rolling mills drivetrain by proposing customized maximal-overlap multiwavelet denoising method. The effectiveness of wavelet denoising method mainly relies on the appropriate selections of wavelet base, transform strategy and threshold rule. First, in order to realize exact matching and accurate detection of fault feature, customized multiwavelet basis function is constructed via symmetric lifting scheme and then vibration signal is processed by maximal-overlap multiwavelet transform. Next, based on spatial dependency of multiwavelet transform coefficients, spatial neighboring coefficient data-driven group threshold shrinkage strategy is developed for denoising process by choosing the optimal group length and threshold via the minimum of Stein's Unbiased Risk Estimate. The effectiveness of proposed method is first demonstrated through compound fault identification of reduction gearbox on rolling mill. Then it is applied for weak fault identification of dedusting fan bearing on rolling mill and the results support its feasibility.

  14. Plate Rolling Modeling at Mill 5000 of OJSC ``Magnitogorsk Iron and Steel'' for Analysis and Optimization of Temperature Rates

    Science.gov (United States)

    Salganik, V.; Shmakov, A.; Pesin, A.; Pustovoytov, D.

    2010-06-01

    Modeling of strip deflected mode and thermal state in rolling is an integral part of the technology and perspective rolling-mill machinery such as plate mill 5000 of the OJSC "Magnitogorsk Iron and Steel". To comprehend metal behavior in the deformation zone in the rough passes during plate rolling it is essential to assess the impact of various temperature factors on variations in field of stress and strain intensities as well as temperature fields in deformation. To do such researches in consideration of various software products and adequate results one of the most effective methods nowadays is regarded as the method of finite elements. The research shows modeling of roughing rolling of a pipe steel sheet with strength category X80 according to standard API-5L. In the research of the metal deflected mode software product DEFORM 2D has been used for the isothermal and nonisothermic process. The mathematical modeling allows revealing the impact of temperature field on the metal deflected mode in the rough passes in plate rolling. Supposedly, it is deformation heating that can have more impact on the ingot temperature profile in the finishing passes in controlled rolling of the pipe steel grades. It is defined by high percent reduction, rolling speeds; more area of heat exchange surface; less thickness and lower temperature of rolling. The results can be used to develop efficient modes of plate rolling of the pipe steels.

  15. Bearing restoration by grinding

    Science.gov (United States)

    Hanau, H.; Parker, R. J.; Zaretsky, E. V.; Chen, S. M.; Bull, H. L.

    1976-01-01

    A joint program was undertaken by the NASA Lewis Research Center and the Army Aviation Systems Command to restore by grinding those rolling-element bearings which are currently being discarded at aircraft engine and transmission overhaul. Three bearing types were selected from the UH-1 helicopter engine (T-53) and transmission for the pilot program. No bearing failures occurred related to the restoration by grinding process. The risk and cost of a bearing restoration by grinding programs was analyzed. A microeconomic impact analysis was performed.

  16. INTERACTION EFFECTS OF FIVE MILLING VARIABLES ON DURUM WHEAT IN THE FIRST BREAK SYSTEM

    Science.gov (United States)

    Interactions among five major milling variables (flute angle, number of corrugations, flute orientation, speed differential of the grinding rolls, and wheat moisture) were investigated from the "First Break" products of a pilot-scale durum mill. A complete factorial design was arranged for statisti...

  17. Finite elements method (FEM simulation based prediction of deformation and temperature at rolling of tubes on a pilgrim mill

    Directory of Open Access Journals (Sweden)

    R. Kocich

    2009-10-01

    Full Text Available 3D - FEM simulation was used as an efficient tool for description of stress-deformation thermal field at rolling of tubes on a pilgrim mill. The monitored objectives comprised also behaviour of working tools at this rolling. This paper assumes rolling of already pierced thick-walled blank, which passes through the pilgrim stand at simultaneous reduction of thickness of inside and outside diameters at the expense of elongation of initial length. Main attention is focused on the mentioned parameters with respect to various conditions of rolling, such as different heat transfer, different friction or different distance of insertion of the rolled product into the gauge. The input data used at simulation were derived from real conditions of tubemaking.

  18. A novel real-time fuzzy-based diagnostic system of roll eccentricity influence in finishing hot strip mills

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, D.F.; Lopez, J.M.; Suarez, F.J.; Garcia, J. [Univ. of Oviedo, Gijon (Spain); Obeso, F.; Gonzalez, J.A. [Centro de Desarrollo, Aviles (Spain)

    1998-11-01

    This paper proposes a method for the diagnosis of the influence of roll eccentricity on the strip thickness at the exit of a finishing hot strip mill (FHSM). Each strip thickness defect on exit is related to a roll of the FHSM, allowing the implementation of an optimal policy for the substitution and maintenance of the rolls, thereby maintaining the required quality level of the strip. This policy allows the minimization of roll changes and the concentration of several changes at the same time, reducing production costs. Fuzzy logic is used to compare spectra, looking for common patterns, which allows for a totally automated diagnostic system. Moreover, an innovative estimate of roll eccentricity based on a least-squares algorithm has been developed, which provides higher accuracy than classical algorithms, as well as a drastic reduction in the time required to perform eccentricity tests.

  19. Gradient structure produced by three roll planetary milling: Numerical simulation and microstructural observations

    Energy Technology Data Exchange (ETDEWEB)

    Li Wang, Ya [School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); Center for Advanced Hybrid Materials, Department of Materials Engineering, Monash University, Clayton, Victoria 3800 (Australia); Molotnikov, Andrey [Center for Advanced Hybrid Materials, Department of Materials Engineering, Monash University, Clayton, Victoria 3800 (Australia); Diez, Mathilde [Department of Materials Science and Engineering, Seoul National University, 151-742 (Korea, Republic of); Lapovok, Rimma [Center for Advanced Hybrid Materials, Department of Materials Engineering, Monash University, Clayton, Victoria 3800 (Australia); Kim, Hyoun-Ee [Department of Materials Science and Engineering, Seoul National University, 151-742 (Korea, Republic of); Tao Wang, Jing, E-mail: jtwang@njust.edu.cn [School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); Estrin, Yuri, E-mail: yuri.estrin@monash.edu [Center for Advanced Hybrid Materials, Department of Materials Engineering, Monash University, Clayton, Victoria 3800 (Australia); Laboratory of Hybrid Nanostructured Materials, NITU MISIS, Leninskii prospect 4, Moscow 119049 (Russian Federation)

    2015-07-15

    In this study a gradient grain structure was produced by processing rod billets through three roll planetary milling (also known as PSW process). This kind of gradient structure is reported to provide an excellent combination of strength and ductility owing to an ultrafine-grained surface layer and a coarse-grained interior of the billet. Specifically, copper rod samples were subjected to up to six passes of PSW at room temperature. To study the evolution of the microstructure during the deformation, microhardness measurements and Electron Backscatter Diffraction (EBSD) analysis were performed after one, three and six passes. Additionally, the distributions of the equivalent stress during PSW and the equivalent strain after processing were studied by finite element analysis using the commercial software QFORM. The results showed the efficacy of PSW as a means of imparting a gradient ultrafine-grained structure to copper rods. A good correlation between the simulated equivalent strain distribution and the measured microhardness distribution was demonstrated.

  20. Gradient structure produced by three roll planetary milling: Numerical simulation and microstructural observations

    International Nuclear Information System (INIS)

    In this study a gradient grain structure was produced by processing rod billets through three roll planetary milling (also known as PSW process). This kind of gradient structure is reported to provide an excellent combination of strength and ductility owing to an ultrafine-grained surface layer and a coarse-grained interior of the billet. Specifically, copper rod samples were subjected to up to six passes of PSW at room temperature. To study the evolution of the microstructure during the deformation, microhardness measurements and Electron Backscatter Diffraction (EBSD) analysis were performed after one, three and six passes. Additionally, the distributions of the equivalent stress during PSW and the equivalent strain after processing were studied by finite element analysis using the commercial software QFORM. The results showed the efficacy of PSW as a means of imparting a gradient ultrafine-grained structure to copper rods. A good correlation between the simulated equivalent strain distribution and the measured microhardness distribution was demonstrated

  1. Aplicação de prensas de rolos em minério de ferro High pressure grinding rolls for iron ore

    Directory of Open Access Journals (Sweden)

    Farley Santos Ribeiro

    2010-06-01

    Full Text Available O Projeto Minas-Rio, de propriedade da Anglo Ferrous Brazil, prevê a utilização de prensa de rolos para cominuição do undersize do peneiramento (-25,4 mm. Esta é uma aplicação que se torna cada dia mais comum, porém relativamente nova em minério de ferro. Foram realizados estudos no Centro de Pesquisa da Krupp/Polysius na Alemanha, com o objetivo de validar a aplicação de prensa de rolos para minério de ferro, de determinar os principais parâmetros usados no dimensionamento e de avaliar o impacto do aumento da umidade da alimentação na capacidade específica e na distribuição granulométrica do produto. Os excelentes resultados obtidos, nos ensaios em escala-piloto, somados aos ganhos financeiros da aquisição e operação, à maior estabilidade do processo diante variações de w i (work index e à distribuição granulométrica da alimentação, contribuíram para aprovar, de forma irrestrita, a aplicação de prensa de rolos para cominuição de minério de ferro no Projeto Minas-Rio.The Minas-Rio Project that is being implemented by Anglo Ferrous Brazil, foresees the use of HPGR (High Pressure Grinding Rolls to grind the undersize from screening at (-25.4 mm. This application is recent for iron ore comminuting. The study described herein, took place at the Krupp/Polysius Research Center, in Germany, aiming to validate the HPGR application for iron ore, as well as to determine the main parameters used in equipment sizing. The study also aimed to assesses the impact of moisture variation on ore feed in respect to specific grinding capacity and product size distribution. The great results obtained from the sample tests that demonstrated more process stability for the work index (w i and granulometric feed distribution variations, together with the possible financial gains from the HPGR implementation, contributed to the unrestricted approval of the HPGR application for iron ore comminuting in the Minas-Rio Project.

  2. Simulation of two Stands Cold Rolling Mill Process Using a Combination of Neural Networks and Genetic Algorithms to Avoid the Chatter Phenomenon

    OpenAIRE

    Behzad BahramiNejad; Sayed Ali Mousavi; Mehrdad Dehghani

    2015-01-01

    Rolling mill Industry is one of the most profitable industries in the world. Chatter phenomenon is one of the key issues in this industry. Chatter or rolling unwanted vibrations not only has an adverse effect on product quality, but also reduces considerably the efficiency with reduced rolling velocities of rolling lines. This paper is an attempt to simulate the phenomenon of Chatter more accurate than the previous performed simulations. In order to increase the production speed, it needs to ...

  3. Steel balls forming by cross rolling with upsetting

    Directory of Open Access Journals (Sweden)

    Z. Pater

    2013-01-01

    Full Text Available The paper describes a process of forming four balls with a diameter of 22 mm by means of cross rolling with upsetting. The paper also presents the tool used to form semi-finished balls. Owing to the application of the finite element method (FEM, the course of the rolling process as well as temperature and strain distributions in the obtained balls could be presented. The rolling tests conducted in laboratory conditions at the Lublin University of Technology have proved that the balls produced with the developed rolling method meet the demands for grinding media used in ball mills.

  4. Investigation of the influence of the chemical composition of HSLA steel grades on the microstructure homogeneity during hot rolling in continuous rolling mills using a fast layer model

    Science.gov (United States)

    Schmidtchen, M.; Rimnac, A.; Warczok, P.; Kozeschnik, E.; Bernhard, C.; Bragin, S.; Kawalla, R.; Linzer, B.

    2016-03-01

    The newly developed LaySiMS simulation tool provides new insight for inhomogeneous material flow and microstructure evolution in an endless strip production (ESP) plant. A deepened understanding of the influence of inhomogeneities in initial material state, temperature profile and material flow and their impact on the finished product can be reached e.g. by allowing for variable layer thickness distributions in the roll gap. Coupling temperature, deformation work and work hardening/recrystallization phenomena accounts for covering important effects in the roll gap. The underlying concept of the LaySiMS approach will be outlined and new insight gained regarding microstructural evolution, shear and inhomogeneous stress and strain states in the roll gap as well as local residual stresses will be presented. For the case of thin slab casting and direct rolling (TSDR) the interrelation of inhomogeneous initial state, micro structure evolution and dissolution state of micro alloying elements within the roughing section of an ESP line will be discussed. Special emphasis is put on the influence of the local chemical composition arising from direct charging on throughthickness homogeneity of the final product. It is concluded that, due to the specific combination of large reductions in the high reduction mills (HRM) and the highly inhomogeneous inverse temperature profile, the ESP-concept provides great opportunities for homogenizing the microstructure across the strip thickness.

  5. Evaluation of Health Consequences of Air Pollution Induced by Beam Rolling Mills Factory (Iran

    Directory of Open Access Journals (Sweden)

    Rafiei Masoud

    2014-10-01

    Full Text Available The increases in air pollution over the metropolitan cities are a threat to human health and environment. An attempt has been made to evaluate the health consequences of indoor air pollution induced by Beam Rolling Mills Factory at Ahwaz (Iran. A questionnaire was prepared to obtain information on health of 481 workers, out of which 200 each were selected from exposed and non-exposed category by stratified randomized method. Fisher exact test and chi-square test were used to calculate the values. The study concludes that more than 80% of the workers have high exposure risk to diseases. Analysis of the health impacts reveals that exposed workers are more prone to various diseases as compared to the non-exposed workers. It is also observed that exposure to air pollutants might be the causative factor for various diseases among the smokers but also nonsmoking workers. The analysis also reveals that there is higher relative risk in occupational fatigue and cardio-vascular disease. Further, the study found that percentage of workers having various diseases is much higher in the indoor environment as compared to the outdoor environment

  6. Genetic based sensorless hybrid intelligent controller for strip loop formation control between inter-stands in hot steel rolling mills.

    Science.gov (United States)

    Thangavel, S; Palanisamy, V; Duraiswamy, K

    2008-04-01

    Safe operating environment is essential for all complex industrial processes. The safety issues in steel rolling mill when the hot strip passes through consecutive mill stands have been considered in this paper. Formation of sag in strip is a common problem in the rolling process. The excessive sag can lead to scrap runs and damage to machinery. Conventional controllers for mill actuation system are based on a rolling model. The factors like rise in temperature, aging, wear and tear are not taken into account while designing a conventional controller. Therefore, the conventional controller cannot yield a requisite controlled output. In this paper, a new Genetic-neuro-fuzzy hybrid controller without tension sensor has been proposed to optimize the quantum of excessive sag and reduce it. The performance of the proposed controller has been compared with the performance of fuzzy logic controller, Neuro-fuzzy controller and conventional controller with the help of data collected from the plant. The simulation results depict that the proposed controller has superior performance than the other controllers. PMID:18093589

  7. HOT ROLLING OF A FERRITIC STAINLESS STEEL IN A STECKEL MILL: THERMOMECHANICAL AND MICROSTRUCTURAL CARACTERIZATION AND MATHEMATICAL MODELLING OF THE EVOLUTION OF RECRYSTALLIZED VOLUME FRACTION OF FERRITE

    Directory of Open Access Journals (Sweden)

    Willy Schuwarten Júnior

    2013-10-01

    Full Text Available A thermomechanical and a microstructure caracterization and a mathematical model of the evolution of the recrystallized volume fraction of ferrite in hot rolling in a Steckel mill have been carried out here. The proposed model is able to reasonably predict the observed in hot rolling, that is, there is 100% recrystallization of ferrite after roughing and partial recrystallization only after finishing

  8. INFLUENCE OF CONFIGURATION OF EQUIPMENT OF A HIGH-SPEED ROD MILL ON QUALITATIVE CHARACTERISTICS OF HIGH-CARBON ROLLED WIRE

    Directory of Open Access Journals (Sweden)

    V. A. Lutsenko

    2015-11-01

    Full Text Available The quality of output production has increased in the result of new arrangement of finishing train of block construction of rod mill of RUP «BMZ». Additional using in rolled line of reducing-sizing block at production of high- carbon rolled wire enabled to reduce the dispersion of mechanical characteristics, to decrease the depth of decarburized layer.

  9. Simulation of two Stands Cold Rolling Mill Process Using a Combination of Neural Networks and Genetic Algorithms to Avoid the Chatter Phenomenon

    Directory of Open Access Journals (Sweden)

    Behzad BahramiNejad

    2015-03-01

    Full Text Available Rolling mill Industry is one of the most profitable industries in the world. Chatter phenomenon is one of the key issues in this industry. Chatter or rolling unwanted vibrations not only has an adverse effect on product quality, but also reduces considerably the efficiency with reduced rolling velocities of rolling lines. This paper is an attempt to simulate the phenomenon of Chatter more accurate than the previous performed simulations. In order to increase the production speed, it needs to avoid parameters which effect on the Chatter and varieties with the rolling lines condition. Actual values of these parameters were determined in the archives of the Mobarakeh two stand cold rolling mills and collected on the 210 case study of real chattering. To simulate the experiment, a neural network is trained and weights and bias values of the neural network with genetic optimization algorithm were used to get an optimal neural network which reduces bugs on the test data. So this model is capable to predict speed of Chatter threshold on rolling process of two stand cold rolling mill with the accuracy less than one percent. So it can be used in rolling process with the building intelligent recognition systems to prevent the creator conditions of the chatter frequency range.

  10. Defect structure of Fe-Al and Fe-Al-Ni metallic powders obtained by the self-decomposition method and intensive grinding in an electro-magneto-mechanical mill

    International Nuclear Information System (INIS)

    The Fe-Al and Fe-Al-Ni metallic powders produced by the self-decomposition method and then intensive grinding in an electro-magneto-mechanical mill with Fe and Ni additions were examined by X-ray powder diffraction, scanning electron microscopy and Moessbauer spectroscopy. The concentration of vacancies and Fe atoms occupying Al positions (Fe-AS atoms) was determined from the Moessbauer spectra analysis connected with distinct Fe environments. The results show that nickel addition causes both an increase in vacancy concentrations in comparison with values found for Fe-Al metallic powders and a significant increase in the antisite Fe-AS atoms concentration. Intensive high energy grinding in the electro-magneto-mechanical mill modifies the phase composition of the studied materials and changes the concentration of point defects. (authors)

  11. Failure analysis of work rolls of a thin hot strip mill

    Directory of Open Access Journals (Sweden)

    Piyas Palit

    2015-04-01

    Destructive testing (including metallography and chemical analysis was carried out on the failed roll samples in the first case and gross abnormality in microstructure was observed. Some foreign particle/entrapment was observed after dressing of the working surface of roll at 566 mm diameter (initial diameter of roll was 620 mm and scrap diameter was projected to be 540 mm. The chemical composition of the particle was analyzed by a portable X-Ray Fluorescence (XRF alloy analyzer and it was confirmed that the particle is basically a ferroalloy which was entrapped in the shell of the roll, probably during casting/manufacturing of roll.

  12. Micromill designed for the measurement of the wheat kernel grinding resistance, in the grinding process

    Directory of Open Access Journals (Sweden)

    Ioan DANCIU

    2010-12-01

    Full Text Available In the era of global slowdown and recession, saving energy becomes a ”must have” characteristic of every industrial consumer. In the industrial milling process of the wheat, 60-75 % of the total specific energy consumption is used in the grinding process. The measurement of the grinding resistance of the wheat kernel can estimate the energy consumption in the grinding process and can lead to a diminution of the total energy consumption, in the milling process.

  13. Assessment of Air Pollution and its Effects on Health of Workers of Steel Re-Rolling Mills in Hyderabad

    OpenAIRE

    Altaf Alam Noonari; Rasool Bux Mahar; Abdul Razaque Sahito

    2016-01-01

    The SRRMs (Steel Re-Rolling Mills) are being releasing air pollutants in the environment. In order to evaluate their effect on the health of the workers, health and safety issues were analyzed by first measuring the concentrations of SO x (OIxides of Sulphur), NO x (Oxides of Nitrogen), CO (Carbon Monoxide) and O2 (Oxygen) produced in the three SRRMs located in SITE area Hyderabad. The mean concentration of SO x , NO x and CO were in the order of 0.35, 0.280, 6.333 ppm, respectively, whereas ...

  14. Catalytic surface modification of roll-milled poly({epsilon}-caprolactone) biaxially stretched to ultra-thin dimension

    Energy Technology Data Exchange (ETDEWEB)

    Foo, H.L. [Graduate Programme in Bioengineering, National University of Singapore (Singapore); Bionic Materials Technology Group, Biomaterials Center, National Institute for Materials Science (Japan); Taniguchi, A. [Bionic Materials Technology Group, Biomaterials Center, National Institute for Materials Science (Japan); Yu, H. [Graduate Programme in Bioengineering, National University of Singapore (Singapore); Department of Physiology, National University of Singapore (Singapore); Okano, T. [Bionic Materials Technology Group, Biomaterials Center, National Institute for Materials Science (Japan); Institute of Biomedical Engineering, Tokyo Women' s Medical University (Japan); Teoh, S.H. [Graduate Programme in Bioengineering, National University of Singapore (Singapore) and Department of Mechanical Engineering, National University of Singapore (Singapore)]. E-mail: mpetsh@nus.edu.sg

    2007-03-15

    A novel roll-milling polymer processing technique along with biaxial stretching was used to fabricate 10 {mu}m thick poly({epsilon}-caprolactone) films. A less invasive collagen surface modification was used, involving a reaction between corona-preactivated membranes and ferrous-containing acrylic acid solution at the low temperature of 42 {sup o}C. Successful modified films were characterized by Toluidine Blue O assay and X-ray photoelectron spectroscopy. Human umbilical vein endothelial cells also showed both higher proliferation rate and differentiated cobblestone morphology on these collagen-immobilized substrates.

  15. Using the eight-roller mill in the purifier-less mill flow.

    Science.gov (United States)

    Fistes, Aleksandar; Rakić, Dušan

    2015-07-01

    Double grinding of mill streams without intermediate sieving, i.e. the eight-roller milling system provides opportunities for significant reduction of capital cost compared to conventional wheat flour milling system. In this study the effects of using the eight-roller mill in the purifier-less mill flow were investigated. Middlings from the break system of commercial flour mill, which would be sent to the purification system, were intercepted and employed in the experiments. Milling results obtained with double grinding of middlings were compared with the results obtained by conventional system with intermediate sifting before regrinding of stock. At the same roll gap setting and under the same sieving conditions, the eight-roller system produced less flour compared to the conventional system. Results showed that the most efficient way to increase flour yield in the eight-roller milling system is to increase the upper size limit of flour by increasing the sieve aperture. This is not followed by the deterioration of flour quality as determined by ash content. Increase of the upper size limit of flour particles is followed by the decrease of the flour ash content suggesting that it is possible to implement the eight-roller mills in the purifier-less mill flow. PMID:26139941

  16. Maintenance strategy for tilting table of rolling mill based on reliability considerations

    International Nuclear Information System (INIS)

    Reliability centred maintenance (RCM) is a new strategic framework for ensuring that any asset continues to perform, as its users want it to perform. RCM is a process used to determine the maintenance requirement of any physical asset in its operating context. RCM process entails asking seven questions about each of the selected assets. It makes use of two documents namely, RCM information worksheet and RCM decision worksheet. RCM decision diagram integrates all the decision processes into a single strategic framework. RCM concept developed by US commercial airlines industry has been successfully implemented by Military, Navy, Nuclear power plants, electric power generation and distribution undertakings and several other sectors. These projects have been carried out in the United Kingdom, The Republic of Ireland, the United States, Hong Kong, Australia, Spain and Singapore. The fact that people has enthusiastically received RCM at all levels and has enabled users to achieve some remarkable successes in all of these countries, suggests that it can be universally employed. Literature review indicates that RCM approach is not conventionally applied in process industries in India. Presently, predictive maintenance (PDM) approach along with conventional preventive maintenance is used in continuous/process industries. This approach if implemented in totality will increase the production cost to a large degree and make the production uneconomical. Similarly breakdown maintenance (BDM) approach cannot be applied in such industries as each breakdown involves huge costs. RCM approach is a compromise between PDM and BDM approach for optimising the cost and ensuring the availability of machine. The RCM approach has been applied to the tilting table system of rolling mill for the research work reported in this paper. In the present study, preventive maintenance tasks suggested for power transmission subsystem, guiding and transportation subsystem and hydraulic subsystem in tilting tables are 14 scheduled on-condition tasks, 10 scheduled on-restoration tasks, seven scheduled discard task. Whereas for 14 failure modes no scheduled maintenance has been proposed. Existing maintenance schedule for tilting tables indicates the maintenance action as and when required. Hence RCM based schedule specifies that additional preventive maintenance tasks need to be executed as compared to none initially. Cost incurred for this can be offset from the savings accrued from reduction in loss of production due to repetitive breakdowns. The methodology of RCM adopted in western industries cannot be applied as it is to Indian industries because of labour oriented nature, partially computerised information systems, non-availability of the information about cost of loss of production due to breakdown and age-reliability pattern of equipment, insufficient maintenance database. These problems can be overcome by development of sound MMIS, formulation of RCM review group and imparting suitable training to acquire the relevant skills in RCM. Thus RCM methodology can be applied to Indian industry for reduction of breakdowns as well as optimisation of preventive maintenance cost. This can further boost up the prospects of Indian industry to offer the products at globally competitive prices

  17. "Grinding" cavities in polyurethane foam

    Science.gov (United States)

    Brower, J. R.; Davey, R. E.; Dixon, W. F.; Robb, P. H.; Zebus, P. P.

    1980-01-01

    Grinding tool installed on conventional milling machine cuts precise cavities in foam blocks. Method is well suited for prototype or midsize production runs and can be adapted to computer control for mass production. Method saves time and materials compared to bonding or hot wire techniques.

  18. Grain refinement of magnesium alloy sheets by ARB using high-speed rolling mill

    International Nuclear Information System (INIS)

    Applications of ARB to magnesium alloys were limited due to low deformability. The authors recently found that the rollability of the alloys is significantly improved in highspeed rolling. It is supposed that the severe plastic deformation of magnesium alloy sheets is feasible if rolling in ARB processes is conducted at high speed. In this study, AZ31B and ZK60A sheets are processed by ARB up to five cycles at 423K with a speed of 1000m/min. Vickers hardness increases with increasing number of ARB cycles, while the tensile strength shows the maximum after the second cycle. The grain size is reduced significantly at the first cycle and decreases gradually from the second cycle. The mean grain sizes after five cycles are 1.6?m for AZ31B and 1.8?m for ZK60A. It is concluded that ARB using high-speed rolling is effective for grain refinement of magnesium alloys.

  19. Tracer analysis and modelling of industrial ore grinding systems

    International Nuclear Information System (INIS)

    Residence time distribution of the open loop grinding mill is obtained through a radiotracer test. Screen analyses and numerical solution of the model are then used for values of the kinetic grinding parameters. An algorithm is derived for the extraction of the residence time distribution of the mill in closed loop, in the presence of the recycling tracer. The construction of the grinding system model is based on the models of its components

  20. Analysis of the technology of rolling 5,5 mm-diameter wire rod of cold upsetting steel in the morgan block mill

    Directory of Open Access Journals (Sweden)

    K. Laber

    2015-04-01

    Full Text Available The commercial technology of rolling 5,5 mm-diameter wire rod in Poland’s most modern rolling line has been examined within the study. The material used for the investigation was the 20MnB4 steel intended for subsequent cold working. From the performed analysis of the investigation results it has been found that the technology of rolling wire rod of cold upsetting steel, which is used currently in the Rolling Mill under examination, allows the production of finished products that can be deformed with a relative reduction of about 33 %. At larger plastic deformations,cracks occur in the material, which disqualifies it from further cold working.

  1. Comparison between a high chromium steel and a semi HSS grades used as work rolls in the roughing stands of a hot strip mill

    OpenAIRE

    Tchuindjang, Jérôme Tchoufack; Lecomte-Beckers, Jacqueline

    2010-01-01

    Two alloys grades for work rolls used in the roughing stand of Hot Strip Mill (HSM) were compared. The first grade known as High Chromium Steel (HCS) is actually the alloy widely used for such an application, while the second one known as semi-High Speed Steel (semi-HSS) is the new grade developed to improve overall properties of the work roll in the roughing stands of the HSM. In the present work, the new semi-HSS grade is studied starting from 3 chemical compositions closed one to anoth...

  2. Assessment of Air Pollution and its Effects on Health of Workers of Steel Re-Rolling Mills in Hyderabad

    Directory of Open Access Journals (Sweden)

    Altaf Alam Noonari

    2016-04-01

    Full Text Available The SRRMs (Steel Re-Rolling Mills are being releasing air pollutants in the environment. In order to evaluate their effect on the health of the workers, health and safety issues were analyzed by first measuring the concentrations of SO x (OIxides of Sulphur, NO x (Oxides of Nitrogen, CO (Carbon Monoxide and O2 (Oxygen produced in the three SRRMs located in SITE area Hyderabad. The mean concentration of SO x , NO x and CO were in the order of 0.35, 0.280, 6.333 ppm, respectively, whereas the mean concentration of O 2 was 203.53 thousand ppm. As per results, the concentration ofair pollutants, including SOx and NO x were significantly higher than to the NEQS (National Environmental Quality Standards and NAAQS (National Ambient Air Quality Standards. The concentration ofCO was lower than to the NAAQS, but higher than to the NEQs, while the concentration of O2 was slightly lower than to the standard value. The workers who were exposed to these air pollutants are being suffering from chronic diseases related to breathing and allergies. Moreover, labour staff was lifting heavy loads manually, which causes them to muscular and joint problems. In all the SRRMs under study, the electrical and mechanical equipments were used without any safety. The MSDS were not displayed on the workstations, the housekeeping was inadequate and most of the workers were performing their jobs without personal protective equipment. In addition to these, the other serious issues related to the occupational health and safety were an unhygienic supply of water, higher noise level, placement of explosive cylinders in the open atmosphere and unavailability of the first aid facilities in the Mill premises.

  3. Energy Use of Fine Grinding in Mineral Processing

    Science.gov (United States)

    de Bakker, Jan

    2013-12-01

    Fine grinding, to P80 sizes as low as 7 μm, is becoming increasingly important as mines treat ores with smaller liberation sizes. This grinding is typically done using stirred mills such as the Isamill or Stirred Media Detritor. While fine grinding consumes less energy than primary grinding, it can still account for a substantial part of a mill's energy budget. Overall energy use and media use are strongly related to stress intensity, as well as to media size and quality. Optimization of grinding media size and quality, as well as of other operational factors, can reduce energy use by a factor of two or more. The stirred mills used to perform fine grinding have additional process benefits, such as polishing the mineral surface, which can enhance recovery.

  4. Surface finishing and levelling of thermomechanically hardened rolled steel

    International Nuclear Information System (INIS)

    The finishing of high-strength merchant shapes from alloy steel was tried out under industrial conditions with the equipment of metallurgical plants. After thermomechanical hardening in the production line of the rolling mill, 30KhGSN2A and 40Kh1NVA steel rounds 32 and 31 mm in diameter were straightened on a two-roller straightening machine designed by the All-Union Scientific Research Institute for Metallurgical Machinery (VNII Metmash). This made possible subsequent turning and grinding of the rods. The conditions of straightening, turning and grinding have been worked so as to obtain thermomechanically strengthened and ground rolled products approximating the gauged and ground metal in shape geometry and surface finish. It is shown that the labour-consuming operation of turning can be eliminated by reducing the machining pass of the rolled product, and this lowers the labour required for the finishing operations by 75%. After grinding with 40- and 25-grain abrasive wheels, high strength rolled shapes were obtained with a diameter of 30-0.20 mm and a surface finish of class 6-5 satisfying the technical specifications. (author)

  5. Pitt Mill Demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Oder, R.R.; Borzone, L.A.

    1990-05-01

    Results of a technical and economic evaluation of application of the Pitt Mill to fine coal grinding are presented. The Pitt Mill is a vertically oriented, batch operated, intermediate energy density (0. 025 kW/lb media), stirred ball mill. The mill grinds coal from coarse sizes (typically 3/16 inch or 4 mesh topsize) to the 10 micron to 20 micron mean particle diameter size range in a single step using a shallow grinding bed containing inexpensive, readily available, course grinding media. Size reduction is efficient because of rapid product circulation through the grinding bed caused by action of a novel circulation screw mounted on the agitator shaft. When a dispersant is employed, the grinding can be carried out to 50% to 60% solids concentration. Use of coarse grinding media offers the possibility of enhanced mineral liberation because size reduction is achieved more by impact shattering than by attrition. The batch method offers the possibility of very close control over product particle size distribution without overproduction of fines. A two- phase program was carried out. In the first phase, Grinding Studies, tests were run to determine a suitable configuration of the Pitt Mill. Machine design parameters which were studied included screw configuration, media type, agitator RPM, time, media size, and slurry chamber aspect ratio. During the last part of this phase of the program, tests were carried out to compare the results of grinding Pocahontas seam, Pittsburgh {number sign}8, and East Kentucky Mingo County coals by the Pitt Mill and by a two-stage grinding process employing a Netzsch John mill to feed a high energy density (0.05 kW/Lb media) disc mill. 22 refs., 25 tabs.

  6. Effect of the microstructure on tribological phenomena occurring on the surface of a mill roll made of SA5T cast iron (GJSL-HV600 - GJSL-330NiMoCr12-8-3

    Directory of Open Access Journals (Sweden)

    J. Krawczyk

    2008-07-01

    Full Text Available This paper deals with the role of the microstructure in the tribological wear processes occurring in a cast iron mill roll. For this purpose, a piece of a broken roll, made in Italy, was collected. Its microstructure consisted of modular graphite, transformed ledeburite and a matrix composed of bainite and martensite. Metallographic investigations were performed on the roll working surface in conjunction with metallographic tests effected within its surface layer. There was established the relation between the microstructure of the roll and the process of its tribological wear. The following was ascertained: micro-shrinkages or graphite precipitations nearby the working area cause cracks between those places and the working area; in the surface layer, cracks occur usually in the zone of ledeburitic cementite. At places of considerable precipitations of ledeburitic cementite, the tribological wear intensity of the roll is lower. A banded layout of precipitations of ledeburitic cementite facilitates a selective spalling of some parts of the roll material. The results of this study allow broadening the data base related to the effect of the microstructure on tribological wear of mill rolls, which in future will permit one to design their proper microstructure of cast iron mill rolls.

  7. Process for grinding graphite

    Energy Technology Data Exchange (ETDEWEB)

    Junttila, J. D.

    1985-08-06

    Disclosed is a process for grinding graphite comprising: forming a mixture of graphite and a graphite grinding aid; grinding the mixture of graphite and graphite grinding aid to reduce the size of the graphite; forming an aqueous slurry of the graphite particles, graphite grinding aid and water; adding an amount of hydrocarbon oil to the aqueous slurry with agitation to form graphite-oil agglomerates; separating the graphite-oil agglomerates from the grinding aid and water; and removing hydrocarbon oil from the graphite-oil agglomerates to provide graphite particles reduced in size.

  8. Ultra-fine grinding and mechanical activation of mine waste rock using a high-speed stirred mill for mineral carbonation

    Science.gov (United States)

    Li, Jia-jie; Hitch, Michael

    2015-10-01

    CO2 sequestration by mineral carbonation can permanently store CO2 and mitigate climate change. However, the cost and reaction rate of mineral carbonation must be balanced to be viable for industrial applications. In this study, it was attempted to reduce the carbonation costs by using mine waste rock as a feed stock and to enhance the reaction rate using wet mechanical activation as a pre-treatment method. Slurry rheological properties, particle size distribution, specific surface area, crystallinity, and CO2 sequestration reaction efficiency of the initial and mechanically activated mine waste rock and olivine were characterized. The results show that serpentine acts as a catalyst, increasing the slurry yield stress, assisting new surface formation, and hindering the size reduction and structure amorphization. Mechanically activated mine waste rock exhibits a higher carbonation conversion than olivine with equal specific milling energy input. The use of a high-speed stirred mill may render the mineral carbonation suitable for mining industrial practice.

  9. AISI/DOE Advanced Process Control Program Vol. 3 of 6: MICROSTRUCTURAL ENGINEERING IN HOT-STRIP MILLS Part 2 of 2: Constitutive Behavior Modeling of Steels Under Hot-Rolling Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Yi-Wen Cheng; Patrick Purtscher

    1999-07-30

    This report describes the development of models for predicting (1) constitutive behaviors and (2) mechanical properties of hot-rolled steels as functions of chemical composition, microstructural features, and processing variables. The study includes the following eight steels: A36, DQSK, HSLA-V, HSLA-Nb, HSLA-50/Ti-Nb, and two interstitial-free (IF) grades. These developed models have been integrated into the Hot-Strip Mill Model (HSMM), which simulates the hot strip rolling mills and predicts the mechanical properties of hot-rolled products. The HSMM model has been developed by the University of British Columbia-Canada as a part of project on the microstructural engineering in hot-strip mills.

  10. AISI/DOE Advanced Process Control Program Vol. 3 of 6: MICROSTRUCTURAL ENGINEERING IN HOT-STRIP MILLS Part 2 of 2: Constitutive Behavior Modeling of Steels Under Hot-Rolling Conditions; FINAL

    International Nuclear Information System (INIS)

    This report describes the development of models for predicting (1) constitutive behaviors and (2) mechanical properties of hot-rolled steels as functions of chemical composition, microstructural features, and processing variables. The study includes the following eight steels: A36, DQSK, HSLA-V, HSLA-Nb, HSLA-50/Ti-Nb, and two interstitial-free (IF) grades. These developed models have been integrated into the Hot-Strip Mill Model (HSMM), which simulates the hot strip rolling mills and predicts the mechanical properties of hot-rolled products. The HSMM model has been developed by the University of British Columbia-Canada as a part of project on the microstructural engineering in hot-strip mills

  11. Improving energy efficiency of reheating furnace of sheet ingot plant and rolling mill Calibers of Gecamines / Lubumbashi by the recovery of waste heat of smoke

    International Nuclear Information System (INIS)

    The economic management of energy is an important topic in industrial processes to the extent that it ensures the competitiveness of any firm and ensures its survival. Within this framework we plan to improve the energy efficiency of the powerful furnace for reheating lingots Rolling Mills and Cable Factory (of which the fuel is diesel) where we propose to install a head recovery exchanger between the hot fumes out of the oven (60 C) and combustion air taken initially at room temperature (250C). Without recovery the oven consumes on the average 101 liters of diesel per hour for its operation and yields a thermal efficiency of 68,6%. Whereas with recovery, it can reach a thermal efficiency of 86% on one of recoverers that we have proposed, and save up to 15,8 liters of diesel on its hourly consumption

  12. Effects of grinding on certain crystalline structures

    International Nuclear Information System (INIS)

    The effects of grinding on certain crystalline substances (ZnO, ZnS, Sb), have been studied using X-ray diffraction and electron microscopy. The treatments were carried out using a vibrating mill which involves a higher energy than more conventional equipment such as ball-mills. Various methods have been proposed for determining the width of the intrinsic profile (β). In the case of zinc oxide it has been shown possible to differentiate the respective contributions of the fragmentation effects and of lattice deformation effects to the overall effects of the grinding. For the two types of zinc sulfide (blend and Wurtzite) it has been shown that the blend-wurtzite) transition point is very much decreased, and that the rate of transformation of wurtzite into the stable form (blend) at room temperature is considerably increased by the grinding. In the case of antimony, the method of fragmentation shows the existence of an anisotropy which appears to be connected with easily cleavable planes. These observations show that in the case of grinding carried out with sufficient energy, the accumulation of this energy in the matter through the creation of lattice defects can accelerate the reaction rate or bring about physical transformations. (author)

  13. Effect of wet grinding on structural properties of ball clay

    International Nuclear Information System (INIS)

    In this paper, the effect of wet grinding on structural properties of ball clay is undertaken. The wet grinding treatment was performed employing ball and vibro mills for different time spells of 2, 4, 8 and 16 hours. The structural properties were carried out using X-ray diffraction (XRD). The structure of ground samples is found to be simple cubic. The crystallographic parameters are calculated and slight change in lattice constant, inter planner spacing and particle size is observed with grinding treatment. The results are in agreement with the available literature

  14. Effect of particle size on performance. 3. Grinding pelleting interactions.

    Science.gov (United States)

    Nir, I; Hillel, R; Ptichi, I; Shefet, G

    1995-05-01

    Three experiments were conducted to study the effect of particle size obtained by grinding wheat and sorghum in a hammer mill (HM) or roller mill (RM) on broiler performance. Broilers were fed a mash diet or crumbles to 4 wk of age, then pellets to 7 wk of age. When fed as a mash, diets produced with RM-ground grain improved performance. The effect of grinding was additive to that of pelleting. The interactive effects observed between grinding method and the form of the feed on body weight and feed intake were explained by the higher response to pelleting when grains were ground in HM vs RM. The positive effect of grinding in RM on feed utilization was found to be additive to that of pelleting in all three experiments. The response of females to feed texture was less pronounced than that of males. In males, feeding pellets vs mash increased mortality due to ascites threefold, whereas grinding method had no effect. Females were less susceptible to ascites than males, and feed texture had no effect in this respect. The effects of grinding and pelleting on the gastrointestinal tract segments were additive. The main effects of feed texture were a significant increase in stomach weight and that of its contents following HM grinding and a decrease in these following pelleting, with no interactions between the two. PMID:7603952

  15. STABLE DIAMOND GRINDING

    Directory of Open Access Journals (Sweden)

    Yury Gutsalenko

    2010-06-01

    Full Text Available The paper generalizes on the one hand theory of kinematic-geometrical simulation of grinding processes by means of tools with working part as binding matrix with abrasive grains located in it in random manner, for example diamond grains, and on the other hand practical performance of combined grinding process, based on introduction of additional energy as electric discharges and called by the organization-developer (Kharkov Polytechnic Institute diamond-spark grinding as applied to processing by means of diamond wheel. Implementation of diamond-spark grinding technologies on the basis of developed generalized theoretical approach allows to use the tool with prescribed tool-life, moreover to make the most efficient use of it up to full exhausting of tool-life, determined by diamond-bearing thickness. Development is directed forward computer-aided manufacturing.

  16. Effects of concentration of dispersions on particle sizing during production of fine particles in wet grinding process

    OpenAIRE

    Inam, Muhammad Asif; Ouattara, Soualo; Frances, Christine

    2011-01-01

    Stirred media milling is a prospective technology for producing colloidal dispersions by means of wet grinding process. In the past, many researchers have studied the effects of different operating parameters such as size, shape, nature and quantity of grinding medium, the speed of agitator in grinding chamber, the feed rate of dispersions, etc. in stirred media mills. However, it is still less known how particle sizing which generates valuable information of particle size of the product to i...

  17. Influence of Agglomeration and Contamination in the Course of Amorphous Powder Grinding on Structure and Microstructure of Sintered Mullite

    OpenAIRE

    Stanislav KURAJICA; Tkalčec, Emilija; MATIJAŠIĆ, Gordana; Ćurković, Lidija; Schauperl, Zdravko; Juraj ŠIPUŠIĆ; Mandić, Vilko

    2011-01-01

    The process of grinding of amorphous pre-mullite powder has been investigated. The powder has been obtained by sol-gel process followed by drying, calcination and wet milling in planetary ball mill for various periods. While particle size distributions shifts to finer size distributions as the grinding time increase, the specific surface area dependence on the grinding time shows complex behavior. This was attributed to the agglomeration in the course of calcinations partially pro...

  18. Adsorption of single-strand alkylammonium salts on bentonite, surface properties of the modified clay and polymer nanocomposites formation by a two-roll mill

    Energy Technology Data Exchange (ETDEWEB)

    Hoshino, Jumpei [Materials Science and Engineering Programme and Nanotec Center of Excellence at Mahidol University, Faculty of Science, Mahidol University, Rajathavee, Bangkok 10400 (Thailand); Limpanart, Sarintorn; Khunthon, Srichalai [Metallurgy and Materials Research Institute, Chulalongkorn University, Phayathai, Bangkok 10330 (Thailand); Osotchan, Tanakorn [Materials Science and Engineering Programme and Nanotec Center of Excellence at Mahidol University, Faculty of Science, Mahidol University, Rajathavee, Bangkok 10400 (Thailand); Physics Department, Faculty of Science, Mahidol University, Rajathavee, Bangkok 10400 (Thailand); Traiphol, Rakchart [Laboratory of Advanced Polymers and Nanomaterials, Department of Chemistry and Center for Innovation in Chemistry, Faculty of Science, Naresuan University, Phitsanulok 65000 (Thailand); Srikhirin, Toemsak, E-mail: sctsk@mahidol.ac.th [Materials Science and Engineering Programme and Nanotec Center of Excellence at Mahidol University, Faculty of Science, Mahidol University, Rajathavee, Bangkok 10400 (Thailand); Physics Department, Faculty of Science, Mahidol University, Rajathavee, Bangkok 10400 (Thailand)

    2010-10-01

    The adsorption of tallow alkylammonium salts onto bentonite from the Lopburi province in Thailand, and the effect of surface wettability on the formation of polymer-clay nanocomposites are reported. We looked specifically at octadecyltrimethyl ammonium chloride (S18), a popular member of the tallow alkylammonium salt family. The adsorption of S18 onto the bentonite interlayer can be divided into three distinct stages depending upon the initial concentration of S18. These stages are (a) monolayer formation, (b) intermediate state of double layer formation and (c) double layer formation. A decrease in surface energy driven by drops in the values of the polar and dispersive components was observed as the amount of surfactant surface coverage increased. Using thermal gravimetric analysis (TGA), the critical surface energy (CSE) of organoclay was found to decrease as the amount of absorbed S18 increased. S18 organoclay with different degrees of surface coverage was used in a two-roll mill to prepare high-density polyetheylene (HDPE)-clay nanocomposites. The oxidized polyethylene wax (OWax) was used as a dispersing agent to promote the delamination of the organoclay platelets. The results from X-ray diffraction (XRD) and transmission electron microscope (TEM) indicated a difference in the dispersing capability of the organoclay.

  19. Assessment of air pollution and its effects on the health status of the workers in beam rolling mills factory (Iran National Steel Industrial Group from Ahvaz-Iran

    Directory of Open Access Journals (Sweden)

    Rafiei Masoud

    2009-01-01

    Full Text Available Background: Air pollutants of iron- and steel-making operations have historically been an environmental and health hazard. These pollutants include gaseous substances such as sulfur oxide, nitrogen dioxide, and carbon monoxide. The Iran National Steel Industrial Group beam rolling mills factory has two production lines viz. line 630 and line 650, with different beam production capabilities and is capable of producing different types of beams. Materials and Methods: A retrospective cross-sectional study on 400 workers in different exposure levels to environmental pollution was performed during 2005 to determine the mean value of respirable particulate matter (RPM concentrations and its effects on the health status of workers. To elicit information regarding the health status of the worker, the National Institute for Occupational Safety and Health standard questionnaire was used. Fisher′s exact test was performed to assess the relative risk (RR of exposure to air pollution on cardiovascular diseases, chest tightness, cough, difficulty in retention, i.e. loss of memory, tension, occupational fatigue, and occupational stress in exposed workers. Results: There was significant difference in RPM pollution level between two product lines. The RR of exposure to air pollution on cardiovascular diseases, chest tightness, cough, difficulty in retention, i.e. loss of memory, tension, occupational fatigue, and occupational stress in exposed workers were 2.78, 2.44, 2.15, 1.92, 1.57, 3.90, and 2.09, respectively.

  20. Adsorption of single-strand alkylammonium salts on bentonite, surface properties of the modified clay and polymer nanocomposites formation by a two-roll mill

    International Nuclear Information System (INIS)

    The adsorption of tallow alkylammonium salts onto bentonite from the Lopburi province in Thailand, and the effect of surface wettability on the formation of polymer-clay nanocomposites are reported. We looked specifically at octadecyltrimethyl ammonium chloride (S18), a popular member of the tallow alkylammonium salt family. The adsorption of S18 onto the bentonite interlayer can be divided into three distinct stages depending upon the initial concentration of S18. These stages are (a) monolayer formation, (b) intermediate state of double layer formation and (c) double layer formation. A decrease in surface energy driven by drops in the values of the polar and dispersive components was observed as the amount of surfactant surface coverage increased. Using thermal gravimetric analysis (TGA), the critical surface energy (CSE) of organoclay was found to decrease as the amount of absorbed S18 increased. S18 organoclay with different degrees of surface coverage was used in a two-roll mill to prepare high-density polyetheylene (HDPE)-clay nanocomposites. The oxidized polyethylene wax (OWax) was used as a dispersing agent to promote the delamination of the organoclay platelets. The results from X-ray diffraction (XRD) and transmission electron microscope (TEM) indicated a difference in the dispersing capability of the organoclay.

  1. Study on anaerobic treatment of hazardous steel-mill waste rolling oil (SmWRO) for multi-benefit disposal route.

    Science.gov (United States)

    Ma, Huanhuan; Li, Zifu; Yin, Fubin; Kao, William; Yin, Yi; Bai, Xiaofeng

    2014-01-01

    Steel-mill waste rolling oil (SmWRO) is considered as hazardous substance with high treatment and disposal fees. Anaerobic process could not only transform the hazardous substance into activated sludge, but also generate valuable biogas. This study aimed at studying the biochemical methane potential of SmWRO under inoculum to substrate VS ratios (ISRs) of 0.25, 0.5, 1, 1.5, 2 and 3 using septic tank sludge as inoculum in mesophilic and thermophilic conditions, with blank tests for control. Specific biogas yield (mL/g VS(added)), net biogas yield (mL/g VS(removed)) and VS removal were analyzed. The ANOVA results indicated great influence of ISR and temperature on studied parameters. ISR of 1.5 at 55°C and ISR of 1.5 and 2 at 35°C were suggested with the highest specific biogas yield (262-265 and 303mL/g VS(added)). Kinetic analysis showed that Gompertz model fit the experimental data best with the least RMSE and largest R(2). PMID:24212130

  2. Dynamics of Entangled Polymeric Fluids in Two-roll Mill studied via Dynamic Light Scattering and Two-color flow Birefringence; 1, Steady flow

    CERN Document Server

    Sanyal, S; Leal, L C; Sanyal, Subrata; Yavich, Dmitry

    2000-01-01

    We present the experimental results on a series of high molecular weight, entangled polystyrene solutions subjected to a ``mixed'' shear and elongational flow-type generated in a co-rotating two-roll mill. For steady-flows as well as for start-up of flows from rest, we used two different optical methods to study the dynamics of entangled polymeric fluids: two-color flow birefringence (TCFB) and dynamic light scattering (DLS). Using the TCFB method, we measured the birefringence, $\\Delta n$, and the orientation angle, $\\chi$, of the optic axes in the solution and thereby the generalized viscosity function, $\\eta$ (with the use of stress-optical relations). The DLS method was applied to measure the velocity-gradient, \\gdot, and the flow-type parameter $\\lambda$ for the polymer solutions under flow conditions identical to the TCFB measurements. For low deformation rates the symmetry of the flow-field was reduced with the use of polymeric fluids compared to that seen with a Newtonian fluid. A molecular constituti...

  3. Applications of High-Efficiency Abrasive Process with CBN Grinding Wheel

    OpenAIRE

    Yan Zhou; Changhe Li; Yali Hou

    2010-01-01

    High-efficiency abrasive process with CBN grinding wheel is one of the important techniques of advanced manufacture. Combined with raw and finishing machining, it can attain high material removal rate like turning, milling and planning. The difficult-to-grinding materials can also be ground by means of this method with high performance. In the present paper, development status and latest progresses on high-efficiency abrasive machining technologies with CBN grinding wheel relate to high speed...

  4. Effects of High Pressure ORE Grinding on the Efficiency of Flotation Operations

    Science.gov (United States)

    Saramak, Daniel; Krawczykowska, Aldona; Młynarczykowska, Anna

    2014-10-01

    This article discusses issues related to the impact of the high pressure comminution process on the efficiency of the copper ore flotation operations. HPGR technology improves the efficiency of mineral resource enrichment through a better liberation of useful components from waste rock as well as more efficient comminution of the material. Research programme included the run of a laboratory flotation process for HPGR crushing products at different levels of operating pressures and moisture content. The test results showed that products of the high-pressure grinding rolls achieved better recoveries in flotation processes and showed a higher grade of useful components in the flotation concentrate, in comparison to the ball mill products. Upgrading curves have also been marked in the following arrangement: the content of useful component in concentrate the floatation recovery. All upgrading curves for HPGR products had a more favourable course in comparison to the curves of conventionally grinded ore. The results also indicate that various values of flotation recoveries have been obtained depending on the machine operating parameters (i.e. the operating pressure), and selected feed properties (moisture).

  5. A New Method of Manufacturing Small-Diameter Bars and Tubes from Hardly Deformable Steels in Skew Rolling

    Directory of Open Access Journals (Sweden)

    Gałkin, A. M.

    2007-01-01

    Full Text Available The paper discusses the process of hot rolling on skew rolling mills and compares it with other methods of manufacturing rods (shape milling and tubes (pilger rolling. The method and results of calculation of the optimal price of a three-roll skew rolling mill taking into account the benefits for the purchaser and the manufacturer are given.

  6. The effects of grinding methods on metals concentrations in soil.

    Science.gov (United States)

    Felt, Deborah R; Bednar, Anthony J; Georgian, Thomas

    2008-10-19

    Multi-increment sampling (MIS) has been most extensively used for munitions constituents at environmental sites where a high degree of contaminant heterogeneity exits. A revised method (USEPA Method 8330B) for explosives that uses MIS was announced in the fall of 2006, but similar guidance has not been reported for testing metals in soils. Questions have been raised as how to prepare representative analytical samples for metals determination from field composites. Three different grinding procedures were used in this study for three soil types to determine if grinding (relative to homogenizing soil without grinding) increases metal concentrations and decreases variability. The performance of these procedures was demonstrated via the analysis of replicates (n=16 for two soil types) using statistical evaluations that included calculations of various descriptive statistics (e.g., medians, means and standard deviations), Kruskal-Wallis (KW) tests for the medians and two tests for the variances (Bartlett's and Levene's test). There was a slight increase in concentrations for several of the metals in the clay loam soil after grinding, although the increases were a small percentage of the concentrations measured. The standard deviations (and variances) for replicate digestions and analyses generally decreased, although anomalies were observed. The grinding methods increased precision overall, however, the data indicated that the roller mill grinding was not as effective as the other grinding methods tested. PMID:18804649

  7. Photoacoustic study of nanocrystalline silicon produced by mechanical grinding

    International Nuclear Information System (INIS)

    Mechanical grinding (MG) was used to produce nanocrystalline silicon and its thermal and transport properties were investigated by photoacoustic absorption spectroscopy (PAS). The experimental results suggest that in as-milled nanocrystalline silicon for 10 h the heat transfer through the crystalline and interfacial components is similar, and after annealed at 470 oC the heat transfer is controlled by crystalline component.

  8. Nitramine Drying & Fine Grinding Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Nitramine Drying and Fine Grinding Facility provides TACOM-ARDEC with a state-of-the-art facility capable of drying and grinding high explosives (e.g., RDX and...

  9. Effects of mill type and particle size uniformity on growth performance, nutrient digestibility, and stomach morphology in finishing pigs.

    Science.gov (United States)

    Wondra, K J; Hancock, J D; Behnke, K C; Stark, C R

    1995-09-01

    The effects of particle size uniformity and mill type used to grind corn were determined in three experiments. In Exp. 1, 120 pigs (47.8 kg initial BW) were used. Treatments were 1) a 40:60 blend of coarsely rolled (in a roller mill) and finely ground (in a hammermill) corn with a large standard deviation (sgw) of particle size (sgw of 2.7), 2) hammermilled corn with an sgw of 2.3, and 3) roller-milled corn with an sgw of 2.0. Mean particle size of the corn was approximately 850 microns for all treatments. Growth performance was not affected (P > .11); but, stomach keratinization tended to be less severe (P roller mill to 800 and 400 microns. Pigs fed corn ground to 400 microns were more efficient (P Mill type did not affect growth performance (P > .40), but pigs fed corn ground in the roller mill had greater apparent nutrient digestibilities (P roller mill fed in meal and pelleted forms. Pigs fed pelleted diets had greater ADG (P roller-milled corn were more efficient (P mill type had inconsistent effects on growth performance, but more uniform particle sizes consistently gave greater nutrient digestibilities. PMID:8582845

  10. Knowledge Management for Grinding Technology

    OpenAIRE

    Alabed, Asmaa

    2011-01-01

    This thesis describes an investigation concerned with development of a grinding knowledge warehouse system (GKWS). Based on a study of previous work on knowledge management and technique for a selection of grinding conditions, the thesis proposes a novel methodology to deal with missing data in surface and cylindrical grinding using Genetic Programming. The GKWS provides a guided tool for users to support the decision-making process to provide suggestions for selecting grinding condition...

  11. Tensile mechanical behavior and fracture toughness of MWCNT and DWCNT modified vinyl-ester/polyester hybrid nanocomposites produced by 3-roll milling

    International Nuclear Information System (INIS)

    This study aims to investigate the tensile mechanical behavior and fracture toughness of vinyl-ester/polyester hybrid nanocomposites containing various types of nanofillers, including multi- and double-walled carbon nanotubes with and without amine functional groups (MWCNTs, DWCNTs, MWCNT-NH2 and DWCNT-NH2). To prepare the resin suspensions, very low contents (0.05, 0.1 and 0.3 wt.%) of carbon nanotubes (CNTs) were dispersed within a specially synthesized styrene-free polyester resin, conducting 3-roll milling technique. The collected resin stuff was subsequently blended with vinyl-ester via mechanical stirring to achieve final suspensions prior to polymerization. Nanocomposites containing MWCNTs and MWCNT-NH2 were found to exhibit higher tensile strength and modulus as well as larger fracture toughness and fracture energy compared to neat hybrid polymer. However, incorporation of similar contents of DWCNTs and DWCNT-NH2 into the hybrid resin did not reflect the same improvement in the corresponding mechanical properties. Furthermore, experimentally measured elastic moduli of the nanocomposites containing DWCNTs, DWCNT-NH2, MWCNTs and MWCNT-NH2 were fitted to Halphin-Tsai model. Regardless of amine functional groups or content of carbon nanotubes, MWCNT modified nanocomposites exhibited better agreement between the predicted and the measured elastic moduli values compared to nanocomposites with DWCNTs. Furthermore, Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM) were used to reveal dispersion state of the carbon nanotubes within the hybrid polymer and to examine the CNT induced failure modes that occurred under mechanical loading, respectively. Based on the experimental findings obtained, it was emphasized that the types of CNTs and presence of amine functional groups on the surface of CNTs affects substantially the chemical interactions at the interface, thus tuning the ultimate mechanical performance of the resulting nanocomposites.

  12. Finite element analysis of deflection of rolls and its correction by providing camber on rolls

    OpenAIRE

    Vijay Gautam

    2013-01-01

    Rolling process is a key step in the production of flat steel products. Because of automation commonly implemented in flat product rolling mills, the products should meet the requirements of tight tolerances. one of the major defects observed in the rolling process is flatness and lack of attainment of the desired surface profile due to deflection of the rolls. The spatial shape and dimensions of the roll gap are influenced by the elastic deformation of all parts of the rolling stand equipmen...

  13. Dead time and recovery time investigations on grinding plants with the aid of radioisotopes

    International Nuclear Information System (INIS)

    With the aid of the radionuclides Mn 56 and Na 24 as tracers, respectively, the following characteristics were investigated for a roller mill and for a tandem air-swept grinding plant: the time of passage of the mill feed material, the retention time distribution in the grinding system (most frequent and mean retention time), and the time required for, respectively, 50%, 90% and 95% of the material to pass, in some instances separately for the three raw material components limestone, clay and sand. In addition, in the case of the air-swept grinding plant the time required for conveying the raw meal sample from the sampling point to the X-ray fluorescence analysis apparatus was determined. The mean retention time of the material in the two roller mills IV and V was 2.93 and 2.55 minutes respectively; for the tandem air-swept grinding plant it was 8 minutes. The time taken for 90% of the mill feed to pass through the mill was 5.5 and 5 minutes for the roller mills respectively and was about 18.3 minutes for the air-swept plant. The dead time vor conveying the raw meal sample to the X-ray fluorescence apparatus, including further grinding of the sample in a vibratory mill, was 12 minutes. (orig.)

  14. Low-Rank Coal Grinding Performance Versus Power Plant Performance

    Energy Technology Data Exchange (ETDEWEB)

    Rajive Ganguli; Sukumar Bandopadhyay

    2008-12-31

    The intent of this project was to demonstrate that Alaskan low-rank coal, which is high in volatile content, need not be ground as fine as bituminous coal (typically low in volatile content) for optimum combustion in power plants. The grind or particle size distribution (PSD), which is quantified by percentage of pulverized coal passing 74 microns (200 mesh), affects the pulverizer throughput in power plants. The finer the grind, the lower the throughput. For a power plant to maintain combustion levels, throughput needs to be high. The problem of particle size is compounded for Alaskan coal since it has a low Hardgrove grindability index (HGI); that is, it is difficult to grind. If the thesis of this project is demonstrated, then Alaskan coal need not be ground to the industry standard, thereby alleviating somewhat the low HGI issue (and, hopefully, furthering the salability of Alaskan coal). This project studied the relationship between PSD and power plant efficiency, emissions, and mill power consumption for low-rank high-volatile-content Alaskan coal. The emissions studied were CO, CO{sub 2}, NO{sub x}, SO{sub 2}, and Hg (only two tests). The tested PSD range was 42 to 81 percent passing 76 microns. Within the tested range, there was very little correlation between PSD and power plant efficiency, CO, NO{sub x}, and SO{sub 2}. Hg emissions were very low and, therefore, did not allow comparison between grind sizes. Mill power consumption was lower for coarser grinds.

  15. High Performance Grinding and Advanced Cutting Tools

    CERN Document Server

    Jackson, Mark J

    2013-01-01

    High Performance Grinding and Advanced Cutting Tools discusses the fundamentals and advances in high performance grinding processes, and provides a complete overview of newly-developing areas in the field. Topics covered are grinding tool formulation and structure, grinding wheel design and conditioning and applications using high performance grinding wheels. Also included are heat treatment strategies for grinding tools, using grinding tools for high speed applications, laser-based and diamond dressing techniques, high-efficiency deep grinding, VIPER grinding, and new grinding wheels.

  16. Grind hardening process

    CERN Document Server

    Salonitis, Konstantinos

    2015-01-01

    This book presents the grind-hardening process and the main studies published since it was introduced in 1990s.  The modelling of the various aspects of the process, such as the process forces, temperature profile developed, hardness profiles, residual stresses etc. are described in detail. The book is of interest to the research community working with mathematical modeling and optimization of manufacturing processes.

  17. THE INFLUENCE OF DIAGENETIC AND TECTONIC PROCESSES IN DOLOMITES ON THE GRINDING

    Directory of Open Access Journals (Sweden)

    Ivan Tomašić

    1990-12-01

    Full Text Available Origin and occurence of dolomites are important for the physical and mechanical properties, especially grinding. The influence of diagenetic and tectonic processes in dolomites on the grinding of rocks was investigated in samples from two diag-netically different deposit types, and that separately from the compact and tectonized part of the rock masses. The grinding tests were carried out in a ball mill. By petrographic and granulometric analysis as well as by determination of the grinding rate and Bond's Working Index it was found that the state of rock fissures influences the crushability down to grain sizes even of 1...2 mm, and that the grinding rate is lower for rocks of higher crystal lattice order and a higher content of small crystals. Also, samples with clean regular crystals, formed by recrystallization, manifest a stronger resistance to grinding (the paper is published in Croatian.

  18. Grinding Inside A Toroidal Cavity

    Science.gov (United States)

    Mayer, Walter; Adams, James F.; Burley, Richard K.

    1987-01-01

    Weld lines ground smooth within about 0.001 in. Grinding tool for smoothing longitudinal weld lines inside toroidal cavity includes curved tunnel jig to guide grinding "mouse" along weld line. Curvature of tunnel jig matched to shape of toroid so grinding ball in mouse follows circular arc of correct radius as mouse is pushed along tunnel. Tool enables precise control of grindout shape, yet easy to use.

  19. Surface Fine Grinding via a Regenerative Grinding Methodology

    International Nuclear Information System (INIS)

    This paper presents a regenerative surface fine grinding methodology to remove grinding defects of traditional operations and to improve the quality of surface flatness. All possible surface defects produced by traditional and creep-feed grinding operations are carefully reviewed and circumvented. These defects include non -uniform traces, pitting spots, scratches, burnouts, and quenching breakage. To alleviate these traditional grinding defects, the paper presents a new approach by designing and constructing a regenerative surface fine grinding system that includes a mechanism that carries the submerged workpart in an oil-contained open box. The fine grinding tool held by the spindle-chuck unit of the CNC machine is moved in relative to the workpart surfaces by a combined trajectory of a cycloid path, a linear feed and a lateral travel. Some numerical simulations for selecting appropriate grinding trajectories are presented and simulated. The trajectory is selected based upon the resulting quality of contact uniformity and homogeneity as expressed in terms of contact frequency to each point on the workpart surface. The simulation model is then used to characterize appropriate working range of each grinding parameter. Different grinding paths are thus generated and superposed. A working machine is designed and built based upon the simulation results. Several experiments are carried out on the constructed grinding system with the grinding tool mounted to the spindle-chuck unit of the CNC machine. The surface quality of the ground workpart is measured. Tests on different system parameters demonstrate the importance of choosing the correct grinding wheel and grit size and an illustration of the proper selection of process and system parameters are presented. The experimental results are compared with those of analytical solutions. Good agreement between them is observed. In ninety minutes fine-grinding operations using the proposed method, the workpart surfaces generally possess no damage and surface roughness is reduced to the range of 0.02∼0.04μm in Ra. To verify the effectiveness of the proposed method, the results of fine grinding operations using various process parameters are measured and recorded. The effects of various combinations of process parameters including trajectory density, uniformity and grinding efficiency on the effect of surface flatness enhancement are carefully examined and concluded

  20. Design of the Soymilk Mill based on TRIZ Theory

    Directory of Open Access Journals (Sweden)

    Jiang Fan

    2013-05-01

    Full Text Available The soymilk mill is an important food machine, but its volume is too large to be suitable for house using. This study first analyzes some problems in the soymilk mill miniaturization. For these problems, the thinking tools, evolutionary tools and contradiction solving tool of TRIZ theory are used to resolve the conflict in the integration of grinding and boiling and in the keep grinding effect, to tackle the optimization problem in the grinding stria structure and mill plate speed, then the Dwarfs method and substance-field analysis model is used in solving the interference and the conditions water supply problems which are encountered in the design of the global structure and a micro soymilk mill is designed. Finally, the mechanical analysis model about soy granules, soymilk particles in the grinding zone and the computational model of motor starting torque are obtained; they provide the reference data for application of soymilk mill.

  1. Computation of Rolling Stand Parameters by Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Frantiek ?urovsk

    2008-05-01

    Full Text Available Mathematical model of rolling process is used at cold mill rolling on tandemmills in metallurgy. The model goal is to analyse rolling process according to process datameasured on the mill and get immeasurable variables necessary for rolling control andoptimal mill pre-set for next rolled coil. The values obtained by model are used asreferences for superimposed technology controllers (thickness, speed, tension, etc. as well.Considering wide steel strip assortment (different initial and final thickness, differenthardness, and fluctuation of tandem mill parameters (change of friction coefficient, workrolls abrasion, temperature fluctuation, etc. the exact analysis of tandem is complicated.The paper deals with an identification of friction coefficient on a single rolling mill standby a genetic algorithm. Mathematical description of tandem mill stand is based on themodified Bland-Ford model. Results are presented in graphical form.

  2. Vibration-Assisted Grinding with a Newly Developed Rotary Mechanism using Induction Motor

    Directory of Open Access Journals (Sweden)

    Noel Williamson*1

    2014-04-01

    Full Text Available This paper presents the analysis of mechanisms of removal in vibration-assisted grinding process. It is known that generally for machining, application of vibration helps to increase material removal rate, reduces tool wear rate and increases depth of machining. As the failure of a component originates from the surface, effect of assisted grinding is carried out on a milling machine. The machine is equipped with a grinding wheel on which small frequency vibrations are applied. The resultant path of the tool is analytically evaluated. Longitudinal vibrations are developed by using a rotary mechanism. It was demonstrated that there are several favorable effects of vibrations in grinding process including: reduced tool forces, better surface finish and improved tool life. It is observed that the application of vibrations improve the process characteristics in grinding, to a large extent.

  3. Justification of the resource-saving during grinding of ingredients for feed production lines in agriculture

    OpenAIRE

    Піскун, Віктор Іванович; Яценко, Юрій Васильович

    2010-01-01

    This article highlights the experimental research results on the grinders evaluation according to specific energy expenses. The grinders were estimated by combined feed ingredients grinding. ‘Kharkovchanka” type grinder proved to be implemented for corn grinding incorporated to combined feeds. Score mills showed that the specific energy consumption reduced Crushers ”Kharkovchanka” less than a crushing type DZ.3”,”ATDM2R”,”CD-2”,”D-2”.

  4. Finite element analysis of deflection of rolls and its correction by providing camber on rolls

    Directory of Open Access Journals (Sweden)

    Vijay Gautam

    2013-10-01

    Full Text Available Rolling process is a key step in the production of flat steel products. Because of automation commonly implemented in flat product rolling mills, the products should meet the requirements of tight tolerances. one of the major defects observed in the rolling process is flatness and lack of attainment of the desired surface profile due to deflection of the rolls. The spatial shape and dimensions of the roll gap are influenced by the elastic deformation of all parts of the rolling stand equipment affected by the roll pressure. The current study aims to determine the variation of the deflection in rolls in a two high mill with varying percentage reduction of the sheet i.e, 20%, 25% and 30% on annealed and non-annealed IF steel sheet and analyzing possible solutions to reduce the elastic deflection of rolls with special emphasis on cambering and modelling of the same in Abaqus CAE.

  5. Rolling Stonesi kinokontsert kannab toorest rokivge / Maris Meiessaar

    Index Scriptorium Estoniae

    Meiessaar, Maris

    2009-01-01

    Martin Scorsese muusikalisest dokumentaalfilmist "Shine a Light - Valgus peale" (USA-Suurbritannia, 2008), mille keskmes on 2006. a. New Yorgi Beaconi teatris toimunud briti ansambli Rolling Stones kontsert

  6. Roll-to-Roll production of carbon nanotubes based supercapacitors

    Science.gov (United States)

    Zhu, Jingyi; Childress, Anthony; Karakaya, Mehmet; Roberts, Mark; Arcilla-Velez, Margarita; Podila, Ramakrishna; Rao, Apparao

    2014-03-01

    Carbon nanomaterials provide an excellent platform for electrochemical double layer capacitors (EDLCs). However, current industrial methods for producing carbon nanotubes are expensive and thereby increase the costs of energy storage to more than 10 Wh/kg. In this regard, we developed a facile roll-to-roll production technology for scalable manufacturing of multi-walled carbon nanotubes (MWNTs) with variable density on run-of-the-mill kitchen Al foils. Our method produces MWNTs with diameter (heights) between 50-100 nm (10-100 μm), and a specific capacitance as high as ~ 100 F/g in non-aqueous electrolytes. In this talk, the fundamental challenges involved in EDLC-suitable MWNT growth, roll-to-roll production, and device manufacturing will be discussed along with electrochemical characteristics of roll-to-roll MWNTs. Research supported by NSF CMMI Grant1246800.

  7. THE CHARACTERIZATION OF GRINDING FORCES

    Directory of Open Access Journals (Sweden)

    E.F. Fielding

    2012-01-01

    Full Text Available Traditionally the grinding process has been a finishing process and the operating parameters and the resuns obtained in this mode are well known. However, wHh the advent of more modern techniques in grinding, there is a need for a greater understanding of the process and in particular a need to be able to predict the forces in grinding. The work reported here is part of an overall programme to study the effects of different dress leads, wheel formulations and metal removal rates on grinding ratios, surlace finish and grinding forces. The work so far has led to the development of empirical relationships based on the various factors in the dressing and grinding operations, these empirical relationships are more easily applied than the relationships developed by other researchers that rely on measurements obtained during testing. The work is now being extended to develop a theoretical derivation on the same principles, the implications of which will be discussed in the paper.

  8. Contamination introduced during rock sample powdering. Effects from different mill materials on trace element contamination

    International Nuclear Information System (INIS)

    We examined blanks during powdering processes for thirty-three trace elements using ICP-MS (inductively coupled plasma mass spectrometry). Quartz sand was used as target of powdering with grinding mills of several kinds: an agate hand mill, agate ball mill, Fe hand mill, alumina ceramic hand mill and artificial crystalline quartz hand mill. The results show that the artificial crystalline quartz hand mill is the purest grinder among the analyzed ones. This grinder is suitable for soft rock samples such as limestone. The alumina ceramic hand mill can reduce contamination, except for Cs, W and Pb. The agate hand mill and the agate ball mill introduce contamination whose level is depending on the individual device due to heterogeneity of the natural agate. The Fe hand mill introduces contamination of some si-derophile elements such as Mo and W. The results of this study emphasize careful choice of a grinding mill for sample pulverizing. (author)

  9. Spray rolling aluminum alloy strip

    International Nuclear Information System (INIS)

    Spray rolling combines spray forming with twin-roll casting to process metal flat products. It consists of atomizing molten metal with a high velocity inert gas, cooling the resultant droplets in flight and directing the spray between mill rolls. In-flight convection heat transfer from atomized droplets teams with conductive cooling at the rolls to rapidly remove the alloy's latent heat. Hot deformation of the semi-solid material in the rolls results in fully consolidated, rapidly solidified product. While similar in some ways to twin-roll casting, spray rolling has the advantage of being able to process alloys with broad freezing ranges at high production rates. This paper describes the process and summarizes microstructure and tensile properties of spray-rolled 2124 and 7050 aluminum alloy strips. A Lagrangian/Eulerian poly-dispersed spray flight and deposition model is described that provides some insight into the development of the spray rolling process. This spray model follows droplets during flight toward the rolls, through impact and spreading, and includes oxide film formation and breakup when relevant

  10. Efficient Fuel Pretreatment: Simultaneous Torrefaction and Grinding of Biomass

    DEFF Research Database (Denmark)

    Saleh, Suriyati Binti; Hansen, Brian Brun; Jensen, Peter Arendt; Dam-Johansen, Kim

    2013-01-01

    Combining torrefaction and grinding of biomass in one reactor may be an attractive fuel pretreatment process. A combined laboratory torrefaction and ball mill reactor has been constructed for studies of the influence of temperature and residence time on the product yields and particle size...... reductions of Danish wheat straw, spruce chips, and pine chips. On the basis of initial experiments, which evaluated the influence of reactor mass loading, gas flow, and grinding ball size and material, a standard experimental procedure was developed. The particle size reduction capability of the...... of straw for 90 min yielded a higher mass loss (27–60 wt %) and relative size reduction (59–95%) compared with spruce (mass loss of 10–56 wt % and size reduction of 20–60%). The two types of biomass investigated differ with respect to hemicellulose type, lignocellulosic composition, particle...

  11. Spatial distribution studies of milling particles, milling charge and grist

    International Nuclear Information System (INIS)

    Applications of the narrow-beamγ-ray method for dry grinding power technology are discussed. In a model of a vertically agitated ball-mill, the spatial distribution of model milling charge with and without model grist and the spatial distribution of the grist were investigated. The model volume was 10 litres. Polystyrene balls (diameter 4.5 mm) were used as a model of the milling charge and limestone -CaC03 of diameter 0.04-0.1 mm as a model of the grist. A system of mixing discs (10 rev s-1) on a coaxial shaft kept the mill-charge in vibrational motion. The results are presented in the form of graphs of the bulk density of the mill balls or the bulk density of the grist plotted against the height or distance from the stirred axis. The radionuclides 241Am and 137Cs were used as radiation sources. (author)

  12. Online SAG Mill Pluse Measurement and Optimization

    Energy Technology Data Exchange (ETDEWEB)

    Raj Rajamani; Jose Delgadillo; Vishal Duriseti

    2007-06-30

    The grinding efficiency of semi autogenous milling or ball milling depends on the tumbling motion of the total charge within the mill. Utilization of this tumbling motion for efficient breakage of particles depends on the conditions inside the mill. However, any kind of monitoring device to measure the conditions inside the mill shell during operation is virtually impossible due to the severe environment presented by the tumbling charge. An instrumented grinding ball, which is capable of surviving a few hours and transmitting the impacts it experiences, is proposed here. The spectrum of impacts collected over 100 revolutions of the mills presents the signature of the grinding environment inside mill. This signature could be effectively used to optimize the milling performance by investigating this signature's relation to mill product size, mill throughput, make-up ball size, mill speed, liner profile and ball addition rates. At the same time, it can also be used to design balls and liner systems that can survive longer in the mill. The technological advances made in electronics and communication makes this leap in instrumentation certainly viable. Hence, the instrumented grinding ball offers the ability to qualitatively observe and optimize the milling environment. An instrumented load cell package that can measure the force of impacts inside the grinding chamber of a mill is developed here. The signal from the instrumented load cell package is interpreted in terms of a histogram termed as an impact spectrum which is a plot of the number of impacts at a specific energy level against the energy. It reflects on the average force regime of the mill. The instrumented load cell package was calibrated against the ultra fast load cell which has been unanimously accepted as a standard to measure single breakage events. The load cell package was successfully used to produce impact spectra in an 8.5 inch lab scale mill. The mill speed and the ball size were varied to study their effect on the impact spectra. A good correlation was found between the process variables and the impact spectra. The load cell package was then used in a 16 inch pilot scale mill. The mill speed, ball size, and mill filling were varied here and a consistent trend between these variables and impact spectra was observed. With a better understanding developed from the initial tests, the design of the load cell package was significantly changed to eliminate noise. With the new design, the impact spectra were re-determined in the 16 inch pilot mill varying the process variables - ball size, mill speed, and mill filling. Finally, it is successfully shown that a change in the operating variables of a mill can be seen in the impact spectra and that this concept can be successfully developed to monitor the grinding operation of industrial mills. To adapt it to industrial level it is mandatory to make the load cell package wireless. A design of a wireless circuit that is capable of transferring data at the required speed of 1000 kbps was also developed and tested at Cortez Gold Mines (CGM), Nevada.

  13. Optimization of Process Variables for Grinding of Ibuprofen using Response Surface Methodology

    International Nuclear Information System (INIS)

    Ibuprofen, non-steroidal anti-inflammatory drugs; NSAIDs, is a highly crystalline substance with the pharmaceutical properties of poor solubility and low bioavailability. The size reduction of ibuprofen is needed to improve the solubility. The objective of this study is to optimize the grinding condition of ibuprofen. Grinding of ibuprofen was carried out using a planetary mill. Grinding parameters were optimized using Box-Behnken experimental design method. The physical characteristics of ground ibuprofen were investigated for the particle size by particle size analyzer, for the crystal size by X-ray diffraction (XRD), and for the tensile strength by tensile/compression tester. The optimum conditions for the milling of ibuprofen were 290 rpm of the revolution number of mill, 24.6 g of the weight of sample, and 10minutes of grinding time. The measured value of the particle size of ground ibuprofen at these optimum conditions was 13.5 µm. The results showed that the crystal size of ibuprofen was reduced by the planetary milling process. In case the relative density of the tablets formulated of ground ibuprofen was range of 0.85-0.90, the tensile strength of them was range of 12-14 Kgf/cm2

  14. APPLICATION OF HACCP TO CONTROL MYCOTOXINS IN THE DRY GRIND ETHANOL PROCESS

    Science.gov (United States)

    Ethanol has been used as a fuel source in the United States since the early 1900’s and is receiving a renewed and increased interest as an alternative to petroleum. Today most fuel ethanol is produced by the dry grind mill process creating a valuable co-product, namely distillers dried grain with s...

  15. Optimization of Process Variables for Grinding of Ibuprofen using Response Surface Methodology

    Energy Technology Data Exchange (ETDEWEB)

    Sim, Chol-Ho [Sangji University, Wonju (Korea, Republic of)

    2013-12-15

    Ibuprofen, non-steroidal anti-inflammatory drugs; NSAIDs, is a highly crystalline substance with the pharmaceutical properties of poor solubility and low bioavailability. The size reduction of ibuprofen is needed to improve the solubility. The objective of this study is to optimize the grinding condition of ibuprofen. Grinding of ibuprofen was carried out using a planetary mill. Grinding parameters were optimized using Box-Behnken experimental design method. The physical characteristics of ground ibuprofen were investigated for the particle size by particle size analyzer, for the crystal size by X-ray diffraction (XRD), and for the tensile strength by tensile/compression tester. The optimum conditions for the milling of ibuprofen were 290 rpm of the revolution number of mill, 24.6 g of the weight of sample, and 10minutes of grinding time. The measured value of the particle size of ground ibuprofen at these optimum conditions was 13.5 µm. The results showed that the crystal size of ibuprofen was reduced by the planetary milling process. In case the relative density of the tablets formulated of ground ibuprofen was range of 0.85-0.90, the tensile strength of them was range of 12-14 Kg{sub f}/cm{sup 2}.

  16. Developments in precision optical grinding technology

    Science.gov (United States)

    Fess, Edward; Bechtold, Mike; Wolfs, Frank; Bechtold, Rob

    2013-09-01

    Optical systems that utilize complex optical geometries such as aspheres and freeform optics require precise control through the manufacturing process. As the preparatory stage for polishing, this is especially true for grinding. The quality of the grinding process can greatly influence the polishing process and the resultant finished product. OptiPro has performed extensive development work in evaluating components of a precision grinding machine to determine how they influence the overall manufacturing process. For example, spindle technology has a strong effect on how a grinding machine will perform. Through metrology techniques that measure the vibration characteristics of a machine and measurements of grinding forces with a dynamometer, OptiPro has also developed a detailed knowledge of how the machine can influence the grinding process. One of the outcomes of this work has led OptiPro to develop an ultrasonic head for their grinding platform to aid in reducing grinding forces. Initial results show a reduction in force by ~50%.

  17. Surface Grinding Machine Stability Characteristics Limited Prediction

    OpenAIRE

    Yuting Yang; Jianzhong Lin; Shilong Xu

    2012-01-01

    The chatter in the grinding process has a great influence in improving work piece surface quality and production efficiency. The formula of flutter system limit grinding depth and the rotating speed of the grinding wheel are induced based on the chatter theory and the chatter dynamitic model of the grinding system. The computer modeling and simulation are carried out to get flutter stability predicted picture. Finally the reliability and validity of the predicted picture are verified by the e...

  18. Ceramic-bonded abrasive grinding tools

    Science.gov (United States)

    Holcombe, Jr., Cressie E. (Farragut, TN); Gorin, Andrew H. (Knoxville, TN); Seals, Roland D. (Oak Ridge, TN)

    1994-01-01

    Abrasive grains such as boron carbide, silicon carbide, alumina, diamond, cubic boron nitride, and mullite are combined with a cement primarily comprised of zinc oxide and a reactive liquid setting agent and solidified into abrasive grinding tools. Such grinding tools are particularly suitable for grinding and polishing stone, such as marble and granite.

  19. Ultrasonic precision optical grinding technology

    Science.gov (United States)

    Cahill, Michael J.; Bechtold, Michael J.; Fess, Edward; Wolfs, Frank L.; Bechtold, Rob

    2015-10-01

    As optical geometries become more precise and complex and a wider range of materials are used, the processes used for manufacturing become more critical. As the preparatory stage for polishing, this is especially true for grinding. Slow processing speeds, accelerated tool wear, and poor surface quality are often detriments in manufacturing glass and hard ceramics. The quality of the ground surface greatly influences the polishing process and the resulting finished product. Through extensive research and development, OptiPro Systems has introduced an ultrasonic assisted grinding technology, OptiSonic, which has numerous advantages over traditional grinding processes. OptiSonic utilizes a custom tool holder designed to produce oscillations in line with the rotating spindle. A newly developed software package called IntelliSonic is integral to this platform. IntelliSonic automatically characterizes the tool and continuously optimizes the output frequency for optimal cutting while in contact with the part. This helps maintain a highly consistent process under changing load conditions for a more accurate surface. Utilizing a wide variety of instruments, test have proven to show a reduction in tool wear and increase in surface quality while allowing processing speeds to be increased. OptiSonic has proven to be an enabling technology to overcome the difficulties seen in grinding of glass and hard optical ceramics. OptiSonic has demonstrated numerous advantages over the standard CNC grinding process. Advantages are evident in reduced tool wear, better surface quality, and reduced cycle times due to increased feed rates. These benefits can be seen over numerous applications within the precision optics industry.

  20. Metal rolling - Asymmetrical rolling process

    Science.gov (United States)

    Alexa, V.; Raţiu, S.; Kiss, I.

    2016-02-01

    The development of theory and practice related to the asymmetric longitudinal rolling process is based on the general theory of metalworking by pressure and symmetric rolling theory, to which a large number of scientists brought their contribution. The rolling of metal materials was a serious problem throughout history, either economically or technically, because the plating technologies enabled the consumption of raw materials (scarce and expensive) to be reduced, while improving the mechanical properties. Knowing the force parameters related to asymmetric rolling leads to the optimization of energy and raw material consumption. This paper presents data on symmetric rolling process, in order to comparatively highlight the particularities of the asymmetric process.

  1. Fused silica fine grinding with low roughness

    Science.gov (United States)

    Dai, Lei; Gu, Yongqiang; Wu, Di

    2014-08-01

    Lithography-optics is one of the most complex optical systems. The fine grinding process is the most important step before polishing. Roughness and sub-surface damage (SSD) are essential outputs of fine grinding. We demonstrate the method that use fix abrasive cup tool with CNC grinding machine to complete the fine grinding process, even instead of lapping process. And experiment sample roughness can reach 23.40nm rms and Ra 18.554nm. The SSD estimate is about 2 μm which is also smaller than commercial lapping process. The fine grinding output can satisfy the lithography optic fabrication demands and efficiently reduce the polishing time.

  2. THE EFFECT OF PARAMATERS IN THE GRINDING

    Directory of Open Access Journals (Sweden)

    Halil DEMİR

    2001-02-01

    Full Text Available The main purpose of grinding is to produce workpiece in required precision and surface finish. It is also used to machine workpiece above 50 Rc. Since the grinding is a finishing process or for a better passage to the following processes better combination of parameters in grinding must be achieved. In grinding process, because of the effect of the friction and subsequent plastic deformation residual stresses and metallurgic damages occurs in finished workpiece surfaces. Much work has been carried out to minimize these damages. In this article, the experimental and theoretical studies towards the improvement of grinding quality are reviewed.

  3. Surface grinding of intermetallic titanium aluminides

    CERN Document Server

    Gröning, Holger Andreas

    2014-01-01

    A deductive kinematic model of creep-feed and speed-stroke grinding processes is developed to identify possibilities to reduce the energy introduced into the workpiece. By computer tomography analysis and tactile measurements of the grinding wheel the pore volume and the static cutting edge number are determined and included in the model. Based on the kinematic model and the grinding wheel characteristics an analytical evaluation of the specific grinding energy for speed-stroke and creep-feed grinding is carried out. The deducted process design is evaluated in experimental investigations. The

  4. Rolling Ribbons

    OpenAIRE

    Raux, P. S.; Reis, P. M.; Bush, J. W. M.; Clanet, Christophe

    2010-01-01

    We present the results of a combined experimental and theoretical investigation of rolling elastic ribbons. Particular attention is given to characterizing the steady shapes that arise in static and dynamic rolling configurations. In both cases, above a critical value of the forcing (either gravitational or centrifugal), the ribbon assumes a two-lobed, peanut shape similar to that assumed by rolling droplets. Our theoretical model allows us to rationalize the observed shapes through considera...

  5. Failure Analysis of Rollers in mill stand using Failure mode Effect Analysis

    OpenAIRE

    Tadisetti Premsai; Anga Kiran Vikram; Varma, S.Sivarajan

    2014-01-01

    Rolling is an important steel production process. Productivity and quality improvements in metal rolling are possible by paying a detailed attention to the various roll failure modes.A proper understanding of the causes of roll failure modes is usually complex and depends on the metallurgical quality of rolls, improper mill usage practices and abnormal rolling conditions. The work rolls operate under severe condition and should posses excellent wear resistance and very little ...

  6. Nanozeolite Produced by Wet Milling at Different Milling Time

    Science.gov (United States)

    Mukhtar, N. Z. F.; Borhan, M. Z.; Abdullah, S.; Rusop, M.

    2013-06-01

    Recently, there has been a considerable growing interest in utilizing nanozeolites due to their advantages over conventional micron sized materials. Zeolite particle may be reduced by mechanical treatment such as ball milling or grinding in order to get smaller particles. In this paper, effect of milling time on particle size and surface morphology of Zeolite were investigated by a few designed of experiments in aqueous environment. Zeta-sizer Nano series of particle sizer and Field Emission Scanning Electron Microscopy (FESEM) have been used to characterize this nanozeolite. Results shown that, there were changes of particle size and also the surface morphology of Zeolite.

  7. Production of grinding wheels with high grinding force ratio and high efficiency for glassy materials

    International Nuclear Information System (INIS)

    A new method to produce grinding wheels for glass materials is discussed. The production method maker uses pulsed electric current sintering (PECS). The new grinding wheels were evaluated by influencing factors, such as porosity, grinding forces, grinding pressure, and removal rate. A quick evaluation method of 'reciprocal grinding tests' is developed to estimate grinding ratio. In the reciprocal grinding test, porosity of around 30 % shows the higher grinding force ratio. Apart of cost considerations, to obtain a high grinding ratio with grain size of 12-15 μ m and particle size of cast-iron of 11 μ m, the 30 % grain fraction is better than the 1.5 % and 7.5 % grain fraction. Copyright (2000) AD-TECH - International Foundation for the Advancement of Technology Ltd

  8. Surface grinding characteristics of ferrous metals under high-speed and speed-stroke grinding conditions

    International Nuclear Information System (INIS)

    Some ferrous metals have been ground under different conditions with high-speed and speed-stroke in surface grinding operation. The paper describes experimental investigation of grinding forces in grinding some ferrous metals with the application of cutting fluids. Grinding tests have been carried out on mild steel, assab steel and stainless steel with different combinations of down feed and cross feed. The wheel speed was 27 m/sec while the table speed was maintained at the maximum possible 25 m/min. The grindability has been evaluated by measuring the grinding forces, grinding ratio, and surface finish. Grinding forces have been plotted against down feed of the grinding wheel and cross feed of the table. It has been observed that the radial and tangential grinding forces in stainless steel were higher than those in assab steel and mild steel

  9. Type of grinding of the main cereal of the diet affects production of brown egg-laying hens

    OpenAIRE

    Pérez Bonilla, A.; M. Frikha; Lazaro Garcia, Rosa Pilar; Gonzalez Mateos, Gonzalo

    2014-01-01

    The influence of method of grinding of the cereal of the diet on production and egg quality was studied in 420 Hy-line brown egg-laying hens. The design was completely randomized with six treatments arranged as a 3 × 2 factorial with three cereals (barley, dented maize and soft wheat) and two grinding procedures (hammer mill vs. roller mill). Each treatment was replicated seven times and the experimental unit was an enriched cage with ten hens. Production was recorded every four weeks from 24...

  10. Prediction of work-roll temperature distribution in continuous hot strip rolling process

    International Nuclear Information System (INIS)

    Prediction of temperature distribution within the work-rolls during the hot slab rolling process is of great importance to mill designers. This is because, not only the temperature distribution in rolling material and the dimensional accuracy are depended on work-roll temperature but also the roll life is a function of its temperature distribution. In this paper using the heat transfer equations for moving media and a two dimensional finite element method, the work-roll temperature distribution during continuous hot strip rolling process is predicted. To achieve an accurate temperature field the effects of various factors including the rolling speed, interface heat transfer coefficient, and the amount of slab thickness reduction at each deformation pass are taken into account. Comparison between the predicted and experimental published results depicts the validity of the mathematical model. (author)

  11. Wedge - rolls rolling of hollowed parts

    Directory of Open Access Journals (Sweden)

    Z. Pater

    2006-08-01

    Full Text Available Purpose: Presentation of the possibilities of application of a new manufacturing method, called wedge rollsrolling (WRR in forming of axi – symmetrical hollowed parts.Design/methodology/approach: The research work was done in a specially designed laboratory rolling millLUW-2. During the research, hollowed parts from steel were rolled in hot forming conditions. Basic kinematicaland force parameters of the process were noticed during rolling.Findings: On the basis of the conducted research it was stated that the WRR method could be used for formingof hollowed parts with the precision compared with the precision obtained in the typical cross wedge rollingprocesses (CWR. At the same time, it was proved that this method could be used for rolling from billets withthe wall thinner than the wall given in the CWR.Research limitations/implications: The research were limited to the wedges with spreading angles withinrange of β = (5° ÷ 9°, with the constant values of forming angle α = 30° and relative reduction ratio δ = 1.45.In the future, it is planned to analyse the influence of changes of angle α and relative reduction ratio δ on theWRR process.Practical implications: The conducted research can be used for designing of a new industrial method of metalforming of hollowed parts.Originality/value: The innovation of this solution is based on the application of only one wedge for forming.Because of that, the WRR method is cheaper for implementation than used so far CWR processes. This methodcan be applied mainly in automotive and aviation industries.

  12. ELID supported grinding of thin sapphire wafers

    Science.gov (United States)

    Makarenko, Igor; Vogt, Christian; Rascher, Rolf; Sperber, Peter; Stirner, Thomas

    2010-10-01

    Sapphire material is, due to its crystal structure, difficult to machine in an economic way. There is a request for thin, i.e. below 0.2 mm thickness, sub surface damage free wafers to produce sensor elements. ELID -- electrolytic in process dressing -- is an innovative high end grinding technology, using small grain sizes, which enable to manufacture surfaces in a quality that is close to polished. ELID grinding requires exactly aligned machining parameters of the grinding process. To grind sapphire the material's behavior is additionally to be considered. Studies on the necessary oxide layer on the grinding wheel and influences on its build-up process will be presented. The presentation shows the results of comparing grinding experiments on different -- c-plane and r-plane -- sapphire materials. Different tool specifications are used. Infeed and grinding velocity are varied and the results on wear, removal rate and surface quality are shown. The process parameters the stiffness of the machine, the grinding forces and pressure are evaluated. The ELID grinding is compared in its results to conventional grinding steps. The material removal rate on sapphire is relatively small due to the extreme hardness of sapphire. The achieved excellent surface roughness will be discussed.

  13. Simulation analysis of grinding wheel motion trajectory on SiC ceramics aspheric surface grinding

    Science.gov (United States)

    Zhang, Feihu; Liu, Lifei; Li, Chunhui

    2014-08-01

    In grinding process of SiC ceramics aspheric surface, the motion trajectory of grinding wheel has great influence on the surface forming. The paper provides mathematical models of grinding wheel movements; analytical simulation was done to describe the trajectories of the grinding wheel in manufacturing an aspherical workpiece. The effect of grinding parameters (including the rotation speed of the workpiece, the feed rate of grinding wheel etc.) on the aspheric surface coverage rate was conducted and discussed in detail. An experimental study was done according to the simulation results and an aspheric surface with form error less than 10μm was gained.

  14. Mechanical alloying and reactive milling in a high energy planetary mill

    International Nuclear Information System (INIS)

    Powder refinement in a planetary mill (Retsch PM 400-MA) is investigated experimentally and analyzed using discrete element modeling (DEM). Refinement is defined as the average size of the individual components in a composite powder. The specific milling dose, defined as the product of charge ratio and milling time, is used as an experimental parameter tracking the progress of the material refinement. This parameter is determined experimentally for milling of boron and titanium powders, for which the time of initiation of a self-sustained reaction is measured under different milling conditions. It is assumed that the reaction becomes self-sustaining when the same powder refinement is achieved. The DEM calculations established that the milling balls primarily roll along the milling container's perimeter. The inverse of the rate of energy dissipation resulting from this rolling motion is used as the DEM analog of the specific milling dose. The results correlate well with experimental observations.

  15. Model Predictive Control for an Industrial SAG Mill

    DEFF Research Database (Denmark)

    Ohan, Valeriu; Steinke, Florian; Metzger, Michael; Runkler, Thomas; Jørgensen, John Bagterp

    2012-01-01

    We discuss Model Predictive Control (MPC) based on ARX models and a simple lower order disturbance model. The advantage of this MPC formulation is that it has few tuning parameters and is based on an ARX prediction model that can readily be identied using standard technologies from system...... identication. When applied to MIMO systems we call this controller a MIMO-ARX based MPC. We use an industrial Semi-Autogenous Grinding (SAG) mill to illustrate the performance of this controller. SAG mills are the primary units in a grinding chain and also the most power consuming units. Therefore, improved...... control of SAG mills has the potential to signicantly improve eciency and reduce the specic energy consumption for mineral processes. Grinding circuits involving SAG mills are multivariate processes. Commissioning of a control system based on a classical single-loop controllers with logic is time...

  16. Influence of the charge properties on the milling tools wear during intensive milling in liquid environment

    Directory of Open Access Journals (Sweden)

    tevulov Nadeda

    2002-06-01

    Full Text Available Grinding belongs to the basic technological operations in the treatment and processing of minerals. The method of the intensive grinding in a liquid environment has become attractive for the preparation of technologically advanced materials of the high fineness. Its choice was motivated by the intensification of dispersion and by the protection of ground powder against oxidation. The result of energy and material interactions among the grinding media and grinding environment is the wear of the grinding media and contamination of the ground material. The hardness of the particles has an important influence on the rate of wear. Particles with hardness lower than that of the surface of milling tools cause much less wear than harder particles. The wear rate becomes much more sensitive to the ratio of the abrasive hardness Ha to the surface hardness Hs when Ha/Hs <1.The paper deals with the influence of four minerals with various microhardness (corundum, quartz, silicon and magnesite on the steel milling tools wear during intensive milling.. Experiments were performed in a vibration mill in methanol under same conditions. The grinding time was changed in a geometric sequence from 0,125 to 4 hours. The newly created surface area providesa basic information on grinding. The specific surface area was determined by the standard Brunauer-Emmett-Teller (BET method using the appratus Gemini 2360 (Sylab, Austria. The concentration of iron was determined by AAS (SpectrAA-30, Varian, Australia. It was confirmed that the rate of ball wear depends on the hardness of feed materials. It was found that the relation between the contamination of the ground powders by wear and the specific surface area increment is linear and the slope depends on the microhardness of the ground material.

  17. The method of assessment of the grinding wheel cutting ability in the plunge grinding

    Science.gov (United States)

    Nadolny, Krzysztof

    2012-09-01

    This article presents the method of comparative assessment of the grinding wheel cutting ability in the plunge grinding kinematics. A new method has been developed to facilitate multicriterial assessment of the working conditions of the abrasive grains and the bond bridges, as well as the wear mechanisms of the GWAS, which occur during the grinding process, with simultaneous limitation of the workshop tests range. The work hereby describes the methodology of assessment of the grinding wheel cutting ability in a short grinding test that lasts for 3 seconds, for example, with a specially shaped grinding wheel, in plunge grinding. The grinding wheel macrogeometry modification applied in the developed method consists in forming a cone or a few zones of various diameters on its surface in the dressing cut. It presents an exemplary application of two variants of the method in the internal cylindrical plunge grinding, in 100Cr6 steel. Grinding wheels with microcrystalline corundum grains and ceramic bond underwent assessment. Analysis of the registered machining results showed greater efficacy of the method of cutting using a grinding wheel with zones of various diameters. The method allows for comparative tests upon different grinding wheels, with various grinding parameters and different machined materials.

  18. The Effects of Wear upon the Axial Profile of a Grinding Wheel in the Construction of Innovative Grinding Wheels for Internal Cylindrical Grinding

    OpenAIRE

    B. S?owi?ski; K. Nadolny

    2011-01-01

    The article describes the effects of wear upon the axial profile of a grinding wheel in the axial cylindrical grinding processes. This mechanism was used to develop a grinding wheel with zone diversified structure made of microcrystalline sintered corundum abrasive grains and vitrifies bond. Such a grinding wheel is characterized by the conical rough grinding zone that is made by grains of a relatively large size, and a cylindrical finish grinding zone with grains of a smaller size and can be...

  19. Investigation of AE Features in Grinding

    International Nuclear Information System (INIS)

    This paper presents recent investigation of acoustic emission (AE) behaviours in grinding processes. It demonstrated the acoustic emission features characterized in time and frequency domain are influenced by thermal behaviours of materials. By control laser conditions, the temperature elevation under laser irradiation can be similar to that in a grinding process. Therefore, an innovative concept that grinding process can be monitored by using thermal AE signatures from laser irradiation tests has been proposed. Accordingly, an artificial neural network (ANN), built on laser irradiation tests, was applied to monitor grinding thermal performance. The results showed that grinding performance variation due to wheel wear can be identified by using the ANN. This development could bring great benefits by reducing experimental works in the preparation of an ANN for grinding monitoring.

  20. High-performance grinding - a review

    OpenAIRE

    Krajnik, Peter; Kopač, Janez

    2015-01-01

    Presented paper deals with the contemporary aspects of grinding with regards to enhanced productivity and precision demands. High-performance grinding is essential to achieve high dimensional accuracy and surface integrity of ground components at optimum cost efficiency. The objectives of this paper refer to a review of state of the art technology of high-performance grinding at increased wheel speeds with highly efficient abrasives. The review relies on notable academic publications and rece...

  1. Ductile grinding of ultraprecise aspherical optical lenses

    Science.gov (United States)

    Koenig, Wilfried; Sinhoff, Volker

    1993-04-01

    The manufacturing of glass lenses has always set exacting requirements on the finishing technique. If, in addition, the design deviates from the conventional geometry of plane and sphere, the standard manufacturing process of rough grinding with cup-wheels and subsequent precision grinding and polishing with reproductive techniques fails. In order to achieve highest form accuracies and surface qualities combined with a flexible surface shape, ductile single- point-grinding meets the requirements for the production of rotationally symmetric aspheres.

  2. Rolling Stonesi kinokontsert kannab toorest rokiväge / Maris Meiessaar

    Index Scriptorium Estoniae

    Meiessaar, Maris

    2009-01-01

    Martin Scorsese muusikalisest dokumentaalfilmist "Shine a Light - Valgus peale" (USA-Suurbritannia, 2008), mille keskmes on 2006. a. New Yorgi Beaconi teatris toimunud briti ansambli Rolling Stones kontsert

  3. Changeing of fly ash leachability after grinding

    Science.gov (United States)

    Lakatos, J.; Szabo, R.; Racz, A.; Banhidi, O.; Mucsi, G.

    2016-04-01

    Effect of grinding on the reactivity of fly ash used for geopolymer production was tested. Extraction technique using different alkaline and acidic solutions were used for detect the change of the solubility of elements due to the physical and mechano-chemical transformation of minerals in function of grinding time. Both the extraction with alkaline and acidic solution have detected improvement in solubility in function of grinding time. The enhancement in alkaline solution was approx. 100% in case of Si and Al. The acidic medium able to dissolve the fly ash higher manner than the alkaline, therefore the effect of grinding was found less pronounced.

  4. IMPACT GRINDING OF DAMP MATERIALS

    Directory of Open Access Journals (Sweden)

    Ladaev Nikolay Mikhaylovich

    2012-10-01

    Centrifugal grinders were used to analyze the grinding process. The experimental data have proven that the probability of destruction of damp samples is a lot higher than the one of dry samples, given the same initial dimensions of particles and the loading intensity. The rise in the probability of destruction is stipulated by the fact that that the grinder speed at which crushing is triggered is lower in case of damp samples than in case of dry ones. Expressions for speed that describes destruction initiation and the probability of destruction depending on the type of materials, the moisture content and the loading intensity have been derived.

  5. Specific grinding energy and surface roughness of nanoparticle jet minimum quantity lubrication in grinding

    Directory of Open Access Journals (Sweden)

    Zhang Dongkun

    2015-04-01

    Full Text Available Nanoparticles with the anti-wear and friction reducing features were applied as cooling lubricant in the grinding fluid. Dry grinding, flood grinding, minimal quantity of lubrication (MQL, and nanoparticle jet MQL were used in the grinding experiments. The specific grinding energy of dry grinding, flood grinding and MQL were 84, 29.8, 45.5 J/mm3, respectively. The specific grinding energy significantly decreased to 32.7 J/mm3 in nanoparticle MQL. Compared with dry grinding, the surface roughness values of flood grinding, MQL, and nanoparticle jet MQL were significantly reduced with the surface topography profile values reduced by 11%, 2.5%, and 10%, respectively, and the ten point height of microcosmic unflatness values reduced by 1.5%, 0.5%, and 1.3%, respectively. These results verified the satisfactory lubrication effects of nanoparticle MQL. MoS2, carbon nanotube (CNT, and ZrO2 nanoparticles were also added in the grinding fluid of nanoparticle jet MQL to analyze their grinding surface lubrication effects. The specific grinding energy of MoS2 nanoparticle was only 32.7 J/mm3, which was 8.22% and 10.39% lower than those of the other two nanoparticles. Moreover, the surface roughness of workpiece was also smaller with MoS2 nanoparticle, which indicated its remarkable lubrication effects. Furthermore, the role of MoS2 particles in the grinding surface lubrication at different nanoparticle volume concentrations was analyzed. MoS2 volume concentrations of 1%, 2%, and 3% were used. Experimental results revealed that the specific grinding energy and the workpiece surface roughness initially increased and then decreased as MoS2 nanoparticle volume concentration increased. Satisfactory grinding surface lubrication effects were obtained with 2% MoS2 nanoparticle volume concentration.

  6. Rolling reloaded

    International Nuclear Information System (INIS)

    Not so long ago a new observation about rolling motion was described: for a rolling wheel, there is a set of points with instantaneous velocities directed at or away from the centre of the wheel; these points form a circle whose diameter connects the centre of the wheel to the wheel's point of contact with the ground (Sharma 1996 Eur. J. Phys. 17 353-6). We provide a detailed experimental verification of this observation, collecting 3D data from a rolling wheel with a commercially available optical tracking system. We also extend the observation to a generalized form: for a rolling wheel, there is a set of points with instantaneous velocities directed at or away from any point P; these points form a circle whose diameter connects the point P to the wheel's point of contact with the ground. This generalization is also verified experimentally

  7. Manufacturing processes 2 grinding, honing, lapping

    CERN Document Server

    Klocke, Fritz

    2009-01-01

    Presents a view of the most common machining and non-machining manufacturing processes. This volume describes the characteristics of abrasive tools, their design and manufacturing, followed by the fundamentals of grinding fluids. It also discusses grinding of different materials (steel, cast iron, hard and brittle materials, nickel and titanium).

  8. Theoretical considerations of machining with grinding wheels

    Directory of Open Access Journals (Sweden)

    Andrew Oyakhobo Odior

    2013-03-01

    Full Text Available Grinding is one of the most versatile methods of removing material from machine parts by the cutting action of the countless hard and sharp abrasive particles of a revolving grinding wheel. It works by forcing the abrasive grains into the surface of the workpiece so that each grain cuts away a small bit of material in the form of chips. Abrasive grinding wheel is an expendable wheel that carries an abrasive compound on its periphery. They are made of small, sharp and very hard natural or synthetic abrasive minerals, bonded together in a matrix to form a wheel. The paper presents a review of some of the characteristics as well as theoretical considerations of operations of abrasive grinding wheel. The relationships among the various grinding parameters; the radial force f, the force on individual grit of grinding wheel F, velocity of grinding wheelg Vg, velocity of work piecew Vw, the wheel diameterg Dg, and the diameter of the work piece Dw were established for given grinding operations.

  9. Diamond-Bronze Coatings for Grinding Applications

    Science.gov (United States)

    Tillmann, W.; Vogli, E.; Nebel, J.

    2008-12-01

    Grinding applications for the machining of stone and concrete require composite tools where large diamonds are perfectly embedded into a metallic matrix. With the detonation flame spraying process, it is possible to manufacture these super abrasive composites. Excellent embedment of the voluminous super abrasive particles into the matrix coating material can be realized to produce high quality composite layers for grinding applications of stone and concrete. In this paper, different diamond gradings as well as different volume contents of diamond in matrix are compared. Especially, the influence of particle size on its implantation efficiency is investigated and the influence of process and substrate temperature is analyzed. The thermal sprayed grinding tools are evaluated with respect to their microstructure as well as their grinding abilities. Compared to sintered diamond-bronze samples, the results of an adaptively designed grinding test for the machining of concrete are presented and analyzed.

  10. Precision diamond grinding of ceramics and glass

    Energy Technology Data Exchange (ETDEWEB)

    Smith, S.; Paul, H.; Scattergood, R.O.

    1988-12-01

    A new research initiative will be undertaken to investigate the effect of machine parameters and material properties on precision diamond grinding of ceramics and glass. The critical grinding depth to initiate the plastic flow-to-brittle fracture regime will be directly measured using plunge-grind tests. This information will be correlated with machine parameters such as wheel bonding and diamond grain size. Multiaxis grinding tests will then be made to provide data more closely coupled with production technology. One important aspect of the material property studies involves measuring fracture toughness at the very short crack sizes commensurate with grinding damage. Short crack toughness value`s can be much less than the long-crack toughness values measured in conventional fracture tests.

  11. Improved coal grinding and fuel flow control in thermal power plants

    DEFF Research Database (Denmark)

    Niemczyk, Piotr; Bendtsen, Jan Dimon

    2011-01-01

    mill by employing a special variant of a Luenberger observer. The controller uses the rotating classifier to improve the dynamical performance of the overall system. The proposed controller is compared with a PID-type controller with available pulverized coal flow measurements under nominal conditions...... as well as when parameter uncertainties and noise are present. The proposed controller lowers the grinding power consumption while in most cases exhibiting superior performance in comparison with the PID controller.......A novel controller for coal circulation and pulverized coal flow in a coal mill is proposed. The design is based on optimal control theory for bilinear systems with additional integral action. The states are estimated from the grinding power consumption and the amount of coal accumulated in the...

  12. A new transducer for local load measurements of friction and roll pressure in cold flat rolling

    DEFF Research Database (Denmark)

    Lagergren, J.; Wanheim, Tarras; Precz, W.; Henningsen, Poul; Arentoft, Mogens; Jonsson, N.G.

    2006-01-01

    The only way to establish the true rolling pressure and the true friction condition in cold rolling is to conduct measurements in the roll bite. A new transducer design is therefore proposed, in order to overcome problems in previous measurements in the past 70 years. The new idea is to increase...... the contact surface of the transducer, to be larger than the arc of contact. This is in contrast to the smaller and smaller contact pin design that has been prevailing. The measurements were conducted during cold dry rolling of both copper strips and stainless steel strips in a pilot mill. The...

  13. Strip Crown Prediction: Developing a Refined Dynamic Roll-Stack Model for the Hot Rolling Process

    OpenAIRE

    Slaughter, Derek Emerson

    2009-01-01

    The steel industry has been producing flat plates through the process of hot rolling since the late 1600s. Hot rolling uses a series of rolls to progressively thin a strip of steel to a desired thickness. In deforming the strip, the rolling process causes variations in thickness across the width of the strip. These variations are commonly referred to as crown, which is specifically the difference in thickness between the center and edge of a strip. For most applications steel mill clients req...

  14. A study of ball milling of powdered nuclear oxides

    International Nuclear Information System (INIS)

    The nuclear fuel named MOX, Mixed Oxide Fuels, composed of about 3% to 10% of plutonium oxide in uranium allows to recycle plutonium in Pressurized Water Reactors Fuel performances and recycling are strongly connected with the homogeneity of the (U, Pu)O2 solid solution. Because of the low U and Pu cations interdiffusion during sintering, the quality of the mixing of the uranium and plutonium oxides powders obtained by dry ball milling conditions the homogeneity of the MOX fuel. This study contributes to a better understanding of this key step of the fuel fabrication process. The first part of this work deals with the objectives of the study, that is the maximum PuO2 and UO2 particles sizes that are acceptable after the milling operation as far as they will be resorbed by sintering. The second part investigates the micronizing of powders. The grinding mechanisms involved in the ball mill and their effect on the fragmentation of each single powder are analyzed. The third part concludes with the examination of the grinding/mixing of UO2 + CeO2 powders (cerium oxide powder simulates plutonium oxide) with the adjustment of a characterization technique on green pellets of the co-milled mix. This technique allows to evaluate the efficiency of the grinding/mixing by quantifying CeO2 particles size and their distribution in the mix as a function of grinding time, media size and rotational speed on the ball mill. Even with the most severe grinding conditions (increase of rotational speed or decrease of media size), a number of UO2 particles of size larger than the critical size acceptable after the grinding operation still persists. In contrast, from 2 h of grinding, the corresponding fraction associated with CeO2 particles does not exist. Therefore the penalizing parameter for the homogenization is not the PuO2 (CeO2) particles size, but rather that of UO2 aggregates. (author)

  15. En route to a multi-model scheme for clinker comminution with chemical grinding aids

    CERN Document Server

    Mishra, R K; Carmona, H A; Wittel, F K; Sawley, M L; Weibel, M; Gallucci, E; Herrmann, H J; Heinz, H; Flatt, R J

    2015-01-01

    We present a multi-model simulation approach, targeted at understanding the behavior of comminution and the effect of grinding aids (GAs) in industrial cement mills. On the atomistic scale we use Molecular Dynamics (MD) simulations with validated force field models to quantify elastic and structural properties, cleavage energies as well as the organic interactions with mineral surfaces. Simulations based on the Discrete Element Method (DEM) are used to integrate the information gained from MD simulations into the clinker particle behavior at larger scales. Computed impact energy distributions from DEM mill simulations can serve as a link between large-scale industrial and laboratory sized mills. They also provide the required input for particle impact fragmentation models. Such a multi-scale, multi-model methodology paves the way for a structured approach to the design of chemical additives aimed at improving mill performance.

  16. Vibration characteristics analysis of a 20-high Sendzimir mill with localized defect on the working roller

    International Nuclear Information System (INIS)

    The working roller associating with local defect of the twenty-high roll mill not only significantly affects the mill performance, but also reduces surface quality of the strip steel. In this paper, the roll mill model with local defect on the working roller is established. The dynamic rolling process is simulated using the Finite Element Analysis. Effects of the local defect on the vibration characteristics of the roll mill and the surface quality of the strip steel are presented. The calculated results are validated using experimental data.

  17. NORMAL PRESSURE AND FRICTION STRESS MEASUREMENT IN ROLLING PROCESSES

    DEFF Research Database (Denmark)

    Henningsen, Poul; Arentoft, Mogens; Lagergren, Jonas; Jonsson, Nils-Göran; Presz, W.

    2005-01-01

    A load transducer has been developed to measure the contact forces in the deformation zone during rolling. The transducer consists of a strain gauge equipped insert, embedded in the surface of the roll. The length of the insert exceeds the contact length between material and roll. By analyzing the...... steel strips with a width of 40 mm was rolled with reduction varying from 2.7% to 29%, in a pilot mill. For evaluating the transducer, the measured contact forces are compared with external measurements of roll separating forces and torque. The determined friction coefficients are compared with values...

  18. Progress in abrasive and grinding technology

    CERN Document Server

    Xu, Xipeng

    2009-01-01

    The grinding and abrasive processing of materials are machining techniques which use bonded or loose abrasives to remove material from workpieces. Due to the well-known advantages of grinding and abrasive processes, advances in abrasive and grinding technology are always of great import in enhancing both productivity and component quality. In order to highlight the recent progress made in this field, the editor invited 21 world-wide contributions with the aim of gathering together all of the achievements of leading researchers into a single publication. The authors of the 21 invited papers, of

  19. Effect of plate asymmetric rolling parameters on the change of the total unit pressure of roll

    Directory of Open Access Journals (Sweden)

    A. Kawalek

    2011-07-01

    Full Text Available This work shows the results of theoretical analysis of asymmetric rolling process of plates in the finishing mill of plate rolling. Its aim was to determine the influence of asymmetry velocity of working rolls on decrease of unit pressure of metal on the rolls. The lower value of the unit pressure will reduce the elastic deflection of the finishing stand and improve the cross-section shape of plate. Three-dimensional simulation of asymmetric hot rolling of S355J2G3 steel plates was done with the aid of FORGE 2008® software. The tensor polynomial interpolation was used for comparing the values of the unit pressure obtaining from symmetric and asymmetric rolling.

  20. Using of fluidized-bed jet mill to a super fine comminution of steel composite

    Directory of Open Access Journals (Sweden)

    D. Urbaniak

    2015-01-01

    Full Text Available In many industries the demand for very fine material increases. In the metallurgical industry, for example, there is increasing use of the production of high density metal elements with the use of metallurgical powder composites. The use of powder composites requires prior their grinding. Unfortunately, the very fine grinding is not an easy process. The using for this purpose fluidized-bed jet mill was proposed in the paper. The attempts of grinding of metallurgical powder were carried out in the fluidized-bed jet mill. After the experiment analyses of particle size distribution of grinding products were performed. The results are presented in graphs. Analyses of the obtained results concluded that the grinding of very fine metallurgical composite is possible and produces positive results.

  1. The Inlet Engine Valves Grinding Using Different Types of Cutting Fluids and Grinding Wheels

    Scientific Electronic Library Online (English)

    Eraldo Jannone da, Silva; Eduardo Carlos, Bianchi; Joo Fernando Gomes de, Oliveira; Paulo Roberto de, Aguiar.

    2002-06-01

    Full Text Available In this paper an experimental research is presented in which different types of cutting fluids (a cutting oil and three different types of soluble oils) and grinding wheels (alumina and vitrified CBN) were tested in the inlet engine valves grinding. As evaluation parameters the workpiece residual st [...] ress and the grinding wheel wear were analyzed. The cutting fluid and the grinding wheel types adopted resulted in changes in all the parameters, due to the different lubricant abilities among the fluids and due to the differences in the mechanical and thermal properties among the abrasives tested. For grinding this steel, the CBN wheel is the best choice, mainly due to compressive residual stress results obtained for all cutting fluids tested. The cutting oil is the most adequate cutting fluid to be used, due to its higher lubricity and ability in keeping the wheel sharp for longer periods of time, reducing the overall grinding energy and the thermal damage.

  2. The Inlet Engine Valves Grinding Using Different Types of Cutting Fluids and Grinding Wheels

    Directory of Open Access Journals (Sweden)

    Silva Eraldo Jannone da

    2002-01-01

    Full Text Available In this paper an experimental research is presented in which different types of cutting fluids (a cutting oil and three different types of soluble oils and grinding wheels (alumina and vitrified CBN were tested in the inlet engine valves grinding. As evaluation parameters the workpiece residual stress and the grinding wheel wear were analyzed. The cutting fluid and the grinding wheel types adopted resulted in changes in all the parameters, due to the different lubricant abilities among the fluids and due to the differences in the mechanical and thermal properties among the abrasives tested. For grinding this steel, the CBN wheel is the best choice, mainly due to compressive residual stress results obtained for all cutting fluids tested. The cutting oil is the most adequate cutting fluid to be used, due to its higher lubricity and ability in keeping the wheel sharp for longer periods of time, reducing the overall grinding energy and the thermal damage.

  3. Delamination of hexagonal boron nitride in a stirred media mill

    International Nuclear Information System (INIS)

    A scalable process for delamination of hexagonal boron nitride in an aqueous solution of the non-ionic surfactant TWEEN85 using a stirred media mill is presented. The size of the ZrO2 beads used as grinding media governs the dimensions of the ground boron nitride particles as atomic force microscopic investigations (AFM) reveal: the mean flakes thickness decreases from 3.5 to 1.5 nm and the ratio between mean flake area and mean flake thickness increases from 2,200 to 5,800 nm if the grinding media size is reduced from 0.8 to 0.1 mm. This result shows that a high number of stress events in combination with low stress energy (small grinding media) facilitate delamination of the layered material whereas at high stress energies in combination with a low number of stress events (large grinding media) breakage of the layers dominates over delamination. The results of particle height analyses by AFM show that few-layer structures have been formed by stirred media milling. This result is in agreement with the layer thickness dependence of the delamination energy for hexagonal boron nitride. The concentration of nanoparticles remaining dispersed after centrifugation of the ground suspension increases with grinding time and with decreasing grinding media size. After 5 h of grinding using 0.1 mm ZrO2 grinding media the yield of nanoparticle formation is about 5 wt%. The nanoparticles exhibit the typical Raman peak for hexagonal boron nitride at 1,366 cm−1 showing that the in-plane order in the milled platelets is remained.

  4. High-speed milling of light metals

    Directory of Open Access Journals (Sweden)

    F. Cus

    2007-01-01

    Full Text Available Purpose: Purpose of this paper: Introduction applicability of high-speed cutting of light metals is presented inthis paper.Design/methodology/approach:HSC is the result of numerous technical advances ensuring that milling hasbecome faster than conventional milling and has gained importance as a cutting process. The advantages ofthe HSC milling are higher productivity owing to the reduction of machining times increase of the flow timeof production, reduction of the number of technological operations, increase of the surface quality and longerservice life of tools. The machining conditions for execution of the HSC (36000min-1 and feeding 20m/minrequire modernly built machine tools to meet those machining conditions.Findings: Continuous development of new materials is more and more dynamical, particularly, in theautomobile, aircraft and electronic industry and in the manufacture of various mechanical parts. Also theachievements in the area of building of machines and tools, ensuring high cutting speeds (highly efficientmachining have contributed to development of the process.Research limitations/implications: High quality of the surfaces, the quality of this so-called HSC milling canbe compared to grinding.Practical implications: High-speed milling of light metals from aluminium and magnesium is more and morefrequently used in practice. This result is high quality of the surface and shorter machining times. In some caseswhen machining by grinding is specified, the latter is omitted.Originality/value: The applicability of high-speed milling has proved to be successful, when aluminum andmagnesium alloying materials are machined.

  5. Analysis of the cutting fluid influence on the deep grinding process with a CBN grinding wheel

    Directory of Open Access Journals (Sweden)

    Ronaldo Yoshinobu Fusse

    2004-09-01

    Full Text Available The application of cutting fluid in a deep grinding process is becoming more and more important, mainly where the cutting fluids are used as an "external" agent to the grinding conditions. The role of the fluid in grinding operations is in refrigeration of the workpiece, removal of the shavings, lubrication of the grinding zone, and refrigeration and cleaning of the wheel. The efficiency of a cutting fluid will depend mainly of the type of fluid that will be used. In this work, the influences of the type of cutting fluid used in a deep grinding process of the steel VC131 using CBN grinding wheel are analyzed. Three different types of cutting fluids were used: a vegetable emulsion, a synthetic solution and a integral oil. The variables analyzed during and after the grinding process were the grinding force, the superficial roughness, the acoustic emission (EA, the temperature of the piece and the G ratio (relationship between the volume of material removed from the piece and the volume worn off the grinding wheel. The integral oil showed the best performance relative to the following output variables: EA, cutting force and G ratio. The vegetal emulsion was the fluid that best dissipated heat from the cutting region.

  6. Adequacy of matrix experiment in grinding

    OpenAIRE

    Krajnik, Peter; Kopač, Janez

    2015-01-01

    Over the recent years, grinding technology has considerably increased in termsof performance with regard to its productivity and quality. Grinding represents a complex manufacturing process with numerous parameters that influence the actual technological output. In this paper, adequacy of simple matrix screening experiment is discussed in terms of factor effects determination and their comparison to referential values obtained by industrially validated empirical model. In this way, the purpos...

  7. Separation of P Phase and Fe Phase in High Phosphorus Oolitic Iron Ore by Ultrafine Grinding and Gaseous Reduction in a Rotary Furnace

    Science.gov (United States)

    Gao, Jintao; Guo, Lei; Guo, Zhancheng

    2015-10-01

    Due to the oolitic structure of the high phosphorus iron ore and the closely wrapping of apatite and hematite phases, an approach using jet mill was utilized to grind the ore to ultrafine 0.01 to 0.001 mm, which realizes the dissociation of apatite phase and hematite phase. Then in a laboratory scale rotary furnace, high phosphorus ores of different sizes were reduced by reducing gas at sub-melting point temperatures (973 to 1173 K [700 to 900 °C]). In the rotating inclined reactor, the ore particles reacted with the reducing gas coming from the opposite direction in a rolling and discrete state, which greatly improved the kinetic conditions. In this study, the reaction rate increases significantly with the decrease of particle size. For the ultrafine high phosphorus iron ores, the metallization ratio can reach 83.91 to 97.32 pct, but only 33.24 to 40.22 pct for powders with the size of 0.13 to 0.15 mm. The reduced particles maintained their original sizes, without the presence of sintering phenomenon or iron whisker. Hence, two kinds of products were easily obtained by magnetic separation: the iron product with 91.42 wt pct of Fe and 0.19 wt pct of P, and the gangue product with 13.77 wt pct of Fe and 2.32 wt pct of P.

  8. The grinding of uranium dioxide from fluidized beds

    International Nuclear Information System (INIS)

    This work deals with the UO2 vibratory grinding, the UO2 obtained from fluidized beds. In this study the grinding time has been correlated with surface area, stoichiometry, granulometry and grinded product contamination. The efficiency losses in the grinding of moisten UO2 are outlined. Finally it is made a brief study of the granulate obtained from the grinded UO2 as well as the green pellets resulting from it, taking into consideration the dispersion of its density and height. (Author)

  9. Kinetics of Grinding of Secondary Serpentine Raw Material at Cascade Operating Mode

    Directory of Open Access Journals (Sweden)

    Marek Matik

    2004-12-01

    Full Text Available The paper deals with the grinding of secondary serpentine material from the Dobšiná´s heap in a ball ceramic mill. The raw material was pre-sieved to prepare fraction of +250 –1,000 µm that was fed to the mill. During batch experiment an amount of oversize on the screen with a mesh size of 200 µm was observed as a function of time. Two speed modes were tested. Firstly, it was the mode designed by mill producer implicit from the structure of milling stand equipped by electromotor, friction gear onto driving shaft with given diameter. The speed of this original alignment attains 40 rmp. Secondly, it was cascade speed mode according to the Haase´s equation, namely 53 rmp, achieved by enlargement of driving shaft diameter. As to winning of required final product 90 % –200 µm, increased speed resulted in the shortening of grinding time from 17.5 to15.7 hour.

  10. Modelling of dynamic contact length in rail grinding process

    Science.gov (United States)

    Zhi, Shaodan; Li, Jianyong; Zarembski, A. M.

    2014-09-01

    Rails endure frequent dynamic loads from the passing trains for supporting trains and guiding wheels. The accumulated stress concentrations will cause the plastic deformation of rail towards generating corrugations, contact fatigue cracks and also other defects, resulting in more dangerous status even the derailment risks. So the rail grinding technology has been invented with rotating grinding stones pressed on the rail with defects removal. Such rail grinding works are directed by experiences rather than scientifically guidance, lacking of flexible and scientific operating methods. With grinding control unit holding the grinding stones, the rail grinding process has the characteristics not only the surface grinding but also the running railway vehicles. First of all, it's important to analyze the contact length between the grinding stone and the rail, because the contact length is a critical parameter to measure the grinding capabilities of stones. Moreover, it's needed to build up models of railway vehicle unit bonded with the grinding stone to represent the rail grinding car. Therefore the theoretical model for contact length is developed based on the geometrical analysis. And the calculating models are improved considering the grinding car's dynamic behaviors during the grinding process. Eventually, results are obtained based on the models by taking both the operation parameters and the structure parameters into the calculation, which are suitable for revealing the process of rail grinding by combining the grinding mechanism and the railway vehicle systems.

  11. Studying possibilities to improve the functional properties of metallurgical rolls

    OpenAIRE

    Stradomski, Z.; A. Pirek; S. Stachura

    2008-01-01

    Thc paper prcscnts rcsults nT invcst igations and at~thors' opinion on improving functional propcrtics of mciall urgicnl rolls cast fromGZOOCrMoNi 4-9-3 cast wccl. onc nf most oftcn ilscd lor rolls in scction mills. Thcsc mills Icn~urcq uickcr than flat rolls wear or 1001'spass. whar rcquircs morc Crcqocnt rcpcncr;lt ion. 'Thc machining rcquircs n rclat ivcly low hardness, which is cnsurcd hy ~ h pcc arliiic matrixof casr steel strldid. 7 % ~au thors silggcst 10 achicvc thc optimisntion o f t...

  12. Theoretical and experimental investigation of grinding marks in sphere NC grinding process

    Science.gov (United States)

    Wang, Peng; Zhang, Hao; Hui, Changshun

    2014-08-01

    Sphere ultra-precision NC grinding process with diamond cup wheel is widely used as an indispensable working procedure for manufacturing spherical, most aspherical, and some freeform surfaces. This paper presents a mathematic model of sphere grinding with cup diamond wheel based on homogeneous transformation method to simulate grinding marks. Different kinds of grinding marks are obtained by changing the geometrical parameters including the shift in axis X and Y axis and inclination angle deviation. Form accuracy and dimensional errors caused by geometrical parameters are also analyzed, and hence a three-step method utilizing grinding marks is proposed to correct these errors. A series of experiments are conducted and the results show that the proposed method is very efficient and effective in actual spherical surface generating process.

  13. DETERMINATION ОF DRESS ROLL OPTIMAL RADIUS WHILE PRODUCING PARTS WITH TROCHOIDAL PROFILE

    Directory of Open Access Journals (Sweden)

    E. N. Yankevich

    2015-01-01

    Full Text Available The paper considers determination of the dress roll optimal radius while producing parts having trohoidal profile with the help of grinding method that presupposes application of grinding disk. In this case disk profile has been cut-in by diamond dressing. Two methods for determination of calculation of the dress roll optimal radius have been proposed in the paper. On the basis of the satellite gear of the planetary pin reducer whose profile presents a trochoid it has been shown that the obtained results pertaining to two proposed methods conform with each other.

  14. Kinematics of rolling-cutter bit with offset rolling-cutter axes

    Energy Technology Data Exchange (ETDEWEB)

    Abdullin, M.M.; Trushkin, B.N.; Spivak, A.I.

    1981-11-01

    Results of test-bench investigations of kinematic parameters of operation of the equipment of the serially produced rolling-cutter bit, Sh215 9S-GV, are presented. They made it possible to record the mean and ''instantaneous'' frequencies of rotation of milling cutters for any frequency of rotation of the bit. The effect of the bit load on the mean gear ratios of the rolling cutters is established. The degree of nonuniformity of rotation of rolling cutters is shown and a relation is found between the position of teeth of the peripheral rolling cutter rings with respect to the bottom hole and the character of variation of the ''instantaneous'' rolling-cutter gear ratios.

  15. Twyman effect mechanics in grinding and microgrinding.

    Science.gov (United States)

    Lambropoulos, J C; Xu, S; Fang, T; Golini, D

    1996-10-01

    In the Twyman effect (1905), when one side of a thin plate with both sides polished is ground, the plate bends: The ground side becomes convex and is in a state of compressive residual stress, described in terms of force per unit length (Newtons per meter) induced by grinding, the stress (Newtons per square meter) induced by grinding, and the depth of the compressive layer (micrometers). We describe and correlate experiments on optical glasses from the literature in conditions of loose abrasive grinding (lapping at fixed nominal pressure, with abrasives 4-400 ?m in size) and deterministic microgrinding experiments (at a fixed infeed rate) conducted at the Center for Optics Manufacturing with bound diamond abrasive tools (with a diamond size of 3-40 ?m, embedded in metallic bond) and loose abrasive microgrinding (abrasives of less than 3 ?m in size). In brittle grinding conditions, the grinding force and the depth of the compressive layer correlate well with glass mechanical properties describing the fracture process, such as indentation crack size. The maximum surface residual compressive stress decreases, and the depth of the compressive layer increases with increasing abrasive size. In lapping conditions the depth of the abrasive grain penetration into the glass surface scales with the surface roughness, and both are determined primarily by glass hardness and secondarily by Young's modulus for various abrasive sizes and coolants. In the limit of small abrasive size (ductile-mode grinding), the maximum surface compressive stress achieved is near the yield stress of the glass, in agreement with finite-element simulations of indentation in elastic-plastic solids. PMID:21127579

  16. MECHANICAL DISINTEGRATION OF WHEAT STRAW BY ROLLER-PLATE GRIND SYSTEM WITH SHARP-EDGED SEGMENTS

    Directory of Open Access Journals (Sweden)

    Lukas Kratky

    2015-04-01

    Full Text Available Colloid mills and extruders are widely used for disintegrating wet fibrous biomass. However, their main disadvantages are a high energy requirement in the range of hundreds or thousands of kWh per ton of material, and the fact that they grind in process cycles. Efforts have therefore been made to design a new type of continuously operated grinder. Its disintegration principle uses a roller-plate grinding system with sharp-edged segments, where the compressive and shear forces combine to comminute the particles. Test experiments verified that the grinder disintegrates wet untreated straw to particles below 10mm in an effective manner in a single pass, with an energy requirement of 50 kWht−1 TS. A 23% increase in biogas yield was achieved, leading to a net gain in electric energy of310 kWht−1 TS.

  17. Physical fabrication of colloidal ZnO nanoparticles combining wet-grinding and laser fragmentation

    Science.gov (United States)

    Wagener, Philipp; Lau, Marcus; Breitung-Faes, Sandra; Kwade, Arno; Barcikowski, Stephan

    2012-09-01

    Combination of wet-grinding and laser fragmentation is a promising approach to advance both methods: Laser fragmentation will be more efficient when combined with mechanical treatment and wet-grinding may take advance of the abrasion-free laser process to achieve fabrication of smaller particles. By mechanical pre-treatment of zinc oxide microparticles in a stirred-media mill, the starting material is activated by generation of crystallographic defects, which strongly enhance the efficiency of subsequent laser fragmentation. Picosecond-laser irradiation of mechanically treated and untreated microparticles suspended in water yielded in colloidal zinc oxide nanoparticles. Furthermore, nanoparticle productivity and properties can be controlled by variation of anionic surfactant concentration.

  18. Analysis on the grinding quality of palm oil fibers by using combined grinding equipment

    Science.gov (United States)

    Gan, H. L.; Gan, L. M.; Law, H. C.

    2015-12-01

    As known, Malaysia is the second largest palm oil producer worldwide after Indonesia, therefore indicating the abundance of its wastes within the country. The plantation would be seen to increase to at least 5.2 million ha by 2020, and the waste generation would be 50-70 times the plantation. However, the efficiency of bulk density is reduced. This is one of the main reasons of the initiation of this size reduction/ grinding research. With appropriate parameters, grinding will be seen to be helping in enhancing the inter-particle bindings, subsequently increasing the quality of final products. This paper focuses on the grinding quality involving palm oil wastes by using the Scanning Electron Microscope (SEM). The samples would first be ground to powder at varying grinding speed and finally got the randomly chosen particles measured to obtain the size range. The grinding speed was manipulated from 15 Hz to 40 Hz. From the data obtained, it was found the particles fineness increased with increasing grinding speed. In general, the size ranged from 45 μm to about 600 μm, where the finest was recorded at the speed of 40 Hz. It was also found that the binding was not so encouraging at very low speeds. Therefore, the optimum grinding speed for oil palm residues lied in the range of 25 Hz to 30 Hz. However, there were still limitations to be overcome if the accuracy of the image clarity is to be enhanced.

  19. Effect of deep cryogenic treatment on the microstructure and wear performance of Cr-Mn-Cu white cast iron grinding media

    Science.gov (United States)

    Vidyarthi, M. K.; Ghose, A. K.; Chakrabarty, I.

    2013-12-01

    The phase transformation and grinding wear behavior of Cr-Mn-Cu white cast irons subjected to destabilization treatment followed by air cooling or deep cryogenic treatment were studied as a part of the development program of substitute alloys for existing costly wear resistant alloys. The microstructural evolution during heat treatment and the consequent improvement in grinding wear performance were evaluated with optical and scanning electron microscopy, X-ray diffraction analysis, bulk hardness, impact toughness and corrosion rate measurements, laboratory ball mill grinding wear test etc. The deep cryogenic treatment has a significant effect in minimizing the retained austenite content and converts it to martensite embedded with fine M7C3 alloy carbides. The cumulative wear losses in cryotreated alloys are lesser than those with conventionally destabilized alloys followed by air cooling both in wet and dry grinding conditions. The cryotreated Cr-Mn-Cu irons exhibit comparable wear performance to high chromium irons.

  20. Creep-feed grinding: A modern variant of the plane surface grinding process

    Science.gov (United States)

    Koenig, W.; Laeur-Schmaltz, H.

    1982-07-01

    Creep feed and conventional grinding are compared. Specifications for an automated combined plane surface - creep feed grinder are presented. It must be possible to preprogram two different grinding cycles with an intervening dressing cycles. The automatic grinder must be equipped with a rigid feed system for the two-stage process, which can provide a steplessly controlled, stick-slip - free workpiece speed over the range 0.01 to 30 m/min. Spindle drive and spindle bearings are to be adapted to the increased demands placed on the machine system by the plungecut grinding technique. An efficient coolant system must be available to provide high pressures and throughput quantities.

  1. Surface integrity of GH4169 affected by cantilever finish grinding and the application in aero-engine blades

    Directory of Open Access Journals (Sweden)

    Li Xun

    2015-10-01

    Full Text Available GH4169 is the main material for aero-engine blades and integrated blisks. Because GH4169 has a poor milling performance, the profile precision and surface integrity of blades and integrated blisks are difficult to be met by utilizing the conventional milling process, which directly influence the global performance and reliability of aero-engines. Through grinding experiments on parameters and surface integrity optimization, the helical cantilever grinding process utilizing a 300# CBN RB wheel is presented and applied in finish machining of GH4169 blades. The profile errors of the blade surface are within ±0.01 mm, the roughness is less than 0.4 μm, the residual compressive stresses and the hardening rate are appropriate, there are no phenomena of burr and smearing with the grinding chips, and the leading/trailing edge can be smoothly connected with the suction/pressure surface. All the experimental results indicate that this grinding process is greatly suitable for the profile finish machining of GH4169 blades.

  2. KINEMATICS OF MATERIAL REMOVAL AND FORMING OF SURFACE AT GRINDING

    OpenAIRE

    Feodor NOVIKOV

    2013-01-01

    The mathematical model of kinematics of material removal and a forming of surfaces isdeveloped at grinding. Conditions of increase of productivity of processing are defined and newkinematic schemes of high-performance grinding are offered

  3. KINEMATICS OF MATERIAL REMOVAL AND FORMING OF SURFACE AT GRINDING

    Directory of Open Access Journals (Sweden)

    Feodor NOVIKOV

    2013-05-01

    Full Text Available The mathematical model of kinematics of material removal and a forming of surfaces isdeveloped at grinding. Conditions of increase of productivity of processing are defined and newkinematic schemes of high-performance grinding are offered

  4. Energy requirement for fine grinding of torrefied wood

    Energy Technology Data Exchange (ETDEWEB)

    Repellin, Vincent; Govin, Alexandre; Guyonnet, Rene [Department of Powder and Multi-Components Materials (PMMC), SPIN Research Center, Ecole des Mines de Saint Etienne (EMSE), 158 Cours Fauriel, F-42023 Saint-Etienne (France); Rolland, Matthieu [Process Developments and Engineering Division, Chemical Engineering Department, Institut Francais du Petrole (IFP-Lyon), F-69390 Vernaison (France)

    2010-07-15

    The purpose of this study is to investigate the influence of torrefaction on wood grinding energy. Wood chips were torrefied at different temperatures and durations. The energy required to obtain fine powder was measured. Particle size analyses were carried out on each powder sample. It is showed that torrefaction decreases both grinding energy and particle size distribution. A criterion to compare grindability of natural and torrefied wood is proposed. It takes into account both grinding energy and particle size distribution. It accounts the energy required for grinding particles to sizes inferior to 200 {mu}m, for given grinding conditions. Torrefaction is characterised by the anhydrous weight loss (AWL) of wood. For AWL inferior to around 8%, grinding energy decreases fast. Over 8%, grinding energy decreases at a slow rate. Particle size distribution decreases linearly as the AWL increases. Both for spruce and beech, the grinding criterion is decreased of 93% when the AWL is around 28%. (author)

  5. The flexible grinding technology based on the electric current control

    Science.gov (United States)

    Peng, Liwen; Yao, Bin; Li, Fei; Wang, Xiao; Yao, Boshi

    2012-01-01

    A flexible grinding technology based on the electric current control is presented to resolve the problem of low rigidity of PCB during grinding, the thickness of which varies from 0.1mm up to 3.5 mm. The comparative results between the real-time current and the setting current in the process of grinding control the frequency and the number of servo pulse, and then the servo motor adjusts the grinding depth of brushing roller at several different rotational speeds, namely, realizing the constant grinding force during grinding. The results show that the PCB can be grinded efficiently and accurately by means of the flexible grinding technology based on the electric current control.

  6. Effect of Home Grinding on Properties of Brewed Coffee

    OpenAIRE

    Christopher Murray; Thamara Laredo

    2014-01-01

    We present measurements of particle size distribution, density, loss of coffee on brewing and caffeine content in brewed coffee (as measured using Fourier Transform Infrared Spectroscopy) as a function of grinding time using a blade-type grinder. In general, there is not a lack of correlation between coffee properties and grinding for grinding times in excess of 42 s, but mass loss on brewing and caffeine content are both increased with grinding times between 0 and 42 s. In addition, we prese...

  7. Effective Manufacturing Method for Automated Inside Diameter Grinding

    Science.gov (United States)

    Slowinski, Bronislaw; Nadolny, Krzysztof

    This paper presents essence and results of experimental investigations of highly efficient automated internal cylindrical grinding method. The essence of this method consists in the removal of the whole grinding allowance in one pass of a grinding wheel, parallel to preserving the required quality of the surface layer of a workpiece. A grinding wheel applied to the developed method had a zonal diversified internal structure and a properly prepared conical chamfer.

  8. Simulation of Grinding Surface Creation – A Single Grit Approach

    OpenAIRE

    Chen, Xun; Opoz, Tahsin Tecelli

    2010-01-01

    The paper presents an investigation of grinding material removal mechanism using finite element method. Understanding of grinding removal mechanism relies on the investigation of material removal by each individual grain. Although some analytical formulations have been developed to predict and to quantify the machining events in grinding, they do not illustrate every stage of abrasive actions. Finite element analysis provides good facility to present details of physical behaviour in grinding....

  9. Precision replenishable grinding tool and manufacturing process

    Energy Technology Data Exchange (ETDEWEB)

    Makowiecki, D.M.; Kerns, J.A.; Blaedel, K.L.; Colella, N.J.; Davis, P.J.; Juntz, R.S.

    1998-06-09

    A reusable grinding tool consisting of a replaceable single layer of abrasive particles intimately bonded to a precisely configured tool substrate, and a process for manufacturing the grinding tool are disclosed. The tool substrate may be ceramic or metal and the abrasive particles are preferably diamond, but may be cubic boron nitride. The manufacturing process involves: coating a configured tool substrate with layers of metals, such as titanium, copper and titanium, by physical vapor deposition (PVD); applying the abrasive particles to the coated surface by a slurry technique; and brazing the abrasive particles to the tool substrate by alloying the metal layers. The precision control of the composition and thickness of the metal layers enables the bonding of a single layer or several layers of micron size abrasive particles to the tool surface. By the incorporation of an easily dissolved metal layer in the composition such allows the removal and replacement of the abrasive particles, thereby providing a process for replenishing a precisely machined grinding tool with fine abrasive particles, thus greatly reducing costs as compared to replacing expensive grinding tools. 11 figs.

  10. Precision replenishable grinding tool and manufacturing process

    Energy Technology Data Exchange (ETDEWEB)

    Makowiecki, Daniel M. (Livermore, CA); Kerns, John A. (Livermore, CA); Blaedel, Kenneth L. (Livermore, CA); Colella, Nicholas J. (Livermore, CA); Davis, Pete J. (Pleasanton, CA); Juntz, Robert S. (Hayward, CA)

    1998-01-01

    A reusable grinding tool consisting of a replaceable single layer of abrasive particles intimately bonded to a precisely configured tool substrate, and a process for manufacturing the grinding tool. The tool substrate may be ceramic or metal and the abrasive particles are preferably diamond, but may be cubic boron nitride. The manufacturing process involves: coating a configured tool substrate with layers of metals, such as titanium, copper and titanium, by physical vapor deposition (PVD); applying the abrasive particles to the coated surface by a slurry technique; and brazing the abrasive particles to the tool substrate by alloying the metal layers. The precision control of the composition and thickness of the metal layers enables the bonding of a single layer or several layers of micron size abrasive particles to the tool surface. By the incorporation of an easily dissolved metal layer in the composition such allows the removal and replacement of the abrasive particles, thereby providing a process for replenishing a precisely machined grinding tool with fine abrasive particles, thus greatly reducing costs as compared to replacing expensive grinding tools.

  11. Physicochemical and grinding characteristics of dragonhead seeds

    Science.gov (United States)

    Dziki, D.; Mi?, A.; G?adyszewska, B.; Laskowski, J.; Kwiatkowski, S.; Gawlik-Dziki, U.

    2013-12-01

    The results of investigations on the physicochemical and grinding characteristics of Moldavian dragonhead seeds are presented. The data obtained showed that the physical properties (average size, sphericity, surface area, 1 000 seed mass, dynamic angle of repose, coefficient of static friction, and bulk and true densities) of the white and blue form of dragonhead seeds were not significantly different. Both forms of dragonhead showed similar levels of protein (average of 21%), whereas the blue form of dragonhead had a lower fat content (average of 23.1%) and higher mucilage content (13.35%) in comparison to the blue form of seed (24.6 and 9.95%, respectively). Antioxidant capacity of dragonhead seeds was comparable for both forms and averaged about 40%, which corresponded to EC50 values of 0.12 and 0.13 mgml-1 for the white and blue forms, respectively. The grinding material showed similar particle size distribution of ground material for both forms of dragonhead seeds. The lowest values of specific grinding energy were obtained for the white form of dragonhead seeds, those for the blue form were significantly higher. Grinding of dragonhead seeds using a screen 2.0 mm mesh size caused screen hole clogging. This problem did not occur when dragonhead seeds were mixed with wheat grain.

  12. Bruxism (Teeth Grinding or Clenching) (For Parents)

    Science.gov (United States)

    ... teacher). Even arguing with parents and siblings can cause enough stress to prompt teeth grinding or jaw clenching. Some kids who are hyperactive also have bruxism. And sometimes kids with other medical conditions (such as cerebral palsy) or who take certain medicines can develop bruxism. ...

  13. Evaluation of the influence of a milling system on the coal consumption in a PF utility boiler

    Energy Technology Data Exchange (ETDEWEB)

    Domingo, E.; Gil, A.; Arauzo, I.; Iranzo, I. [Universidad de Zaragoza, Zaragoza (Spain). Center for Power Plant Efficiency Research (CIRCE)

    2001-07-01

    This paper presents a methodology for milling system performance analysis in coal fired power plants. A mill model has been designed. As inputs of the model, the following parameters are chosen: air mass flow rates, coal flow rates, grinding pieces age and classifier position. The outputs are: mill drive current, pressure drop through the mill and percentage of pulverized coal passing through 150, 75 and 45 {mu}m sieves. The developed models have been applied to the Teruel Power Station, a pulverized coal fired plant in Spain with a milling system of six planetary rod mills, each feeding a row of four burners. 7 refs., 13 figs., 4 tabs.

  14. Research on high precision centering assembly method of roll edge optical elements

    Science.gov (United States)

    Liu, Hua; Liu, Xiaomei

    2015-08-01

    In order to improve the imaging quality of target imaging optical system, in the special environment of large temperature difference, the centering assembly precision of roll edge optical elements was studied. According to the hole-axis coordinate error theory of mechanics, by analyzing the factors affected the precision of mechanical heating surface, combining with the existing method to eliminate error and centering assembly process, a new kind of high precision centering assembly method was put forward. Using additional grinding device to grinding roll edge of optical element, eliminate the machining error on the surface of the mechanical hot working, thus improve the centering assembly precision between the roll edge optical element and lens tube. The result of experiment shows that the centering precision can reach less than 3μm when assembled optical element after roll edge using new centering assembly method, and improved by 25% compared to the traditional method of roll edge optical elements are assembled directly after hot working. New assembly method with additional grinding device can improve the centering assembly precision of roll edge optical elements, and greatly reduce the difficulty of optical design of such optical imaging system using in large temperature difference environment, when meet the same image quality.

  15. Rolling-Element Bearings

    Science.gov (United States)

    Hamrock, B. J.; Anderson, W. J.

    1983-01-01

    Rolling element bearings are a precision, yet simple, machine element of great utility. A brief history of rolling element bearings is reviewed and the type of rolling element bearings, their geometry and kinematics, as well as the materials they are made from and the manufacturing processes they involve are described. Unloaded and unlubricated rolling element bearings, loaded but unlubricated rolling element bearings and loaded and lubricated rolling element bearings are considered. The recognition and understanding of elastohydrodynamic lubrication covered, represents one of the major development in rolling element bearings.

  16. Rolling Process Modeling Report. Finite-Element Model Validation and Parametric Study on various Rolling Process parameters

    Energy Technology Data Exchange (ETDEWEB)

    Soulami, Ayoub [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lavender, Curt A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Paxton, Dean M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Burkes, Douglas [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-06-15

    Pacific Northwest National Laboratory (PNNL) has been investigating manufacturing processes for the uranium-10% molybdenum alloy plate-type fuel for high-performance research reactors in the United States. This work supports the U.S. Department of Energy National Nuclear Security Administration’s Office of Material Management and Minimization Reactor Conversion Program. This report documents modeling results of PNNL’s efforts to perform finite-element simulations to predict roll-separating forces for various rolling mill geometries for PNNL, Babcock & Wilcox Co., Y-12 National Security Complex, Los Alamos National Laboratory, and Idaho National Laboratory. The model developed and presented in a previous report has been subjected to further validation study using new sets of experimental data generated from a rolling mill at PNNL. Simulation results of both hot rolling and cold rolling of uranium-10% molybdenum coupons have been compared with experimental results. The model was used to predict roll-separating forces at different temperatures and reductions for five rolling mills within the National Nuclear Security Administration Fuel Fabrication Capability project. This report also presents initial results of a finite-element model microstructure-based approach to study the surface roughness at the interface between zirconium and uranium-10% molybdenum.

  17. Rolling Process Modeling Report. Finite-Element Model Validation and Parametric Study on various Rolling Process parameters

    International Nuclear Information System (INIS)

    Pacific Northwest National Laboratory (PNNL) has been investigating manufacturing processes for the uranium-10% molybdenum alloy plate-type fuel for high-performance research reactors in the United States. This work supports the U.S. Department of Energy National Nuclear Security Administration's Office of Material Management and Minimization Reactor Conversion Program. This report documents modeling results of PNNL's efforts to perform finite-element simulations to predict roll-separating forces for various rolling mill geometries for PNNL, Babcock & Wilcox Co., Y-12 National Security Complex, Los Alamos National Laboratory, and Idaho National Laboratory. The model developed and presented in a previous report has been subjected to further validation study using new sets of experimental data generated from a rolling mill at PNNL. Simulation results of both hot rolling and cold rolling of uranium-10% molybdenum coupons have been compared with experimental results. The model was used to predict roll-separating forces at different temperatures and reductions for five rolling mills within the National Nuclear Security Administration Fuel Fabrication Capability project. This report also presents initial results of a finite-element model microstructure-based approach to study the surface roughness at the interface between zirconium and uranium-10% molybdenum.

  18. The Effect of Cutting Speed in Metallic Glass Grinding

    Science.gov (United States)

    Serbest, Erdinc; Bakkal, Mustafa; Karipcin, Ilker; Derin, Bora

    2011-01-01

    In this paper, the effects of the cutting speed in metallic glass grinding were investigated in dry conditions. The results showed that grinding forces decrease as grinding energy increase with the increasing cutting speeds. The present investigations on ground surface and grinding chips morphologies -shows that material removal and surface formation of the BMG are mainly due to the ductile chip deformation and ploughing as well as brittle fracture of some particles from the edges of the tracks. The roughness values obtained with the Cubic Boron Nitride wheels are acceptable for the grinding operation.

  19. The Effect of Cutting Speed in Metallic Glass Grinding

    International Nuclear Information System (INIS)

    In this paper, the effects of the cutting speed in metallic glass grinding were investigated in dry conditions. The results showed that grinding forces decrease as grinding energy increase with the increasing cutting speeds. The present investigations on ground surface and grinding chips morphologies -shows that material removal and surface formation of the BMG are mainly due to the ductile chip deformation and ploughing as well as brittle fracture of some particles from the edges of the tracks. The roughness values obtained with the Cubic Boron Nitride wheels are acceptable for the grinding operation.

  20. Effects of hot-rolling temperature and reduction ratio on edge cracking of hot-rolled boron-stainless steel

    International Nuclear Information System (INIS)

    The effects of hot-rolling temperature and reduction ratio on edge cracking in hot-rolled stainless steel containing 1.1% boron were investigated by using a hot-mill simulator. The main results are as follows: (1) The temperature at the side of hot-rolled steel sheets (Ts) during hot-rolling was significantly lower than at the center of hot-rolled steel sheets (Tp) just before hot rolling. (2) Ts at the start of edge cracking was not constant and increased with increasing reduction per pass. (3) The total reduction until the start of edge cracking was constant and was not dependent on Ts or the reduction per pass. (4) It is concluded that total reduction is the main factor in edge cracking due to rapid work hardening of the matrix (γphase), and owing to cavities occurring at the interface of the matrix and boride under constant strain conditions. (author)

  1. Mechanochemical Effect in ZnTe Powder Associated with Grinding

    Science.gov (United States)

    Takeuchi, Manabu

    1983-03-01

    Single crystalline ZnTe powder was mechanically ground in air using an agate mortar and pestle, and changes in the structural and photoconductive properties were studied. The mean particle size was reduced to about 5 ?m in the early stage of grinding. In the X-ray diffraction patterns, Te and ZnO lines appeared as 5 h and 8 h grindings, respectively. However, all the diffraction lines disappeared after 50 h grinding. Dark current in the ground ZnTe powder becomes maximum around 8 h grinding. This can be explained by the separation of Te associated with grinding. The original ZnTe powder showed photoconductive sensitivity to visible light. The sensitivity increased slightly in the early stage of grinding and then decreased with further grinding. Temperature dependences of the dark currents were measured in the temperature range of 170-370 K.

  2. A new transducer for local load measurements of friction and roll pressure in cold flat rolling

    DEFF Research Database (Denmark)

    Lagergren, J.; Wanheim, Tarras; Precz, W.; Henningsen, Poul; Arentoft, Mogens; Jonsson, N.G.

    2006-01-01

    The only way to establish the true rolling pressure and the true friction condition in cold rolling is to conduct measurements in the roll bite. A new transducer design is therefore proposed, in order to overcome problems in previous measurements in the past 70 years. The new idea is to increase...... recordings were selected from a steady state with no disturbance from the material flow. The transducer was able to simultaneously measure both the normal pressure and the friction stress. An estimation of the coefficient of friction was accordingly performed. The new transducer works very well, it was seen...... the contact surface of the transducer, to be larger than the arc of contact. This is in contrast to the smaller and smaller contact pin design that has been prevailing. The measurements were conducted during cold dry rolling of both copper strips and stainless steel strips in a pilot mill. The...

  3. Dressing of fine grained diamond grinding wheels for ultra precision grinding of structured molds in brittle hard materials

    Science.gov (United States)

    Bletek, Thomas; Klocke, Fritz; Hünten, Martin; Dambon, Olaf

    2013-09-01

    The manufacturing of structured molds calls for alternatives in terms of grinding wheel geometry and dressing. To manufacture geometric features in the micron range on molds, sharp edged fine grained grinding wheels can be used. A dressing procedure with metal alloy blocks is used to create sharp edged grinding wheels. This paper presents results and achieved tip radii of dressed resin bonded and metal bonded grinding wheels. Furthermore, a grinding test on a tungsten carbide mold is carried out to create a diffractive structure and the achieved form accuracy and surface roughness are presented.

  4. Development of dissimilar metal transition joint by hot bond rolling

    International Nuclear Information System (INIS)

    Metallurgically bonded transition joints which enable to connect reprocessing equipments made of superior corrosion resistant valve metals (Ti-5Ta, Zr or Ti) to stainless steel piping are required for nuclear fuel reprocessing plants. The authors have developed dissimilar transition joints made of stainless steel and Ti-5Ta, Zr or Ti with an insert metal of Ta by the hot bond rolling process of clad bars and clad pipes, using a newly developed mill called 'rotary reduction mill'. This report presents the manufacturing process of dissimilar transition joints produced from the clad pipe with three layers by the hot bond rolling. First, the method of hot bond rolling of clad pipe is proposed. Then, the mechanical and corrosion properties of the dissimilar transition joints are evaluated in detail by carrying out various tests. Finally, the rolling properties in the clad pipe method are discussed. (author)

  5. Observed Binary Fraction Sets Limits on the Extent of Collisional Grinding in the Kuiper Belt

    CERN Document Server

    Nesvorny, David; Bottke, William F; Noll, Keith; Levison, Harold F

    2011-01-01

    The size distribution in the cold classical Kuiper belt can be approximated by two idealized power laws: one with steep slope for radii R>R* and one with shallow slope for Rroll-over at R* can be the result of extensive collisional grinding in the Kuiper belt that led to the catastrophic disruption of most bodies with Rroll-over could indeed be explained by collisional grinding provided that the initial mass in large bodies was much larger than the one in the present Kuiper belt, and was dynamically depleted. In addition to the size distribution changes, our code also tracks the effects of collisions on binary systems. We find that it is generally easier to dissolve wide binary systems, such as the ones existing in the cold Kuiper belt today, than to catastrophically disrupt objects with R~R*. Thus, the binary survival sets important lim...

  6. High-speed milling of light metals

    Directory of Open Access Journals (Sweden)

    F. Cus

    2007-09-01

    Full Text Available Purpose: of this paper: Introduction applicability of high-speed cutting of light metals is presented in this paper.Design/methodology/approach: HSC is the result of numerous technical advances ensuring that milling has become faster than conventional milling and has gained importance as a cutting process. The advantages of the HSC milling are higher productivity owing to the reduction of machining times increase of the flow time of production, reduction of the number of technological operations, increase of the surface quality and longer service life of tools. The machining conditions for execution of the HSC (36000min-1 and feeding 20m/min require modernly built machine tools to meet those machining conditions.Findings: Continuous development of new materials is more and more dynamical, particularly, in the automobile, aircraft and electronic industry and in the manufacture of various mechanical parts. Also the achievements in the area of building of machines and tools, ensuring high cutting speeds (highly efficient machining have contributed to development of the process.Research limitations/implications: High quality of the surfaces, the quality of this so-called HSC milling can be compared to grinding.Practical implications: High-speed milling of light metals from aluminium and magnesium is more and more frequently used in practice. This result is high quality of the surface and shorter machining times. In some cases when machining by grinding is specified, the latter is omitted.Originality/value: The applicability of high-speed milling has proved to be successful, when aluminum and magnesium alloying materials are machined.

  7. Development of a knowledge warehouse for grinding

    OpenAIRE

    Alabed, Asmaa; Chen, Xun

    2009-01-01

    Successful of grinding in practice is highly depending on the level of expertise of the machinist and engineer. Knowledge Management might offer a strategy to keep the valuable knowledge. The main objective of Knowledge Management (KM) is to manage knowledge process, the knowledge itself could not be managed, what can be managed is the knowledge gathering, storing and organizing, retrieving, and sharing. The organization should have an effective and efficient information system to facilitate ...

  8. Robotic Grinding and Polishing Process Technology

    OpenAIRE

    Tecelli Opoz, Tahsin; Chen, Xun

    2009-01-01

    Robotic abrasive finishing inclusive of both high grinding efficiency in material removal and excellent polishing quality in material surface is a new challenging technology to meet demands for today’s and future front-end technology products. With the development of this technology, huge application areas are opened up especially in precision free-form component manufacturing, which is the key challenge in today’s aerospace, energy and biomedicine industries. In the ongoing project, ro...

  9. Precision grinding of micro-aspherical surface

    Science.gov (United States)

    Suzuki, Hirofumi; Shibutani, Hideo; Higuchi, Toshiro; Horiuchi, Osamu

    2003-05-01

    Recently, micro aspherical glass lenses are required for electric devices, optical devices and advanced optical fiber transmission equipments. The glass lenses are manufactured with glass molding method by using ceramics dies such as tungsten carbide and therefore molding dies are most important. The ceramics molding dies must be ground ultra-precisely with micro diamond wheel. In this report, our developed micro grinding methods/systems are discussed according to a variety of the workpiece shapes.

  10. Quenching simulation of steel grinding balls

    OpenAIRE

    Zapata-Hernndez, Oscar; Reyes, Luis A.; Camurri, Carlos; Carrasco, Claudia; Garza-Montes-de-Oca, Nelson F.; Cols, Rafael

    2015-01-01

    The phase transformations of high carbon steel during quenching and equalizing were modelled using commercial computer packages based on the finite element method and the kinetic transformation of steel. The model was used to predict the temperature and microstructural changes taking place within balls of two different sizes that are used for grinding mineral ores. A good correlation between the temperatures measured by inserted thermocouples and those predicted by the model was obtained afte...

  11. Production of talc nano sheets via fine grinding and sonication processes

    International Nuclear Information System (INIS)

    Fine grinding of high purity talc in jet mill at low grinding pressure was carried out by varying the feed rate and classifier rotational speed. These ground particles were sonicated in laboratory ultrasonic bath by varying the soniction period at five levels. The ground and sonicated particles were characterized in terms of particle size and particle size distribution. Mechanochemical and sonochemical effect of talc was determine via X-ray diffraction. Particle shape and surface texture of the ground and sonicated product was determined via scanning electron microscope and transmission electron microscope. The ground particle size exhibited particle size below 10 ?m with narrow size distribution. The reduction of peak intensity in (002) plane indicated the layered structure has been distorted. The sonicated talc shows that the thickness of the talc particles after the sonication process is 20 nm but the lateral particle size still remains in micron range. The reduction of the XRD peak intensity for (002) plane and thickness of sonicated talc as shown in SEM and TEM micrographs proves that fine grinding and sonication process produces talc nano sheets. (author)

  12. Freeform grinding and polishing with PROSurf

    Science.gov (United States)

    Wolfs, Franciscus; Fess, Edward; DeFisher, Scott; Torres, Josh; Ross, James

    2015-10-01

    Recently, the desire to use freeform optics has been increasing, including shapes such as torics and anamorphic aspheres. Freeform optics can be used to expand capabilities of optical systems. They can compensate for limitations in rotationally symmetric optics. These same traits that give freeform optics the ability to improve optical systems also makes them more challenging to manufacture. This holds true for grinding, polishing, and metrology. As freeform optics become more prevalent in the industry, tolerances will become more stringent, requiring deterministic manufacturing processes. To generate freeforms, it is crucial to have control over all aspects of the process. Controlling the surface definition is important for achieving a better surface finish during processing. Metrology will be required to adjust tool paths at various stages in manufacturing. During grinding, metrology will be used to adjust tool positions relative to the nominal tool path to compensate for repeatable machine and tooling error. For polishing, metrology will be used to deterministically adjust dwell relative to the amount of the error in different surface locations, allowing for convergence towards the desired surface at a uniform rate. OptiPro has developed PROSurf, a CAM software package for creating freeform tool paths and applying metrology-based corrections. The software can be used for both grinding and polishing freeform optics. The software has flexibility to allow for different methods of modelling the surface: mathematical equations, solid models, and point clouds. The software is designed to make it easier to manufacture and polish complex freeform optics.

  13. Lapping: Polishing and shear mode grinding

    Science.gov (United States)

    Brown, Norman J.

    1990-02-01

    It is the thesis of this paper that shear mode grinding (SMG), (ductile grinding, nanogrinding, fractureless grinding) is just a particular form of polishing. It may be unique in that it can involve a hard wheel of very precise dimensions compared to the soft laps usually used in polishing. Such a wheel would permit the fabrication of a precision surface on a brittle material such as glass at a precisely located and oriented position on a part. The technological and economic consequences of such a process seem important but the technical obstacles to implementing the technique are for the moment formidable. It is in production in Japan. This paper provides a bit of understanding of that process obtained by making an end run around the obstacles to view the process from the vantage point of lapping. The paper will lay out some of the concepts and terminology necessary to understand the papers that have supplied the real labor to get us to this point. It will refer to parts of this work briefly in passing so the readers who need the details know where to look, and for what, in the bibliography appended.

  14. Off-line calculation of pass schedule for hot rolling stainless steel strip and establishment of model parameters for on-line set up calculation

    International Nuclear Information System (INIS)

    In this paper, the method to calculate the roughing and finishing rolling forces is described. The way to establish the model parameters for on-line process set up calculation during developing hot rolling stainless steel strip in 2050mm hot rolling mill of Baosteel, is also introduced. Rolling test shows that the rolling forces calculated by on-line process set up model agree well with measured data. (author)

  15. Study Friction Distribution during the Cold Rolling of Material by Matroll Software

    International Nuclear Information System (INIS)

    Rolling process is one of the most important ways of metal forming. Since the results of this process are almost finished product, therefore controlling the parameters affecting this process is very important in order to have cold rolling products with high quality. Among the parameters knowing the coefficient of friction within the roll gap is known as the most significant one. That is because other rolling parameters such as rolling force, pressure in the roll gap, forward slip, surface quality of sheet, and the life of work rolls are directly influenced by friction. On the other hand, in rolling calculation due to lake of a true amount for coefficient of friction a supposed value is considered for it. In this study, a new software (Matroll), is introduced which can determine the coefficient of friction (COF) and plot the friction hills for an industrial mill. Besides, based on rolling equations, it offers about 30 rolling parameters as outputs. Having the rolling characteristics as inputs, the software is able to calculate the coefficient of friction. Many rolling passes were performed on real industrial aluminum mill. The coefficient of friction was obtained for all passes. The results are in good agreement with the findings of the other researchers

  16. Performance of Disk Mill Type Mechanical Grinder for Size Reducing Process of Robusta Roasted Beans

    Directory of Open Access Journals (Sweden)

    Sri Mulato

    2006-12-01

    Full Text Available One of improtant steps in secondary coffee processing that influence on final product quality such as consistency and uniformity is milling process. Usually, Indonesian smallholder used "lumpang" for milling coffee roasted beans to coffee powder product which caused the final product not uniformed and consistent, and low productivity. Milling process of coffee roasted beans can be done by disk mill type mechanical grinder which is used by smallholder for milling several cereals. Indonesian Coffee and Cocoa Research Institute have developed disk mill type grinding machine for milling coffee roasted beans. Objective of this research is to find performance of disk mill type grinding machine for size reducing process of Robusta roasted beans from several size dried beans and roasting level treatments. Robusta dried beans which are taken from dry processing method have 13—14% moisture content (wet basis, 680—685 kg/m3 density, and classified in 3 sizes level. The result showed that the disk mill type of grinding machine could be used for milling Robusta roasted beans. Machine hascapacity 31—54 kg/h on 5,310—5,610 rpm axle rotation and depend on roasting level. Other technical parameters were 91—98% process efficientcy, 19—31 ml/ kg fuel consumption, 0.3—1% slips, 50—55% particles had diameter less than 230 mesh and 38—44% particles had diameter bigger than 100 mesh, 32—38% lightness was increased, 0.6—12.6% density was decreased, and solubility of coffee powder between 28—30%. Cost milling process per kilogram of Robusta roasted beans which light roast on capacity 30 kg/hour was Rp362.9. Key words : Coffee roasted, Robusta, disk mill, mechanical grinder, size reduction.

  17. Recent developments in semiprocessed cold rolled magnetic lamination steel

    International Nuclear Information System (INIS)

    Over the past 10 years the magnetic property performance of semi-processed cold rolled magnetic lamination steels in North America have approached those of nonoriented, semi-processed silicon steel. This improvement was accomplished via higher alloy levels in conjunction with hot band annealing. New temper rolling strategies can produce weakly oriented steels tailored to specific applications, such as small transformers used in fluorescent lighting ballasts. Recently, production trials for 0.0138 in product cold rolled on tin mills has been undertaken. Efforts to further improve properties through a better understanding of texture control and via implementation of new production processes, such as thin slab or strip casting, continue

  18. Recent developments in semiprocessed cold rolled magnetic lamination steel

    Science.gov (United States)

    Hilinski, E. J.

    2006-09-01

    Over the past 10 years the magnetic property performance of semi-processed cold rolled magnetic lamination steels in North America have approached those of nonoriented, semi-processed silicon steel. This improvement was accomplished via higher alloy levels in conjunction with hot band annealing. New temper rolling strategies can produce weakly oriented steels tailored to specific applications, such as small transformers used in fluorescent lighting ballasts. Recently, production trials for 0.0138 in product cold rolled on tin mills has been undertaken. Efforts to further improve properties through a better understanding of texture control and via implementation of new production processes, such as thin slab or strip casting, continue.

  19. Remote-controlled grinding robot system for repair work

    International Nuclear Information System (INIS)

    A new teleoperated grinding robot has been developed which can safely and efficiently carry out grinding tasks in hostile environments using remote control and automatic control. This robot system incorporates a new method for the measurement of grinding force, in which the grinding force is measured from a moment about the grinder head's center of gravity. The influence of inertial forces caused by translational motion is removed, so that high stability is achieved. Furthermore, this robot can change the grinder's orientation to follow the surface of an object automatically, and can also grind the surface of an object into a desired shape. The new robot is expected to be applied to various types of grinding work in hostile environments. (author)

  20. Measurement of the wear rate of cast grinding balls using radioactive tracers

    International Nuclear Information System (INIS)

    The wear rate of grinding balls used in ball mills is usually hard to determine under operational conditions and little is known-about the factors determining ball life. Radioactive tracers have been used successfully to mark cast steel balls to obtain information on their life under various operating conditions for comparison with balls of different type or composition. A batch of marked steel balls has been followed through a milling operation over several weeks and statistics on wear and loss of weight have been obtained. In the test runs cobalt-60 was added to the molten metal before casting and the balls were then observed in use at an iron mine. The radioactive batch was added to a ball mill with a normal charge of about 75 tons and the mill charge was sampled at weekly intervals to pick out active balls. These balls were inspected and weighed, and the wear rate has been calculated. This procedure has proved to be a practical way of investigating wear properties under plant operating conditions. (author)

  1. Energy requirement for fine grinding of torrefied wood

    OpenAIRE

    Repellin, Vincent; Govin, Alexandre; Rolland, Mathieu; Guyonnet, Ren

    2010-01-01

    The purpose of this study is to investigate the influence of torrefaction on wood grinding energy. Wood chips were torrefied at different temperatures and durations. The energy required to obtain fine powder was measured. Particle size analyses were carried out on each powder sample. It is showed that torrefaction decreases both grinding energy and particle size distribution. A criterion to compare grindability of natural and torrefied wood is proposed. It takes into account both grinding ene...

  2. Grinding Surface Creation using Finite Element Method and Molecular Dynamics

    OpenAIRE

    Chen, X.; Opoz, Tahsin Tecelli; Oluwajobi, Akinjide O.

    2012-01-01

    This paper presents some research results of the application of finite element method and molecular dynamics in the simulation of grinding surface creation. The comparison of these two methods shows that both methods could illustrate the material removal phenomena and provide useful information of grinding mechanics, but they have different feasible application arranges depending on the level of size scales. The investigation demonstrated that rubbing hypothesis of grinding material removal m...

  3. Grinding processes and their effects on surface integrity

    OpenAIRE

    Comley, Paul

    2005-01-01

    The introduction of high performance grinding machines in combination with the latest superabrasive technology has the potential to impact significantly on existing process chains. The aim of the research was to look at both the high and low rate removal grinding processes and their effects on the surface integrity, as a means to exploit the above technologies. A major objective was to determine the feasibility of High Efficiency Deep Grinding (HEDG) in cylindrical plunge gr...

  4. The general approach to the analysis of the temperature grinding

    OpenAIRE

    Гершиков, Илья Владимирович

    2012-01-01

    The theoretical analysis of temperature reduction in grinding the rigid and elastic schemes. It is shown that when grinding therigid scheme to reduce the temperature without the performance of processing can be achieved by reducing the apparent stress of cutting (byincreasing the cutting capacity of the circle and reduce the intensity of the friction in the cutting zone) and time of contact with the fixedcircle section of the workpiece (through periodic interruption of the process grinding in...

  5. ELID-grinding of hardened steel for industrial applications

    OpenAIRE

    Qian, Jun; Torfs, Kevin; Kersschot, Bruno; Reynaerts, Dominiek

    2012-01-01

    The goal of this study is to investigate the capability of electrolytic in-process dressing (ELID)-grinding for achieving high material removal rate (MRR) on hardened steels without adversely affecting the surface quality of the workpiece. Grinding experiments with wheels of ~50μm grits on a cylindrical grinder (Studer S20) indicate that the best achievable roughness is mainly determined by the abrasive grit size and depends very little on the grinding technique (ELID versus conventional g...

  6. Fundamentals of grinding : surface conditions of ground materials

    OpenAIRE

    Hegeman, Johannes Bernardus Jan-Willem,

    2000-01-01

    This thesis describes the research on the fundamental and physical aspects of the grinding process of hard and brittle materials. The objective of this research is to develop a physical model in order to explain and predict the change in functional properties. Besides that, such a model can be used to optimise the grinding process. Two different materials, cemented carbide and MnZn ferrite, were used in order to verify the grinding model. ... Zie: Summary

  7. CHARACTERIZATION OF THE FRICTION CONDITIONS IN THE FINISHING STANDS OF A HOT STRIP MILL

    Directory of Open Access Journals (Sweden)

    Antonio Augusto Gorni

    2012-06-01

    Full Text Available The decrease in hot strength or even rolling load as strain increases in some stands of the finishing hot strip mill with no metallurgical reasons is a relatively common event. Apparently this fact is associated with modification in the tribological conditions between rolling stock and work roll surfaces due to unexpected interactions with scale. The aim of this work is to determine the values of the friction coefficient in the several stands of the finishing hot strip mill at Usiminas-Cubato, as well to determine quantitative relationships between this coefficient and relevant process parameters, like strain degree and peripherical work roll speed.

  8. Kinetics of wet grinding of submicrone tungsten carbide powders

    International Nuclear Information System (INIS)

    The influence of temperature of ultradisperse tungsten carbidizing treatment on dispersion, fine structure and character of carbide frinding in the process of mixture preparation with 8%Co was studied. Considerable difference in grinding kinetics for submicron doped and standard tungsten carbide during wet grinding was ascertained. It is expressed in a less intensive growth of characteristics of dispersion and X-ray band width of submicron powder. It proved possible to reduce grinding time of mixtures on the basis of such powders. A change in grinding ability of finely dispersed tungsten carbide with an increase in the temperature of its production up to 1600-1700 deg C was detected

  9. Minimizing the edge buckling of the cold roll-forming process

    Science.gov (United States)

    Cavaguti, M.; Ferreira, J. V.

    2010-06-01

    In this work, the cold roll-forming process was numerically simulated by MSC SuperForm 2002 software based on finite element method. The strips were modelled with U-profile and a pre-punched hole located at the web zone was introduced. Two different configurations of the roll-forming mills were simulated, named as the Conventional and Curved. The conventional roll-forming mill was obtained by using the same diameters of the bottom rolls. The downhill roll-forming mill was achieved by increasing the diameters of the bottom rolls. This study investigated the occurrence of edge buckling in the hole lateral edge of the pre-punched sheet during the forming process. It could be concluded that, during the cold roll-forming process, reducing or even eliminating the compression stress in the web zone by the downhill roll-forming mill is possible to minimize occurrence of the edge buckling in the hole lateral edge of the pre-punched sheet during the forming process.

  10. Minimizing the edge buckling of the cold roll-forming process

    International Nuclear Information System (INIS)

    In this work, the cold roll-forming process was numerically simulated by MSC SuperForm 2002 software based on finite element method. The strips were modelled with U-profile and a pre-punched hole located at the web zone was introduced. Two different configurations of the roll-forming mills were simulated, named as the Conventional and Curved. The conventional roll-forming mill was obtained by using the same diameters of the bottom rolls. The downhill roll-forming mill was achieved by increasing the diameters of the bottom rolls. This study investigated the occurrence of edge buckling in the hole lateral edge of the pre-punched sheet during the forming process. It could be concluded that, during the cold roll-forming process, reducing or even eliminating the compression stress in the web zone by the downhill roll-forming mill is possible to minimize occurrence of the edge buckling in the hole lateral edge of the pre-punched sheet during the forming process.

  11. Quenching simulation of steel grinding balls

    Energy Technology Data Exchange (ETDEWEB)

    Zapata-Hernandez, O.; Reyes, L. A.; Camurri, C.; Carrasco, C.; Garza-Monte-de-Oca, F.; Colas, R.

    2015-07-01

    The phase transformations of high carbon steel during quenching and equalizing were modelled using commercial computer packages based on the finite element method and the kinetic transformation of steel. The model was used to predict the temperature and microstructural changes taking place within balls of two different sizes that are used for grinding mineral ores. A good correlation between the temperatures measured by inserted thermocouples and those predicted by the model was obtained after modifying the thermal conductivity of the steel within the temperature domain at which mixed phases are present. The phase transformations predicted were confirmed by metallographic analyses. (Author)

  12. Application of copper nanoparticles as additions to a grinding fluid to increase the quality of grinding of magnetic ceramic materials

    Science.gov (United States)

    Krevchik, V. D.; Skryabin, V. A.; Sokolov, A. V.; Men'shova, S. B.; Artemov, I. I.; Prokof'ev, M. V.; Karasev, N. Ya.

    2015-12-01

    The influence of copper nanoparticles in a grinding fluid (GF) used for grinding on the characteristics of the surface layer of ferrite parts and their service properties is studied. Profilograms of the ground surfaces and their roughness are measured. The electromagnetic losses of 10000NN ferrite parts ground in an GF medium with copper nanoparticles are estimated. The use of metal nanoparticles as additions to a grinding fluid is shown to be useful for processing of brittle nonmetallic materials.

  13. A new approach for remediation of As-contaminated soil: ball mill-based technique.

    Science.gov (United States)

    Shin, Yeon-Jun; Park, Sang-Min; Yoo, Jong-Chan; Jeon, Chil-Sung; Lee, Seung-Woo; Baek, Kitae

    2016-02-01

    In this study, a physical ball mill process instead of chemical extraction using toxic chemical agents was applied to remove arsenic (As) from contaminated soil. A statistical analysis was carried out to establish the optimal conditions for ball mill processing. As a result of the statistical analysis, approximately 70 % of As was removed from the soil at the following conditions: 5 min, 1.0 cm, 10 rpm, and 5 % of operating time, media size, rotational velocity, and soil loading conditions, respectively. A significant amount of As remained in the grinded fine soil after ball mill processing while more than 90 % of soil has the original properties to be reused or recycled. As a result, the ball mill process could remove the metals bound strongly to the surface of soil by the surface grinding, which could be applied as a pretreatment before application of chemical extraction to reduce the load. PMID:26667646

  14. Rolling friction and bistability of rolling motion

    CERN Document Server

    Pschel, T; Brilliantov, N; Zaikin, A; Poeschel, Thorsten; Schwager, Thomas; Brilliantov, Nikolai; Zaikin, Alexei

    2005-01-01

    The rolling motion of a rigid cylinder on an inclined flat viscous surface is investigated and the nonlinear resistance force against rolling, $F_R(v)$, is derived. For small velocities $F_R(v)$ increases with velocity due to increasing deformation rate of the surface material. For larger velocity it decreases with velocity due to decreasing contact area between the rolling cylinder and the deformed surface. The cylinder is, moreover, subjected to a viscous drag force and stochastic fluctuations due to a surrounding medium (air). For this system, in a wide range of parameters we observe bistability of the rolling motion. Depending on the material parameters, increasing the noise level may lead to increasing or decreasing average velocity.

  15. Recrystallization of niobium stabilized ferritic stainless steel during hot rolling simulation by torsion tests

    Directory of Open Access Journals (Sweden)

    Flávia Vieira Braga

    2016-01-01

    Full Text Available The aim of this study was to investigate the effect of finishing hot rolling temperature in promoting interpass recrystallization on a Nb-stabilized AISI 430 ferritic stainless steel. Torsion tests were performed in order to simulate the Steckel mill rolling process by varying the temperature ranges of the finishing passes. Interrupted torsion test were also performed and interpass recrystallization was evaluated via optical microscopy and electron backscatter diffraction (EBSD. As a result of this work, it has been established, within the restrictions of a Steckel mill rolling schedule, which thermomechanical conditions mostly favor SRX.

  16. Mechanical alloying of powder materials by ultrasonic milling.

    Science.gov (United States)

    Mordyuk, B N; Prokopenko, G I

    2004-04-01

    An ultrasonic grinding mill was designed. It permits to carry out simultaneously intensive ultrasonic, mechanical and cavitation treatments of powder materials that in turn leads to sharp acceleration of diffusion, mass-transfer processes and solid phase reactions due to crystallite size and structure changing. It was shown that meta-stable non-equilibrium solid solution (Cu+Ni+Fe, Fe+C), and crystalline structure transformed (Fe(4)N: fcc-hcp transformation) powders could be obtained for the much shorter time in compare with traditional mechanical alloying in planetary ball mill. PMID:15047259

  17. Evaluation of grinding methods for pellets preparation aiming at the analysis of plant materials by laser induced breakdown spectrometry.

    Science.gov (United States)

    Gomes, Marcos da Silva; Santos, Drio; Nunes, Lidiane Cristina; de Carvalho, Gabriel Gustinelli Arantes; Leme, Flvio de Oliveira; Krug, Francisco Jos

    2011-09-30

    It has been demonstrated that laser induced breakdown spectrometry (LIBS) can be used as an alternative method for the determination of macro (P, K, Ca, Mg) and micronutrients (B, Fe, Cu, Mn, Zn) in pellets of plant materials. However, information is required regarding the sample preparation for plant analysis by LIBS. In this work, methods involving cryogenic grinding and planetary ball milling were evaluated for leaves comminution before pellets preparation. The particle sizes were associated to chemical sample properties such as fiber and cellulose contents, as well as to pellets porosity and density. The pellets were ablated at 30 different sites by applying 25 laser pulses per site (Nd:YAG@1064 nm, 5 ns, 10 Hz, 25J cm(-2)). The plasma emission collected by lenses was directed through an optical fiber towards a high resolution echelle spectrometer equipped with an ICCD. Delay time and integration time gate were fixed at 2.0 and 4.5 ?s, respectively. Experiments carried out with pellets of sugarcane, orange tree and soy leaves showed a significant effect of the plant species for choosing the most appropriate grinding conditions. By using ball milling with agate materials, 20 min grinding for orange tree and soy, and 60 min for sugarcane leaves led to particle size distributions generally lower than 75 ?m. Cryogenic grinding yielded similar particle size distributions after 10 min for orange tree, 20 min for soy and 30 min for sugarcane leaves. There was up to 50% emission signal enhancement on LIBS measurements for most elements by improving particle size distribution and consequently the pellet porosity. PMID:21872013

  18. Occlusal Grinding Pattern during Sleep Bruxism and Temporomandibular Disorder

    Directory of Open Access Journals (Sweden)

    Yeni Wijaya

    2013-09-01

    Full Text Available Sleep Bruxism is a significant etiology of temporomandibular disorder (TMD and causes many dental or oral problems such as tooth wear or facet. There is no study analyzing the relationship between sleep bruxism and TMD. Objective: To investigate any relationship between occlusal grinding pattern during sleep bruxism and temporomandibular disorder. Methods: A cross-sectional study involving 30 sleep bruxism patients attended the Faculty Dentistry Universitas Indonesia Teaching Hospital (RSGMP FKG UI. Completion of 2 forms of ID-TMD index and questionnaire from American Academy of Sleep Medicine were done. BruxChecker was fabricated and used for two nights to record the occlusal grinding pattern. The occlusal grinding pattern was categorized into laterotrusive grinding (LG and mediotrusive side. Further divisons of LG were: incisor-canine (IC, incisor-caninepremolar (ICP and incisor-canine-premolar-molar (ICPM. Mediotrusive side was classified as mediotrusive contact (MC and mediotrusive grinding (MG. Results: It was found that occlusal grinding pattern in non-TMD subjects were IC+MC, in subjects with mild TMD were ICP+MG and in subjects with moderate TMD were ICP+MG and ICPM+MG. TMJ was more significantly affected by ICP and ICPM grinding pattern than that of IC. Conclusion: There was a significant relationship between occlusal grinding pattern during sleep bruxism and TMD.DOI: 10.14693/jdi.v20i2.149

  19. Validation of the Hot Strip Mill Model

    Energy Technology Data Exchange (ETDEWEB)

    Richard Shulkosky; David Rosberg; Jerrud Chapman

    2005-03-30

    The Hot Strip Mill Model (HSMM) is an off-line, PC based software originally developed by the University of British Columbia (UBC) and the National Institute of Standards and Technology (NIST) under the AISI/DOE Advanced Process Control Program. The HSMM was developed to predict the temperatures, deformations, microstructure evolution and mechanical properties of steel strip or plate rolled in a hot mill. INTEG process group inc. undertook the current task of enhancing and validating the technology. With the support of 5 North American steel producers, INTEG process group tested and validated the model using actual operating data from the steel plants and enhanced the model to improve prediction results.

  20. Three-dimensional measurement and characterization of grinding tool topography

    Science.gov (United States)

    Cui, Changcai; Blunt, Liam; Jiang, Xiangqian; Xu, Xipeng; Huang, Hui; Ye, Ruifang

    2013-01-01

    A comprehensive 3-dimensional measurement and characterization method for grinding tool topography was developed. A stylus instrument (SOMICRONIC, France) was used to measure the surface of a metal-bonded diamond grinding tool. The sampled data was input the software SurfStand developed by Centre for Precision Technology (CPT) for reconstruction and further characterization of the surface. Roughness parameters pertaining to the general surface and specific feature parameters relating to the grinding grits, such as height and angle peak curvature have been calculated. The methodology of measurement has been compared with that using an optical microscope. The comparison shows that the three-dimensional characterization has distinct advantages for grinding tool topography assessment. It is precise, convenient and comprehensive so it is suitable for precision measurement and analysis where an understanding of the grinding tool and its cutting ability are required.

  1. Investigations of spherical grinding parameters on circularity error, finished diameter, and grinding forces for porous polyurethane foam

    Directory of Open Access Journals (Sweden)

    Isarawit Chaopanich

    2010-07-01

    Full Text Available The aim of this study was to examine the effect of grinding variables on the circularity error, finished diameter, andgrinding forces of porous polyurethane foam (PPUF. A cube of PPUF having the size of 21 mm was transformed into a roundshape using a vertical wheel grinding with the circular groove pad developed. The grinding speed (Vs of the wheel wasvaried between 1.41 and 5.18 m/s. The cross head speed of the circular groove pad (f was controlled at 1, 3, 5 mm/min. Theabrasive grit size (A of 20 and 53 μm made of silicon carbide were applied. Two replications of experiment were randomlyperformed. Diameter and circularity error of the ground specimen were determined by vision measuring machine. The tangentialand normal forces of grinding were obtained using a dynamometer. The experimental data were statistically analyzed. The study found that (1 the grinding speed could remarkably affect the circularity error, finished diameter, and grinding forces,(2 the grinding speed ranged between 2.83 and 3.77 m/s could contribute to sphere shape specimens, and (3 the grinding speed of 3.30 m/s, cross head speed of 1 mm/min, and abrasive grit size of 20 μm provided the least circularity error.

  2. Cocrystal Formation through Mechanochemistry: from Neat and Liquid-Assisted Grinding to Polymer-Assisted Grinding.

    Science.gov (United States)

    Hasa, Dritan; Rauber, Gabriela Schneider; Voinovich, Dario; Jones, William

    2015-06-15

    Mechanochemistry is an effective method for the preparation of multicomponent crystal systems. In the present work, we propose an alternative to the established liquid-assisted grinding (LAG) approach. Polymer-assisted grinding (POLAG) is demonstrated to provide a new class of catalysts for improving reaction rate and increasing product diversity during mechanochemical cocrystallization reactions. We demonstrate that POLAG provides advantages comparable to the conventional liquid-assisted process, whilst eliminating the risk of unwanted solvate formation as well as enabling control of resulting particle size. It represents a new approach for the development of functional materials through mechanochemistry, and possibly opens new routes toward the understanding of the mechanisms and pathways of mechanochemical cocrystal formation. PMID:25939405

  3. Chirality Change by Grinding Crystals in Solution

    International Nuclear Information System (INIS)

    One of the greatest unsolved problems in chemistry is the origin of homochirality in the biosphere, that is, the fact that l-amino acids and d-sugars dominate in biology, while laboratory experiments with stereoselective reactions only produce racemic mixtures. Several models have been proposed to address the question of how enantiomerically pure solutions or crystalline phases could have emerged from a presumably racemic prebiotic world. Here we show that two populations of amino acid crystals of 'left' and 'right' hand cannot coexist in solution: one of the chiral populations disappears in an irreversible autocatalytic process that nurtures the other one. Final and complete chiral purity seems to be an inexorable fate in our systems, under grinding, in the course of the common process of growth-dissolution. This unexpected chiral symmetry breaking has become firmly established but the underlying mechanism is being debated and we have no definitive answer.

  4. Rolling Shutter Motion Deblurring

    KAUST Repository

    Su, Shuochen

    2015-06-07

    Although motion blur and rolling shutter deformations are closely coupled artifacts in images taken with CMOS image sensors, the two phenomena have so far mostly been treated separately, with deblurring algorithms being unable to handle rolling shutter wobble, and rolling shutter algo- rithms being incapable of dealing with motion blur. We propose an approach that delivers sharp and undis torted output given a single rolling shutter motion blurred image. The key to achieving this is a global modeling of the camera motion trajectory, which enables each scanline of the image to be deblurred with the corresponding motion segment. We show the results of the proposed framework through experiments on synthetic and real data.

  5. The Grinding Wheel Performance in the Transverse Cylindrical Grinding of an Eutetic Alloy

    Directory of Open Access Journals (Sweden)

    Bianchi Eduardo Carlos

    2002-01-01

    Full Text Available This paper presents a research in which the performance of two different grinding wheels (a conventional and a CBN wheel was evaluated in a transverse cylindrical grinding of a eutectic alloy. Three cutting conditions were tested: rough, semi-finishing and finishing. As evaluating parameters, the cutting force, the roughness and the wheel wear were measured. As a result, the best values of the cutting force and the roughness were obtained when grinding with the conventional wheel, due to the best dressing operation performed, for all the cutting conditions. The CBN presented the best G ratio values. Although, the G ratio values observed for the CBN wheel were lower than the expected one due to the non-effective dressing operation applied. In the conditions tested, in terms of cutting force and roughness, the conventional wheel is the best choice. In terms of G ratio, a cost analysis is crucial to determine if the differences observed among the wheels can justify the use of the CBN wheel. In a positive case, the dressing operation must be improved.

  6. Ultraprecision, high stiffness CNC grinding machines for ductile mode grinding of brittle materials

    Science.gov (United States)

    McKeown, Patrick A.; Carlisle, Keith; Shore, Paul; Read, R. F.

    1990-10-01

    Under certain controlled conditions it is now possible to machine brittle materials such as glasses and ceramics using single or multi-point diamond tools (grinding), so that material is removed by plastic flow, leaving crack-free surfaces. This process is called 'shear' or 'ductile' mode grinding. It represents a major breakthrough in modern manufacturing engineering since it promises to enable: - complex optical components, both transmission and reflecting to be generated by advanced CNC machines with very little (or even zero) subsequent polishing. - complex shaped components such as turbine blades, nozzle guide vanes, etc. to be finish machined after near net shape forming, to high precision in advanced ceramics such as silicon nitride, without inducing micro-cracking and thus lowering ultimate rupture strength and fatigue life. Ductile mode "damage free" grinding occurs when the volume of materials stressed by each grit of the grinding wheel is small enough to yield rather than exhibit brittle fracture, i.e. cracking. In practice, this means maintaining the undeformed chip thickness to below the ductile-brittle transition value; this varies from material to material but is generally in the order of 0.1 pm or 100 nm, (hence the term "nanogrinding" is sometimes used) . Thus the critical factors for operating successfully in the ductile regime are machine system accuracy and dynamic stiffness between each grit and the workpiece. In detail this means: (i) High precision 'truing' of the diamond grits, together with dressing of the wheel bond to ensure adequate ' openness'; (ii) Design and build of the grinding wheel spindle with very high dynamic stiffness; error motions, radial and axial, must be considerably less than 100 nfl. (iii) Design and build of the workpiece carriage motion system with very high dynamic stiffness; error motions, linear or rotary, must be well within 100 nm. (iv) Smooth, rumble-free, high-stiffness servo-drives controlling the motions which form the chip. In general, and as a rule of thumb, a machine "loop-stiffness" (between tool and workpiece) not less than 300 N,4im (static) is necessary.

  7. Effect of Mechanical Grinding and Ionic Liquid Pre-Treatment on Oil Palm Frond

    International Nuclear Information System (INIS)

    The present study was set to investigate the chemical structural group of different particle size of Oil palm frond (OPF) after mechanical and Ionic liquid (IL) pretreatment by FTIR analysis. The particle sizes range of biomass used were 0-75, 75-125, 125-180, 180-250 and 250-355 μm which were prepared through mechanical grinding process by using an analytical mill. IL used in this experiment was 1-ethyl-3-methylimidazolium chloride [EMIM][Ac] with two different concentration of 1M and 3M. Pretreatment by IL was done on BioshakeIQ for 3 hours at 800 rpm and 85 degree Celsius. The pretreated OPF was then analyzed using FTIR spectroscopy in order to evaluate the performance of mechanical grinding and IL pretreatment based on the change observed in chemical structure through functional group existed. It was found that after size reduction through grinding process, the spectra between all particle sizes obtained did not differ much except for particle size range of 75-125 μm. The particle size range showed on much characteristics of cellulose due to the broad peak within the 3600-3100 cm-1 which stand for O-H bonding. However, when the FTIR spectra were compared between before and after IL pretreatments, there were some different in peaks trend which explained there were some chemical structure changes within the OPF samples. There were some appearances and disappearances of certain peak were observed after the IL pretreatment especially the peak at band near 1700 cm-1 and 1550 cm-1. (author)

  8. Quadropol RD. The world's first vertical roller mill with driven rollers; Quadropol RD. Weltweit erste Vertikalrollenmuehle mit angetriebenen Rollen

    Energy Technology Data Exchange (ETDEWEB)

    Schmitz, Thomas [ThyssenKrupp Resource Technologies GmbH, Neubeckum (Germany). Enginering Cement Production; Berger, Markus [ThyssenKrupp Resource Technologies GmbH, Neubeckum (Germany). R and D Automation; Fornefeld, Heiko [ThyssenKrupp Resource Technologies GmbH, Neubeckum (Germany). Engineering Design Roller Mills; Kimmeyer, Ludger [ThyssenKrupp Resource Technologies GmbH, Neubeckum (Germany). R and D Communication Technology

    2013-11-01

    The cement industry increasingly requires energy-efficient grinding systems for the production of ultra-fine cements. The vertical mill with driven rollers meets this requirement thanks to the innovative design of its drive system. Although no CO{sub 2} emissions are released in the mill itself, the mill contributes to reducing specific CO{sub 2} emissions in the production of ultra-fine composite cements. (orig.)

  9. IMPROVING ENERGY EFFICIENCY VIA OPTIMIZED CHARGE MOTION AND SLURRY FLOW IN PLANT SCALE SAG MILLS

    Energy Technology Data Exchange (ETDEWEB)

    Raj K. Rajamani; Sanjeeva Latchireddi; Sravan K. Prathy; Trilokyanath Patra

    2005-12-01

    The U.S. mining industry operates approximately 80 semi-autogenesis grinding mills (SAG) throughout the United States. Depending on the mill size the SAG mills draws between 2 MW and 17 MW. The product from the SAG mill is further reduced in size using pebble crushers and ball mills. Hence, typical gold or copper ore requires between 2.0 and 7.5 kWh per ton of energy to reduce the particle size. Considering a typical mining operation processes 10,000 to 100,000 tons per day the energy expenditure in grinding is 50 percent of the cost of production of the metal. A research team from the University of Utah is working to make inroads into saving energy in these SAG mills. In 2003, Industries of the Future Program of the Department of Energy tasked the University of Utah team to build a partnership between the University and the mining industry for the specific purpose of reducing energy consumption in SAG mills. A partnership was formed with Cortez Gold Mines, Kennecott Utah Copper Corporation, Process Engineering Resources Inc. and others. In the current project, Cortez Gold Mines played a key role in facilitating the 26-ft SAG mill at Cortez as a test mill for this study. According to plant personnel, there were a number of unscheduled shut downs to repair broken liners and the mill throughput fluctuated depending on ore type. The University team had two softwares, Millsoft and FlowMod to tackle the problem. Millsoft is capable of simulating the motion of charge in the mill. FlowMod calculates the slurry flow through the grate and pulp lifters. Based on this data the two models were fine-tuned to fit the Cortez SAG will. In the summer of 2004 a new design of shell lifters were presented to Cortez and in September 2004 these lifters were installed in the SAG mill. By December 2004 Cortez Mines realized that the SAG mill is drawing approximately 236-kW less power than before while maintaining the same level of production. In the first month there was extreme cycling and operators had to learn more. Now the power consumption is 0.3-1.3 kWh/ton lower than before. The actual SAG mill power draw is 230-370 kW lower. Mill runs 1 rpm lesser in speed on the average. The re-circulation to the cone crusher is reduced by 1-10%, which means more efficient grinding of critical size material is taking place in the mill. All of the savings have resulted in reduction of operating cost be about $0.023-$0.048/ ton.

  10. The Ball Mill Driving Device Fault and the Main Bearing Lubrication Analysis

    Directory of Open Access Journals (Sweden)

    Tong Junfeng

    2013-04-01

    Full Text Available This article from the analysis of the power consumption of the ball mill and the work characteristic of the motor, analyzes the fault reason of ball mill transmission equipment. The paper mainly deals with a side-transmission ball mill. The main fault is about the breakdown in the elastic rubber coupling of the transmission system. It is found from the analysis of the real cases and data that the actual power consumption is increased and it is caused by the overload. The main parameters which influence the ball mill power consumption are load of the mill, feed material mass, ball mill rotational speed and friction. The main part of power consumption for ball mill is used to elevating grinding body and material, a portion is used to overcome the friction force between the main bearing. Under the conditions in which the load of the mill and feed material mass are kept the same, the parameters which influence the ball mill power consumption are rotational speed and friction status. When the ball mill voltage decreased, according to the motor characteristics, its rotation speed will decrease, which will disrupt the hydrodynamic lubrication state of the hollow shaft and spherical surface, so that the power consumption of the ball mill increase. The larger power leads to the transmission fault. This paper also put forward to make sure kept the ball mill main bearing lubrication status.

  11. Production of scallop shell nanoparticles by mechanical grinding as a formaldehyde adsorbent

    International Nuclear Information System (INIS)

    Scallop shells, which are a waste product in the seafood industry, are disposed more than 200,000 ton per year in Hokkaido, Japan. We report effective uses and simple application for discarded shells as a formaldehyde adsorbent. The adsorption performance of scallop shells to remove formaldehyde vapor is investigated. Planetary ball milling under dry conditions and subsequent water addition realize shells with a crystallite size (3590 nm) and equivalent size of the specific surface area (41191 nm) in the nanometer range. The comminution properties of the scallop shells, especially the grinding limit, are estimated via a semi-theoretical consideration for the grinding limit. Additionally, the adsorbed amount of gaseous formaldehyde using a self-designed adsorption line is estimated. The nanosized scallop shells exhibit an excellent adsorption performance rather than the feed shell, and the adsorbed amount is positively correlated with the specific surface area of the shell. Hence, scallop shells have potential to adsorb volatile organic compounds.

  12. Properties of nano-structured pure Al produced by mechanical grinding and spark plasma sintering

    International Nuclear Information System (INIS)

    Air-atomised pure aluminium powder was mechanically grinded (MG) using a vibrational ball mill, and mechanically grinded powder was sintered by spark plasma sintering (SPS). Solid-state reactions of MG powder after various heat treatments were studied by X-ray diffraction (XRD). The mechanical properties of the SPS materials were evaluated by hardness and compression testing. Characterisations of the solid-state reactions between the MG powder and process control agent (PCA) after heating at temperatures from 573 to 873 K for 24 h suggested the following products. No solid-state reaction was observed after heating up to 573 K for 24 h. Formation of γ-Al2O3 occurred in the 4 h MG powder after heating at 773 K for 24 h, whereas the mixture of γ-Al2O3 and Al4C3 was observed in the 8 h MG powder after heating at 773 K for 24 h. The full density of the SPS material was obtained with the condition of applied pressure at 49 MPa at 873 K for 1 h. The Vickers hardness of the SPS material produced from no MG process and 64 h MG powders exhibited HV39 and HV159, respectively, and the SPS material based on no MG process and 8 h MG powders showed room temperature compressive proof stresses of 173 and 440 MPa, respectively

  13. MECHANICAL GRINDING OF SOLID POWDER MATERIALS

    Directory of Open Access Journals (Sweden)

    Dmitrenko D. V.

    2015-10-01

    Full Text Available The article is dedicated to the determination of conditions for solid bodies’ fragmentation, providing minimal size of particles by means of their mechanical dispersion through the example of powders of titanium carbide (TiC, cubic boron nitride – borazon (CBN and boron carbide (B4C. The theoretical and practical aspects of the process of mechanical fragmentation of particles of solid powder materials in ball mill for their further utilization in furnace charge for high-speed gas-flame sputtering of wear-resistant composite materials are examined in the article. Methods of preliminary calculation of minimum allowable size of solid particles of powder materials during mechanical fragmentation, based upon Griffiths’ mechanical theory of rapture using experimental data for hardness of material and its yield are proposed and theoretically substantiated. There we have the results of experiments on mechanical fragmentation of titanium carbide in attritor, boron carbide and cubic boron nitride in centrifugal planetary mill, confirming correctness of theoretical propositions and calculations are set out. Recommendations on mechanical fragmentation of solid powder materials in ball mills are formulated as well

  14. Eco-efficiency of grinding processes and systems

    CERN Document Server

    Winter, Marius

    2016-01-01

    This research monograph aims at presenting an integrated assessment approach to describe, model, evaluate and improve the eco-efficiency of existing and new grinding processes and systems. Various combinations of grinding process parameters and system configurations can be evaluated based on the eco-efficiency. The book presents the novel concept of empirical and physical modeling of technological, economic and environmental impact indicators. This includes the integrated evaluation of different grinding process and system scenarios. The book is a valuable read for research experts and practitioners in the field of eco-efficiency of manufacturing processes but the book may also be beneficial for graduate students.

  15. Numerical analysis of small recessed silicon carbide grinding wheels

    Directory of Open Access Journals (Sweden)

    M.J. Jackson

    2010-11-01

    Full Text Available Purpose: Silicon carbide grinding wheels are tools used in manufacturing industry to form precision componentsand continue to be used to increase production rates due to their ability to remove high volumes of material athigh speeds. There is a demand to increase the speed of rotation of the grinding wheel in order to achieve highremoval rates. The increase in speed creates a situation where the grinding machine and the operator are subjectedto a possible catastrophic failure of the wheel due to the stresses generated in the coarse brittle structure of thevitrified grinding wheel. The study focused on building and analyzing computer models of grinding wheels withrecessed features spinning at different rotational speeds. By employing a computational approach, it was possibleto determine the maximum principal stresses in the wheel together with the location of the stresses. The geometryof vitrified wheels considered included a plain-sided rotating wheel and a recessed rotating wheel.Design/methodology/approach: The paper shows how stresses and factors of safety are calculated in order topredict the bursting speeds of small recessed SiC grinding wheels. The main methods used include finite elementanalysis and mechanical testing of abrasive materials. The approach of the paper is to integrate the use of numericalanalysis techniques and experimental techniques to predict the safe operating conditions of SiC abrasive products.Findings: Calculations were conducted to determine maximum stress in parallel-sided and recessed cup wheels.Relevant factors of safety and bursting speed were also calculated and compared with experimental data. Thepaper proves the usefulness and applicability of a method developed for taking account of stress concentrationsat the recess of small cup-shaped silicon carbide grinding wheels.Research limitations/implications: The paper is limited to analyzing small recessed SiC grinding wheels.Further work should focus on large recessed wheels and wheels made with different abrasive grains and bondingmaterials. The type of porosity distribution should also be investigated.Practical implications: The paper shows how numerical methods are used to design safe operating conditionsfor brittle grinding wheels. The methods used show that numerical techniques are suitable for calculating themeasures of safety that are an important consideration when designing high speed rotating grinding wheels thatcan be devastating if allowed to fail in service.Originality/value: The originality in the paper is revealed owing to the fact that fracture mechanics principlesare applied to the prediction of failure of rotating grinding wheels. The paper is of practical importance tomechanical designers who are responsible for the safe design of grinding wheels.

  16. Annular Fuel Pellet Fabrication without Surface Grinding

    International Nuclear Information System (INIS)

    In order to increase the power density of a Pressurized Water Reactor fuel assembly, a dual cooled annular fuel has been seriously considered as a favorable option. A configurationally inherent merit of an annular fuel such as an increased heat transfer area and a thin pellet thickness results in a lot of advantages from the point of a fuel safety and its economy. Annular pellet with precisely controlled diametric tolerance is an essential element to actualize the dual cooled fuel. An hour-glassing usually occurs in a sintered cylindrical PWR fuel pellet fabricated by a conventional double-acting press due to an inhomogeneous green density distribution in a powder compact. An inhomogeneous green density distribution in a powder compact is attributed to granule-granule frictions and granule to pressing mold wall frictions. Frictions result in an irregular pressing load distribution in a powder compact. Thus, a sintered pellet undergoes a centerless grinding process in order to secure diametric tolerance specifications. In the case of an annular pellet fabrication using a conventional double-acting press, the same hour-glass shape would probably occur. The green density gradient in a powder compact depends on the pressing direction and the amount of the sintering deformation is inversely proportional to the initial green density. In case of a double-acting pressing, the middle portion of the green pellet has a lower green density than those of the top and the bottom portions of the green pellet. However, the top or the bottom portion which is far from the acting punch surface has the lowest green density in a single-acting pressing. In the present study, we are trying to find a way to minimize the diametric tolerance of the sintered annular pellet without surface grinding. Annular compacting mold with inclined inner and outer surfaces was designed by considering a difference in the diametric changes depending on the pellet height during sintering. By using a compacting mold with inclined surfaces and a single-acting press, an annular pellet can be fabricated successfully with a tolerance of less than ± 13 μm which is the diametric tolerance specification of a conventional PWR fuel pellet

  17. High coercivity induced by mechanical milling in cobalt ferrite powders

    Energy Technology Data Exchange (ETDEWEB)

    Ponce, A.S. [Instituto de Fsica, Universidade Federal de Mato Grosso, 78060-900, Cuiab, MT (Brazil); Chagas, E.F., E-mail: efchagas@fisica.ufmt.br [Instituto de Fsica, Universidade Federal de Mato Grosso, 78060-900, Cuiab, MT (Brazil); Prado, R.J. [Instituto de Fsica, Universidade Federal de Mato Grosso, 78060-900, Cuiab, MT (Brazil); Fernandes, C.H.M.; Terezo, A.J. [Departamento de Qumica, Universidade Federal do Mato Grosso, 78060-900, Cuiab, MT (Brazil); Baggio-Saitovitch, E. [Centro Brasileiro de Pesquisas Fsicas, Rua Xavier Sigaud 150 Urca. Rio de Janeiro (Brazil)

    2013-10-15

    In this work we report a study of the magnetic behavior of ferrimagnetic oxide CoFe{sub 2}O{sub 4} treated by mechanical milling with different grinding balls. The cobalt ferrite nanoparticles were prepared using a simple hydrothermal method and annealed at 500 C. The non-milled sample presented coercivity of about 1.9 kOe, saturation magnetization of 69.5 emu/g, and a remanence ratio of 0.42. After milling, two samples attained coercivity of 4.2 and 4.1 kOe, and saturation magnetization of 67.0 and 71.4 emu/g respectively. The remanence ratio M{sub R}/M{sub S} for these samples increase to 0.49 and 0.51, respectively. To investigate the influence of the microstructure on the magnetic behavior of these samples, we used X-ray powder diffraction (XPD), transmission electron microscopy, and vibrating sample magnetometry. The XPD analysis by the WilliamsonHall plot was used to estimate the average crystallite size and strain induced by mechanical milling in the samples. - Highlights: Magnetic behavior of milled CoFe{sub 2}O{sub 4} is studied. The coercivity is increase of about 150%. The remanence ratio are increase to all milled samples. The strain and pinning effects are observed in milled samples.

  18. Surface topography of parallel grinding process for nonaxisymmetric aspheric lens

    International Nuclear Information System (INIS)

    Workpiece surface profile, texture and roughness can be predicted by modeling the topography of wheel surface and modeling kinematics of grinding process, which compose an important part of precision grinding process theory. Parallel grinding technology is an important method for nonaxisymmetric aspheric lens machining, but there is few report on relevant simulation. In this paper, a simulation method based on parallel grinding for precision machining of aspheric lens is proposed. The method combines modeling the random surface of wheel and modeling the single grain track based on arc wheel contact points. Then, a mathematical algorithm for surface topography is proposed and applied in conditions of different machining parameters. The consistence between the results of simulation and test proves that the algorithm is correct and efficient. (authors)

  19. Changes in Magnetic Susceptibility of Chalcopyrite Induced by Vibration Grinding

    OpenAIRE

    Baláž, Peter; Tkáčová, Klára

    1992-01-01

    Changes in magnetic susceptibility of chalcopyrite brought about by vibration grinding in air and methanol were investigated. Significant increase in magnetic susceptibility is ascribed to plastic strain that results in destruction of the long-range order.

  20. Gemstone Grinding Process Improvement by using Impedance Force Control

    Directory of Open Access Journals (Sweden)

    Hamprommarat Chumpol

    2015-01-01

    Full Text Available Chula Automatic Faceting Machine has been developed by The Advance Manufacturing Research Lab, Chulalongkorn University to support Thailand Gems-Industry. The machine has high precision motion control by using position and force control. A contact stiffness model is used to estimate grinding force. Although polished gems from the Faceting Machine have uniform size and acceptable shape, the force of the grinding and polishing process cannot be maintain constant and has some fluctuation due to indirect force control. Therefor this research work propose a new controller for this process based on an impedance direct force control to improve the gemstone grinding performance during polishing process. The grinding force can be measured through motor current. The results show that the polished gems by using impedance direct force control can maintain uniform size as well as good shape and high quality surface.

  1. In-Process Chatter Detection in Surface Grinding

    Directory of Open Access Journals (Sweden)

    Tangjitsitcharoen Somkiat

    2015-01-01

    Full Text Available The chatter causes the poor surface finish during the surface grinding. It is therefore necessary to monitor the chatter during the process. Hence, this research has proposed the in-process chatter detection in the surface grinding process by utilizing the dynamic cutting forces. The ratios of the average variances of three dynamic cutting forces have been adopted and applied to identify the chatter during the surface grinding process to eliminate the effects of the cutting conditions. The effects of the cutting conditions on the chatter are also studied and analyzed. The algorithm has been proposed to detect the chatter regardless of the cutting conditions. The verification of the proposed system has been proved through another experiment by using the new cutting conditions. The experimental results have run satisfaction. It is understood that the chatter can be avoided during the in-process surface grinding even though the cutting conditions are changed.

  2. A critical study of high efficiency deep grinding

    CERN Document Server

    Johnstone, I

    2002-01-01

    The recent years, the aerospace industry in particular has embraced and actively pursued the development of stronger high performance materials, namely nickel based superalloys and hardwearing steels. This has resulted in a need for a more efficient method of machining, and this need was answered with the advent of High Efficiency Deep Grinding (HEDG). This relatively new process using Cubic Boron Nitride (CBN) electroplated grinding wheels has been investigated through experimental and theoretical means applied to two widely used materials, M50 bearing steel and IN718 nickel based superalloy. It has been shown that this grinding method using a stiff grinding centre such as the Edgetek 5-axis machine is a viable process. Using a number of experimental designs, produced results which were analysed using a variety of methods including visual assessment, sub-surface microscopy and surface analysis using a Scanning Electron Microscope (SEM), residual stress measurement using X-Ray Diffraction (XRD) techniques, Ba...

  3. Quenching simulation of steel grinding balls

    Directory of Open Access Journals (Sweden)

    Zapata-Hernndez, Oscar

    2015-09-01

    Full Text Available The phase transformations of high carbon steel during quenching and equalizing were modelled using commercial computer packages based on the finite element method and the kinetic transformation of steel. The model was used to predict the temperature and microstructural changes taking place within balls of two different sizes that are used for grinding mineral ores. A good correlation between the temperatures measured by inserted thermocouples and those predicted by the model was obtained after modifying the thermal conductivity of the steel within the temperature domain at which mixed phases are present. The phase transformations predicted were confirmed by metallographic analyses.Las transformaciones de fase en aceros de alto carbono durante su temple y un posterior periodo de estabilizacin fueron modelizadas por medio del uso de paquetes computacionales basados en el mtodo del elemento finito y de la transformacin cintica de los aceros. El modelo se us para predecir los cambios de temperatura y microestructura que se presentan en bolas de dos diferentes tamaos empleadas en estaciones de molienda de minerales. Se encontr una buena correlacin entre las temperaturas medidas mediante la insercin de termopares y aquellas predichas por el modelo una vez que se modific la conductividad trmica del acero en el intervalo mixto de fases. La prediccin de las transformaciones de fase se confirm a travs del anlisis metalogrfico.

  4. Sludge minimization achieved through grinding and reaeration

    International Nuclear Information System (INIS)

    A parallel, bench-scale study was undertaken to study the effect of grinding/blending biological solids followed by subsequent aeration for 24-hours on overall sludge production. This was compared to a completely-mixed system from which solids were wasted directly back to the aeration basin. In essence, both treatment trains employed total recycle of the waste biological solids, except that the solids from Train 2 were ground and aerated prior to re-introduction. The bench-scale reactors were continuously operated from November through December 2000 and from January through April 2001. Temperature of the wastewater during the first and second runs was maintained at 14o C and 25o C, respectively. Each parallel train was fed synthetic wastewater at a flow rate of approximately 2.25 gallons per day resulting in a hydraulic detention time of approximately 13 hours. Samples of the influent, effluent, and mixed liquor were collected weekly and the following analyses were performed: COD, pH, temperature, total solids, suspended solids, volatile suspended solids, dissolved solids, and oxygen uptake rate (OUR). Results of the study indicate that the system in which the solids were ground and re-aerated produced less sludge than the conventional system. Substrate removal rates were the same for both systems. Statistical analyses using the analysis of variance indicated the results were significant at the 95 % confidence level. (author)

  5. Environmental Impact of Electricity Consumption in Crushing and Grinding Processes of Traditional and Urban Gold Mining by Using Life Cycle Assessment (LCA

    Directory of Open Access Journals (Sweden)

    Nur Rafidah Yahaya

    2012-01-01

    Full Text Available Mining is not only an essential component of social and economic development since prehistoric time, but it also gives a large impact on our civilization. Gold is a noble metal that is highly valued. The extraction of minerals from earth is known as traditional mining. Gold also can be extracted from electronic waste or e-waste, and this new concept is called urban mining. There are many stages in traditional and urban mining process. However, in this study, the focus was on crushing and grinding processes to produce 1 kg of gold. Crushing and grinding are processes in the milling stage. This research evaluates and compares the environmental impacts of crushing and grinding processes, based on electricity consumption. About 50 to 65% of total electricity in milling was used for crushing and grinding processes. Life Cycle Assessment (LCA methodology was used as a tool to evaluate the environmental burdens of electricity usage in converting ore and electronic waste to gold bars. The Life Cycle Impact Assessment (LCIA of this process was interpreted by using Eco-indicator 99 assessment methods in SimaPro software. The impact categories included in this study were carcinogens, respiratory organics, respiratory inorganics, radiation, climate change, ozone layer, ecotoxicity, acidification or eutrophication, land use and minerals. The results showed that crushing and grinding from traditional mining gave the largest impact to the environment with single score of 399 Pt compared to the urban mining with only 1.81 Pt score. The highest impact in both types of mining is to human health.

  6. Surface grinding of space materials using specially formulated vitrified grinding wheels

    Science.gov (United States)

    Jackson, M. J.; Robinson, G.

    2006-04-01

    The quantum leap that is expected in the reliability and safety of machined engineering components over the next 20 years, especially in the space industries, will require improvements in the quality of cutting tools if science-based manufacturing is the goal for manufacturing by 2020. Significant improvements have been made in the past 10 years by understanding the properties of vitrified bonding systems used to bond conventional and superabrasive materials in grinding tools. The nature of the bonding system is of paramount importance if next-generation cutting tools are to be used for aerospace materials, especially if they are dressed using laser beams.

  7. Performance analysis of magnesium phosphate cement mortar containing grinding dust

    OpenAIRE

    Daniel Véras Ribeiro; Márcio Raymundo Morelli

    2009-01-01

    Magnesium phosphate cement materials are formed by reacting magnesium oxide with water-soluble phosphates such as monoammonium dihydrogen phosphate (ADP), which solidifies at ambient temperature through the formation of hydrated phases in the material. Cylindrical specimens of magnesium phosphate cement were molded and varying amounts (0 to 30% weight) of grinding dust were added to the ceramic matrices. The influence of the addition of grinding dust on the characteristics of the mortars in t...

  8. Integrated Modeling and Intelligent Control Methods of Grinding Process

    OpenAIRE

    Na-na Shen; Shi-feng Sun; Jie-sheng Wang

    2013-01-01

    The grinding process is a typical complex nonlinear multivariable process with strongly coupling and large time delays. Based on the data-driven modeling theory, the integrated modeling and intelligent control method of grinding process is carried out in the paper, which includes the soft-sensor model of economic and technique indexes, the optimized set-point model utilizing case-based reasoning, and the self-tuning PID decoupling controller. For forecasting the key technology indicators (gri...

  9. Optimizing the Grinding Process for Ceramic Materials; TOPICAL

    International Nuclear Information System (INIS)

    There is probably no such thing as an optimized grinding process that stays optimized, but we should still strive for one. There is a strong need for standardized test methodologies that can be conducted in a production environment at reasonable costs and without sophisticated instrumentation. There is a need for better analytical models whose results closely match real-world grinding processes. Accurate measurement of wheel performance and wheel wear is a key enabling technology that needs further work and standardization

  10. Applying laser irradiation and intelligent concepts to identify grinding phenomena

    OpenAIRE

    Mohammed, Arif

    2012-01-01

    The research discussed in this thesis explores a new method for the detection of grinding burn temperature using a laser irradiation acoustic emission (AE) sensing technique. This method is applicable for the grinding process monitoring system, providing an early warning for burn detection on metal alloy based materials (specifically nickel alloy based materials: Inconel718 and MarM002). The novelty in this research is the laser irradiation induced thermal AE signal that represents the grindi...

  11. Innovative grinding wheel design for cost-effective machining of advanced ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Licht, R.H.; Kuo, P.; Liu, S.; Murphy, D.; Picone, J.W.; Ramanath, S.

    2000-05-01

    This Final Report covers the Phase II Innovative Grinding Wheel (IGW) program in which Norton Company successfully developed a novel grinding wheel for cost-effective cylindrical grinding of advanced ceramics. In 1995, Norton Company successfully completed the 16-month Phase I technical effort to define requirements, design, develop, and evaluate a next-generation grinding wheel for cost-effective cylindrical grinding of advanced ceramics using small prototype wheels. The Phase II program was initiated to scale-up the new superabrasive wheel specification to larger diameters, 305-mm to 406-mm, required for most production grinding of cylindrical ceramic parts, and to perform in-house and independent validation grinding tests.

  12. Roll force prediction of high strength steel using foil rolling theory in cold skin pass rolling

    International Nuclear Information System (INIS)

    Skin pass rolling is a very important process for applying a certain elongation to a strip in the cold rolling and annealing processes, which play an important role in preventing the stretching of the yield point when the material is processed. The exact prediction of the rolling force is essential for obtaining a given elongation with the steel grade and strip size. Unlike hot rolling and cold rolling, skin pass rolling is used to apply an elongation of within 2% to the strip. Under a small reduction, it is difficult to predict the rolling force because the elastic deformation behavior of the rolls is complicated and a model for predicting the rolling force has not yet been established. Nevertheless, the exact prediction of the rolling force in skin pass rolling has gained increasing importance in recent times with the rapid development of high strength steels for use in automobiles. In this study, the possibility of predicting the rolling force in skin pass rolling for producing various steel grades was examined using foil rolling theory, which is known to have similar elastic deformation behavior of rolls in the roll bite. It was found that a noncircular arc model is more accurate than a circular model in predicting the roll force of high strength steel below TS 980 MPa in skin pass rolling

  13. Design and fabrication of nano-scale single crystal diamond cutting tool by focused ion beam (FIB) milling

    Science.gov (United States)

    Baek, Seung-Yub

    2015-07-01

    Micro/nanoscale diamond cutting tools used in ultra-precision machining can be fabricated by precision grinding, but it is hard to fabricate a tool with a nanometric cutting edge and complex configurations. High-precision geometry accuracy and special shapes for microcutting tools with sharp edges can be achieved by FIB milling. Because the FIB milling method induces much smaller machining stress compared with conventional precision grinding methods. In this study, the FIB milling characteristics of single-crystal diamond were investigated, along with methods for decreasing the FIB-induced damage on diamond tools. Lift-off process method and Pt(Platinum) coating process method with FIB milling were investigated to reduce the damage layer on diamond substrate and quadrilateral-shaped single-crystal diamond cutting tool with cutting edge width under 500 nm were obtained.

  14. Conversion of Mill Scale Waste into Valuable Products via Carbothermic Reduction

    OpenAIRE

    Mamdouh Eissa; Azza Ahmed; Mohamed El-Fawkhry

    2015-01-01

    Mill scale is one of waste materials which is produced as a result of hot rolling of steel in all steel companies. On the other hand, mill scale is considered a rich iron source with minimum impurities. This work aims at conversion of mill scale by adjusting smelting processes to produce different valuable products. The smelting processes were carried out using carbothermic reduction in a submerged arc furnace. Two carbonaceous reducing agents and different fluxing materials have been used to...

  15. Grinding process monitoring based on electromechanical impedance measurements

    Science.gov (United States)

    Marchi, Marcelo; Guimarães Baptista, Fabricio; de Aguiar, Paulo Roberto; Bianchi, Eduardo Carlos

    2015-04-01

    Grinding is considered one of the last processes in precision parts manufacturing, which makes it indispensable to have a reliable monitoring system to evaluate workpiece surface integrity. This paper proposes the use of the electromechanical impedance (EMI) method to monitor the surface grinding operation in real time, particularly the surface integrity of the ground workpiece. The EMI method stands out for its simplicity and for using low-cost components such as PZT (lead zirconate titanate) piezoelectric transducers. In order to assess the feasibility of applying the EMI method to the grinding process, experimental tests were performed on a surface grinder using a CBN grinding wheel and a SAE 1020 steel workpiece, with PZT transducers mounted on the workpiece and its holder. During the grinding process, the electrical impedance of the transducers was measured and damage indices conventionally used in the EMI method were calculated and compared with workpiece wear, indicating the surface condition of the workpiece. The experimental results indicate that the EMI method can be an efficient and cost-effective alternative for monitoring precision workpieces during the surface grinding process.

  16. Grinding aspheric and freeform micro-optical molds

    Science.gov (United States)

    Tohme, Yazid E.

    2007-02-01

    Fueled by the need for better performing optics, glass optics are now replacing plastic optics in many industrial and consumer electronic devices. One of these devices is the mobile phone camera. The optical sub-assembly in a mobile phone includes several micro lenses that are spherical and/or aspherical in shape and require form tolerances in the submicron range. These micro glass lenses are mass produced by a replication process known as glass press molding. The process entails the compression of a glass gob between two precise optical quality molds at an elevated temperature, usually near the transition temperature of the glass material. The elevated forces and temperatures required in the glass molding process limits the materials of the molds to very tough materials such as tungsten carbide or silicon carbide. These materials can withstand large pressing forces at high temperatures without any significant deformation. These materials offer great mechanical properties for glass press molding but they are also a challenge to machine to submicron accuracy. The work in this paper discusses a deterministic micro grinding manufacturing process referred to as wheel normal grinding, which is utilized to produce these optical quality molds. Wheel normal grinding is more accurate and more deterministic than most other grinding techniques and can produce molds to the form and finish tolerances required for optical molding. This method relies on the ability to recognize and compensate for grinding wheel wear and machine repeatable errors. Results will be presented to illustrate the accuracy of this micro grinding technique.

  17. A review of high-speed grinding and high-performance abrasive tools

    OpenAIRE

    Krajnik, Peter; Kopač, Janez

    2015-01-01

    This paper reviews the modern aspects of grinding with regards to enhanced productivity and manufacturing quality demands. The basic mechanism of grinding and the applications for the state-of-the-art technology of high-speed grinding (HSG) with high-performance grinding wheels are presented.In addition to the improvements in the technology associated with HSG, the grinding machine-tool, the coolant system and the process monitoring also need to adapt to high-speed machining. In addition, the...

  18. Experimental research and computer simulation of face grind-hardening technology

    OpenAIRE

    Li, Jianping; Liu, Songyong; Du, Changlong

    2015-01-01

    The influence of technical parameters on face grind-hardening surface hardness and hardened layer depth were determined by systematic experimental studies on technological parameters, such as grinding methods and grinding parameters, which provides a reference for choosing reasonable parameters in face grind-hardening processing. By FEA simulation of the grinding temperature field using ANSYS software, the variation in temperature at different points on the workpiece surface and the temperatu...

  19. Study on the influence of shear and impact forces on the phase transformations of materials for mechanical treatment in a planetary ball mill

    International Nuclear Information System (INIS)

    The influence of milling on the transformations of the calcium carbonate phase has been studied using a laboratory centrifuge mill as well as a high energy planetary mill for grinding. The second one was fitted with two motors for freely selecting the translation and rotation movements of the grinding jars and therefore to vary the relative contribution of the shear and impact forces. The transformation phase of the calcite and aragonite has been observed although it is not thermodynamically aided. This transformation is helped by the application of shear forces more than by the energy released by the impact of the balls against the grinding material. A mechanism is proposed that explains this behavior (CW)

  20. Study on Effect of Ultrasonic Vibration on Grinding Force and Surface Quality in Ultrasonic Assisted Micro End Grinding of Silica Glass

    OpenAIRE

    Zhang Jianhua; Zhao Yan; Zhang Shuo; Tian Fuqiang; Guo Lanshen; Dai Ruizhen

    2014-01-01

    Ultrasonic vibration assisted micro end grinding (UAMEG) is a promising processing method for micro parts made of hard and brittle materials. First, the influence of ultrasonic assistance on the mechanism of this processing technology is theoretically analyzed. Then, in order to reveal the effects of ultrasonic vibration and grinding parameters on grinding forces and surface quality, contrast grinding tests of silica glass with and without ultrasonic assistance using micro radial electroplate...

  1. Biomechanics of leukocyte rolling

    OpenAIRE

    Sundd, Prithu; POSPIESZALSKA, MARIA K.; Cheung, Luthur Siu-Lun; Konstantopoulos, Konstantinos; Ley, Klaus

    2011-01-01

    Leukocyte rolling on endothelial cells and other P-selectin substrates is mediated by P-selectin binding to P-selectin glycoprotein ligand-1 expressed on the tips of leukocyte microvilli. Leukocyte rolling is a result of rapid, yet balanced formation and dissociation of selectin-ligand bonds in the presence of hydrodynamic shear forces. The hydrodynamic forces acting on the bonds may either increase (catch bonds) or decrease (slip-bonds) their lifetimes. The force-dependent catch-slip bond ...

  2. The Evolution of the Surface Morphologies and Microstructures of an Unleveled Hot-Rolled Steel Strip During Cold Rolling After Hydrogen Reduction

    Science.gov (United States)

    Jing, Yu-An; Shang, Qiuyue; Zang, Xiaoming; Zhang, Lei; Peng, Xingdong; Jia, Pinfeng

    2015-10-01

    The removal of oxide scale from a hot-rolled strip surface can completely eliminate environmental pollution if performed by hydrogen-reduction descaling instead of traditional pickling descaling. However, a large number of cracks appear on the surface of a leveled hot-rolled steel strip after hydrogen reduction. This effect is likely to impede the application of reduction descaling to cold-rolled products. Nevertheless, there are almost no cracks on the surface of an unleveled hot-rolled steel strip if the hot-rolled steel strip is not subjected to repeated bending by the leveler machine. The surface quality of a reduced steel strip will be better than that of a pickled steel strip. To investigate the evolution of the surface morphologies, microstructures, and properties of an unleveled strip steel during cold rolling, unleveled strip steel samples were rolled using a four-high mill after hydrogen reduction and after pickling. The surface morphologies and cross-sectional microstructures of the samples were observed by SEM, and the surface-roughness values were measured using a TR200 profilometer before and after cold-rolling deformation. The evolution of the surface morphologies and cross-sectional microstructures of the sample after cold rolling were analyzed. The results show that the oxide scale formed on the surface turns into a metallic iron layer, and a decarburization layer appears between the metallic iron layer and the steel matrix after hydrogen reduction. Few cracks, besides pores, and bubbles, appeared on the surface of the sample after hydrogen reduction. The pores and bubbles were roll-flattened after five passes of cold rolling. The work hardening degree and mechanical properties of the reduced sample are similar to those of the pickled sample after cold rolling. Compared with the rolled sample after pickling, the surface qualities of the reduced samples are better than those of the pickled samples and better than those of the reduced samples that were subjected to leveling prior to reduction.

  3. The Evolution of the Surface Morphologies and Microstructures of an Unleveled Hot-Rolled Steel Strip During Cold Rolling After Hydrogen Reduction

    Science.gov (United States)

    Jing, Yu-An; Shang, Qiuyue; Zang, Xiaoming; Zhang, Lei; Peng, Xingdong; Jia, Pinfeng

    2016-01-01

    The removal of oxide scale from a hot-rolled strip surface can completely eliminate environmental pollution if performed by hydrogen-reduction descaling instead of traditional pickling descaling. However, a large number of cracks appear on the surface of a leveled hot-rolled steel strip after hydrogen reduction. This effect is likely to impede the application of reduction descaling to cold-rolled products. Nevertheless, there are almost no cracks on the surface of an unleveled hot-rolled steel strip if the hot-rolled steel strip is not subjected to repeated bending by the leveler machine. The surface quality of a reduced steel strip will be better than that of a pickled steel strip. To investigate the evolution of the surface morphologies, microstructures, and properties of an unleveled strip steel during cold rolling, unleveled strip steel samples were rolled using a four-high mill after hydrogen reduction and after pickling. The surface morphologies and cross-sectional microstructures of the samples were observed by SEM, and the surface-roughness values were measured using a TR200 profilometer before and after cold-rolling deformation. The evolution of the surface morphologies and cross-sectional microstructures of the sample after cold rolling were analyzed. The results show that the oxide scale formed on the surface turns into a metallic iron layer, and a decarburization layer appears between the metallic iron layer and the steel matrix after hydrogen reduction. Few cracks, besides pores, and bubbles, appeared on the surface of the sample after hydrogen reduction. The pores and bubbles were roll-flattened after five passes of cold rolling. The work hardening degree and mechanical properties of the reduced sample are similar to those of the pickled sample after cold rolling. Compared with the rolled sample after pickling, the surface qualities of the reduced samples are better than those of the pickled samples and better than those of the reduced samples that were subjected to leveling prior to reduction.

  4. Spray Rolling Aluminum Strip

    Energy Technology Data Exchange (ETDEWEB)

    Lavernia, E.J.; Delplanque, J-P; McHugh, K.M.

    2006-05-10

    Spray forming is a competitive low-cost alternative to ingot metallurgy for manufacturing ferrous and non-ferrous alloy shapes. It produces materials with a reduced number of processing steps, while maintaining materials properties, with the possibility of near-net-shape manufacturing. However, there are several hurdles to large-scale commercial adoption of spray forming: 1) ensuring strip is consistently flat, 2) eliminating porosity, particularly at the deposit/substrate interface, and 3) improving material yield. Through this program, a new strip/sheet casting process, termed spray rolling, has been developed, which is an innovative manufacturing technique to produce aluminum net-shape products. Spray rolling combines the benefits of twin-roll casting and conventional spray forming, showing a promising potential to overcome the above hurdles associated with spray forming. Spray rolling requires less energy and generates less scrap than conventional processes and, consequently, enables the development of materials with lower environmental impacts in both processing and final products. Spray Rolling was developed as a collaborative project between the University of California-Davis, the Colorado School of Mines, the Idaho National Engineering and Environmental Laboratory, and an industry team. The following objectives of this project were achieved: (1) Demonstration of the feasibility of the spray rolling process at the bench-scale level and evaluation of the materials properties of spray rolled aluminum strip alloys; and (2) Demonstration of 2X scalability of the process and documentation of technical hurdles to further scale up and initiate technology transfer to industry for eventual commercialization of the process.

  5. Critical parameters for grinding large sapphire window panels

    Science.gov (United States)

    Bashe, Joseph R.; Dempsey, Gene; Akwani, Ikerionwu A.; Jacoby, Keith T.; Hibbard, Douglas L.

    2007-04-01

    Advances in optical manufacturing and testing technologies for sapphire material are required to support the increasing use of large-aperture sapphire panels as windscreens for various electro-optical system applications. Single surface grinding is a crucial process step in both the figuring and finishing of optical components. Improper grinding can make subsequent polishing operations more difficult and time consuming. Poor grinding can also lead to the introduction of surface stress and sub-surface damage which can affect critical opto-mechanical performance characteristics such as strength and durability. Initial efforts have been completed at Exotic Electro-Optics under the funding of the Office of Naval Research and the Air Force Research Laboratory to investigate a number of process enhancements in the grinding of a-plane sapphire panels. The information gained from this study will ultimately provide a better understanding of the overall manufacturing process leading to optimized process time and cost. EEO has completed two sets of twelve-run Plackett-Burman designs of experiment (DOE) to study the effects of fundamental grinding parameters on sapphire panel surfaces. The relative importance of specific process parameters on window characteristics including surface roughness, stress, sub-surface damage are reported.

  6. Development of morphology in laser dressed grinding wheels

    Directory of Open Access Journals (Sweden)

    M.J. Jackson

    2007-05-01

    Full Text Available Purpose: The paper describes the development of faceted morphology in laser dressed grinding wheels.Design/methodology/approach: The approach used in the paper is based on locally melting a vitrified grinding wheel and measuring features such as grain size, cooling rate and melt depth as a function of laser fluence and relating these measures to the morphology shown in the microstructures presented in the paper.Findings: The findings of this course of research lead the authors to believe that a specific morphology is dependent upon cooling rate and laser fluence.Research limitations/implications: The findings show that further research is required to fully understand how certain morphologies form as a function of cooling rate and laser fluence. It should be noted that morphologies observed in laser processed grinding wheels include cellular and fully dendritic morphologies in addition to faceted vertices.Practical implications: The results imply that laser dressed grinding wheels can be used for machining different materials at different grinding speeds. The paper also shows that much development is needed to identify laser processing conditions that are appropriate for different workpiece materials.Originality/value: The paper shows that different morphologies can be used to machine workpiece materials under different conditions. The originality in the paper is focused on the formation on minute cutting points using increasing laser fluences.

  7. Ductile streaks in precision grinding of hard and brittle materials

    Indian Academy of Sciences (India)

    V C Venkatesh; S Izman; S Sharif; T T Mon; M Konneh

    2003-10-01

    Ductile streaks produced during diamond grinding of hard and brittle materials have aided the subsequent process of polishing. Two novel techniques were used to study the formation of ductile mode streaks during diamond grinding (primary process) of germanium, silicon, and glass. In the first technique, aspheric surfaces were generated on Ge and Si at conventional speeds (5000 rpm). In the second technique, diamond grinding of plano surfaces on glass and Si surfaces using high speed (100,000 rpm) was carried out. Form accuracy, surface finish and ductile mode grinding streaks are discussed in this paper. It was found that resinoid diamond wheels gave more ductile streaks than metal-bonded wheels but better form accuracy was obtained with the latter. Ductile streaks were obtained more easily with pyrex rather than with BK 7 glass thus necessitating very little time for polishing. Ductile streaks appeared in abundance on germanium rather than silicon. Both the novel grinding techniques were used on CNC machining centres.

  8. Ultraprecision grinding of optical materials for high-power lasers

    Science.gov (United States)

    Namba, Yoshiharu; Yoshida, Kunio; Yoshida, Hidetsugu; Nakai, Sadao

    1998-04-01

    Grinding is considered to be a rough machining process in the field of optics; a polishing process must follow the grinding process for getting optical-quality surfaces. An ultraprecision surface grinder with hydrostatic oil bearings and a glass-ceramic spindle of extremely low thermal expansion was developed to get smooth optical surfaces without any polishing process. Various optical materials such as NbF1, BK7, LHG08 fused silica, KTP, KDP and CLBO were ground into optical surfaces after empirically determining the conditions required to attain ductile-mode grinding. An extremely smooth surface less than 0.1 nm rms was obtained on BK7 glass by the ultraprecision grinding process. The laser-induced damage threshold was measured on variously finished LHG-8 laser glass at (lambda) equals 1.053 micrometers and 1-ns pulse width. The damage threshold was measured at 22.2 J/cm2 on a ground surface with the polarization parallel to the grinding direction. This number is higher than that obtained by optical polish. The damage threshold of 293 J/cm2 was also obtained on a ground LHG-8 glass surface at (lambda) equals 1.053 micrometers and 30-ns pulse width.

  9. Investigation of surface layer on rolled recycled AA5050 in relation to Filiform Corrosion

    OpenAIRE

    Premendra

    2007-01-01

    The presence of a heavily deformed surface layer (a few microns thick) on rolled aluminium alloy is understood to be one of the main reasons contributing to the Filiform Corrosion (FFC) susceptibility of the alloy. The surface layer is formed during the thermo-mechanical processing of the sheet metal, in the rolling mills. The surface layer characteristics are process dependent, i.e. depends on thermo-mechanical processing and the composition of the alloy in addition to post-production surfac...

  10. Multi-scale modelling of hot rolled dual phase steels for process design

    OpenAIRE

    Suwanpinij, Piyada

    2012-01-01

    This thesis investigates and models the austenite to ferrite transformation in the hot rolling of two different dual phase steels. The investigation has been carried out in a deformation dilatometer as well as a 4-stand pilot rolling mill. Three different modelling approaches were employed to give different aspects of information and for different applications. Macroscopic kinetics model base on JMAK rate form gives simple overall kinetics information and indicates the appropriate process win...

  11. Microstructure evolution during spray rolling and heat treatment of 2124 Al

    International Nuclear Information System (INIS)

    Spray rolling is a strip-casting technology that combines elements of spray forming and twin-roll casting. It consists of atomizing molten metal with a high velocity inert gas, quenching the resultant droplets in flight, and directing the spray between mill rolls. In-flight convection heat transfer from atomized droplets and conduction heat transfer at the rolls rapidly remove the metal's latent heat. Hot deformation of the semi-solid material in the rolls results in fully consolidated, rapidly-solidified strip. Spray rolling operates at a higher solidification rate than conventional twin-roll casting and is able to process a broader range of alloys at high production rates. A laboratory-scale strip caster was constructed and used to evaluate the interplay of processing parameters and strip quality for strips up to 200 mm wide and 1.6-6.4 mm thick. This paper examines microstructure evolution during spray rolling and explores how gas-to-metal mass flow ratio influences the microstructure and mechanical properties of spray-rolled 2124 Al. The influences of solution heat treatment and cold rolling on grain structure and constituent particle spheroidization are also examined

  12. Effect of Carbon Content in Stainless Steels on Quantity of Grinding Energy

    Directory of Open Access Journals (Sweden)

    Wójcik R.

    2014-10-01

    Full Text Available The paper presents a study of the process of grinding stainless steels with different carbon contents. Verified the size and scope of the energy which is introduced in the surface layers for different types of abrasive grains and binders. The influence of parameters in plunge grinding process was considered in studies. The energy ratio was used for this purpose, which was calculated by multiplying energy and time of grinding wheel contact with the workpiece. To investigate influence of different carbon content on the level of energy density generated during grinding process special parameter Bp have been evaluated. The grinding tests were conducted in dry grinding technique.

  13. REVIEW OF DRESSING AND TRUING OPERATIONS FOR GRINDING WHEELS

    Directory of Open Access Journals (Sweden)

    UJJAWAL MAYANK SRIVASTAVA

    2013-01-01

    Full Text Available Grinding is an operation applied in almost every type of manufacturing process. It aims to produce high surface finish and to maintain close tolerances in the manufactured product. To make the grinding operation more productive and efficient, dressing and truing operations are performed on the grinding wheels. Various techniques are available and are used for the same. Since many permutations and combinations exists among the factors like economics, efficiency, accuracy, complexity, etc. of the dressing process, so continuous efforts are made to develop or adopt a technique that gives the best result while fulfilling the maximum number of factors. This can be accomplished by comparing the present techniques on the same ground. With this aim, the unconventional techniques with in-process configuration were developed that have several advantages over theirconventional counterparts.

  14. Characterization of grinding wheels: An annotated Bibliography. Final report

    Energy Technology Data Exchange (ETDEWEB)

    McClung, R.W.

    1995-12-01

    The characteristics of grinding wheels, after both fabrication and periods of operation, have a significant effect on the processed surface and the mechanical properties of advanced ceramics. An extensive literature survey and review has been conducted to determine and catalogue the various characterization methods that have been investigated and reported. Although many of the references have addressed the grinding of metals, the historical and technical merit justify their inclusion in this bibliography. For convenience, the references have been subdivided into nine subheadings: Nondestructive examination; elasticity and stiffness; wheel hardness; topography and profilometry; observation of texture of wheel surfaces wheel wear; in process monitoring of grinding, acoustic emission, other; characteristics of ground surfaces; and miscellaneous.

  15. Research on Grinding and Polishing Force Control of Compliant Flange

    Directory of Open Access Journals (Sweden)

    Li Chuang

    2015-01-01

    Full Text Available The automation of the grinding and polishing process is important to improve the production efficiency of the part surfaces. In this paper, a new compliant flange mounted on the end of the industrial robots for the robotic grinding and polishing force control is developed. With regard to the non-linear and time-varying problem of the contact force, the mathematical model of the new force control system was presented and the fuzzy PID control strategy was used to drive the proposed system. Especially, the air spring and electric proportional valve is studied to establish the model. The simulation results show that the selected control strategy has quick response and good robustness, which satisfies the real-time requirements of the grinding and polishing force control in processing.

  16. Quantitative control and optimization of grinding and polishing processes

    International Nuclear Information System (INIS)

    The possibilities for the control and optimization of preparation processes and for the quantitative description of the quality of polished specimens are discussed using sintered aluminium oxide bodies as an example. A microscopic photometer and a TV image analyser were used in addition to the reflected light and scanning electron microscopes to control the grinding, lapping, and polishing processes. The photometer gave a very sensitive record of the nature of the surface from the grinding and lapping processes as well as from the first polishing step, whereas the fraction of regions that had not been levelled (pores and popouts) during polishing could be determined with an image analyser. Photographic documentation of the various stages of grinding, lapping, and polishing proved to be useful in selecting the most suitable method of preparation from the series of photographs. (orig.)

  17. Flow Stress Evaluation in Hot Rolling of Steel

    Science.gov (United States)

    Aghasafari, P.; Salimi, M.; Daraei, A.

    2014-08-01

    In this paper, an inverse analysis technique is used to obtain the flow curve of materials in a hot rolling finishing mill. This technique is based on minimization of the differences between the experimental and computed values. The flow curves and the friction coefficients at roll/work-piece interface are derived from two different models. Model I is based on simple slab method of analysis. Model II is based on a modified slab method in which the effect of shear stress in calculating the rolling force and torque is taken into account. It is shown that the developed inverse analysis technique is reliable and can simultaneously determine a more accurate flow stress for the material as well as a better estimation for the interface friction factors.

  18. Biomass torrefaction mill

    Energy Technology Data Exchange (ETDEWEB)

    Sprouse, Kenneth M.

    2016-05-17

    A biomass torrefaction system includes a mill which receives a raw biomass feedstock and operates at temperatures above 400 F (204 C) to generate a dusty flue gas which contains a milled biomass product.

  19. Ship Roll Damping Control

    DEFF Research Database (Denmark)

    Perez, Tristan; Blanke, Mogens

    2012-01-01

    The technical feasibility of roll motion control devices has been amply demonstrated for over 100 years. Performance, however, can still fall short of expectations because of difficulties associated with control system designs, which have proven to be far from trivial due to fundamental performance...... limitations and large variations of the spectral characteristics of wave-induced roll motion. This tutorial paper presents an account of the development of various ship roll motion control systems together with the challenges associated with their design. It discusses the assessment of performance and the...... applicability of different mathematical models, and it surveys the control methods that have been implemented and validated with full scale experiments. The paper also presents an outlook on what are believed to be potential areas of research within this topic....

  20. Control system for the surface quality of hot-rolled metal

    International Nuclear Information System (INIS)

    Full text: The modern ideas about quality of products are based on the principle of absolute satisfaction of the requirements and recommendations of the buyer. The presence of surface defects of steel-smelting and rolling origin is characteristic for the production of hot-rolling mill. The automatic surface inspection system (ASIS) includes two digital line video cameras for the filming of the upper and lower surface of the flat bar, a block for illumination of the upper and lower surface of the flat bar and a computer equipment. A system which secures 100 % control of the upper and lower surface of the rolled metal, detects automatically and classifies the sheet defects in the real time mode, was mounted 2003 for the first time in the domestic practice at the hot rolling mill 2000 JSC «Novolipetsk Iron & Steel Corporation» (NISC). The whole assortment of the mill 2000 was divided into five groups according to the outward appearance of the surface. The work on identifying the defects of hot-rolled metal and on widening the data base of knowledge of ASIS was continued after the guarantee tests. More than ten thousand images of defects were added to the data base during the year. key words: hot-rolling sheet, surface quality control, data base of defects

  1. Assessment of heavy metals introduced into food through milling process: health implications

    International Nuclear Information System (INIS)

    The present study was conducted to characterised and assesss heavy metal contamination in food through milling process and their health implications. Grinding plate made from Ghana, India and Nigeria purchased from the Ghanaian open market were used for this work. Maize from the same farm was milled into flour using the three grinding plate inserted into three different corn milling machines operating on commercial bases. Th first grinding was done immediately after the insertion of the newly sharpened plates into the machines. The plates were left for continuous daily usage. Subsequent milling of the maize was done after intervals of one month. The grinding plates and maize flour was analysed using Atomic absorption spectrophometer (AAS). The resultes recorded indicated that the heavy metals content o the Ghanaian, Indian and Nigerian made plates had the e similar metal contents but varied in terms of the individual metal concentrations. Flour from the Ghanaian made plates had the highest level of contaminants with the least from that of the Indian made plates. Generally, the highest levels of contamination were observed in the fist milling for the three plates as compared to the three subsequent milling at monthly interval. The contamination levels showed a decreasing trend from the first month (first milling ) to the fourth month (fourth milling). Cu, Cr and Ni showed concentrations above the permissible limit set by FAO/WHO in milled maize using Ghanaian made plate. Copper (Cu) recorded a concentration value between 15.04 mg/kg to 10.21mg.kg, 11.25 mg/kg to 9.13mg/kg and 10.36mg/kg and 9.68mg/kg using the Ghanaian-, Indian and Nigerian made plate respectively. Chromium (Cr) recorded a concentration between 1.51 mg/kg to 0.96 mg/kg, 1.03mg/kg to 0.91 mg/kg and 0.98mg/kg to 0.80 mg/kg using Ghanaian-, Indian and Nigerian made plates respectively. Nickel (Ni) recorded a concentration value between 23.23 mg/kg to 10.43 mg/kg, 11.46mg/kg to 10.43 mg/kg and 12.55 mg/kg to 10.09 mg/kg using Ghanaian-, Indian and Nigerian made plates respectively. which shows that the Cu, Cr and Ni concentration decreases from the first month (first milling) to the fourth month (fourth milling). The Ghanaian made plate was found to wear faster relative to Nigerian- , Indian and Nigerian made plate with that of showing the least rate of wear. The Ghananaian made plates was found to cause more contamination than the other two but generally, the Indian made plates caused least contamination.The Indian made plates had the least Cd and Pb concentration levels. The elemental concentration and the risk assessment calculations have shown that contamination of milled products are highest within the first month of the use of the grinding plates but can decreases considerably with time. The HRI value for first milled maize with locally made grinding plate showed human health problem for Cr and Ni metals contaminations in the maize flour. (author)

  2. Sliding and Rolling: The Physics of a Rolling Ball.

    Science.gov (United States)

    Hierrezuelo, J.; Carnero, C.

    1995-01-01

    Presents an approach that provides a simple and adequate procedure for introducing the concept of rolling friction. Discusses some aspects related to rolling motion that are the source of students' misconceptions. Presents several didactic suggestions. (JRH)

  3. EVOLUTION OF THE AUSTENITE GRAIN SIZE DURING HOT STRIP ROLLING OF NIOBIUM MICROALLOYED STEELS

    OpenAIRE

    Antonio Augusto Gorni; Marcos Roberto Soares da Silva

    2015-01-01

    The occurrence of dynamic recrystallization in the intermediate stands of the Finishing Mill of a Hot Strip Mill promotes substantial softening of the rolling stock, a situation that can cause operational problems and even scrapping of the strip. The aim of this work was to identify the specific process conditions that can lead to this situation, which was carried out through the application of a microstructural evolution model. It was verified, for the specific conditions of the ...

  4. Analysis of cement superplasticizers and grinding aids a literature survey

    International Nuclear Information System (INIS)

    This literature survey reviews the methods for analysis of cement plasticizers and organic grounding aids in cement solutions in preparation of grouts/concrete and methods for determination of plasticizers and grinding aids in groundwater conditions. The survey focuses on three different types of superplasticizers: sulphonated naphthalene condensates, sulphonated melamine condensates and polycarboxylates. There are various organic grinding aids, such as alkanolamines, glycols or phenolic compounds, used in the cement industry. This review is concerned with the following compounds: triethylenetetramine, tetraethylenepentamine, diethanolamine, triethanolamine, triisopropanolamine, ethyleneglycol, diethyleneglycol, aminoethylethanolamine, hydroxyethyl diethylenetriamine and phenol. (orig.)

  5. Performance analysis of magnesium phosphate cement mortar containing grinding dust

    Directory of Open Access Journals (Sweden)

    Daniel Véras Ribeiro

    2009-03-01

    Full Text Available Magnesium phosphate cement materials are formed by reacting magnesium oxide with water-soluble phosphates such as monoammonium dihydrogen phosphate (ADP, which solidifies at ambient temperature through the formation of hydrated phases in the material. Cylindrical specimens of magnesium phosphate cement were molded and varying amounts (0 to 30% weight of grinding dust were added to the ceramic matrices. The influence of the addition of grinding dust on the characteristics of the mortars in terms of microstructure (SEM, mechanical strength and capillary water absorption was verified. The results obtained proved very satisfactory for the use of this waste as an additive in magnesium phosphate mortars.

  6. Quality Improvement in the Production Process of Grinding Balls.

    OpenAIRE

    Andrew Muzinda; Rumbidzai Muvunzi; Catherine Maware

    2013-01-01

    The paper outlines how experiments were carried out to determine the optimum chromium/carbon (Cr/C) ratio that brings the required hardness of 65HRC and to establish a quenching technique for the grinding balls. Matlab was also used to develop a mathematical model for the ball wear rate and its cost effectiveness basing on surface theory and volume theory. From the experimental results, the Cr/C ratio in the chemical composition 18:2 gave the required hardness. Also water quenched grinding ba...

  7. Development of micro-grinding mechanics and machine tools

    Science.gov (United States)

    Park, Hyung Wook

    Micro-grinding with microscale machine tools is a micro-machining process in precision manufacturing of microscale parts such as micro sensors, micro actuators, micro fluidic devices, and micro machine parts. Mechanical micro-machining generally consists of various material removal processes. Micro-grinding of these processes is typically the final process step and it provides a competitive edge over other fabrication processes. The quality of the parts produced by this process is affected by process conditions, micro-grinding wheel properties, and microstructure of materials. Although a micro-grinding process resembles a traditional grinding process, this process is distinctive due to the size effect in micro-machining because the mechanical and thermal interactions between a single grit and a workpiece are related to the phenomena observed in micro-machining. However, there have not been enough modeling studies of the micro-grinding process and as a result, little knowledge base on this area has been accumulated. In this study, the new predictive model for the micro-grinding process was developed by consolidating mechanical and thermal effects within the single grit interaction model at microscale material removal. The size effect of micro-machining was also included in the proposed model. In order to assess thermal effects, the heat partition ratio was experimentally calibrated and compared with the prediction of the Hahn model. Then, on the basis of this predictive model, a comparison between experimental data and analytical predictions was conducted in view of the overall microgrinding forces in the x and y directions. Although there are deviations in the predicted micro-grinding forces at low depths of cut, these differences are reduced as the depth of cut increases. On the other hand, the optimization of micro machine tools was performed on the basis of the proposed design strategy. Individual mathematical modeling of key parameters such as volumetric error, machine working space, and static, thermal, and dynamic stiffness were conducted and supplemented with experimental analysis using a hammer impact test. These computations yield the optimal size of miniaturized machine tools with the technical information of other parameters.

  8. Dry recycling of grinding sludge in MOX fuel fabrication

    International Nuclear Information System (INIS)

    Advanced Fuel Fabrication Facility (AFFF) is manufacturing MOX (U,Pu)O2 fuel on regular basis for TAPS reactor. Fuel pellet fabrication is done by powder metallurgy route involving cold compaction and sintering. In order to get diametrical specification the sintered pellets are centerless ground using diamond grind wheel in presence of liquid coolant which generates grinding sludge. The sludge contains uranium and plutonium with some amount of impurities. An attempt has been made to study recycling of this sludge (dirty reject oxide) by dry recycling route. This paper discusses the process developed at AFFF. (author)

  9. Research on Grinding and Polishing Force Control of Compliant Flange

    OpenAIRE

    Li Chuang; Wang Zhenhua; Fan Cheng; Chen Guodong; Huang Ting

    2015-01-01

    The automation of the grinding and polishing process is important to improve the production efficiency of the part surfaces. In this paper, a new compliant flange mounted on the end of the industrial robots for the robotic grinding and polishing force control is developed. With regard to the non-linear and time-varying problem of the contact force, the mathematical model of the new force control system was presented and the fuzzy PID control strategy was used to drive the proposed system. Esp...

  10. Ship Roll Motion Control

    DEFF Research Database (Denmark)

    Perez, Tristan; Blanke, Mogens

    2010-01-01

    The technical feasibility of roll motion control devices has been amply demonstrated for over 100 years. Performance, however, can still fall short of expectations because of deciencies in control system designs, which have proven to be far from trivial due to fundamental performance limitations....... This tutorial paper presents an account of the development of various ship roll motion control systems and the challenges associated with their design. The paper discusses how to assess performance, the applicability of dierent models, and control methods that have been applied in the past....

  11. Rolling at small scales

    DEFF Research Database (Denmark)

    Nielsen, Kim L.; Niordson, Christian F.; Hutchinson, John W.

    2016-01-01

    The rolling process is widely used in the metal forming industry and has been so for many years. However, the process has attracted renewed interest as it recently has been adapted to very small scales where conventional plasticity theory cannot accurately predict the material response. It is well...... plasticity. Metals are known to be stronger when large strain gradients appear over a few microns; hence, the forces involved in the rolling process are expected to increase relatively at these smaller scales. In the present numerical analysis, a steady-state modeling technique that enables convergence...

  12. INFLUENCE OF DEFORMATION IN THE LINE OF WIRE MILL 150 ON DISPERSION OF PEARLITE OF STEEL 80K

    OpenAIRE

    V. A. Lutsenko; P. A. Bobkov; Lutsenko, O. V.; T. N. Golubenko; V. V. Gordiyenko

    2015-01-01

    Peculiarities of formation and distribution of pearlitic structure of steel 80K in a blank and after deformation in various areas of wire mill (in semi-finished rolled products and rolled wire) are established. It is shown that irregularity of temperature field by the section of semi-finished rolled products influences on processes of structure formation. It is shown by researches that the increase of deformation degree and the subsequent controlled accelerated cooling in the line of wire mil...

  13. Texture comparison between cold rolled and cryogenically rolled pure copper

    Science.gov (United States)

    Lapeire, L.; Sidor, J.; Martinez Lombardia, E.; Verbeken, K.; De Graeve, I.; Terryn, H.; Kestens, L. A. I.

    2015-04-01

    Nowadays, there is a considerable scientific interest in bulk ultrafine grained materials, due to their potential for superior mechanical properties. One of the possible formation methods of nano-grained materials is cryogenic rolling. The influence of rolling at cryogenic temperatures has been investigated. Significant differences in the textures and the microstructures can be observed between the cryogenically rolled copper and conventionally cold rolled copper, reduced to the same thickness.

  14. High-speed, low-damage grinding of advanced ceramics Phase 1. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Kovach, J.A. [Eaton Corp., Willoughby Hills, OH (United States). Mfg. Technologies Center; Malkin, S. [Univ. of Massachusetts (United States)

    1995-03-01

    In manufacture of structural ceramic components, grinding costs can comprise up to 80% of the entire manufacturing cost. Most of these costs arise from the conventional multi-step grinding process with numerous grinding wheels and additional capital equipment, perishable dressing tools, and labor. In an attempt to reduce structural ceramic grinding costs, a feasibility investigation was undertaken to develop a single step, roughing-finishing process suitable for producing high-quality silicon nitride ceramic parts at high material removal rates at lower cost than traditional, multi-stage grinding. This feasibility study employed combined use of laboratory grinding tests, mathematical grinding models, and characterization of resultant material surface condition. More specifically, this Phase 1 final report provides a technical overview of High-Speed, Low-Damage (HSLD) ceramic grinding and the conditions necessary to achieve the small grain depths of cut necessary for low damage grinding while operating at relatively high material removal rates. Particular issues addressed include determining effects of wheel speed and material removal rate on resulting mode of material removal (ductile or brittle fracture), limiting grinding forces, calculation of approximate grinding zone temperatures developed during HSLD grinding, and developing the experimental systems necessary for determining HSLD grinding energy partition relationships. In addition, practical considerations for production utilization of the HSLD process are also discussed.

  15. Design and experimental study of a micro-groove grinding wheel with spray cooling effect

    Directory of Open Access Journals (Sweden)

    Shi Chaofeng

    2014-04-01

    Full Text Available The effectiveness of grinding fluid supply has a crucial impact on grinding quality and efficiency in high speed grinding. In order to improve the cooling and lubrication, through in-depth research of self-inhaling internal cooling method and intermittent grinding mechanism, a new spray cooling method used in high speed grinding is proposed. By referring to the structure of bowl-shaped dispersion disk, the grinding wheel matrix with atomization ability is designed; through studying heat transfer of droplet collision and the influence of micro-groove on the boiling heat transfer, grinding segment with micro-groove is designed to enhance the heat flux of coolant and achieve maximum heat transfer between droplets and grinding contact zone. High-speed grinding experiments on GH4169 with the developed grinding wheel are carried out. The results show that with the micro-groove grinding wheel just 5.4% of pump outlet flow rate and 0.5% of spindle energy is needed to reduce the grinding temperature to 200C, which means the developed grinding wheel makes cooling high efficient and low energy consuming.

  16. Slitting criterion for various rolling speeds in MSR rolling process

    Directory of Open Access Journals (Sweden)

    A. Stefanik

    2008-03-01

    Full Text Available Purpose: The main idea of MSR technology is the capability of producing two, three, four and even five rods simultaneously from a single strip in a hot rolling process. Correctly separation of the joined strips is the one of the mainly problem in MSR process. Changing the rolling speed may causes easier of the strand division. In this paper results of the computer simulation of the double slitting rolling process were presented.Design/methodology/approach: For numerical modelling of the multi rolling process a computer program Forge 2005, based by the finished element method was used. As a slitting criterion normalised Cockroft – Latham criterion was used.Findings: For the analysis performed in this study, it was found that increasing of the rolling speed causes of increasing the normalized Cockroft – Latham criterion. For the small values of rolling velocity the strip separation was easier.Research limitations/implications: Multi Slit Rolling process is applied in ribbed rods rolling. Adjusting of the rolling speed in multi slit rolling process could improve of the slitting band to the separated strips.Originality/value: Incorrect construction or bad gap matching could cause lack of separation propelled slitting rolls. The separation of the band is effected by means of separating rollers, which shape must be properly designed to suit to the slitting pass. Changing of the rolling speed could improve of the separation to the single strips.

  17. Person og Rolle

    DEFF Research Database (Denmark)

    Szatkowski, Janek

    2011-01-01

    Distinktionen mellem person og rolle forslås som grundlag for et præcist og anlytisk anvendeligt begreb om performativitet. Begrebet tager sigte på at beskrive enkeltindividers og gruppers kommunikation med henblik på hvordan kommunikation etableres. Performativitet gør det muligt at iagttage den...

  18. Rolling Cylinder Phase 1

    DEFF Research Database (Denmark)

    Margheritini, Lucia; Taraborrelli, Valeria Taraborrelli

    Margheritini and Valeria Taraborrelli(valeria.taraborrelli@hotmail.it) with a total of 3 day visit from the developers. Laboratory tests in irregular waves will be performed by Lucia Margheritini. The report is aimed at the first stage testing of the Rolling Cylinder wave energy device. This phase includes...

  19. Research on Stability Prediction of the Crankshaft CNC Tangential Point Tracing Grinding

    OpenAIRE

    Zhuoda Jiang; Yongyi He

    2015-01-01

    As the key part of internal combustion engines, crankshaft with high efficiency and accuracy processing has always been the target of the engine manufacturer’s pursuit. Grinding is used to obtain the ultimate dimensional accuracy and surface finish in the crankshaft machining. Grinding of the main journals and the pin journals can be accomplished in a single clamping operation by CNC Tangential Point Tracing grinding technology. However, the chatter in the grinding process is harmful to the p...

  20. Temperature Prediction in High Speed Bone Grinding using Motor PWM Signal

    OpenAIRE

    Tai, Bruce L.; Zhang, Lihui; Wang, Anthony C.; Sullivan, Stephen; Wang, Guangjun; Albert J. Shih

    2013-01-01

    This research explores the feasibility of using motor electrical feedback to estimate temperature rise during a surgical bone grinding procedure. High-speed bone grinding is often used during skull base neurosurgery to remove cranial bone and approach skull base tumors through the nasal corridor. Grinding-induced heat could propagate and potentially injure surrounding nerves and arteries, and therefore, predicting the temperature in the grinding region would benefit neurosurgeons during the o...

  1. ANALYSIS OF THE SURFACE PROFILE AND ITS MATERIAL SHARE DURING THE GRINDING INCONEL 718 ALLOY

    OpenAIRE

    Martin Novk; Nataa Nprstkov; Jerzy Jzwik

    2015-01-01

    Grinding is still an important method for surface finishing. At FPTM JEPU research, which deals with this issue is conducted. Experiments are carried out with grinding various materials under different conditions and then selected components of the surface integrity are evaluated. They include roughness Ra, Rm and Rz, Material ratio curve (Abbott Firestone curve) and also the obtained roundness. This article deals with grinding nickel Inconel 718 alloy, when selected cutting grinding conditio...

  2. Evaluation of superalloy heavy-duty grinding based on multivariate tests

    OpenAIRE

    Liu, Qiang; Chen, Xun; Gindy, Nabil

    2007-01-01

    The quality and economy of grinding depend on proper selection of grinding conditions for the materials to be ground. In order to evaluate the effect of heavy-duty grinding, a new performance index, which includes specific material removal rate, size accuracy, and grinding forces, was proposed. Robust design of experiment, including orthogonal arrays, the signal-to-noise ratio (SNR) method, and analysis of variance (ANOVA) for multivariate data, was employed to estimate the effect of uniform ...

  3. The Graduate Grind: A Critical Look at Graduate Education

    OpenAIRE

    Annabelle L. Grundy; McGinn, Michelle K.

    2010-01-01

    Abandonment, abuse, anxiety, betrayal, bitterness, breaking point, burnout, collapse, danger, death, desperation, discouragement, divorce, exhaustion, frustration, grind, hardships, hazing, hurdles, ignorance, impossible dream, isolation, killing the spirit, leaving, loneliness, murder, neglect, peril, ridicule, ritual, self-protection, sexual harassment, shock, snobbery, strain, strangulation, stress, suffering, suicide, survival of the fittest, trauma, and violence.

  4. Computer numerical control grinding of spiral bevel gears

    Science.gov (United States)

    Scott, H. Wayne

    1991-01-01

    The development of Computer Numerical Control (CNC) spiral bevel gear grinding has paved the way for major improvement in the production of precision spiral bevel gears. The object of the program was to decrease the setup, maintenance of setup, and pattern development time by 50 percent of the time required on conventional spiral bevel gear grinders. Details of the process are explained.

  5. 30 CFR 56.14115 - Stationary grinding machines.

    Science.gov (United States)

    2010-07-01

    ... 56.14115 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Machinery and Equipment Safety Devices and Maintenance Requirements 56.14115 Stationary grinding machines....

  6. Automatic programming of grinding robot restoration of contours

    Directory of Open Access Journals (Sweden)

    Are Willersrud

    1995-07-01

    Full Text Available A new programming method has been developed for grinding robots. Instead of using the conventional jog-and-teach method, the workpiece contour is automatically tracked by the robot. During the tracking, the robot position is stored in the robot control system every 8th millisecond. After filtering and reducing this contour data, a robot program is automatically generated.

  7. GRINDING OF SHAPED TOOLS ON CNC TOOL GRINDER

    Directory of Open Access Journals (Sweden)

    Ján Kráľ

    2013-03-01

    Full Text Available Worm gears are special gears consisting of a worm wheel and a worm. Worm gears can be produced in different ways, depending on the size of the transmission, the number of courses, the pitch angle of worm profile, the number of units produced, the purpose of application, etc. As cylindrical worm gears we consider the cylindrical worms with globoid gears, globoid worm with globoid worm gear and globoid worm with cylindrical worm gearing. This paper deals with the evolvent worm whose curve of the tooth side in the front plane is evolvent. The production of worm with an optimal profile for optimal meshing conditions is an increasingly frequent focus of worm gear manufacturers. The problem of designing the tool cutting edge can be divided into several steps. This article deals with the problems of optimum design of a tool shape for the production of worms; and the problems of calculating the coordinates of the transition cutting edge shape, and thus the path of grinding wheel for sharpening the tool cutting edge shape are solved. By grinding tool of grinding machine we can complete the worm shape and also sharpen the cutting edges of tools for production of worm surface. The problems of calculation of the coordinates are solved with regard to the functioning of the KON 250 CNC grinding machine logic.

  8. Automatic programming of grinding robot restoration of contours

    OpenAIRE

    Are Willersrud; Fred Godtliebsen; Trygve Thomessen

    1995-01-01

    A new programming method has been developed for grinding robots. Instead of using the conventional jog-and-teach method, the workpiece contour is automatically tracked by the robot. During the tracking, the robot position is stored in the robot control system every 8th millisecond. After filtering and reducing this contour data, a robot program is automatically generated.

  9. Contact and Non-contact Measurements of Grinding Pins

    Directory of Open Access Journals (Sweden)

    Magdziak Marek

    2015-01-01

    Full Text Available The paper presents the results of contact and non-contact measurements of external profiles of selected grinding pins. The measurements were conducted in order to choose the appropriate measuring technique in the case of the considered measurement task. In the case of contact measurements the coordinate measuring machine ACCURA II was applied. The used coordinate measuring machine was equipped with the contact scanning probe VAST XT and the Calypso inspection software. Contact coordinate measurements were performed by using of different measurement strategies. The applied strategies included different scanning velocities and distances between measured points. Non-contact measurements were conducted by means of the tool presetter produced by the Mahr company. On the basis of gained results the guidelines concerning measurements of grinding pins were formulated. The measurements of analyzed grinding pins performed by means of the non-contact measuring system are characterized by higher reproducibility than the contact measurements. The low reproducibility of contact measurements may be connected with the inaccuracy of the selected coordinate measuring machine and the measuring probe, the measurement parameters and environmental conditions in the laboratory where the coordinate measuring machine is located. Moreover, the paper presents the possible application of results of conducted investigations. The results of non-contact measurements can be used in the simulation studies of grinding processes. The simulations may reduce the costs of machining processes.

  10. Facial lesions in piglets with intact or grinded teeth

    Directory of Open Access Journals (Sweden)

    Hansson Monica

    2012-04-01

    Full Text Available Abstract Background Piglets are born with eight sharp teeth that during nursing can cause facial lesions on littermates and teat lesions on the sow. Teeth grinding in piglets is therefore often practiced to reduce these lesions. The aim of this study was to assess the consequences of grinding piglet teeth in regard to the occurrence of lesions. In this study the piglets' teeth were grinded in 28 litters, and in 36 litters the piglets' teeth were kept intact. Twice, one time during the first week and one time during the second week after birth facial lesions of the piglets were scored and the teats of the sows were examined for lesions. The facial lesion score accounted for the amount and severity of lesions. The individual observations on piglets in the litter were synthesized in a litter facial lesion score. Findings 69.8% and 43.5% of the piglets had facial lesions in week 1 and week 2 respectively. The effect of treatment was not significant on litter facial lesion score. The litter facial lesion score was higher in week 1 than in week 2 (p p = 0.003 than in small litters. Mortality between week 1 and week 2 was higher in litters with intact teeth (p = 0.02. Sow teat lesions only occurred if litters had intact teeth. Conclusions According to our results teeth grinding is only justifiable in large litters.

  11. The Graduate Grind: A Critical Look at Graduate Education

    Directory of Open Access Journals (Sweden)

    Michelle K. McGinn

    2010-05-01

    Full Text Available Abandonment, abuse, anxiety, betrayal, bitterness, breaking point, burnout, collapse, danger, death, desperation, discouragement, divorce, exhaustion, frustration, grind, hardships, hazing, hurdles, ignorance, impossible dream, isolation, killing the spirit, leaving, loneliness, murder, neglect, peril, ridicule, ritual, self-protection, sexual harassment, shock, snobbery, strain, strangulation, stress, suffering, suicide, survival of the fittest, trauma, and violence.

  12. INFLUENCE OF DEFORMATION IN THE LINE OF WIRE MILL 150 ON DISPERSION OF PEARLITE OF STEEL 80K

    Directory of Open Access Journals (Sweden)

    V. A. Lutsenko

    2015-05-01

    Full Text Available Peculiarities of formation and distribution of pearlitic structure of steel 80K in a blank and after deformation in various areas of wire mill (in semi-finished rolled products and rolled wire are established. It is shown that irregularity of temperature field by the section of semi-finished rolled products influences on processes of structure formation. It is shown by researches that the increase of deformation degree and the subsequent controlled accelerated cooling in the line of wire mill 150 leads to increase in uniformity of pearlitic structure and its dispersion.

  13. Effect of pass schedule and groove design on the metal deformation of 38MnVS6 in the initial passes of hot rolling

    Indian Academy of Sciences (India)

    R S Nalawade; V R Marje; G Balachandran; V Balasubramanian

    2016-01-01

    The deformation behaviour of a hot rolled micro-alloyed steel bar of grade 38MnVS6 was examined using an FEM model during the initial passes in a blooming mill, as a function of three different pass schedules,roll groove depth, collar taper angle and corner radius. The simulations predicted the effective strain penetration,load, torque, fish tail billet end shapes, and metal flow behaviour at a chosen temperature, mill rpm and draft. The model predictions were validated for typical groove geometry and a typical pass schedule. Lower collar taper angle, lower corner radius and higher depth of groove in hot rolling enabled achievement of higher strain penetration, higher mill load and lower fish tail formation. The present study establishes the capability of the model to improve the internal quality of the rolled billet as measured by effective strain which was corroborated to the rolled bar macrostructure and microstructure. The model enables yield improvement by the choice of draft to minimise fish tail losses. The surface quality is improved by the ability to avoid fin formation that occurs at certain conditions of rolling. Thus, the groove geometry, roll pass schedule and rolling mill parameters and temperature can be optimised for best product quality and yield.

  14. Microstructure and properties of hot roll bonding layer of dissimilar metals. 2. Bonding interface microstructure of Zr/stainless steel by hot roll bonding and its controlling

    International Nuclear Information System (INIS)

    The hot roll bonding of zirconium and stainless steel inserted with tantalium was investigated using the newly developed rolling mill. The effect of hot rolling temperatures of zirconium/stainless steel joints on bonding interface structure was evaluated. Intermetallic compound layer containing cracks was observed at the bonding interface between stainless steel and tantalium when the rolling temperature was above 1373K. The hardness of the bonding layer of zirconium and tantalium bonded above 1273K was higher than tantalium or zirconium base metal in spite of absence of intermetallic compound. The growth of reaction layer at the stainless steel and tantalium interface and at the tantalium and zirconium interface was conforming a parabolic low when that was isothermally heated after hot roll bonding, and the growth rate was almost same as that of static diffusion bonding without using hot roll bonding process. It is estimated that the strain caused by hot roll bonding gives no effect on the growth of reaction layer. It was confirmed that the dissimilar joint of zirconium and stainless steel with insert of tantalium having the sound bonding interface were obtained at the suitable bonding temperature of 1173K by the usage of the newly developed hot roll bonding process. (author)

  15. Recovery of titanium values from titanium grinding swarf by electric furnace smelting

    Energy Technology Data Exchange (ETDEWEB)

    Gerdemann, Stephen J. (Albany, OR); White, Jack C. (Albany, OR)

    1999-01-01

    A method for the recovery of valuable materials from titanium grinding swarf is provided comprising the steps of sieving the accumulated titanium grinding swarf to remove unwanted coarse trash and grinding wheel fragments, pelletizing, and smelting in an electric arc furnace to produce ferrotitanium and/or high titanium slag.

  16. Recovery of titanium values from titanium grinding swarf by electric furnace smelting

    Energy Technology Data Exchange (ETDEWEB)

    Gerdemann, S.J.; White, J.C.

    1999-10-19

    A method for the recovery of valuable materials from titanium grinding swarf is provided comprising the steps of sieving the accumulated titanium grinding swarf to remove unwanted coarse trash and grinding wheel fragments, pelletizing, and smelting in an electric arc furnace to produce ferrotitanium and/or high titanium slag.

  17. Recovery of titanium values from titanium grinding swarf by electric furnace smelting

    Energy Technology Data Exchange (ETDEWEB)

    Gerdemann, S.J.; White, J.C.

    1998-08-04

    A method for the recovery of valuable materials from titanium grinding swarf is provided comprising the steps of sieving the accumulated titanium grinding swarf to remove unwanted coarse trash and grinding wheel fragments, pelletizing, and smelting in an electric arc furnace to produce ferrotitanium and/or high titanium slag. 1 fig.

  18. Recovery of titanium values from titanium grinding swarf by electric furnace smelting

    Energy Technology Data Exchange (ETDEWEB)

    Gerdemann, Stephen J. (Albany, OR); White, Jack C. (Albany, OR)

    1998-01-01

    A method for the recovery of valuable materials from titanium grinding swarf is provided comprising the steps of sieving the accumulated titanium grinding swarf to remove unwanted coarse trash and grinding wheel fragments, pelletizing, and smelting in an electric arc furnace to produce ferrotitanium and/or high titanium slag.

  19. Simulation-Assisted Evaluation of Grinding Circuit Flowsheet Design Alternatives: Aghdarreh Gold Ore Processing Plant / Ocena Alternatywnych Schematw Technologicznych Procesu Rozdrabniania W Zak?adach Przerbki Rud Z?ota W Aghdarreh, Z Wykorzystaniem Metod Symulacji

    Science.gov (United States)

    Farzanegan, A.; Ghalaei, A. Ebtedaei

    2015-03-01

    The run of mine ore from Aghdarreh gold mine must be comminuted to achieve the desired degree of liberation of gold particles. Currently, comminution circuits include a single-stage crushing using a jaw crusher and a single-stage grinding using a Semi-Autogenous Grinding (SAG) mill in closed circuit with a hydrocyclone package. The gold extraction is done by leaching process using cyanidation method through a series of stirred tanks. In this research, an optimization study of Aghdarreh plant grinding circuit performance was done to lower the product particle size (P80) from 70 ?m to approximately 40 ?m by maintaining current throughput using modeling and simulation approach. After two sampling campaigns from grinding circuit, particle size distribution data were balanced using NorBal software. The first and second data sets obtained from the two sampling campaigns were used to calibrate necessary models and validate them prior to performing simulation trials using MODSIM software. Computer simulations were performed to assess performance of two proposed new circuit flowsheets. The first proposed flowsheet consists of existing SAG mill circuit and a new proposed ball mill in closed circuit with a new second hydrocyclone package. The second proposed flowsheet consists of existing SAG mill circuit followed by a new proposed ball mill in closed circuit with the existing hydrocyclone package. In all simulations, SAGT, CYCL and MILL models were selected to simulate SAG mill, Hydrocyclone packages and ball mill units. SAGT and MILL models both are based on population balance model of grinding process. CYCL model is based on Plitt's empirical model of classification process in hydrocyclone units. It was shown that P80 can be reduced to about 40 ?m and 42 ?m for the first and second proposed circuits, respectively. Based on capital and operational costs, it can be concluded that the second proposed circuit is a more suitable option for plant grinding flowsheet modification. Surowy urobek z kopalni rud z?ota Aghdarreh musi najpierw zosta? poddany rozdrobnieniu, aby zapewni? efektywniejsze uwalnianie cz?steczek z?ota. W chwili obecnej obiegi rozdrabniania obejmuj? kruszenie jednostopniowe z wykorzystaniem kruszarek szcz?kowych oraz kruszenie jednostopniowe z u?yciem kruszarek p?automatycznych w obiegu zamkni?tym z hydrocyklonem. Odzysk z?ota odbywa si? przy zastosowaniu procesu ?ugowania, z zastosowaniem metody cyjankowej w szeregu mieszalnikw. W pracy tej przeprowadzono optymalizacj? procesu rozdrabniania rud w zak?adach przerbczych Aghdarreh prowadzonego w celu zmniejszenia rozmiarw uzyskiwanych cz?steczek z?ota (Ps0) z 70 ?m do ok. 40 ?m poprzez zapewnienie ci?g?o?ci procesu, z wykorzystaniem metod modelowania i symulacji. Na podstawie dwch zestaww prbek z ci?gu technologicznego rozdrabniania, rozk?ady wielko?ci cz?stek zosta?y statystycznie zrwnowa?one z wykorzystaniem oprogramowania NorBal. Pierwszy i drugi zbir danych otrzymanych na podstawie dwch zestaww prbek wykorzystany zosta? do kalibracji i walidacji modeli, przed przyst?pieniem do w?a?ciwych bada? symulacyjnych z u?yciem oprogramowania MODSIM. Symulacje komputerowe przeprowadzono w celu oceny wydajno?ci dwch proponowanych ci?gw technologicznych. Pierwszy ci?g obejmuje istniej?ce kruszarki p?automatyczne i nowo proponowan? kruszark? kulow? pracuj?c? w obiegu zamkni?tym z hydrocyklonem. Drugi rozwa?any ci?g stanowi istniej?ca kruszarka p?automatyczna, nast?pnie proponowana kruszarka kulowa pracuj?ca w obiegu zamkni?tym z istniej?cym hydrocyklonem. We wszystkich symulacjach bazowano na modelach SAGT, CYCL i MILL do symulacji pracy kruszarek p?automatycznych, pakietu hydrocyklonu oraz pojedynczych kruszarek. Modele SAGT i MILL oparte s? na modelu zrwnowa?onej populacji w procesie rozdrabniania. Model CYCL opiera si? na empirycznym modelu klasyfikacji Plitta zastosowanym do hydrocyklonw. Wykazano, ?e rozmiar cz?stek zmniejszony zosta? odpowiednio do 40 ?m i 42 ?m dla pier

  20. Effect of Milling Time on Al-Fe-Cr-20 Wt. % Al2O3composite Prepared Through Ball Milling

    Directory of Open Access Journals (Sweden)

    Hameedur Rehman Khan

    2014-07-01

    Full Text Available One of the main challenges towards achieving a homogeneous distribution of the ceramic phase in the metal matrix composites is agglomeration of the reinforcement particles. Mechanical alloying is among the most important processing techniques used for manufacturing of metal matrix composites (MMCs.An attempt was made to synthesize Al-Fe-Cr-Al2O3composites synthesized through mechanical alloying. Al2O3 is used as reinforcement. Ethanol (5 wt. % has been used as a process control agent (PCA. Mechanical alloying is carried out in a conventional ball mill using stainless steel grinding media at 115 rpm in the argon environment for 5h, 10h and 15h. The ball to powder weight ratio was maintained at 20:1. The characterization of the ball milled powder was followed by scanning electron microscopy (SEM. Showed the formation of a homogeneous phase for all compositions after milling for 15 h. XRD patterns were recorded for the milled powders, and analyzed using Williamson–Hall method and Scherrer’s equation to determine the lattice strain and grain size.EDX is performed to check the contamination of composites during the mechanical alloying.XRD is used to study structural evolution of synthesized aluminium composite. Effect of milling time is investigated on synthesized Al-Fe-Cr-20 wt. % Al2O3 composites.

  1. Modeling on the Effect of Coal Loads on Kinetic Energy of Balls for Ball Mills

    OpenAIRE

    Yan Bai; Fang He

    2015-01-01

    This paper presents a solution for the detection and control of coal loads that is more accurate and convenient than those currently used. To date, no research has addressed the use of a grinding medium as the controlled parameter. To improve the accuracy of the coal load detection based on the kinetic energy of balls in a tubular ball mill, a Discrete Element Method (DEM) model for ball kinematics based on coal loads is proposed. The operating process for a ball mill and the ball motion, as ...

  2. Subsurface damage mechanism of high speed grinding process in single crystal silicon revealed by atomistic simulations

    International Nuclear Information System (INIS)

    Highlights: • Molecular dynamic model of nanoscale high speed grinding of silicon workpiece has been established. • The effect of grinding speed on subsurface damage and grinding surface integrity by analyzing the chip, dislocation movement, and phase transformation during high speed grinding process are thoroughly investigated. • Subsurface damage is studied by the evolution of surface area at first time for more obvious observation on transition from ductile to brittle. • The hydrostatic stress and von Mises stress by the established analytical model are studied subsurface damage mechanism during nanoscale grinding. - Abstract: Three-dimensional molecular dynamics (MD) simulations are performed to investigate the nanoscale grinding process of single crystal silicon using diamond tool. The effect of grinding speed on subsurface damage and grinding surface integrity by analyzing the chip, dislocation movement, and phase transformation are studied. We also establish an analytical model to calculate several important stress fields including hydrostatic stress and von Mises stress for studying subsurface damage mechanism, and obtain the dislocation density on the grinding subsurface. The results show that a higher grinding velocity in machining brittle material silicon causes a larger chip and a higher temperature, and reduces subsurface damage. However, when grinding velocity is above 180 m s−1, subsurface damage thickness slightly increases because a higher grinding speed leads to the increase in grinding force and temperature, which accelerate dislocation nucleation and motion. Subsurface damage is studied by the evolution of surface area at first time for more obvious observation on transition from ductile to brittle, that provides valuable reference for machining nanometer devices. The von Mises stress and the hydrostatic stress play an important role in the grinding process, and explain the subsurface damage though dislocation mechanism under high stress status. The dislocation nucleation and motion induced plastic deformation during grinding process can better reveal subsurface damage mechanism considering to stress and temperature acting on the dislocations

  3. A new MPS {sup trademark} mill for the Veltheim Power Station

    Energy Technology Data Exchange (ETDEWEB)

    Baumeister, W. [Gemeinschaftskraftwerk Weser GmbH, Veltheim (Germany); Bischoff, W.; Pannen, H. [BBP Energy GmbH, Oberhausen (Germany)

    2002-07-01

    Extensive tests in the coal grinding test field and in the flow laboratory, form together with the advanced CFD calculations as well as operating experience with over 2000 operating MPS ring and roller mills, the basis for the design of a new mill. In this the well-known principle of the MPS type ring and roller mill as best representative for hard coal pulverising worldwide has been retained. Tests at the size reduction model have shown that there is further potential for a higher output capacity. By means of new design and operating parameters the capacity was increased by more than 30%. It was necessary to verify these results at a test mill in a power plant. (orig.)

  4. New Trends in Hot Strip Mill Roughing Mills: Characterization of High Chromium Steel and Semi-HSS Grades

    OpenAIRE

    Lecomte-Beckers, Jacqueline; Sinnaeve, Mario; Tchuindjang, Jérôme Tchoufack

    2011-01-01

    Two alloys grades for work rolls used in the roughing stand of Hot Strip Mill (HSM) are compared. The first grade known as High Chromium Steel (HCS) is presently the most widely used alloy for such an application, while the second one known as semi-High-speed Steel (semi-HSS) is the new grade developed to improve the overall performance of the work roll in the roughing stands of the HSM. In the present paper, the new semi-HSS grade is studied starting from three chemical compositions close...

  5. Gravity flow operated small electricity generator retrofit kit to flour mill industry.

    Science.gov (United States)

    Shekara, Prithivi; Kumar V, Pavan; Hosamane, Gangadharappa Gundabhakthara

    2013-10-01

    Flour milling is a grinding process to produce flour from wheat through comprehensive stages of grinding and separation. The primary energy is required to provide power used in grinding of wheat. In wheat milling, tempering is the process of adding water to wheat before milling to toughen the bran and mellow the endosperm. Gravity flow of the wheat is utilized to rotate the dampener wheel with cups to add water. Low cost gravity flow operated small electricity generator retrofit kit for dampener was designed and developed to justify low cost energy production without expensive solutions. Results of statistical analysis indicated that there was significant difference in mean values for voltage, rpm and flow rate at the 95% probability level. The resulted maximum mechanical power and measured electrical power were 5.1W and 4.9W respectively at wheat flow rate of 1.6Kg/s and dampener wheel rotational velocity of 4.4rad/s. PMID:24426010

  6. Walk and roll robot

    Science.gov (United States)

    Wilson, Andrew (Inventor); Punnoose, Andrew (Inventor); Strausser, Katherine (Inventor); Parikh, Neil (Inventor)

    2011-01-01

    A mobile robotic unit features a main body, a plurality of legs for supporting the main body on and moving the main body in forward and reverse directions about a base surface, and a drive assembly. According to an exemplary embodiment each leg includes a respective pivotal hip joint, a pivotal knee joint, and a wheeled foot adapted to roll along the base surface. Also according to an exemplary embodiments the drive assembly includes a motor operatively associated with the hip and knee joints and the wheeled foot for independently driving pivotal movement of the hip joint and the knee joint and rolling motion of the wheeled foot. The hip joint may include a ball-and-socket-type joint interconnecting top portion of the leg to the main body, such that the hip joint is adapted to pivot said leg in a direction transverse to a forward-and-reverse direction.

  7. Finite-element Mathematical Modeling of Combined Processes of Hot Rolling and Plastic Bending

    Science.gov (United States)

    Salganik, V.; Pesin, A.

    2004-06-01

    Finite-element viscoplastic mathematical model of combined process of asymmetrical rolling and plastic sheet bending has been created. Modeling of a new technology and its further introduction for a plate mill made it possible to have new expensive production — large-size bodies of revolution in the form of cylinders and cones.

  8. Hot rolling joining process

    International Nuclear Information System (INIS)

    In the case of incorporating nonferrous metal equipment in fuel reprocessing processes, from the viewpoint of reducing maintenance works for the piping connection to peripheral equipments, it is desirable to adopt the pipe joints of joining the materials of different kinds, which have the high reliability against leakage. In order to meet this demand, the development of the manufacturing technology of the pipe joints by hot rolling process has been carried out. As for the structure of this pipe joint, a small diameter nonferrous metal pipe and a large diameter stainless steel pipe are joined by hot rolling by using an inserted material. The materials are Ti-5% Ta, Ti and Zr for the nonferrous metals, SUS 304L for the stainless steel, and Ta foil for the inserted material. The merits and demerits of this pipe joints are shown. The control of the interface structure in the joining of different materials was carried out by using the inserted material. The method of manufacturing the pipe joints and the proper conditions of the rolling joining are explained. As for the performance of the pipe joints, the evaluations of the defects in the joining interface, the strength of the joining, the corrosion resistance and the susceptibility to stress corrosion cracking are reported. (K.I.)

  9. FM Interviews: Stephanie Mills

    OpenAIRE

    Valauskas, Edward

    2002-01-01

    Stephanie Mills is an author, editor, lecturer and ecological activist who has concerned herself with the fate of the earth and humanity since 1969, when her commencement address at Mills College in Oakland, Calif., drew the attention of a nation. Her speech, which the New York Times called "perhaps the most anguished statement" of the year's crop of valedictory speeches, predicted a bleak future. According to Mills, humanity was destined for suicide, the result of overpopulation and overuse ...

  10. Experimental investigation of abrasive electrodischarge grinding of Ti6Al4V titanium alloy

    Directory of Open Access Journals (Sweden)

    R. Święcik

    2009-12-01

    Full Text Available Purpose: This work is focused on determination of effects of grinding conditions on effectiveness of abrasive electrodischarge grinding (AEDG process applied for removal of machining allowance and forming of surface geometrical texture (SGT. These results were compared with one obtained for conventional grinding.Design/methodology/approach: The experimental investigations of deep-seated surface grinding of Ti6Al4V titanium alloy using CBN grinding wheel with metal bond were the ground for this elaboration. The effectiveness of AEDG process was assessed based on specific tangential grinding force and energy of spark electric discharge and machining results were estimated on geometrical structure parameters.Findings: The effectiveness of machining allowance removal depended on conditions of AEDG process. Significant differences in SGT formed by AEDG process and conventional grinding were revealed.Practical implications: Abrasive electrodischarge grinding is useful to be particularly suitable for efficient and effective grinding of very hard structural materials such as high-alloy steel, sintered carbides, metal-based composite materials etc.Originality/value: AEDG experiments were carried out using the typical surface finishing grinder and especially adapted generator of spark discharge pulses. The majority of such experiments in the world were performed with the electrodischarge machine tool equipped with extra grinding wheel mounted on the grinding pin and functioning as one of the electrodes put into operation via pneumatic drive.

  11. Cryogenic Grinding: a Physical Technique to Retain Volatile Content in Natural Products

    Science.gov (United States)

    Saxena, Rohit; Soni, Aditi; Saxna, S. N.; Rathore, S. S.; Barnwal, P.

    Cryogenics is the study of the production of very low temperature (below -150°C, -238°F or 123K) and the behavior of materials at those temperatures. Similarly, cryogenic grinding is a term supported by the act of grinding a thing at very low temperature. This technique is generally used to grind the material, which contains heat labile constituents viz- volatile oils in seed spices. Due to high fat content in spices, heat is generated, while energy is used to fracture a particle into a smaller size in conventional grinding process. During the normal grinding process, this generated heat causes temperature rise of grinder upto 950C. The increased temperature is responsible for a loss of volatile content in the tune of about 30% and also produces dark colour powder. Generally, continuous operation is not possible in normal grinding process due to melting of fat and sticking of powder on the grinding surface. The loss of volatile content can be significantly reduced by cryogenic grinding technique using liquid nitrogen or liquid carbon dioxide that provides the refrigeration needed to pre-cool the spices and maintain the desired low temperature by absorbing the heat generated during the grinding operation. The extremely low temperature during grinder condenses the volatile matter and retains their presence in spices. The application of cryogenic technology for grinding of spices has been scientifically proved to be a suitable technique with negligible loss of volatile content and improved colour of oil and grinding operation of seeds.

  12. Development of ELID mirror surface grinding by cast iron bond grinding wheel. Ohkochi memorial technology prize; Chutetsu bond toishi ni yoru denkai inpurosesu doresshingu (ELID) kyomen kensakuho no kaihatsu. Okochi kinen gijutsusho jusho ni yosete

    Energy Technology Data Exchange (ETDEWEB)

    Omori, H.; Takahashi, I. [Institute of Physical and Chemical Research, Tokyo (Japan); Nakagawa, T. [The University of Tokyo, Tokyo (Japan). Institute of Industrial Science; Hagiuda, Y.; Karikome, K. [Tokyo Metropolitan College of Aeronautical Engineering, Tokyo (Japan)

    1997-08-01

    Development was accomplished on the electrolytic in-process dressing (ELID) mirror surface grinding process using a cast iron bonded grinding wheel. This paper describes the history of the development, which may be summarized as follows: a study was begun on powder forging of cutting chips in 1970; a research was started on powder forging of decarburized cast iron powder; developments were made on powder metallurgy of cast irons and cast iron bonded lapping tools in 1980, and cast iron bonded diamond grinding wheels were put on the market; a high-efficiency grinding process using MC and cast iron fiber-bonded grinding wheels were developed in 1985 and the grinding wheels made therefrom were put on the market; and a study was begun on the ELID grinding in 1987, and marketing was started on power supply, grinding liquid and tools for the ELID grinding process in 1990. Discussions on converting raw materials for the powder forging into cutting chips have triggered developing the cast iron bonded grinding wheel. The cast iron bonded diamond grinding wheel improves dressability and sharpness of conventional grinding wheels. The grinding wheel is fabricated by mixing carbonyl iron powder, diamond grinding grains and cast iron powder, pressing the mixture in a die, sintering it at 1140 degC, and assembling and dressing the sinter. The grinding stone can grind high-tech materials. 4 figs.

  13. Experimental verification of nanoparticle jet minimum quantity lubrication effectiveness in grinding

    International Nuclear Information System (INIS)

    In our experiment, K-P36 precision numerical control surface grinder was used for dry grinding, minimum quantity lubrication (MQL) grinding, nanoparticle jet MQL grinding, and traditional flood grinding of hardened 45 steel. A three-dimensional dynamometer was used to measure grinding force in the experiment. In this research, experiments were conducted to measure and calculate specific tangential grinding force, frictional coefficient, and specific grinding energy, thus verifying the lubrication performance of nanoparticles in surface grinding. Findings present that compared with dry grinding, the specific tangential grinding force of MQL grinding, nanoparticle jet MQL grinding, and flood grinding decreased by 45.88, 62.34, and 69.33 %, respectively. Their frictional coefficient was reduced by 11.22, 29.21, and 32.18 %, and the specific grinding energy declined by 45.89, 62.34, and 69.45 %, respectively. Nanoparticle jet MQL presented ideal lubrication effectiveness, which was attributed to the friction oil film with strong antifriction and anti-wear features formed by nanoparticles on the grinding wheel/workpiece interface. Moreover, lubricating properties of nanoparticles of the same size (50 nm) but different types were verified through experimentation. In our experiment, ZrO2 nanoparticles, polycrystal diamond (PCD) nanoparticles, and MoS2 nanoparticles were used in the comparison of nanoparticle jet MQL grinding. The experimental results manifest that MoS2 nanoparticles exhibited the optimal lubricating effectiveness, followed by PCD nanoparticles. Our research also integrated the properties of different nanoparticles to analyze the lubrication mechanisms of different nanoparticles. The experiment further verified the impact of nanoparticle concentration on the effectiveness of nanoparticle jet MQL in grinding. The experimental results demonstrate that when the nanoparticle mass fraction was 6 %, the minimum specific tangential grinding force, frictional coefficient, and specific grinding energy were 1.285 N/mm, 0.382, and 57.825 J/mm3, respectively. When nanoparticle mass fraction was smaller than 6 %, lubrication effects of nanoparticle jet MQL increased with the rising nanoparticle mass fraction. When nanoparticle mass fraction was larger than 6 %, lubrication effects of nanoparticle jet MQL decreased with the rising nanoparticle mass fraction

  14. Developments in Electrical Discharge Grinding process: A review

    Directory of Open Access Journals (Sweden)

    Dr. Govindan P*1,

    2014-04-01

    Full Text Available Electrical discharge grinding (EDG is a hybrid process involving energy of sparking as well as mechanical grinding. The machining of thin and fragile material is very difficult for manufacturing industries and rapid demand of requirement could not be achieved. Electrical discharge machining is more acceptable machine tool for machining hard and brittle electrically conductive materials but its productivity is very low. In past decade, researchers have focused on EDG for machining these materials because there is no mechanical forces exerted on work piece during machining and it gives better performances than EDM due to the rotating speed of wheel. Therefore, the objective of this paper is to review the array of research works carried out on EDG process. It also focuses on recent developments for practical applications.

  15. Evolution of topography and material removal during nanoscale grinding

    Science.gov (United States)

    Eder, S. J.; Cihak-Bayr, U.; Vernes, A.; Betz, G.

    2015-11-01

    In this work we perform molecular dynamics simulations to quantify and parametrize the evolution of a bcc Fe work piece topography during nanometric grinding with multiple hard abrasive particles. The final surface quality depends on both the normal pressure and the abrasive geometry. We fit the time development of the substrates root mean squared roughness to an exponential function, allowing the definition of a run-in regime, during which the surface forgets about its initial state, and a steady-state regime where the roughness no longer changes. The time constants associated with smoothing and material removal are almost inversely proportional to each other, highlighting the distinctiveness of these two simultaneously occurring processes. We also describe an attempt to reduce the time required to achieve the smoothest possible surface finish by periodically re-adjusting the normal pressure during the grinding process.

  16. Research on automatic loading & unloading technology for vertical hot ring rolling process

    Directory of Open Access Journals (Sweden)

    Xiaokai Wang

    2015-01-01

    Full Text Available The automatic loading & unloading technology is the key to the automatic ring production line. In this paper, the automatic vertical hot ring rolling (VHRR process is taken as the target, the method of the loading & unloading for VHRR is proposed, and the mechanical structure of loading & unloading system is designed, The virtual prototype model of VHRR mill and loading & unloading mechanism is established, and the coordinated control method of VHRR mill and loading & unloading auxiliaries is studied, the movement trace and dynamic characteristic of the critical components are obtained. Finally, a series of hot ring rolling tests are conducted on the VHRR mill, and the production rhythm and the formed rings' geometric precision are analysed. The tests results show that the loading & unloading technology can meet the high quality and high efficiency ring production requirement. The research conclusions have practical significance for the large-scale automatic ring production.

  17. Results of the propagation behaviour and of grain analysis of machining residues when grinding materials of nuclear power station components

    International Nuclear Information System (INIS)

    Machining residues are formed during grinding on the grinding body/plant surface. These residues must be removed for reasons of activation, of keeping the plant clean and due to clogging up the structure and therefore negative grinding results. The results of investigations introduced are an important basis for possible removal variants directly at the plant surface/grinding body. (orig.)

  18. FRACTURE FEATURES OF METAL BINDING WHEN DIAMOND-SPARK GRINDING

    Directory of Open Access Journals (Sweden)

    Yury GUTSALENKO

    2012-05-01

    Full Text Available The hypothesis of the influence of binding energy of metal on the processes of destruction and mass transfer at high-speed machining is considered. Some nonconventional processes of cleaning of intergranularity spaces from waste products at diamond-spark grinding are explained, the approach to assessment of metal resistance in these processes is proposed and eo ipso modern conception of processes in chip formation zone under condition of electric discharge effect is supplemented

  19. Rolling motion in moving droplets

    Indian Academy of Sciences (India)

    Sumesh P Thampi; Rama Govindarajan

    2015-03-01

    Drops moving on a substrate under the action of gravity display both rolling and sliding motions. The two limits of a thin sheet-like drop in sliding motion on a surface, and a spherical drop in roll, have been extensively studied. We are interested in intermediate shapes. We quantify the contribution of rolling motion for any intermediate shape, and recently obtained a universal curve for the amount of roll as a function of a shape parameter using hybrid lattice Boltzmann simulations. In this paper, we discuss the linear relationship which is expected between the Capillary and Bond numbers, and provide detailed confirmation by simulations. We also show that the viscosity of the surrounding medium can qualitatively affect dynamics. Our results provide an answer to a natural question of whether drops roll or slide on a surface and carry implications for various applications where rolling motion may or may not be preferred.

  20. Rotary ultrasonic machining of CFRP: A comparison with grinding.

    Science.gov (United States)

    Ning, F D; Cong, W L; Pei, Z J; Treadwell, C

    2016-03-01

    Carbon fiber reinforced plastic (CFRP) composites have been intensively used in various industries due to their superior properties. In aircraft and aerospace industry, a large number of holes are required to be drilled into CFRP components at final stage for aircraft assembling. There are two major types of methods for hole making of CFRP composites in industry, twist drilling and its derived multi-points machining methods, and grinding and its related methods. The first type of methods are commonly used in hole making of CFRP composites. However, in recent years, rotary ultrasonic machining (RUM), a hybrid machining process combining ultrasonic machining and grinding, has also been successfully used in drilling of CFRP composites. It has been shown that RUM is superior to twist drilling in many aspects. However, there are no reported investigations on comparisons between RUM and grinding in drilling of CFRP. In this paper, these two drilling methods are compared in five aspects, including cutting force, torque, surface roughness, hole diameter, and material removal rate. PMID:26614168

  1. Physical characterization of coffee after roasting and grinding

    Directory of Open Access Journals (Sweden)

    Gabriel Henrique Horta de Oliveira

    2014-09-01

    Full Text Available Flowability is an important characteristic of handling process for efficiency and reliability purpose of post-harvest operations, which are governed by the physical properties of the product. Physical properties determination is an important factor for formulation of machinery projects and sizing of post-harvest operations, which may impact considerably on the products quality, influencing directly the operation cost and company profit. Thus, the objective of this work was to evaluate and determinate some physical properties (repose angle, unit and bulk density, porosity and color coordinates, particle size, moisture content, water activity, angle of internal friction and effective angle of internal friction of coffee, such as to evaluate the influence of different roast and grinding degrees over these properties. Crude grain coffee (Coffea canephora and Coffea arabica, dehulled and dried were used. These were roasted at two levels: medium light and medium-dark brown, which Agtron numbers are, respectively, SCAA#65 and SCAA#45. After roasting process, grains were grinded at three particle sizes (thin, medium and thick. Both particle size and roast degree significantly affected physical properties of coffee. Coffee samples roasted at medium dark level obtained lower values of moisture content, water activity, repose angle, bulk and real density. Coffee samples grinded at level thin presented an increase of angle of internal friction and effective angle of internal friction, repose angle, bulk and real density, porosity and decrease of water activity values.

  2. Cooking and grinding reduces the cost of meat digestion.

    Science.gov (United States)

    Boback, Scott M; Cox, Christian L; Ott, Brian D; Carmody, Rachel; Wrangham, Richard W; Secor, Stephen M

    2007-11-01

    The cooking of food is hypothesized to have played a major role in human evolution partly by providing an increase in net energy gain. For meat, cooking compromises the structural integrity of the tissue by gelatinizing the collagen. Hence, cooked meat should take less effort to digest compared to raw meat. Likewise, less energy would be expended digesting ground meat compared to intact meat. We tested these hypotheses by assessing how the cooking and/or grinding of meat influences the energy expended on its digestion, absorption, and assimilation (i.e., specific dynamic action, SDA) using the Burmese python, Python molurus. Pythons were fed one of four experimental diets each weighing 25% of the snake's body mass: intact raw beef, intact cooked beef, ground raw beef, and ground cooked beef. We measured oxygen consumption rates of snakes prior to and up to 14 days following feeding and calculated SDA from the extra oxygen consumed above standard metabolic rate. Postprandial peak in oxygen consumption, the scope of peak rates, and SDA varied significantly among meal treatments. Pythons digesting raw or intact meals exhibited significantly larger postprandial metabolic responses than snakes digesting the cooked ground meals. We found cooking to decrease SDA by 12.7%, grinding to decrease SDA by 12.4%, and the combination of the two (cooking and grinding) to have an additive effect, decreasing SDA by 23.4%. These results support the hypothesis that the consumption of cooked meat provides an energetic benefit over the consumption of raw meat. PMID:17827047

  3. Possibilities of Pelletizing and Briquetting of Dusts from Castings Grinding

    Directory of Open Access Journals (Sweden)

    A. Pribulová

    2010-04-01

    Full Text Available Foundry dust can be divided into three groups: metallic dust with Fe content over 70%, mixed dust with Fe or SiO2 content between 10 –70% and sand wastes with minimum content of SiO2 about 70%. Dust from castings grinding with high Fe content (87.9% is still landfillin Slovakia. The aim of experiments with dust from grinding has been to find the cheapest way of dust agglomeration with minimumamount of binder because of melting in the electric induction furnace. The dust was pelletized and briquetted and as binders bentonite, water glass and cement were used. Briquettes made from dust from grinding with addition of water glass got compression strength after three months on the air about 82 kPa. Briquettes with addition of water glass were melted together with cast iron in electric induction furnace. Yield of metal from briquettes was around 80% and slag quantity around 4% (without briquettes the slag quantity was 1.4%.

  4. Twin roll casting of magnesium alloys with high aluminum contents

    Directory of Open Access Journals (Sweden)

    H. Watari

    2006-08-01

    Full Text Available Purpose: The purpose of the work is to establish a manufacturing process and technology to facilitate theeconomical manufacture of high-quality magnesium sheet alloys with high aluminum contents, such as AZ61and AZ91. The aim of the work is to establish a twin roll casting technology to facilitate the manufacture ofAZ61 and AZ91 magnesium sheet alloys economically whilst maintaining high quality.Design/methodology/approach: A horizontal type twin roll caster was used to manufacture thin magnesium alloysheets of AZ61 and AZ91. Pair of copper alloy roll and pure copper roll was used for the horizontal type twin roll caster.A closed type tundish was set to the roll caster to keep stable contact of molten magnesium with upper and lower rolls.Findings: The experiment results clarified that AZ61 and AZ91 sheets can be manufactured by twin roll castingprocess. The product sheet thickness in the present experiment is 2.0 to 4.5 mm for AZ91, 2.5 to 5.0mm forAZ61. Mill stiffness and a method of predicting the cast sheets thickness were investigated to determine theappropriate manufacturing conditions. The microstructure of AZ61 cast strips was equiaxed structure and thecrystal sizes are different depending on cross section observed. The dendric and equiaxed microstructure wereseen in the microstructure of AZ91 cross section. The intermetllic Mg17Al12 was seen in the grain boundary inAZ91 when roll speed was very slow. The grain size of the manufactured wrought magnesium alloys sheet wasless than 10 micrometers. The obtained magnesium alloy sheet exhibited an equivalent limiting drawing ratio ina warm-drawing test. The limiting drawing ratio of AZ61 was 2.6 and 2.4 for AZ91.Research limitations/implications: The suitable roll speed was from 9m/min to 15m/min in manufacturingAZ91 and AZ61 strip using copper alloy rolls. When in use of pure copper roll, strips were cast between 6m/minand 20m/min for manufacturing AZ61 and AZ91. The superheats in the experiment were 15C and 30C. Thecast strips should be hot rolled at 300C.Originality/value: value In this experiment, it is clarified that AZ61, AZ91 sheets can be manufactured by twinroll casting. These cast sheet can be hot rolled and the manufacturing process by twin roll casting enable tomanufacure thin magnesium sheet alloys with high aluminum contents. It has been found that the manufacturedcast AZ61 and AZ91 have good formability by a warm deep drawing test.

  5. Influence of clinker grinding-aids on the intrinsic characteristics of cements and on the behaviour of mortars

    Directory of Open Access Journals (Sweden)

    Fernández Luco, L.

    2003-12-01

    Full Text Available In the production of portland cement, grinding aids are used to improve the grinding stage and reduce the energy required to achieve the required fineness. These additives remain in the final product and they might influence the characteristics and properties of the cement, and thus, mortar and concrete. This paper presents an evaluation of two grinding-aid additives used in the production of portland cement ground in a ball mill at a laboratory stage, with suitable proportions of portland cement clinker and gypsum. A control cement mix was also produced without using any admixture and the results are shown on a comparative basis. Conclusions indicate that grinding-aids additives have some influence on the characteristics of portland cement produced, increasing their specific surface and modifying microstructure and its packing ability. Mortars and concretes made with cements ground with the addition of gringing-aids exhibit higher strength at any age and a reduced water demand. Special attention should be taken to consider any interaction with water-reducing admixture in concretes and mortars.

    En la fabricación de cemento portland es una práctica creciente la utilización de aditivos para optimizar el proceso de molienda; éstos quedan incorporados en el producto final y pueden influir sobre las características y propiedades del cemento, morteros y hormigones. En este trabajo se presenta la evaluación de dos aditivos comerciales en la molienda conjunta de clínker de cemento portland y yeso comercial, tratados en un molino a bolas a escala de laboratorio, en forma comparativa con un cemento sin aditivo producido en forma equivalente. Las conclusiones indican que los aditivos de molienda tienen influencia en las características del cemento resultante, incrementando su superficie y modificando su microestructura y estado de agregación; los morteros mejoran sus prestaciones mecánicas a todas las edades y se reduce la demanda de agua, aunque debe prestarse cuidado a las posibles interacciones con aditivos reductores de agua de hormigones.

  6. Compound taper milling machine

    Science.gov (United States)

    Campbell, N. R.

    1969-01-01

    Simple, inexpensive milling machine tapers panels from a common apex to a uniform height at panel edge regardless of the panel perimeter configuration. The machine consists of an adjustable angled beam upon which the milling tool moves back and forth above a rotatable table upon which the workpiece is held.

  7. Development of industrial production of ultrafine grained steel in tandem hot strip mill; Production industrielle d'acier a grain ultra-fin au train a bandes

    Energy Technology Data Exchange (ETDEWEB)

    Kurahashi, R.; Hakomori, K.; Chikushi, I.; Morimoto, T. [Nakayama Steel Works, Ltd. (Japan); Yanagimoto, J. [Tokyo Univ. (Japan); Takaoka, S. [Kawasaki Heavy Industries Ltd., Kobe (Japan)

    2005-04-01

    Based on a model of microstructure evolution, an appropriate rolling schedule has been worked out to produce ultrafine grained steel (2 to 5 {mu}m) on the hot strip mill. This rolling schedule is characterized by a large reduction in the finishers followed by strong cooling. Implementing such a rolling schedule on a conventional HSM raises major problems: increased rolling torque and force, lowered crown and shape control, disturbed looper control, accelerated roll damage, increased slip between strip and roll, insufficient cooling efficiency. These problems have been solved on the new Nakayama HSM by introducing innovative processes such as: single roll drive with different diameter and a new CVC, curtain wall cooling in the finisher, low inertia hydraulic looper, new high-speed steel rolls with solid lubrication. (authors)

  8. Study of morphology and magnetic properties of the HoNi3 crystalline and ball-milled compound

    International Nuclear Information System (INIS)

    The morphology and magnetic properties of the HoNi3 crystalline and ball-milled intermetallic compounds are presented. The polycrystalline HoNi3 bulk compound crystallizes in the rhombohedral PuNi3 — type of crystal structure and indicates ferrimagnetic arrangement with the Curie temperature of TC = 57 ± 2 K, the helimagnetic temperature Th = 23 ± 2 K with the total saturation magnetic moment of 6.84 μB/f.u. at 2 K. The use of the ball-milling method leads to the formation of HoNi3 nanoflakes with typical thickness of less than 100 nm prone to agglomeration upon milling. The increase of grinding duration leads to the reduction in crystallite size, which was confirmed by various complementary microscopical and diffraction studies. Moreover, the increase in milling duration results in the emergence of the relatively small coercivity (HC), remanence (Mr) and a variation of the saturation magnetization (MS). - Graphical abstract: Display Omitted - Highlights: • The ball-milling method exhibits significant potential for producing RT3 nanopowders. • The AFM method was used for the first time in analysis of R–T nanoflakes morphology. • HoNi3 compound forms polycrystalline and textured nanoflakes evolving upon milling. • The decrease in crystallite size via grinding is confirmed by XRD, TEM and AFM. • The magnetic parameters were sensitive to the extension of pulverization b

  9. High coercivity induced by mechanical milling in cobalt ferrite powders

    Science.gov (United States)

    Ponce, A. S.; Chagas, E. F.; Prado, R. J.; Fernandes, C. H. M.; Terezo, A. J.; Baggio-Saitovitch, E.

    2013-10-01

    In this work we report a study of the magnetic behavior of ferrimagnetic oxide CoFe2O4 treated by mechanical milling with different grinding balls. The cobalt ferrite nanoparticles were prepared using a simple hydrothermal method and annealed at 500 C. The non-milled sample presented coercivity of about 1.9 kOe, saturation magnetization of 69.5 emu/g, and a remanence ratio of 0.42. After milling, two samples attained coercivity of 4.2 and 4.1 kOe, and saturation magnetization of 67.0 and 71.4 emu/g respectively. The remanence ratio MR/MS for these samples increase to 0.49 and 0.51, respectively. To investigate the influence of the microstructure on the magnetic behavior of these samples, we used X-ray powder diffraction (XPD), transmission electron microscopy, and vibrating sample magnetometry. The XPD analysis by the Williamson-Hall plot was used to estimate the average crystallite size and strain induced by mechanical milling in the samples.

  10. Relationships of damaged starch granules and particle size distribution with pasting and thermal profiles of milled MR263 rice flour.

    Science.gov (United States)

    Asmeda, R; Noorlaila, A; Norziah, M H

    2016-01-15

    This research was conducted to investigate the effects of different grinding techniques (dry, semi-wet and wet) of milled rice grains on the damaged starch and particle size distribution of flour produced from a new variety, MR263, specifically related to the pasting and thermal profiles. The results indicated that grinding techniques significantly (psize distribution of rice flour. Wet grinding process yields flour with lowest percentage of starch damage (7.37%) and finest average particle size (8.52?m). Pasting and gelatinization temperature was found in the range of 84.45-89.63C and 59.86-75.31C, respectively. Dry ground flour attained the lowest pasting and gelatinization temperature as shown by the thermal and pasting profiles. Correlation analysis revealed that percentage of damaged starch granules had a significant, negative relationship with pasting temperature while average particle size distribution had a significant, strong negative relationship with gelatinization temperature. PMID:26258700

  11. Grinding model and material removal mechanism of medical nanometer zirconia ceramics.

    Science.gov (United States)

    Zhang, Dongkun; Li, Changhe; Jia, Dongzhou; Wang, Sheng; Li, Runze; Qi, Xiaoxiao

    2014-01-01

    Many patents have been devoted to developing medical nanometer zirconia ceramic grinding techniques that can significantly improve both workpiece surface integrity and grinding quality. Among these patents is a process for preparing ceramic dental implants with a surface for improving osseo-integration by sand abrasive finishing under a jet pressure of 1.5 bar to 8.0 bar and with a grain size of 30 µm to 250 µm. Compared with other materials, nano-zirconia ceramics exhibit unmatched biomedical performance and excellent mechanical properties as medical bone tissue and dentures. The removal mechanism of nano-zirconia materials includes brittle fracture and plastic removal. Brittle fracture involves crack formation, extension, peeling, and chipping to completely remove debris. Plastic removal is similar to chip formation in metal grinding, including rubbing, ploughing, and the formation of grinding debris. The materials are removed in shearing and chipping. During brittle fracture, the grinding-led transverse and radial extension of cracks further generate local peeling of blocks of the material. In material peeling and removal, the mechanical strength and surface quality of the workpiece are also greatly reduced because of crack extension. When grinding occurs in the plastic region, plastic removal is performed, and surface grinding does not generate grinding fissures and surface fracture, producing clinically satisfactory grinding quality. With certain grinding conditions, medical nanometer zirconia ceramics can be removed through plastic flow in ductile regime. In this study, we analyzed the critical conditions for the transfer of brittle and plastic removal in nano-zirconia ceramic grinding as well as the high-quality surface grinding of medical nanometer zirconia ceramics by ELID grinding. PMID:24261919

  12. Direct measures of mechanical energy for knife mill size reduction

    Energy Technology Data Exchange (ETDEWEB)

    Bitra, V.S.P. [University of Tennessee; Womac, A.R. [University of Tennessee; Igathinathane, C. [Mississippi State University (MSU); Miu, P.I [University of Tennessee; Yang, Y.T. [University of Tennessee; Smith, D.R. [University of Tennessee; Chevanan, Nehru [University of Tennessee; Sokhansanj, Shahabaddine [ORNL

    2009-08-01

    Lengthy straw/stalk of biomass may not be directly fed into grinders such as hammer mills and disc refiners. Hence, biomass needs to be preprocessed using coarse grinders like a knife mill to allow for efficient feeding in refiner mills without bridging and choking. Size reduction mechanical energy was directly measured for switchgrass (Panicum virgatum L.), wheat straw (Triticum aestivum L.), and corn stover (Zea mays L.) in an instrumented knife mill. Direct power inputs were determined for different knife mill screen openings from 12.7 to 50.8 mm, rotor speeds between 250 and 500 rpm, and mass feed rates from 1 to 11 kg/min. Overall accuracy of power measurement was calculated to be 0.003 kW. Total specific energy (kWh/Mg) was defined as size reduction energy to operate mill with biomass. Effective specific energy was defined as the energy that can be assumed to reach the biomass. The difference is parasitic or no-load energy of mill. Total specific energy for switchgrass, wheat straw, and corn stover chopping increased with knife mill speed, whereas, effective specific energy decreased marginally for switchgrass and increased for wheat straw and corn stover. Total and effective specific energy decreased with an increase in screen size for all the crops studied. Total specific energy decreased with increase in mass feed rate, but effective specific energy increased for switchgrass and wheat straw, and decreased for corn stover at increased feed rate. For knife mill screen size of 25.4 mm and optimum speed of 250 rpm, optimum feed rates were 7.6, 5.8, and 4.5 kg/min for switchgrass, wheat straw, and corn stover, respectively, and the corresponding total specific energies were 7.57, 10.53, and 8.87 kWh/Mg and effective specific energies were 1.27, 1.50, and 0.24 kWh/Mg for switchgrass, wheat straw, and corn stover, respectively. Energy utilization ratios were calculated as 16.8%, 14.3%, and 2.8% for switchgrass, wheat straw, and corn stover, respectively. These data will be useful for preparing the feed material for subsequent fine grinding operations and designing new mills.

  13. Interfacial fatigue stress in PVD TiN coated tool steels under rolling contact fatigue conditions

    OpenAIRE

    Carvalho, N.J.M.; Huis in ’t Veld, A.J.; Hosson, J.Th. De

    1998-01-01

    Titanium–nitrogen (TiN) films were Physical Vapour Deposited (PVD) on tool steel substrates with different hardness and surface roughness, in a Bai 640R unit using a triode ion plating (e-gun) with a high plasma density. The coated substrates were submitted to a rolling contact fatigue test technique (modified pin-on-ring test) to obtain some clarifications of the mechanism of interfacial failure. Tests were run using PVD-coated rings finished by polishing or grinding to produce different sur...

  14. Investigations upon the indefinite rolls quality assurance in multiple regression analysis

    International Nuclear Information System (INIS)

    The rolling rolls quality has been enhanced mainly due to the improvements of the chemical compositions of rolls materials. The realization of an optimal chemical composition can constitute a technical efficient mode to assure the exploitation properties, the material from which the rolling mills rolls are manufactured having a higher importance in this sense. This paper continues to present the scientifically results of our experimental research in the area of the rolling rolls. The basic research contains concrete elements of immediate practical utilities in the metallurgical enterprises, for the quality improvements of rolls, having in last as the aim the durability growth and the safety in exploitation. This paper presents an analysis of the chemical composition, the influences upon the mechanical properties of the indefinite cast iron rolls. We present some mathematical correlations and graphical interpretations between the hardness (on the working surface and on necks) and the chemical composition. Using the double and triple correlations which is really helpful in the foundry practice, as it allows us to determine variation boundaries for the chemical composition, in view the obtaining the optimal values of the hardness. We suggest a mathematical interpretation of the influence of the chemical composition over the hardness of these indefinite rolling rolls. In this sense we use the multiple regression analysis which can be an important statistical tool for the investigation of relationships between variables. The enunciation of some mathematically modeling results can be described through a number of multi-component equations determined for the spaces with 3 and 4 dimensions. Also, the regression surfaces, curves of levels and volumes of variations can be represented and interpreted by technologists considering these as correlation diagrams between the analyzed variables. In this sense, these researches results can be used in the engineers collectives of the foundries and the rolling mills sectors, for quality assurances of rolls as far back as phase of production, as well as in exploitation of these, what lead to, inevitably, to the quality assurance of produced laminates. (Author) 16 refs.

  15. Textures of molybdenum monocrystal deformation in rolling in profiled rolls

    International Nuclear Information System (INIS)

    The texture of molybdenum monocrystals rolled in profiled rolls with epsilon=6-90% cogging is studied by the method of reverse pole figures in Mo Ksub(?) radiation. The crystallographic directions of and were oriented in the deformation direction. At different orientation of the monocrystal in the rolling plane after epsilon=25-27% in the rolling direction (RD) different crystallographic orientations were formed which is caused by pointing accuracy of the monocrystal in the deformation plane. Rolling of a monocrystal with long RD orientation provokes RD reorientation and formation of the (111) [011] texture at high deformation degree. At average cogging degrees (epsilon=35-60%) the total axial texture long RD is formed transforming into a limited axial one and then into an axial one with the deformation degree increase

  16. Rock'n'rolling

    International Nuclear Information System (INIS)

    Rare earths are not particularly hard to find but are extremely difficult to extract and refine. Producing rare-earth alloys is a costly process that involves smelting the minerals in three separate stages at temperatures of more than 1000 deg C. An Australian breakthrough, the ball mill processing technique which can produce alloys in a single step at room temperature is briefly presented. While it is yet to be tested on a commercial scale it is estimated that it could eventually supersede the existing method

  17. Failure Analysis of Rollers in mill stand using Failure mode Effect Analysis

    Directory of Open Access Journals (Sweden)

    Tadisetti Premsai

    2014-07-01

    Full Text Available Rolling is an important steel production process. Productivity and quality improvements in metal rolling are possible by paying a detailed attention to the various roll failure modes.A proper understanding of the causes of roll failure modes is usually complex and depends on the metallurgical quality of rolls, improper mill usage practices and abnormal rolling conditions. The work rolls operate under severe condition and should posses excellent wear resistance and very little plastic deformation to withstand mechanical and thermal shocks. The objective of this study is to analyze different failures associated with rollers in the mill stand using Failure Mode Effect Analysis (FMEA. The values of severity, probability of occurrence and detection of each failure mode are taken according to the FMEA criteria and based on these values, Risk Priority Number of each failure mode is calculated. Based on the risk levels of each failure modes, remedies for the respective failure modes are presented. Thus it results in reduced risk of process failure, improved reliability and quality of the products.

  18. COMPARISON BETWEEN MODELS FOR CALCULATION OF INDUSTRIAL HOT ROLLING LOADS

    Directory of Open Access Journals (Sweden)

    Antonio Augusto Gorni

    2012-09-01

    Full Text Available An evaluation is made about the precision of hot strip rolling mill loads at the F1 stand calculated according to the theoretical models of Orowan, Sims, Alexander-Ford, Orowan-Pascoe, Ekelund and Tselikov in comparison to real values got for carbon-manganese steels. In the deterministic approach, without any fit of the calculated values to real data, Orowan, Sims and Alexander-Models show best levels of precision, as expected from the information got in the literature. However, in the semi-empirical approach, after a linear fit between calculated values and real data, Tselikov and Ekelund models show better adequacy to the industrial data, a fact that can be attributed to more significant errors occurring in the sub-models of temperature, tribology and hot strength than in the rolling load models. For its turn, neural network models show the best levels of precision which make very attractive the adoption of this approach.

  19. Rolling friction of adhesive microspheres

    International Nuclear Information System (INIS)

    The rolling friction of adhesive microspheres is an important quantity as it determines the strength and stability of larger aggregates. Current models predict rolling forces that are 1 to 2 orders of magnitude smaller than observed experimentally. Starting from the well-known JohnsonKendallRoberts (JKR) contact description, we derive an analytical theory for the rolling friction based on the concept of adhesion hysteresis, e.g. a difference in apparent surface energies for opening/closing cracks. We show how adhesion hysteresis causes the pressure distribution within the contact to become asymmetrical, leading to an opposing torque. Analytical expressions are derived relating the size of the hysteresis, the rolling torque, and the rolling displacement, ?. We confirm the existence of a critical rolling displacement for the onset of rolling, the size of which is set by the amount of adhesion hysteresis and the size of the contact area. We demonstrate how the developed theory is able to explain the large rolling forces and particle-size dependence observed experimentally. Good agreement with experimental results is achieved for adhesion hysteresis values of (??/?)?3 for polystyrene, and (??/?)?0.5 for silicates, at crack propagation rates of 0.1ms?1 and 110ms?1, respectively. (paper)

  20. Video Analysis of Rolling Cylinders

    Science.gov (United States)

    Phommarach, S.; Wattanakasiwich, P.; Johnston, I.

    2012-01-01

    In this work, we studied the rolling motion of solid and hollow cylinders down an inclined plane at different angles. The motions were captured on video at 300 frames s[superscript -1], and the videos were analyzed frame by frame using video analysis software. Data from the real motion were compared with the theory of rolling down an inclined…

  1. Preliminary study of sintering of metallic niobium processed for mechanical milling; Estudo preliminar da sinterizacao de niobio metalico processado por moagem de alta energia

    Energy Technology Data Exchange (ETDEWEB)

    Tamura, H.M.; Vurobi Junior, S.; Cintho, O.M., E-mail: lenatamura@interponta.com.b [Universidade Estadual de Ponta Grossa (UEPG), PR (Brazil); Sandim, H.R.Z.; Leite, G.S. [Universidade de Sao Paulo (EEL/USP), Lorena, SP (Brazil). Escola de Engenharia

    2010-07-01

    In present study was preliminary study of mechanical milling influence on preparing of metallic niobium powder for sintering. Sample of metallic niobium in powder passing in sieve no. 635 mesh was processed by mechanical milling in SPEX mill for 8 hours using power grinding of 7:1 and a nitrogen atmosphere. The powder was annealed at different temperatures, 900 deg C, 1000 deg C, 1100 deg C and 1200 deg C for 1 hour in an atmosphere of hydrogen and argon to study their crystallization, which then were formed into blank for analysis of the curves compressibility. These samples were also subjected to x-ray diffraction in that their data were compared between the annealing temperatures. We also evaluate the compressibility curves of niobium samples with and without grinding these samples were subjected to x-ray diffraction and fluorescence. (author)

  2. Rotordynamic Influence on Rolling ELement Bearing Selection and Operation

    Science.gov (United States)

    Queitzsch, Gilbert K., Jr.; Fleming, David P.

    2001-01-01

    Three case studies are presented that illustrate the importance of dynamic considerations in the design of machinery supported by rolling element bearings. The first case concerns a milling spindle that experienced internal rubs and high bearing loads, and required retrofit of an additional . damped bearing. The second case deals with a small high-speed generator that suffered high vibration due to flexible mounting. The third case is a propulsion fan simulator rig whose bearings failed catastrophically due to improper bearing installation (which resulted in inadequate dynamic bearing stiffness) and lack of health monitoring instrumentation.

  3. Analysis of the performance of superabrasive and alumina grinding wheels with different bonds and machining conditions

    Directory of Open Access Journals (Sweden)

    Eduardo Carlos Bianchi

    2003-06-01

    Full Text Available This paper presents a review of researches on CBN (cubic boron nitride grinding wheels with the purpose of identifying the state of art in abrasive machining and serving as the basis for future researches and laboratory tests. The scientific studies investigated here report on interesting results involving grinding, published by Brazilian and foreign authors. The methods and the results are presented and discussed. In addition, a grinding setup is presented which provides more reliable experimental results about the surface integrity of fragile materials. This setup was obtained for grinding tests in several grinding conditions during the wheel service life, using alumina and vitrified and resin bond CBN grinding wheels. Results of cutting force, surface roughness and G ratio are also presented and discussed. They confirm the excellent machining capacity of the CBN wheel, with stable behavior in cutting force and roughness results during the tests. The G ratio values are in agreement with the results found by other researchers.

  4. Computational design of rolling bearings

    CERN Document Server

    Nguyen-Schäfer, Hung

    2016-01-01

    This book comprehensively presents the computational design of rolling bearings dealing with many interdisciplinary difficult working fields. They encompass elastohydrodynamics (EHD), Hertzian contact theory, oil-film thickness in elastohydrodynamic lubrication (EHL), bearing dynamics, tribology of surface textures, fatigue failure mechanisms, fatigue lifetimes of rolling bearings and lubricating greases, Weibull distribution, rotor balancing, and airborne noises (NVH) in the rolling bearings. Furthermore, the readers are provided with hands-on essential formulas based on the up-to-date DIN ISO norms and helpful examples for computational design of rolling bearings. The topics are intended for undergraduate and graduate students in mechanical and material engineering, research scientists, and practicing engineers who want to understand the interactions between these working fields and to know how to design the rolling bearings for automotive industry and many other industries.

  5. Phase transformation of single crystal silicon induced by grinding with ultrafine diamond grits

    International Nuclear Information System (INIS)

    Phase transformation of single crystal silicon (Si) was investigated under various grinding conditions using high-resolution transmission electron microscopy. Nanocrystals with sizes ranging from 6 to 20 nm of diamond cubic silicon (Si-I) and high-pressure phase (Si-III) were observed in the grinding-induced amorphous Si layers. The phase transformation pattern was found to be influenced by the thermal status involved in the grinding processes.

  6. The efficiency rise of the feeds grinding process by optimizing its parameters

    OpenAIRE

    TATYANA B. STANKEVICH; OLGA А. ANPILOGOVA; GENNADY I. MALINOV; TIMMO А. GAVRILOV

    2015-01-01

    Grinding is one of the most complicated and energy-intensive processes in the technology of making feeds for fur-bearing animals. That is why the most important nowadays is the research of the parameters influencing energy consumption during the grinding process. These parameters are: the slip angle of the knife blade and the temperature of the grinding material. The influence of the parameters on energy consumption has not been studied enough yet which prevents the increasing of the efficien...

  7. Effect of Cooling Environment on Grinding Performance of Nickel Based Superalloy Inconel 718

    OpenAIRE

    Raju S. Pawade; Arvind Chavan; Pankaj Chitalkar; Sandeep Huddedar

    2012-01-01

    The study presents the experimental investigation of surface grinding of superalloy Inconel 718. The grinding performance in terms of grinding force, surface roughness and surface topography were examined by conducting statistical experiments. The parameters that have been chosen as control factors are: table speed, infeed, grit size and the type of lubricant. An L27 orthogonal array experiments were conducted. The results show that the grit size and infeed are the most significant para...

  8. SYNTHESIS OF MODEL THE LUENBERGER OBSERVER FOR EXTERNAL CYLINDRICAL GRINDING PROCESS

    Directory of Open Access Journals (Sweden)

    Sergey BRATAN

    2013-05-01

    Full Text Available The problem of diagnosing the actual depth of cut at cylindrical grinding is considered.A mathematical model of the behavior of the grinding wheel and the workpiece during processingis worked out. According to this model it is produced a synthesis the model of the Luenbergerobserver with the Kalman filter to control the process of external cylindrical grinding. Thedeveloped approach is to improve the accuracy of control and the related with them computationalprocedures of assessment and management

  9. Analysis of the performance of superabrasive and alumina grinding wheels with different bonds and machining conditions

    OpenAIRE

    Bianchi Eduardo Carlos; Aguiar Paulo Roberto de; Monici Rodrigo Daun; Dar Neto Luiz; Silva Leonardo Roberto da

    2003-01-01

    This paper presents a review of researches on CBN (cubic boron nitride) grinding wheels with the purpose of identifying the state of art in abrasive machining and serving as the basis for future researches and laboratory tests. The scientific studies investigated here report on interesting results involving grinding, published by Brazilian and foreign authors. The methods and the results are presented and discussed. In addition, a grinding setup is presented which provides more reliable exper...

  10. Optimization of Metal Removal Rateon Cylindrical Grinding For Is 319 Brass Using Taguchi Method

    OpenAIRE

    Gaurav Upadhyay; Ramprasad

    2015-01-01

    Cylindrical grinding is one of the most important metal cutting processes used extensively in the Metal finishing operations. Metal removal rate and surface finish are the important output responses in the production with respect to quantity and quality respectively. The objective of this paper is to arrive at the optimal grinding conditions that will maximize metal removal rate when grinding IS 319 brass. Empirical models were developed using design of experiments by Taguchi L9 O...

  11. Application of cryogenic grinding to achieve homogenization of transuranic wastes

    International Nuclear Information System (INIS)

    This paper describes work done at Los Alamos National Laboratory (LANL) in collaboration with the Department of Energy Rocky Flats Field Office (DOE/RFFO) and with the National Institute of Standards and Technology (NIST), Boulder, Colorado. Researchers on this project have developed a method for cryogenic grinding of mixed wastes to homogenize and, thereby, to acquire a representative sample of the materials. There are approximately 220,000 waste drums owned by the Rocky Flats Environmental Technology Site (RFETS)-50,000 at RFETS and 170,000 at the Idaho National Engineering Laboratory. The cost of sampling the heterogeneous distribution of waste in each drum is prohibitive. In an attempt to produce a homogeneous mixture of waste that would reduce greatly the cost of sampling, researchers at NIST and RFETS are developing a cryogenic grinder. The Los Alamos work herein described addresses the implementation issues of the task. The first issue was to ascertain whether samples of the open-quotes small particleclose quotes mixtures of materials present in the waste drums at RFETS were representative of actual drum contents. Second, it was necessary to determine at what temperature the grinding operation must be performed in order to minimize or to eliminate the release of volatile organic compounds present in the waste. Last, it was essential to evaluate any effect the liquid cryogen might have on the structural integrity and ventilation capacity of the glovebox system. Results of this study showed that representative samples could be and had been obtained, that some release of organics occurred below freezing because of sublimation, and that operation of the cryogenic grinding equipment inside the glovebox was feasible

  12. New Abrasive Materials and Their Influence on the Surface Quality of Bearing Steel After Grinding

    Directory of Open Access Journals (Sweden)

    Ondrej Jusko

    2012-01-01

    Full Text Available This paper focuses on the influence of various types of abrasive grains on cutting properties during the grinding process for bearing steel. In this experiment, not only conventional super-hard abrasive materials but also a new type of abrasive material were employed in grinding wheels. The measurement results were compared, and an evaluation was made of the cutting properties of the new abrasive material. The options were then evaluated for their practical applicability. The measurement results indicated that a grinding wheel with Abral and SG grains is the most suitable for grinding hardened bearing steel in order to achieve the best roughness and geometrical accuracy.

  13. Research for the bearing grinding temperature on-line monitoring system based on the infrared technology

    Science.gov (United States)

    Huang, Zongxiang

    2008-10-01

    On-line monitoring to temperature of grinding arc is an important link absolutely necessarily in bearing grinding automation. This paper introduced a new method, which is to monitor grinding temperature via infrared ray, designed the engineering model of grinding arc temperature on-line monitoring system, and presented with components of grinding temperature automatic detection system and made analysis to workflow of the system. It brought forward the thought to establish factory grinder and central monitoring room to constitute Local Area Network so as that the central monitoring room could transfer information as grinding dosage and finishing of grinding wheel to operators of each grinder. Through analysis to influential factors of measurement results of that system, the paper provides with solutions. Technical tests validate that relative measurement error of that system is less than 0..5°C, which could better achieve on-line monitoring and alarm of grinding temperature and promote surface quality and productivity of grinding parts significantly.

  14. Relations between subsurface damage depth and surface roughness of grinded fused silica

    International Nuclear Information System (INIS)

    Relationships between subsurface damage (SSD) depth and peak to valley surface roughness (Rt) have been widely studied and present a major interest for an easy assessment of the SSD depth. We look at the relation between SSD depth and other surface roughness parameters using the Abbott-Firestone curve on a large campaign of grinding tests (with different abrasive grain size, grinding speed and grinding mode). The results reveal that Abbott-Firestone parameters are better for an assessment of SSD depth and that relationships between SSD depth and surface roughness are not universal but depend on the grinding process. (authors)

  15. ANALYSIS OF THE SURFACE PROFILE AND ITS MATERIAL SHARE DURING THE GRINDING INCONEL 718 ALLOY

    Directory of Open Access Journals (Sweden)

    Martin Novk

    2015-05-01

    Full Text Available Grinding is still an important method for surface finishing. At FPTM JEPU research, which deals with this issue is conducted. Experiments are carried out with grinding various materials under different conditions and then selected components of the surface integrity are evaluated. They include roughness Ra, Rm and Rz, Material ratio curve (Abbott Firestone curve and also the obtained roundness. This article deals with grinding nickel Inconel 718 alloy, when selected cutting grinding conditions were used and subsequently the surface profile and the material ratio curve were measured and evaluated.

  16. Nano finish grinding of brittle materials using electrolytic in-process dressing (ELID) technique

    Indian Academy of Sciences (India)

    M Rahman; A Senthil Kumar; H S Lim; K Fatima

    2003-10-01

    Recent developments in grinding have opened up new avenues for finishing of hard and brittle materials with nano-surface finish, high tolerance and accuracy. Grinding with superabrasive wheels is an excellent way to produce ultraprecision surface finish. However, superabrasive diamond grits need higher bonding strength while grinding, which metal-bonded grinding wheels can offer. Truing and dressing of the wheels are major problems and they tend to glaze because of wheel loading. When grinding with superabrasive wheels, wheel loading can be avoided by dressing periodically to obtain continuous grinding. Electrolytic inprocess dressing (ELID) is the most suitable process for dressing metal-bonded grinding wheels during the grinding process. Nano-surface finish can be achieved only when chip removal is done at the atomic level. Recent developments of ductile mode machining of hard and brittle materials show that plastically deformed chip removal minimizes the subsurface damage of the workpiece. When chip deformation takes place in the ductile regime, a defect-free nano-surface is possible and it completely eliminates the polishing process. ELID is one of the processes used for atomic level metal removal and nano-surface finish. However, no proper and detailed studies have been carried out to clarify the fundamental characteristics for making this process a robust one. Consequently, an attempt has been made in this study to understand the fundamental characteristics of ELID grinding and their influence on surface finish.

  17. Effect of fiber orientations on surface grinding process of unidirectional C/SiC composites

    Science.gov (United States)

    Zhang, Lifeng; Ren, Chengzu; Ji, Chunhui; Wang, Zhiqiang; Chen, Guang

    2016-03-01

    The machining mechanism of woven ceramic matrix composites is one of the most challenging problems in composite application. To elucidate the grinding mechanism of the woven ceramic matrix composites, a new model material consisting of unidirectional CVI-C/SiC was prepared and ground. The composite was ground in three typical directions and the experimental investigation of the surface grinding process for this composite is described. In addition, the micro structural characteristics and grinding mechanism of the composite were analyzed. The result shows that brittle fracture is the dominant removal mechanism for grinding of the C/SiC composites, and the destroy form of the composites is mainly the syntheses of the matrix cracking, fiber fracture, and interfacial debonding. The grinding force follows the order: Normal > Longitudinal > Transverse, and the surface roughness follows: Longitudinal > Normal > Transverse. The grinding parameters (feed speed, cut depth, grinding speed) have great influence on the grinding force and surface roughness. Based on the findings, the grinding force and surface integrity of the woven ceramic matrix composites can be predicted. Furthermore, it is expected to provide a useful guideline for the design, evaluation and optimal application of the C/SiC composites.

  18. Mathematical models of homochiralisation by grinding of crystals

    CERN Document Server

    Wattis, Jonathan AD

    2010-01-01

    We review the existing mathematical models which describe physicochemical mechanisms capable of producing a symmetry-breaking transition to a state in which one chirality dominates the other. A new model is proposed, with the aim of elucidating the fundamental processes at work in the crystal grinding systems of Viedma [Phys Rev Lett 94, 065504, (2005)] and Noorduin [J Am Chem Soc 130, 1158, (2008)]. We simplify the model as far as possible to uncover the fundamental competitive process which causes the symmetry-breaking, and analyse other simplifications which might be expected to show symmetry-breaking.

  19. Mathematical models of the homochiralisation of crystals by grinding.

    Science.gov (United States)

    Wattis, Jonathan A D

    2011-04-01

    We review the existing mathematical models which describe physicochemical mechanisms capable of producing a symmetry-breaking transition to a state in which one chirality dominates the other. A new model is proposed, with the aim of elucidating the fundamental processes at work in the crystal grinding systems of Viedma (Phys Rev Lett 94:065504, 2005) and Noorduin (J Am Chem Soc 130:1158-1159, 2008). We simplify the model as far as possible to uncover the fundamental competitive process which causes the symmetry-breaking, and analyse other simplifications which might be expected to show symmetry-breaking. PMID:20683773

  20. Ion Milling of Sapphire

    Science.gov (United States)

    Gregory, Don A.; Herren, Kenneth A.

    2004-01-01

    The ion milling of sapphire is a complicated operation due to several characteristics of the material itself. It is a relatively hard transparent nonconductive crystalline material that does not transfer heat nearly as well as metals that have been successfully ion milled in the past. This investigation involved designing an experimental arrangement, using existing ion milling equipment, as the precursor to figuring the surface of sapphire and other insulating optical materials. The experimental arrangement employs a laser probe beam to constantly monitor the stresses being induced in the material, as it is being ion milled. The goal is to determine if the technique proposed would indeed indicate the stress being induced in the material so that these stresses can be managed to prevent failure of the optic.

  1. Production of normalized steel plate through normalizing rolling; Producao de chapas grossas normalizadas diretamente do calor de laminacao

    Energy Technology Data Exchange (ETDEWEB)

    Gorni, Antonio Augusto; Cavalcanti, Celso Gomes; Reis, Jackson Soares de Souza; Silveira, Jose Herbert Dolabela da [Companhia Siderurgica Paulista (COSIPA), SP (Brazil)

    1997-12-31

    Normalized plates can be got directly from the rolling heat through the use of a normalizing rolling process. In such way, an additional step of the conventional process of production of normalized plates - the normalizing heat treatment - can be suppressed, reducing the manufacturing cost of the product and shortening its production time. This relatively new production route is being used in several steelworks all over the world for many years. This work describes the implementation trials of normalizing rolling at COSIPA`s plate mill, using an alternative process of controlled rolling called recrystallization controlled rolling. The results got with new technique were successful, as it was able to produce plates with properties very similar to the conventionally normalized material, attending the requirements of the DIN 17100 RR 52-3N standard. This is one of many standards that permit the use of this new route of normalized steel plate production. (author) 14 refs., 8 figs., 2 tabs.

  2. Serpentine Waste Milling

    OpenAIRE

    Leško, M.; Búgel, M.; Pietriková, A.; T. Bakalár

    2005-01-01

    Serpentine heaps in the surroundings of Dobšina are a long-life ecological problem of the city and at the same time a suitable raw material for production of MgCl2 and SiO2. In the technological scheme of chemical processing the milling operation it has an important role. In this context the milling rate is an important parameter for creation of the technological scheme and suggestion of industrial equipment.

  3. Milling induces disorder in crystalline griseofulvin and order in its amorphous counterpart

    Energy Technology Data Exchange (ETDEWEB)

    Otte, Andrew; Zhang, Yan; Carvajal, M. Teresa; Pinal, Rodolfo (Purdue)

    2012-04-02

    This study investigates two apparently similar thermal signatures, shaped as bimodal exotherms, observed when either the crystalline or the amorphous from of the drug are subjected to milling. Crystalline griseofulvin was cryomilled and the (quenched-melt) amorphous form was subjected to either cryomilling or grinding. The thermal and surface properties of the resulting samples were analyzed using differential scanning calorimetry (DSC) and surface energy analysis. After milling, both the crystalline and the amorphous material revealed visually similar bimodal exothermic events when the heating rate was 20 C min{sup -1}. Under different heating rates, the pair of DSC peaks for the bimodal exotherm of each material behaved entirely different from each other. The two peaks of the bimodal event, as well as the glass transition, can be kinetically resolved for the ground amorphous form using standard mode DSC. In contrast, similar analysis was unable to resolve the bimodal exotherm or a glass transition in the case of the cryomilled crystals. Furthermore, cryomilled crystals do not exhibit a glass transition even when analyzed using modulated DSC. Synchrotron sourced X-ray analysis revealed that grinding the amorphous material results in the nucleation and growth of the crystalline form. Milling thus induces disorder in the crystals of griseofulvin but induces order in the amorphous form of the drug. The surface of the two milled systems consistently exhibited different energetics under a wide range of relative humidity conditions. These findings suggest that cryomilling induces both bulk and surface disorder, specifically, a certain level of dislocations on the crystal. In contrast, grinding the amorphous material lowers the activation energy for crystal formation, inducing nuclei formation and growth throughout the amorphous matrix.

  4. Preparation of magnesium ferrite nanoparticles by ultrasonic wave-assisted aqueous solution ball milling.

    Science.gov (United States)

    Chen, Ding; Li, Dian-yi; Zhang, Ying-zhe; Kang, Zhi-tao

    2013-11-01

    Magnesium ferrite, MgFe2O4 nanoparticles with high saturation magnetization were successfully synthesized using ultrasonic wave-assisted ball milling. In this study, the raw materials were 4MgCO3Mg(OH)25H2O and Fe2O3 powders and the grinding media was stainless steel ball. The average particle diameter of the product MgFe2O4 powders was 20 nm and the saturation magnetization of them reached 54.8 emu/g. The different results of aqueous solution ball milling with and without ultrasonic wave revealed that it was the coupling effect of ultrasonic wave and mechanical force that played an important role during the synthesis of MgFe2O4. In addition, the effect of the frequency of the ultrasonic wave on the ball milling process was investigated. PMID:23622867

  5. Improving Energy Efficiency Via Optimized Charge Motion and Slurry Flow in Plant Scale Sag Mills

    Energy Technology Data Exchange (ETDEWEB)

    Raj K. Rajamani

    2006-07-21

    A research team from the University of Utah is working to make inroads into saving energy in these SAG mills. In 2003, Industries of the Future Program of the Department of Energy tasked the University of Utah team to build a partnership between the University and the mining industry for the specific purpose of reducing energy consumption in SAG mills. A partnership was formed with Cortez Gold Mines, Outokumpu Technology, Kennecott Utah Copper Corporation, and Process Engineering Resources Inc. At Cortez Gold Operations the shell and pulp lifters of the semiautogenous grinding mill was redesigned. The redesigned shell lifter has been in operation for over three years and the redesigned pulp lifter has been in operation for over nine months now. This report summarizes the dramatic reductions in energy consumption. Even though the energy reductions are very large, it is safe to say that a 20% minimum reduction would be achieved in any future installations of this technology.

  6. In-process EDM truing to generate complex contours on metal-bond, superabrasive grinding wheels for precision grinding structural ceramics

    International Nuclear Information System (INIS)

    The demand and use of precision grinding of structural ceramics continue to increase as the worldwide advanced ceramic industry surpasses $20 billion is sales. Included in this industry are engineering structural ceramics, electronic ceramics, bioceramics and others. These materials are used in applications such as engine components, casting and extrusion dies, bearings, medical implants, nozzles, thermal insulators, and more. Along with the variety of ceramic applications comes a broad range of precision requirements, which in turn leads to various required processes to accommodate a spectrum of specifications. A process for grinding ceramic components to micrometer tolerances was employed and further developed at Lawrence Livermore National Laboratory for two separate grinding projects

  7. Effects of grind size when alkaline treating corn residue and impact of ratio of alkaline-treated residue and distillers grains on performance of finishing cattle.

    Science.gov (United States)

    Shreck, A L; Nuttelman, B L; Schneider, C J; Burken, D B; Harding, J L; Erickson, G E; Klopfenstein, T J; Cecava, M J

    2015-07-01

    Two studies were conducted to optimize use of alkaline-treated corn stover and wheat straw and distillers grains as partial corn replacements. In Exp. 1, a finishing experiment used 30 pens (12 steers/pen) of calf-fed steers (initial BW = 374 ± 23.9 kg) with a 2 × 2 + 1 factorial arrangement of treatments with 6 replications per treatment. Factors were grind size, where corn stover was processed through a 2.54- or 7.62-cm screen, and chemical treatment (corn stover either fed in native, non-treated form [NT; 93.4% DM] or alkaline treated [AT; 5% CaO hydrated to 50% DM]). No interactions (P ≥ 0.38) were noted between grind size and chemical treatment. Feeding AT compared with NT improved (P ≤ 0.02) final BW, ADG, and G:F. Reducing grind size improved (P ≤ 0.01) ADG and G:F, and no interaction with chemical treatment was observed. Steers fed AT had similar DMI, ADG, G:F, and carcass characteristics compared with a 5% roughage control that contained 15 percentage units (DM basis) more corn. In Exp. 2, 60 individually fed steers (initial BW = 402 ± 61.4 kg) were randomly assigned to 10 diets. Six treatments evaluated 10, 25, or 40% dry-rolled corn (DRC), which was replaced with either a 2:1 or 3:1 ratio (DM basis) of modified distillers grains plus solubles (MDGS) and treated corn stover analyzed as a 2 × 3 factorial. An additional 3 treatments were added where a 3:1 ratio of MDGS:straw were compared with a 3:1 ratio of MDGS:stover. As DRC increased, G:F (P = 0.06) quadratically increased for 3:1 MDGS:stover diets. Increasing DRC increased (P = 0.07) G:F in treated stover diets, regardless of ratio. Increasing DRC increased (P = 0.10) ADG for 3:1 ratios for both straw and stover. Reducing grind size, feeding a maximum of 20% treated crop residue, and maintaining at least 25% corn in the diet are strategies for optimizing cattle performance when replacing dry-rolled and high-moisture corn with treated crop residues and distillers grains. PMID:26440029

  8. THE STUDY OF SCALE FORMATION ON HOT ROLLED INGOTS AND BILLETS

    Directory of Open Access Journals (Sweden)

    GHEORGHE VLAICU

    2010-06-01

    Full Text Available During the heating for rolling, ingots and billets are affected by the chemical action of the heating atmosphere. Between the heating environment elements and steel components there are taking place chemical reactions initiated at the separation surface that may affect a layer in metal of about a few microns to a few millimeters. The thickness of the affected layer is a function of the environment nature, heated material composition, chemical reactions type and kinetics, heating rate and temperature. The aim of this paper is to correlate the oxidation and the decarburization processes during the heating of ingots and billets for rolling. The study was made on ingots and billets rolled at the breakdown mill of the Special Steel Complex, Physics Laboratories from MECHEL Targoviste, Romania. The scope of the study is the analysis of the scale obtained from the rolling mill train in order to obtain specific information that will be used in adjusting the rolling parameters for diminishing the oxidation and decarburization and for recycling the scale in electric furnaces.

  9. Rolling tool calibration for cold rolling of tubes

    International Nuclear Information System (INIS)

    An analysis was made of calibration methods for step-back rolling of tubes from austenitic steels to meet the order of nuclear power for tubes with a high quality of inner surfaces. On the basis of this analysis the optimization criterion chosen was the observance of the constant value of the ratio of wall thickness deformation to the deformation of tube diameter for any length of a tube. A logarithmic function was derived for the shape of the rolling pin. Operating trials showed that rolling instruments of the given design have a favourable effect on the quality of the inner surface of tubes and on the even load of the rolling system in an operating cycle. (Ha)

  10. Roll Control in Fruit Flies

    CERN Document Server

    Beatus, Tsevi; Cohen, Itai

    2014-01-01

    Due to aerodynamic instabilities, stabilizing flapping flight requires ever-present fast corrective actions. Here we investigate how flies control body roll angle, their most susceptible degree of freedom. We glue a magnet to each fly, apply a short magnetic pulse that rolls it in mid-air, and film the corrective maneuver. Flies correct perturbations of up to $100^{\\circ}$ within $30\\pm7\\mathrm{ms}$ by applying a stroke-amplitude asymmetry that is well described by a linear PI controller. The response latency is $\\sim5\\mathrm{ms}$, making the roll correction reflex one of the fastest in the animal kingdom.

  11. Effects of imbalance and geometric error on precision grinding machines

    Energy Technology Data Exchange (ETDEWEB)

    Bibler, J.E.

    1997-06-01

    To study balancing in grinding, a simple mechanical system was examined. It was essential to study such a well-defined system, as opposed to a large, complex system such as a machining center. The use of a compact, well-defined system enabled easy quantification of the imbalance force input, its phase angle to any geometric decentering, and good understanding of the machine mode shapes. It is important to understand a simple system such as the one I examined given that imbalance is so intimately coupled to machine dynamics. It is possible to extend the results presented here to industrial machines, although that is not part of this work. In addition to the empirical testing, a simple mechanical system to look at how mode shapes, balance, and geometric error interplay to yield spindle error motion was modelled. The results of this model will be presented along with the results from a more global grinding model. The global model, presented at ASPE in November 1996, allows one to examine the effects of changing global machine parameters like stiffness and damping. This geometrically abstract, one-dimensional model will be presented to demonstrate the usefulness of an abstract approach for first-order understanding but it will not be the main focus of this thesis. 19 refs., 36 figs., 10 tables.

  12. Dry-grinded ultrafine cements hydration. physicochemical and microstructural characterization

    Directory of Open Access Journals (Sweden)

    Foteini Kontoleontos

    2013-04-01

    Full Text Available The aim of the present research work was the evaluation of the physicochemical and microstructural properties of two ultrafine cements, produced by dry grinding of a commercial CEM I 42.5N cement. The effect of grinding on particle size distribution was determined by laser scattering analyzer. All cements were tested for initial and final setting times, consistency of standard paste, soundness, flow of normal mortar and compressive strengths after 1, 2, 7 and 28 days. The effect of the fineness on the heat of hydration was also investigated. The hydration products were determined by X-ray diffraction analysis and by Fourier transform infrared spectroscopy, at 1, 2, 7 and 28 days. The microstructure of the hardened cement pastes and their morphological characteristics were examined by scanning electron microscopy. Porosity and pore size distribution were evaluated by mercury intrusion porosimetry. The effects of greater fineness on compressive strengths were evident principally at early ages. After the first 24 hours of hydration, the compressive strength of the finest cements was about 3 times higher (over 48 MPa than the corresponding of CEM I 42.5N (15.1 MPa.

  13. Analysis on Large Deformation Compensation Method for Grinding Machine

    Directory of Open Access Journals (Sweden)

    Wang Ya-jie

    2013-08-01

    Full Text Available The positioning accuracy of computer numerical control machines tools and manufacturing systems is affected by structural deformations, especially for large sized systems. Structural deformations of the machine body are difficult to model and to predict. Researchs for the direct measurement of the amount of deformation and its compensation are farly limited in domestic and overseas,not involved to calculate the amount of deformation compensation. A new method to compensate large deformation caused by self-weight was presented in the paper. First of all, the compensation method is summarized; Then,static force analysis was taken on the large grinding machine through APDL(ANSYS Parameter Design Language. It could automatic extract results and form data files, getting the N points displacement in the working stroke of mechanical arm. Then, the mathematical model and corresponding flat rectangular function were established. The conclusion that the new compensation method is feasible was obtained through the analysis of displacement of N points. Finally, the MATLAB as a tool is used to calculate compensate amount and the accuracy of the proposed method is proved. Practice shows that the error caused by large deformatiion compensation method can meet the requirements of grinding.  

  14. Rolling of tungsten base cermet in four-roll grooves

    International Nuclear Information System (INIS)

    The sintered cermet pieces 30 mm in diameter were used to roll square bars sized 32, 16 and 12 mm (the one-pass reduction ratio in the range 1.25-1.80). Studies were made of the contact stresses and energy parameters in the rolling of tungsten bars. The results obtained can be useful in the the design of new equipment and development of industrial technology

  15. Fatigue crack growth and fracture mechanics analysis of a working roll surface layer material

    Directory of Open Access Journals (Sweden)

    M. Drobne

    2014-10-01

    Full Text Available Fatigue crack growth and fracture mechanics analysis of a working roll surface layer material is presented in this paper. The research is done on a hot strip mill working roll where High Chromium Steel is used for roll’s shell material. To obtain corresponding parameters, a rectangular single edge notched bend specimens – SENB, according to standard BS 7448, were used. The fatigue crack growth analysis was done on a resonant testing machine with use of special crack gauges, while for fracture mechanics parameters the electro–mechanical testing machine was used.

  16. Influence of chemistry and hot rolling conditions on high permeability non-grain oriented silicon steel

    International Nuclear Information System (INIS)

    This paper discusses the influence of chemical composition on the final electromagnetic properties in higher permeability material. Furthermore, the effect of the hot rolling practice and the end of austenite transformation temperature range on the hot band microstructure is described. The magnetic polarization J 5000 better than 1.7 T, using hot rolling conditions 40 mm transfer bar thickness, finish mill entry temperature 1000 deg. C, and finishing temperature 800-840 deg. C and after decarburization heat treatment and grain growth treatment, was obtained

  17. Hot rolling of intermetallics FeAl phase based alloys

    Directory of Open Access Journals (Sweden)

    G. Niewielski

    2008-02-01

    Full Text Available Purpose: The one of major problem restricting universal employment of intermetallic phase base alloy istheir low plasticity which leads to hampering their development as construction materials. The following workconcentrates on possibilities to form through rolling process the alloys with various aluminium content.Design/methodology/approach: After casting and annealing, alloy specimens were subjected to axialsymmetriccompression at temperatures ranging from 900 to 1200°C at 10 s-1 strain rates. In order to analyse theprocesses which take place during deformation, the specimens after deformation were intensely cooled with water.Structural examination was carried out using light microscopy. The process was conducted on the K -350 quartorolling mill used for hot rolling of flat products. The process was conducted in some stages in at temperaturesranging from 1200-900°C:Findings: The research carried out enabled the understanding of the phenomena taking place during hot rolling ofthe investigated alloy. An alloy with 38%at. aluminium concentration can be plastically formed at a temperature of upto 900°C, which has been also confirmed in plastometric studies conducted in the form of hot compression tests.Research limitations/implications:Practical implications: The obtained sheets can be used as constructional elements working in complex stressfields, at a high temperature and corrosive environmentsOriginality/value: The tests have shown that it is possible to form the investigated alloys through rolling processingonly where shields are applied. Rolling of the alloys without shields led to the occurrence of a grid of cracks.

  18. Manufacturing Demonstration Facility: Roll-to-Roll Processing

    Energy Technology Data Exchange (ETDEWEB)

    Datskos, Panos G [ORNL; Joshi, Pooran C [ORNL; List III, Frederick Alyious [ORNL; Duty, Chad E [ORNL; Armstrong, Beth L [ORNL; Ivanov, Ilia N [ORNL; Jacobs, Christopher B [ORNL; Graham, David E [ORNL; Moon, Ji Won [ORNL

    2015-08-01

    This Manufacturing Demonstration Facility (MDF)e roll-to-roll processing effort described in this report provided an excellent opportunity to investigate a number of advanced manufacturing approaches to achieve a path for low cost devices and sensors. Critical to this effort is the ability to deposit thin films at low temperatures using nanomaterials derived from nanofermentation. The overarching goal of this project was to develop roll-to-roll manufacturing processes of thin film deposition on low-cost flexible substrates for electronics and sensor applications. This project utilized ORNL s unique Pulse Thermal Processing (PTP) technologies coupled with non-vacuum low temperature deposition techniques, ORNL s clean room facility, slot dye coating, drop casting, spin coating, screen printing and several other equipment including a Dimatix ink jet printer and a large-scale Kyocera ink jet printer. The roll-to-roll processing project had three main tasks: 1) develop and demonstrate zinc-Zn based opto-electronic sensors using low cost nanoparticulate structures manufactured in a related MDF Project using nanofermentation techniques, 2) evaluate the use of silver based conductive inks developed by project partner NovaCentrix for electronic device fabrication, and 3) demonstrate a suite of low cost printed sensors developed using non-vacuum deposition techniques which involved the integration of metal and semiconductor layers to establish a diverse sensor platform technology.

  19. Effects of high energy grinding under different atmospheres on the solubility of lithium in copper an pure copper

    International Nuclear Information System (INIS)

    The mechanical alloying process (MA) has successfully obtained supersaturated solid solutions in a great many binary systems. Increased solubility of over 90% compared to the maximum in equilibrium for the solutes Ag and Co and increases greater than 50% for Cr and Fe have been reported after using MA for the production of copper-based alloys. This has led to the development of much research to determine the maximum solubilities in solid state that can be reached with this process and for different solutes. Lithium is one of the elements investigated. Unlike other metallic elements, lithium has had, comparatively speaking, a recent introduction in the area of investigation of structural materials. The reason is simple, none of lithium's properties had been fundamental in this field until a little more than three decades ago. Lithium is an element with exceptional chemical and physical properties but due to its high reactivity, obtaining it complicates the operating conditions under which it is processed. The formation of a copper-based alloy with lithium has major theoretical advantages particularly relative to reducing the density of the copper-based alloy. However, these elements have other physical and chemical properties that complicate this development when using conventional alloying production processes, particularly those involving a fusion stage, so the use of mechanical alloying as an alternative process has been proposed. Besides developing in solid state, MA has proven to be particularly efficient in obtaining solid solutions of elements that, under conditions of equilibrium, show very limited or even no solubility. This work has studied the effects of two control atmospheres on the high energy grinding of Cu and Li and pure copper, as well as the effect of milling time for both atmospheres. The milling for this study was carried out in a SPEX 8000D mill using a balls to powder ratio of 10:1, with steel containers and balls. The milling times varied from 3 to 30 hours and the control atmospheres used were argon and nitrogen. The microstructural changes of the powders as a function of the variables studied, were analyzed with scanning electron microscopy on a Philips XL-30 SFEG. The phases present in the samples were analyzed using X-ray diffraction on a Siemens 5000 diffractometer. The iron quantities in the samples after milling, were determined with atomic adsorption spectroscopy in a GBS 905 spectrometer and the oxygen contents were determined with infrared spectroscopy on a LECO TC-436 DR. Results show a marked effect of the control atmosphere on the microstructural characteristics and chemical composition of the copper and on the chemical composition in the case of the Cu-Li alloys (cw)

  20. Rolling Process Modeling Report: Finite-Element Prediction of Roll Separating Force and Rolling Defects

    Energy Technology Data Exchange (ETDEWEB)

    Soulami, Ayoub [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lavender, Curt A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Paxton, Dean M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Burkes, Douglas [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-04-23

    Pacific Northwest National Laboratory (PNNL) has been investigating manufacturing processes for the uranium-10% molybdenum (U-10Mo) alloy plate-type fuel for the U.S. high-performance research reactors. This work supports the Convert Program of the U.S. Department of Energy’s National Nuclear Security Administration (DOE/NNSA) Global Threat Reduction Initiative. This report documents modeling results of PNNL’s efforts to perform finite-element simulations to predict roll separating forces and rolling defects. Simulations were performed using a finite-element model developed using the commercial code LS-Dyna. Simulations of the hot rolling of U-10Mo coupons encapsulated in low-carbon steel have been conducted following two different schedules. Model predictions of the roll-separation force and roll-pack thicknesses at different stages of the rolling process were compared with experimental measurements. This report discusses various attributes of the rolled coupons revealed by the model (e.g., dog-boning and thickness non-uniformity).

  1. Electron spin resonance and thermoluminescence in powder form of clear fused quartz: effects of grinding

    International Nuclear Information System (INIS)

    Clear fused quartz (CFQ) tubes were powdered either manually by using a mortar and pestle (for coarse production) or mechanically, using a micronising mill (for fine production). A high and multisignal electron spin resonance (ESR) background was found in the fine powder even after annealing it at 900 deg. C for 20 min. In the case of the coarse powder, the signal (ESR background) varied inversely with particle size and was quite high for particle sizes lower than 38 ?m. In a subsidiary experiment, using fine SiO2 powder (99.8% pure, with the particle size of ?0.007 ?m), manufactured by using flame hydrolysis, only a weak background signal was found. The 60Co gamma-ray irradiated powders (?22 Gy) were subjected to ESR analysis or thermoluminescence (TL) readout. The ESR intensity of the coarse powder varied directly with particle size. Thus, the intensity for a particle size of 20-38 ?m was very low and almost the same as the unirradiated intensity. In TL readout the results were the opposite: the TL intensity of the coarse powder varied inversely with the particle size down to 38 ?m, after which it decreased with decreasing particle size of the material. The fine powder, produced by grinding the CFQ tubes, was insensitive to gamma-rays (at least at doses of up to 50 Gy); but for the flame hydrolysis SiO2 the situation was the opposite. The minimum detectable dose (MDD) for the CFQ in powder form using ESR was ?2 Gy, which is ?2 times higher than that for the bulk form, while the MDD for the powder using TL was ?20 ?Gy, which is ?2 times lower than that for the bulk form of the material

  2. Application of electrolytic in-process dressing for high-efficiency grinding of ceramic parts. Research activities 1995--96

    Energy Technology Data Exchange (ETDEWEB)

    Bandyopadhyay, B.P. [Univ. of North Dakota, Grand Forks, ND (United States). Dept. of Mechanical Engineering

    1997-02-01

    The application of Electrolytic In-Process Dressing (ELID) for highly efficient and stable grinding of ceramic parts is discussed. This research was performed at the Institute of Physical and Chemical Research (RIKEN), Tokyo, Japan, June 1995 through August 1995. Experiments were conducted using a vertical machining center. The silicon nitride work material, of Japanese manufacture and supplied in the form of a rectangular block, was clamped to a vice which was firmly fixed on the base of a strain gage dynamometer. The dynamometer was clamped on the machining center table. Reciprocating grinding was performed with a flat-faced diamond grinding wheel. The output from the dynamometer was recorded with a data acquisition system and the normal component of the force was monitored. Experiments were carried out under various cutting conditions, different ELID conditions, and various grinding wheel bonds types. Rough grinding wheels of grit sizes {number_sign}170 and {number_sign}140 were used in the experiments. Compared to conventional grinding, there was a significant reduction in grinding force with ELID grinding. Therefore, ELID grinding can be recommended for high material removal rate grinding, low rigidity machines, and low rigidity workpieces. Compared to normal grinding, a reduction in grinding ratio was observed when ELID grinding was performed. A negative aspect of the process, this reduced G-ratio derives from bond erosion and can be improved somewhat by adjustments in the ELID current. The results of this investigation are discussed in detail in this report.

  3. Frontal Impact of Rolling Spheres.

    Science.gov (United States)

    Domenech, A.; Casasus, E.

    1991-01-01

    A model of the inelastic collision between two spheres rolling along a horizontal track is presented, taking into account the effects of frictional forces at impact. This experiment makes possible direct estimates of the coefficients of restitution and friction. (Author)

  4. petaja muutuv roll / Anneli Kannus

    Index Scriptorium Estoniae

    Kannus, Anneli

    2003-01-01

    Eesti Kutsehariduse Edendamise hingu ja haridusministeeriumi koosts toimus 2003.a. jaanuaris Phajrvel kutsehariduse talveseminar. hes trhmas arutleti teemal "petaja muutuv roll ja lesanded" ning tdeti, et kutsepetaja ettevalmistus ei vasta koolide ootustele.

  5. Roll bonding of strained aluminium

    DEFF Research Database (Denmark)

    Staun, Jakob M.

    2003-01-01

    This report investigates roll bonding of pre-strained (å ~ 4) aluminium sheets to produce high strain material from high purity aluminium (99.996%) and commercial pure aluminium (99.6%). The degree of bonding is investigated by optical microscopy and ultrasonic scanning. Under the right...... circumstances both materials show good bonding, but the high purity material is excluded because of recrystallisation and the resulting loss of mechanical properties. The effect of cross stacking and roll bonding pre-strained sheets of the commercial purity material is investigated and some dependence of the...... cross rolled volume fraction is found. To further asses this effect, and the anisotropy, it is necessary to acquire knowledge about both texture and microstructure, e.g. by TEM. Roll bonding of pre-strained aluminium is found to be a possible alternative to ARB in the quest for ultra-fine grained...

  6. A new model-based approach for power plant Tube-ball mill condition monitoring and fault detection

    International Nuclear Information System (INIS)

    Highlights: • This is the first mathematical model of power plant Tube-ball mills to cover the whole milling process. • A novel on-line model based power plant condition monitoring method is reported. • The online implementation of the model is achieved and the model was verified through online test. • The model parameters can be on-line updated/optimised using Genetic Algorithms. - Abstract: With the fast growth in intermittent renewable power generation, unprecedented demands for power plant operation flexibility have posed new challenges to the ageing conventional power plants in the UK. Adding biomass to coal for co-fired power generation has become widely implemented practices in order to meet the emission regulation targets. These have impacted the coal mill and power plant operation safety and reliability. The Vertical Spindle mill model was developed through the authors’ work before 2007. From then, the new research progress has been made in modelling and condition monitoring for Tube-ball mills and is reported in the paper. A mathematical model for Tube-ball milling process is developed by applying engineering principles combined with model unknown parameter identifications using a computational intelligent algorithm. The model describes the whole milling process from the mill idle status, start-up to normal grinding and shut-down. The model is verified using on-site measurement data and on-line test. The on-line model is used for mill condition monitoring in two ways: (i) to compare the predicted and measured mill output pressure and temperatures and to raise alarms if there are big discrepancies; and (ii) to monitor the mill model parameter variation patterns which detect the potential faults and mill malfunctions

  7. Fundamentals of Rolling Contact Fatigue:

    OpenAIRE

    Grabulov, A.

    2010-01-01

    In the mechanical industry there is a need for continuous development towards increasing performance of various types of machinery. Critical components in such machines are exposed to gradually harsher operating environments involving higher cyclic stresses and operating temperatures. Examples of such fatigue-exposed components are gears, camshafts and rolling element bearings in engines and gearboxes. The components in the bearing industry are always subject to the high cycle rolling contact...

  8. Grease lubrication in rolling bearings

    CERN Document Server

    Lugt, Piet M

    2012-01-01

    The definitive book on the science of grease lubrication for roller and needle bearings in industrial and vehicle engineering. Grease Lubrication in Rolling Bearings provides an overview of the existing knowledge on the various aspects of grease lubrication (including lubrication systems) and the state of the art models that exist today. The book reviews the physical and chemical aspects of grease lubrication, primarily directed towards lubrication of rolling bearings. The first part of the book covers grease composition, properties and rheology, including thermal

  9. Diamond blade grinding as a means for removing surface contamination from concrete

    International Nuclear Information System (INIS)

    The use of a highway grinding unit for the decontamination of a 5,000 square foot surface is described. The type of equipment presently in use is described. Performance characteristics, waste collection and water usage are commented on. Variables in blade design are discussed. Feasibility of the grinding technique for water soluble contaminants and vertical surfaces is referred to

  10. Thermal model to investigate the temperature in bone grinding for skull base neurosurgery.

    Science.gov (United States)

    Zhang, Lihui; Tai, Bruce L; Wang, Guangjun; Zhang, Kuibang; Sullivan, Stephen; Shih, Albert J

    2013-10-01

    This study develops a thermal model utilizing the inverse heat transfer method (IHTM) to investigate the bone grinding temperature created by a spherical diamond tool used for skull base neurosurgery. Bone grinding is a critical procedure in the expanded endonasal approach to remove the cranial bone and access to the skull base tumor via nasal corridor. The heat is generated during grinding and could damage the nerve or coagulate the blood in the carotid artery adjacent to the bone. The finite element analysis is adopted to investigate the grinding-induced bone temperature rise. The heat source distribution is defined by the thermal model, and the temperature distribution is solved using the IHTM with experimental inputs. Grinding experiments were conducted on a bovine cortical bone with embedded thermocouples. Results show significant temperature rise in bone grinding. Using 50C as the threshold, the thermal injury can propagate about 3mm in the traverse direction, and 3mm below the ground surface under the dry grinding condition. The presented methodology demonstrated the capability of being a thermal analysis tool for bone grinding study. PMID:23683875

  11. Rational modes of round grinding of tough-to-machine materials

    OpenAIRE

    Сурду, Н. В.; Телегин, А. В.

    2010-01-01

    The article presents the cutting condition of cylindrical grinding of hard-to-machining materials tailored to the criteria of manifestation of the adsorption-plasticizing effect. The processing hard-to-machining materials different groups in these cutting condition provide improved performance, guaranteed lack of grinding defects and the formation of the hardened layer.

  12. Improving the the efficiency of centerless grinding of hard-to-cut materials

    OpenAIRE

    Сурду, Николай Васильевич; Телегин, Алексей Васильевич

    2012-01-01

    The article presents the cutting condition of cylindrical grinding of hard-to-machining materials tailored to the criteria of manifestation of the adsorption-plasticizing effect. The processing different groups of hard-to-machining materials provide improved performance, guaranteed lack of grinding defects and the formation of the hardened layer

  13. Creation of a planetary head for flat grinding of tough-to-machine materials

    OpenAIRE

    Сурду, Н. В.; Тарелин, А. А.; Телегин, А. В.; Фистик, А. Г.

    2010-01-01

    Reduced order of working out of the epicyclic head, allowing to realise a flat grinding, hard-tomachine materials, on an example of the trial sample for the machine tool 3Е711. Four-spindle an epicyclic grinding head the construction is developed for wheels in diameter of 80 mm.

  14. Application of a good manufacturing practices checklist and enumeration of total coliform in swine feed mills

    Directory of Open Access Journals (Sweden)

    Debora da Cruz Payao Pellegrini

    2014-02-01

    Full Text Available A cross-sectional study in four swine feed mills aimed to evaluate the correlation between the score of the inspection checklist defined in the Normative Instruction 4 (IN 4/ Brazilian Ministry of Agriculture, Livestock and Food Supply, and the enumeration of total coliforms throughout the manufacturing process. The most of non-conformities was found in the physical structure of the feed mills. Feed mill B showed the lowest number of unconformities while units A and D had the largest number of nonconformities. In 38.53% (489/1269 of the samples the presence of total coliform was detected, however no significant difference in the bacterial counts was observed between sampling sites and feed mills. The logistic regression pointed higher odds ratio (OR for total coliforms isolation at dosing (OR = 9.51, 95% CI: 4.43 to 20.41, grinding (OR = 7.10, 95% CI = 3.27 to 15.40 and residues (OR = 6.21, 95% CI: 3.88 to 9.95 In spite of having the second score in the checklist inspection, feed mill C presented the highest odds for total coliforms isolation (OR= 2,43, IC 95%: 1,68-3,53. The data indicate no association between the score of checklist and the presence of hygienic indicators in feed mills.

  15. Preparation of glibenclamide nanocrystals by a simple laboratory scale ultra cryo-milling

    International Nuclear Information System (INIS)

    The objective of this study is to evaluate the ability to reduce the particle size of glibenclamide (GBC) to the nanometric scale through a very simple and well-known laboratory scale method, the laboratory scale ultra cryo-milling. The effect of milling on GBC crystalline properties and dissolution behaviour was deliberately evaluated in the absence of any surfactants as stabilizers. The milling procedure consisted in adding particles to liquid nitrogen and milling them by hand in a mortar with a pestle for different time intervals (15, 30, 40 min). For comparison, the same milling procedure was also applied without liquid nitrogen. The particle size reduction was evaluated for the coarsest samples (>3 ?m) by measuring the particle Ferrets diameter through scanning electron microscopy, while for the smallest one (<3 ?m) by dynamic light scattering. A time grinding of 40 min in the presence of liquid nitrogen was revealed highly efficacious to obtain particles of nanodimensions, with a geometric mean particle size of 0.55 0.23 ?m and more than the 80 % of particles lower than 1,000 nm. Interestingly, non-agglomerated particles were obtained. Differential scanning calorimetry and X-ray powder diffractometry allowed to assess that under mechanical treatment no polymorphic transitions were observed, while a decrease in crystallinity degree occurred depending on the milling procedure (presence or absence of liquid nitrogen) and the milling time (crystallinity decreases at increasing milling time from 15 to 40 min). A comparison of the intrinsic dissolution rate and the dissolution from particles revealed an interesting improvement of particle dissolution particularly for particles milled in the presence of liquid nitrogen due to an increase in particle surface area and concentration gradient, according to the NoyesWhitney equation.

  16. Study on grinding of free-form optics surface in three-axis CNC machine

    Science.gov (United States)

    Yang, Haicheng; Zhang, Yun-long; Zhang, Feng; Wang, Zhibin; Bao, Long-xiang; Su, Ying; Guo, Rui; Liu, Xuan-min

    2014-08-01

    Due to the glass is a type of brittle material, so the high-precision free-form optics of glass material is usually machined by the technical of grinding. In this paper, for the characteristics of the diamond grinding wheel, analyzing the grinding path of free-form optics and mathematical model of the path is established based on the three-axis CNC grinding device. Moreover, the cause of the interference in the process of grinding is analyzed and the methods of avoiding. Finally, based on the above analysis results, through the experiment, the free-form optics surface accuracy was reached to 3.6um, realize the machining of the free-form optics.

  17. Measurement of Force Components and Ra Surface Roughness Parameter During Grinding Titanium Alloy

    Directory of Open Access Journals (Sweden)

    Grdulska A.

    2014-10-01

    Full Text Available The paper deals with the measurements of selected parameters during grinding process of aerospace industry alloy. Grinding is one of the most important methods of shaping machine elements. As a result of grinding with high dimensional and shape accuracy as well as with the expected parameters describing the state of the surface layer (SL should be obtained. Grinding difficult to machine materials used in the aerospace industry is an issue currently being examined by various research centres. An excellent example is the analysis of the grinding process of titanium alloys, as these materials have very poor machinability due to the tendency to adherence to abrasive materials, low thermal conductivity, high strength and compliance at elevated temperatures, which may adversely impact on the quality of SL. A number of factors influence on shaping SL. Worth mentioning are mechanical and thermal phenomena, as well as the type of cutting fluid and abrasive materials

  18. Investigation of the formation process of two piracetam cocrystals during grinding

    DEFF Research Database (Denmark)

    Rehder, Sönke; Klukkert, Marten; Löbmann, Korbinian A. M.; Strachan, Clare J.; Sakmann, Albrecht; Gordon, Keith; Rades, Thomas; Leopold, Claudia S.

    2011-01-01

    Cocrystal formation rates during dry grinding and liquid-assisted grinding were investigated by X-ray powder diffractometry and Raman spectroscopy. Two polymorphic forms of piracetam were used to prepare known piracetam cocrystals as model substances, i.e.,piracetam-citric acid and piracetam......-tartaric acid cocrystals. Raman spectroscopy in combination with principal component analysis was used to visualize the cocrystal formation pathways. During dry grinding, cocrystal formation appeared to progress via an amorphous intermediate stage, which was more evident for the piracetam-citric acid than for...... the piracetam-tartaric acid cocrystal. It was shown that liquid-assisted grinding led to faster cocrystal formation than dry grinding, which may be explained by the higher transformation rate due to the presence of liquid. The cocrystal formation rate did not depend on the applied polymorphic form of...

  19. Comparison of Materials for Use in the Precision Grinding of Optical Components

    Energy Technology Data Exchange (ETDEWEB)

    Evans, Boyd M. III; Miller, Arthur C. Jr.; Egert, Charles M.

    1997-12-31

    Precision grinding of optical components is becoming an accepted practice for rapidly and deterministically fabrication optical surfaces to final or near-final surface finish and figure. In this paper, a comparison of grinding techniques and materials is performed. Flat and spherical surfaces were ground in three different substrate materials: BK7 glass, chemical vapor deposited (CVD) silicon carbide ceramic, and sapphire. Spherical surfaces were used to determine the contouring capacity of the process, and flat surfaces were used for surface finish measurements. The recently developed Precitech Optimum 2800 diamond turning and grinding platform was used to grind surfaces in 40mm diameter substrates sapphire and silicon carbide substrates and 200 mm BK7 glass substrates using diamond grinding wheels. The results of this study compare the surface finish and figure for the three materials.

  20. Effect of Cooling Environment on Grinding Performance of Nickel Based Superalloy Inconel 718

    Directory of Open Access Journals (Sweden)

    Raju S. Pawade

    2012-01-01

    Full Text Available The study presents the experimental investigation of surface grinding of superalloy Inconel 718. The grinding performance in terms of grinding force, surface roughness and surface topography were examined by conducting statistical experiments. The parameters that have been chosen as control factors are: table speed, infeed, grit size and the type of lubricant. An L27 orthogonal array experiments were conducted. The results show that the grit size and infeed are the most significant parameters on surface roughness Ra measured across the table feed direction. The interaction effect between lubricant and grit size is relatively important as compared to the individual effect of the latter variable. As far as the grinding forces are concerned, the grit size and table speed have largest contribution among the chosen parameters. SEM (Semester examination revealed the flaws such as abrasion marks, smeared layers and micro-particle deposits on the surfaces produced in grinding.

  1. Deformation analysis of micro/nano indentation and diamond grinding on optical glasses

    Science.gov (United States)

    Zhao, Qingliang; Zhao, Lingling; Guo, Bing; Stephensin, David; Corbett, John

    2012-05-01

    The previous research of precision grinding optical glasses with electrolytic in process dressing (ELID) technology mainly concentrated on the action of ELID and machining parameters when grinding, which aim at generating very "smoothed" surfaces and reducing the subsurface damage. However, when grinding spectrosil 2000 and BK7 glass assisted with ELID technology, a deeply comparative study on material removal mechanism and the wheel wear behaviors have not been given yet. In this paper, the micro/nano indentation technique is initially applied for investigating the mechanical properties of optical glasses, whose results are then refereed to evaluate the machinability. In single grit diamond scratching on glasses, the scratching traces display four kinds of scratch characteristics according to different material removal modes. In normal grinding experiments, the result shows BK7 glass has a better machinability than that of spectrosil 2000, corresponding to what the micro/nano indentation vent revealed. Under the same grinding depth parameters, the smaller amplitude of acoustic emission (AE) raw signals, grinding force and grinding force ratio correspond to a better surface quality. While for these two kinds of glasses, with the increasing of grinding depth, the variation trends of the surface roughness, the force ratio, and the AE raw signals are contrary, which should be attributed to different material removal modes. Moreover, the SEM micrographs of used wheels surface indicate that diamond grains on the wheel surface after grinding BK7 glass are worn more severely than that of spectrosil 2000. The proposed research analyzes what happened in the grinding process with different material removal patterns, which can provide a basis for producing high-quality optical glasses and comprehensively evaluate the surface and subsurface integrity of optical glasses.

  2. Optimization of the dressing parameters in cylindrical grinding based on a generalized utility function

    Science.gov (United States)

    Aleksandrova, Irina

    2016-01-01

    The existing studies, concerning the dressing process, focus on the major influence of the dressing conditions on the grinding response variables. However, the choice of the dressing conditions is often made, based on the experience of the qualified staff or using data from reference books. The optimal dressing parameters, which are only valid for the particular methods and dressing and grinding conditions, are also used. The paper presents a methodology for optimization of the dressing parameters in cylindrical grinding. The generalized utility function has been chosen as an optimization parameter. It is a complex indicator determining the economic, dynamic and manufacturing characteristics of the grinding process. The developed methodology is implemented for the dressing of aluminium oxide grinding wheels by using experimental diamond roller dressers with different grit sizes made of medium- and high-strength synthetic diamonds type ??32 and ??80. To solve the optimization problem, a model of the generalized utility function is created which reflects the complex impact of dressing parameters. The model is built based on the results from the conducted complex study and modeling of the grinding wheel lifetime, cutting ability, production rate and cutting forces during grinding. They are closely related to the dressing conditions (dressing speed ratio, radial in-feed of the diamond roller dresser and dress-out time), the diamond roller dresser grit size/grinding wheel grit size ratio, the type of synthetic diamonds and the direction of dressing. Some dressing parameters are determined for which the generalized utility function has a maximum and which guarantee an optimum combination of the following: the lifetime and cutting ability of the abrasive wheels, the tangential cutting force magnitude and the production rate of the grinding process. The results obtained prove the possibility of control and optimization of grinding by selecting particular dressing parameters.

  3. Innovative grinding wheel design for cost-effective machining of advanced ceramics. Phase I, final report

    Energy Technology Data Exchange (ETDEWEB)

    Licht, R.H.; Ramanath, S.; Simpson, M.; Lilley, E.

    1996-02-01

    Norton Company successfully completed the 16-month Phase I technical effort to define requirements, design, develop, and evaluate a next-generation grinding wheel for cost-effective cylindrical grinding of advanced ceramics. This program was a cooperative effort involving three Norton groups representing a superabrasive grinding wheel manufacturer, a diamond film manufacturing division and a ceramic research center. The program was divided into two technical tasks, Task 1, Analysis of Required Grinding Wheel Characteristics, and Task 2, Design and Prototype Development. In Task 1 we performed a parallel path approach with Superabrasive metal-bond development and the higher technical risk, CVD diamond wheel development. For the Superabrasive approach, Task 1 included bond wear and strength tests to engineer bond-wear characteristics. This task culminated in a small-wheel screening test plunge grinding sialon disks. In Task 2, an improved Superabrasive metal-bond specification for low-cost machining of ceramics in external cylindrical grinding mode was identified. The experimental wheel successfully ground three types of advanced ceramics without the need for wheel dressing. The spindle power consumed by this wheel during test grinding of NC-520 sialon is as much as to 30% lower compared to a standard resin bonded wheel with 100 diamond concentration. The wheel wear with this improved metal bond was an order of magnitude lower than the resin-bonded wheel, which would significantly reduce ceramic grinding costs through fewer wheel changes for retruing and replacements. Evaluation of ceramic specimens from both Tasks 1 and 2 tests for all three ceramic materials did not show evidence of unusual grinding damage. The novel CVD-diamond-wheel approach was incorporated in this program as part of Task 1. The important factors affecting the grinding performance of diamond wheels made by CVD coating preforms were determined.

  4. EVOLUTION OF THE AUSTENITE GRAIN SIZE DURING HOT STRIP ROLLING OF NIOBIUM MICROALLOYED STEELS

    Directory of Open Access Journals (Sweden)

    Antonio Augusto Gorni

    2015-06-01

    Full Text Available The occurrence of dynamic recrystallization in the intermediate stands of the Finishing Mill of a Hot Strip Mill promotes substantial softening of the rolling stock, a situation that can cause operational problems and even scrapping of the strip. The aim of this work was to identify the specific process conditions that can lead to this situation, which was carried out through the application of a microstructural evolution model. It was verified, for the specific conditions of the Cubatão Works of Usiminas, that this problem generally occurs during the processing of thin hot coils, with a relatively low Nb content and under rolling temperatures slightly lower than the normal range.

  5. Nano surface generation of grinding process using carbon nano tubes

    Indian Academy of Sciences (India)

    S Prabhu; B K Vinayagam

    2010-12-01

    Nano surface finish has become an important parameter in the semiconductor, optical, electrical and mechanical industries. The materials used in these industries are classified as difficult to machine materials such as ceramics, glasses and silicon wafers. Machining of these materials up to nano accuracy is a great challenge in the manufacturing industry. Finishing of micro components such as micro-moulds, micro-lenses and micro-holes need different processing techniques. Conventional finishing methods used so far become almost impossible or cumbersome. In this paper, a nano material especially multi wall carbon nano tube is used in the machining process like grinding to improve the surface characteristics from micro to nano level.

  6. Pyrolysis of a waste from the grinding of scrap tyres.

    Science.gov (United States)

    Fernndez, A M; Barriocanal, C; Alvarez, R

    2012-02-15

    The fibres that are used to reinforce tyres can be recovered as a waste in the process of grinding of scrap tyres. In this paper beneficiation through pyrolysis is studied since the fibres are made up of polymers with a small amount of rubber because the latter is difficult to separate. The experiments were performed at three temperatures (400, 550 and 900C) in a horizontal oven. The three products - gas, oil and char - obtained from the pyrolysis were investigated. The composition of the gas was analyzed by means of gas chromatography. The oil was studied by gas chromatography and infrared spectroscopy. The char porous structure was determined by N(2) adsorption. In addition, the topography of the chars was studied by means of scanning electron microscopy (SEM). The products resulting from the pyrolysis of the fibres were compared with those obtained from scrap rubber. PMID:22204837

  7. Calculation and Analysis of Temperature Distribution in Hot Rolling Strip

    Directory of Open Access Journals (Sweden)

    Kaixiang Peng

    2013-07-01

    Full Text Available Modern steel grades require constant and reproducible production conditions both in the hot strip mill and in the cooling section to achieve constant material properties along the entire strip length and from strip to strip. Calculation of the temperature in final rolling process always utilizes factors such as the work piece's inner organizational structure, plastic deformation, and it's variations of properties and so on, also as well as the physical parameters such as gauge, shape, etc. In this paper, a finite element model is constructed for the temperature field in a rolling process. The temperature field of strip steel is modeled with a 3-D finite element analysis (FEA structure, simultaneously considering the distribution of the work roll temperature. Then the distribution of field is simulated numerically. From the model, the temperature contours can be obtained by analysis of the temperature distribution of contact area. At the same time, the distribution of temperature in any position at any time can be acquired. These efforts provide the reliable parameters for the later finishing temperature and shape control.  

  8. Comparison of tungsten carbide and stainless steel ball bearings for grinding single maize kernels in a reciprocating grinder

    Science.gov (United States)

    Reciprocating grinders can grind single maize kernels by shaking the kernel in a vial with a ball bearing. This process results in a grind quality that is not satisfactory for many experiments. Tungesten carbide ball bearings are nearly twice as dense as steel, so we compared their grinding performa...

  9. Synthesis of vanadium-modified rutile TiO2 nanoparticle by reactive grinding method and its photocatalytic activity under solar light at room temperature

    International Nuclear Information System (INIS)

    Rutile TiO2 was synthesized by sol–gel method. Vanadium-doped rutile TiO2 nanoparticle was obtained by reactive grinding method. The photocatalytic activity was evaluated by the degradation of methylene blue (MB) under solar light at room temperature. The results show that after 4 h of milling the particle size of rutile decreased from 130 to 14 nm and the Brunauer–Emmet–Teller (BET) specific surface area increased from 7.18 to 15.12 m2 g−1. The vanadium doping promoted the particle growth and the particle size of vanadium-modified rutile TiO2 obtained by 4 h of milling is about 22 nm, but the BET specific surface area increased from 15.12 m2 g−1 for TiO2 to 20.8 m2 g−1 for vanadium-doped TiO2 under the same conditions. The 5% vanadium-doped rutile possessed better absorption ability of solar light; the calculated band gap energy value is 2.7 eV. The degradation rate of MB on vanadium-doped rutile TiO2 was higher than that of pure rutile obtained after the same time of milling. (paper)

  10. Online monitoring and control of particle size in the grinding process using least square support vector regression and resilient back propagation neural network.

    Science.gov (United States)

    Pani, Ajaya Kumar; Mohanta, Hare Krishna

    2015-05-01

    Particle size soft sensing in cement mills will be largely helpful in maintaining desired cement fineness or Blaine. Despite the growing use of vertical roller mills (VRM) for clinker grinding, very few research work is available on VRM modeling. This article reports the design of three types of feed forward neural network models and least square support vector regression (LS-SVR) model of a VRM for online monitoring of cement fineness based on mill data collected from a cement plant. In the data pre-processing step, a comparative study of the various outlier detection algorithms has been performed. Subsequently, for model development, the advantage of algorithm based data splitting over random selection is presented. The training data set obtained by use of Kennard-Stone maximal intra distance criterion (CADEX algorithm) was used for development of LS-SVR, back propagation neural network, radial basis function neural network and generalized regression neural network models. Simulation results show that resilient back propagation model performs better than RBF network, regression network and LS-SVR model. Model implementation has been done in SIMULINK platform showing the online detection of abnormal data and real time estimation of cement Blaine from the knowledge of the input variables. Finally, closed loop study shows how the model can be effectively utilized for maintaining cement fineness at desired value. PMID:25528293

  11. Mathematical simulation of controlled cooling for high speed rolled wire in Stelmor process

    International Nuclear Information System (INIS)

    Mathematical models have been developed to predict the temperature distribution and austenite - pearlite transformation kinetics during the processing of high carbon steel wire in a stelmor machine. For a given rod radius there are three critical fans whose mechanical efficiency should be periodically reviewed to maintain constant cooling condition. These models are currently being applied for rod production control at the transformation at the conveyor of Tangshan Iron and Steel Co. Ltd., High Speed Wire Rod Rolling Mill, China. (author)

  12. Effect of feed grinding methods with and without expansion on prececal and total tract mineral digestibility as well as on interior and exterior egg quality in laying hens.

    Science.gov (United States)

    Hafeez, A; Mader, A; Ruhnke, I; Männer, K; Zentek, J

    2016-01-01

    The grinding of cereals by various milling methods as well as thermal treatment of feed may influence mineral digestibility and egg quality. The present study investigated the effect of feed produced by disc mill (D) and wedge-shaped disc mill (WSD), as mash (M) or expandate (E) on apparent ileal absorption (AIA) and apparent total digestibility (ATD) of calcium, phosphorus, magnesium, zinc, manganese, copper and iron, as well as on egg quality in laying hens. A total of 192 hens (Lohmann Brown) aged 19 wk, were assigned using a randomized design with a 2 × 2 factorial arrangement. Four experimental diets were offered ad libitum. Eggs were analyzed for weight, shape index, area, shell weight per unit surface area, yolk color, air cell, blood spot, Haugh unit, albumen and yolk measures (index, weight, height, width and length), shell measures (surface area, stability, density, thickness and membrane weight), as well as percent contents of albumen, yolk, shell, and shell membrane. The ATD for phosphorus, manganese, and copper was higher in WSD compared with D treatment (P = 0.028, P = 0.028 and P = 0.016, respectively). The interaction between milling methods and thermal treatment influenced ATD of copper (P = 0.033), which was higher in WSD+M group (41.0 ± 20.2) compared with D+E group (-3.21 ± 25.1), whereas no differences were observed for D+M (1.90 ± 37.8) and WSD+E (8.02 ± 36.2) groups. Egg stability tended to be higher in E compared with M treatment (P = 0.055). Albumen weight, percentage albumen weight, and albumen: yolk were higher and percentage yolk weight was lower in D compared with WSD treatment (P = 0.043, P = 0.027, P = 0.024, and P = 0.041, respectively). Number of blood spots was higher in E than M treatment (P = 0.053). In conclusion, use of a wedge-shaped disc mill resulted in higher ATD for phosphorus, manganese, and copper than use of a disc mill; however, digestibility for majority of minerals as well as egg quality parameters was comparable. Therefore, feed produced by either disc mill or wedge-shaped disc mill as mash or expandate may be used for laying hens without negative effects on egg quality. PMID:26574028

  13. Ambient roll-to-roll fabrication of flexible solar cells based on small molecules

    DEFF Research Database (Denmark)

    Lin, Yuze; Dam, Henrik Friis; Andersen, Thomas Rieks; Bundgaard, Eva; Fu, Weifei; Chen, Hongzheng; Krebs, Frederik C; Zhan, Xiaowei

    2013-01-01

    All solution-processed roll-to-roll flexible solar cells based on a starshaped small molecule donor and PCBMacceptor were fabricated by slot-die coating, as the first successful example reported for small molecule roll-to-roll flexible solar cells.......All solution-processed roll-to-roll flexible solar cells based on a starshaped small molecule donor and PCBMacceptor were fabricated by slot-die coating, as the first successful example reported for small molecule roll-to-roll flexible solar cells....

  14. Ready to Rock and Roll

    Science.gov (United States)

    2004-01-01

    This image from the Mars Exploration Rover Spirit hazard-identification camera shows the rover's perspective just before its first post-egress drive on Mars. On Sunday, the 15th martian day, or sol, of Spirit's journey, engineers drove Spirit approximately 3 meters (10 feet)toward its first rock target, a football-sized, mountain-shaped rock called Adirondack (not pictured). In the foreground of this image are 'Sashimi' and 'Sushi' - two rocks that scientists considered investigating first. Ultimately, these rocks were not chosen because their rough and dusty surfaces are ill-suited for grinding.

  15. Modelling of fracture wear in vitrified cBN grinding wheels

    Directory of Open Access Journals (Sweden)

    M.J. Jackson

    2007-09-01

    Full Text Available Purpose: The paper describes modelling of fracture wear in vitrified cBN grinding wheels.Design/methodology/approach: The approach used in the paper is based on using finite elements to model fracture wear processes in vitrified cBN grinding wheels. The approach used models fracture wear processes and ignores abrasive wear of the abrasive grains.Findings: The findings show that during grinding the grain is subjected to forces that create fracture initiation zones in the sharp abrasive grains where tensile and compressive stresses dominate in certain parts of the abrasive grains.Research limitations/implications: The findings show that further research is required that prevents the formation of crack initiation zones and considers the effects of wear flats on the magnitude of stresses in the abrasive grains.Practical implications: The results imply that abrasive fracture wear is the dominant wear mechanism when grinding with sharp vitrified cBN grinding wheels.Originality/value: The originality of this paper is reflected in the fact that this is the first time that fracture wear has been modelled in sharp vitrified cBN grinding wheels. The results presented in this paper will illuminate the need for accurate modelling of the wear of vitrified superabrasive grinding wheels.

  16. Advances and patents about grinding equipments with nano-particle jet minimum quantity lubrication.

    Science.gov (United States)

    Jia, Dongzhou; Li, Changhe; Wang, Sheng; Zhang, Qiang; Hou, Yali

    2014-01-01

    In recent years, a large number of patents have been devoted to developing minimum quantity lubrication (MQL) grinding techniques that can significantly improve both environmentally conscious and energy saving and costeffective sustainable grinding fluid alternatives. Among them, one patent is about a controllable nano-fluids jet MQL grinding system based on electrostatic atomization. Using the principle of electrostatics, it can achieve the control of droplet transfer by charging the sprayed droplets. This system can improve the uniformity of the droplet spectrum, liquid deposition efficiency and effective utilization of liquid. It can also effectively control the movement patterns of the droplets, thereby reducing the pollution of the environment and providing better health protection for workers. Although researchers accomplished profound and systematic studies on MQL, especially on nano-particles jet MQL. It can solve the shortage of MQL in cooling performance, greatly improve the working environment, save energy and reduce costs to achieve a low-carbon manufacturing. The unique lubricating performance and tribological property of solid nano-particles form nano-particle shearing films at the grinding wheel/workpiece interface, which can enhance the lubricating performance of MQL grinding. Existing studies on MQL grinding equipments, however, cannot meet the needs of the technological development. Therefore, our research provided a general introduction of the latest patients and research progress of nanoparticles jet MQL grinding equipments presented by the research team from Qingdao Technological University. PMID:25336175

  17. Controlled wear of vitrified abrasive materials for precision grinding applications

    Indian Academy of Sciences (India)

    M J Jackson; B Mills; M P Hitchiner

    2003-10-01

    The study of bonding hard materials such as aluminium oxide and cubic boron nitride (BN) and the nature of interfacial cohesion between these materials and glass is very important from the perspective of high precision grinding. Vitrified grinding wheels are typically used to remove large volumes of metal and to produce components with very high tolerances. It is expected that the same grinding wheel is used for both rough and finish machining operations. Therefore, the grinding wheel, and in particular its bonding system, is expected to react differently to a variety of machining operations. In order to maintain the integrity of the grinding wheel, the bonding system that is used to hold abrasive grains in place reacts differently to forces that are placed on individual bonding bridges. This paper examines the role of vitrification heat treatment on the development of strength between abrasive grains and bonding bridges, and the nature of fracture and wear in vitrified grinding wheels that are used for precision grinding applications.

  18. Roll casting of 5182 aluminium alloy

    OpenAIRE

    Haga, T; M. Mtsuo; D. Kunigo; Hatanaka, Y; R. Nakamuta; H. Watari; S. Kumai

    2009-01-01

    Purpose: of this paper is investigation of the ability of the high speed roll casting of 5182 aluminium alloy. Appropriate twin roll caster to cast the 5182 strip was researched.Design/methodology/approach: Method used in the present study was an unequal diameter twin roll caster and a vertical type high speed twin roll caster equipped with mild steel rolls without parting material.Findings: are that the vertical type high speed twin roll caster was effective to cast 5182 strip at high speed....

  19. Hot rolling of thick uranium molybdenum alloys

    Energy Technology Data Exchange (ETDEWEB)

    DeMint, Amy L.; Gooch, Jack G.

    2015-11-17

    Disclosed herein are processes for hot rolling billets of uranium that have been alloyed with about ten weight percent molybdenum to produce cold-rollable sheets that are about one hundred mils thick. In certain embodiments, the billets have a thickness of about 7/8 inch or greater. Disclosed processes typically involve a rolling schedule that includes a light rolling pass and at least one medium rolling pass. Processes may also include reheating the rolling stock and using one or more heavy rolling passes, and may include an annealing step.

  20. Interim report on task 1.2: near equilibrium processing requirements - attrition milling part 1 of 2 to Lawrence Livermore National for contract b345772

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, M W A; Vance, E R; Day, R A; Eddowes, T; Moricca, S

    2000-04-30

    The objective of Task 1.2 has only partly been achieved as the work on Pu/U-formulations and to a significant degree on Th/U-formulations has been performed under grinding/blending conditions that did not replicate plant-like fabrication processes, particularly in the case with the small glovebox attritor. Nevertheless the results do show that actinide-rich particles, not present in specimens made via the alkoxide-route (equilibrium conditions), occur when the grinding process is not efficient enough to ensure that high-fired PuO{sub 2}, ThO{sub 2} and UO{sub 2} particles are below a critical size. Our current perception is that the critical size for specimens sintered at 1350 C for 4 hours is about 5 {micro}m in diameter. The critical size is difficult to estimate, as it is equal to the starting diameter of actinide oxides just visible within brannerite regions. Our larger scale attritor experiments as well as experience with wet and dry ball milling suggests that acceptable mineralogy and microstructure can be obtained by dry milling via attritor and ball mills. This is provided that appropriate attention is paid to the size and density of the grinding media, grinding additives that reduce caking of the powder, and in the case of attritors the grinding speed and pot setup. The ideal products for sintering are free flowing granules of {approx} 100 {micro}m containing constituents ground to about 1 {micro}m to ensure homogeneity and equilibrium mineralogy.