WorldWideScience

Sample records for brazing

  1. Brazing

    International Nuclear Information System (INIS)

    This report is a compilation of published literature on high temperature brazing covering the period 1973-1978. The references are listed alphabetically with regard to the base material or combination of base materials to be brazed. Trade names are treated as base materials. The report contains approximately 1500 references, of which 300 are to patents

  2. Brazing handbook

    CERN Document Server

    American Welding Society

    2007-01-01

    By agreement between the American Welding Society C3 Committee on Brazing and Soldering and the ASM Handbook Committee, the AWS Brazing Handbook has been formally adopted as part of the ASM Handbook Series. Through this agreement, the brazing content in the ASM Handbook is significantly updated and expanded. The AWS Brazing Handbook, 5th Edition provides a comprehensive, organized survey of the basics of brazing, processes, and applications. Addresses the fundamentals of brazing, brazement design, brazing filler metals and fluxes, safety and health, and many other topics. Includes new chapters on induction brazing and diamond brazing.

  3. Laser Brazing of High Temperature Braze Alloy

    Science.gov (United States)

    Gao, Y. P.; Seaman, R. F.; McQuillan, T. J.; Martiens, R. F.

    2000-01-01

    The Space Shuttle Main Engine (SSME) consists of 1080 conical tubes, which are furnace brazed themselves, manifolds, and surrounding structural jacket making almost four miles of braze joints. Subsequent furnace braze cycles are performed due to localized braze voids between the coolant tubes. SSME nozzle experiences extremely high heat flux (180 mW/sq m) during hot fire. Braze voids between coolant tubes may result in hot combustion gas escape causing jacket bulges. The nozzle can be disqualified for flight or result in mission failure if the braze voids exceed the limits. Localized braze processes were considered to eliminate braze voids, however, damage to the parent materials often prohibited use of such process. Being the only manned flight reusable rocket engine, it has stringent requirement on the braze process. Poor braze quality or damage to the parent materials limits the nozzle service life. The objective of this study was to develop a laser brazing process to provide quality, localized braze joints without adverse affect on the parent materials. Gold (Au-Cu-Ni-Pd-Mn) based high temperature braze alloys were used in both powder and wire form. Thin section iron base superalloy A286 tube was used as substrate materials. Different Laser Systems including CO2 (10.6 micrometers, 1kW), ND:YAG (1.06 micrometers, 4kW). and direct diode laser (808nm. 150W) were investigated for brazing process. The laser process variables including wavelength. laser power, travel speed and angle of inclination were optimized according to bead geometry and braze alloy wetting at minimum heat input level, The properties of laser brazing were compared to that of furnace brazing. Microhardness profiles were used for braze joint property comparison between laser and furnace brazing. The cooling rate of laser brazing was compared to furnace brazing based on secondary dendritic arm spacing, Both optical and Scanning Electron Microscope (SEM) were used to evaluate the microstructures of

  4. Reversible brazing process

    Science.gov (United States)

    Pierce, Jim D.; Stephens, John J.; Walker, Charles A.

    1999-01-01

    A method of reversibly brazing surfaces together. An interface is affixed to each surface. The interfaces can be affixed by processes such as mechanical joining, welding, or brazing. The two interfaces are then brazed together using a brazing process that does not defeat the surface to interface joint. Interfaces of materials such as Ni-200 can be affixed to metallic surfaces by welding or by brazing with a first braze alloy. The Ni-200 interfaces can then be brazed together using a second braze alloy. The second braze alloy can be chosen so that it minimally alters the properties of the interfaces to allow multiple braze, heat and disassemble, rebraze cycles.

  5. Induction Brazing

    DEFF Research Database (Denmark)

    Henningsen, Poul

    Induction brazing is a fast and appropriate method for industrial joining of complex geometries and metal combinations. In all types of brazing processes it is important to heat the joint interface of the two materials to the same, high temperature. If one of the specimens is warmer than the other...... materials has large influence on the heating time and temperature distribution in induction heating. In order to ensure high and uniform temperature distribution near the interface of a joint between dissimilar materials the precise coil geometry and position is of great importance. The present report...... presents a combined numerical and experimental method for determination of appropriate/optimiged coil geometry and position in induction brazing tube-to-plate joints of different ratios between tube and plate thickness and different combinations of the materials stainless steel, brass and copper...

  6. Induction brazing manual

    Science.gov (United States)

    1971-01-01

    Manual presents standards and techniques which are known or are particular to specific industry, and is useful as guide in closing tolerance brazing. Material and equipment specifications, tool setting tables, and quality control data and instructions are included. Since similar standards are available, manual is supplementary reference.

  7. RFQ Vacuum brazing at CERN

    CERN Document Server

    Mathot, S

    2008-01-01

    The aim of this paper is to describe the vacuum brazing procedure used at CERN for the brazing of Radio Frequency Quadrupole (RFQ). The RFQ is made of high precision machined OFE copper pieces assembled together. Vacuum brazing is one of the most promising techniques used to join the individual components leading to vacuum tightness and high precision alignment. The RFQ modules brazed at CERN are made of four 100 or 120 cm long vanes (two major and two minor vanes). Our brazing procedure consists of two steps. The first step involves the brazing of the four vanes in a horizontal position. The second step consists of brazing the vacuum stainless steel flanges to the copper structure in a vertical position. The paper describes the problems encountered with the alignment and the vacuum tightness. The difficulties related to the stress relaxation of the machined copper pieces during the brazing heat treatment are discussed. In addition, the solutions developed to improve the alignment of the brazed RFQ’s are...

  8. Brazing zone structure at active brazing of alumina ceramics

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ Nowadays one of the most effective methods of joining of oxide ceramics with other elements of construction is active brazing based on using of active metals (Ti, Zr), which increase reactivity of brazing alloy relative to ceramic element of a joining.

  9. Brazing zone structure at active brazing of alumina ceramics

    Institute of Scientific and Technical Information of China (English)

    Demchuk; V.; A.; Kalinichenko; B.; B.

    2005-01-01

    Nowadays one of the most effective methods of joining of oxide ceramics with other elements of construction is active brazing based on using of active metals (Ti, Zr), which increase reactivity of brazing alloy relative to ceramic element of a joining.……

  10. Advances in brazing science, technology and applications

    CERN Document Server

    2013-01-01

    Brazing processes offer enhanced control, adaptability and cost-efficiency in the joining of materials. Unsurprisingly, this has lead to great interest and investment in the area. Drawing on important research in the field, Advances in brazing provides a clear guide to the principles, materials, methods and key applications of brazing. Part one introduces the fundamentals of brazing, including molten metal wetting processes, strength and margins of safety of brazed joints, and modeling of associated physical phenomena. Part two goes on to consider specific materials, such as super alloys, filler metals for high temperature brazing, diamonds and cubic boron nitride, and varied ceramics and intermetallics. The brazing of carbon-carbon (C/C) composites to metals is also explored before applications of brazing and brazed materials are discussed in part three. Brazing of cutting materials, use of coating techniques, and metal-nonmetal brazing for electrical, packaging and structural applications are reviewed, alon...

  11. Vacuum Brazing of Accelerator Components

    International Nuclear Information System (INIS)

    Commonly used materials for accelerator components are those which are vacuum compatible and thermally conductive. Stainless steel, aluminum and copper are common among them. Stainless steel is a poor heat conductor and not very common in use where good thermal conductivity is required. Aluminum and copper and their alloys meet the above requirements and are frequently used for the above purpose. The accelerator components made of aluminum and its alloys using welding process have become a common practice now a days. It is mandatory to use copper and its other grades in RF devices required for accelerators. Beam line and Front End components of the accelerators are fabricated from stainless steel and OFHC copper. Fabrication of components made of copper using welding process is very difficult and in most of the cases it is impossible. Fabrication and joining in such cases is possible using brazing process especially under vacuum and inert gas atmosphere. Several accelerator components have been vacuum brazed for Indus projects at Raja Ramanna Centre for Advanced Technology (RRCAT), Indore using vacuum brazing facility available at RRCAT, Indore. This paper presents details regarding development of the above mentioned high value and strategic components/assemblies. It will include basics required for vacuum brazing, details of vacuum brazing facility, joint design, fixturing of the jobs, selection of filler alloys, optimization of brazing parameters so as to obtain high quality brazed joints, brief description of vacuum brazed accelerator components etc.

  12. Induction brazing of complex joints

    DEFF Research Database (Denmark)

    Henningsen, Poul; Zhang, Wenqi; Bay, Niels

    2003-01-01

    Induction brazing is a fast and appropriate method for industrial joining of complex geometries and metal combinations. In all types of brazing processes it is important to heat the joint interface of the two materials to the same, high temperature. If one of the specimens is warmer than the other...... materials has large influence on the heating time and temperature distribution in induction heating. In order to ensure high and uniform temperature distribution near the interface of a joint between dissimilar materials the precise coil geometry and position is of great importance. The present paper...... presents a combined numerical and experimental method for fast determination of appropriate coil geometry and position in induction brazing tube-to-plate joints of different ratios between tube and plate thickness and different combinations of the materials stainless steel, brass and copper. The method has...

  13. Simulation based analysis of laser beam brazing

    Science.gov (United States)

    Dobler, Michael; Wiethop, Philipp; Schmid, Daniel; Schmidt, Michael

    2016-03-01

    Laser beam brazing is a well-established joining technology in car body manufacturing with main applications in the joining of divided tailgates and the joining of roof and side panels. A key advantage of laser brazed joints is the seam's visual quality which satisfies highest requirements. However, the laser beam brazing process is very complex and process dynamics are only partially understood. In order to gain deeper knowledge of the laser beam brazing process, to determine optimal process parameters and to test process variants, a transient three-dimensional simulation model of laser beam brazing is developed. This model takes into account energy input, heat transfer as well as fluid and wetting dynamics that lead to the formation of the brazing seam. A validation of the simulation model is performed by metallographic analysis and thermocouple measurements for different parameter sets of the brazing process. These results show that the multi-physical simulation model not only can be used to gain insight into the laser brazing process but also offers the possibility of process optimization in industrial applications. The model's capabilities in determining optimal process parameters are exemplarily shown for the laser power. Small deviations in the energy input can affect the brazing results significantly. Therefore, the simulation model is used to analyze the effect of the lateral laser beam position on the energy input and the resulting brazing seam.

  14. Filler alloys for brazing in power industries

    International Nuclear Information System (INIS)

    The problem is discussed of using nickel-based high-temperature brazing solders in nuclear power engineering. Different types of brazing solders are compared with regard to brazing and mechanical properties and oxidation resistance. The advantages of nickel-based brazing solders include their melting temperature which is higher by 150 to 200 degC than the melting temperatures of common solders. The effects of different additions on melting temperature are discussed. It is advisable to use the above brazing solders under hydrogen reduction atmosphere at a temperature of -40 down to -75 degC or at a pressure of 10-3 down to 10-4 Pa. Currently manufactured nickel-based brazing solders may be used at a temperature of up to 1150 degC. (J.B.)

  15. METHODS FOR BRAZING UNUSUAL METAL COMBINATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Bertossa, Robert C.

    1963-10-15

    A method for vacuum pressure braze cladding is described. Application of the method to Mo-OFHC Cu-type 316L stainlcss steel, Ta cladding on OFHC Cu, Nb with Ni, Ti and Zr on steels, and pure Be brazing to austenitic stalnless steel are discussed. The advantages of vacuumpressure bonding are also discussed. (P.C.H.)

  16. Theory and modeling of active brazing.

    Energy Technology Data Exchange (ETDEWEB)

    van Swol, Frank B.; Miller, James Edward; Lechman, Jeremy B.; Givler, Richard C.

    2013-09-01

    Active brazes have been used for many years to produce bonds between metal and ceramic objects. By including a relatively small of a reactive additive to the braze one seeks to improve the wetting and spreading behavior of the braze. The additive modifies the substrate, either by a chemical surface reaction or possibly by alloying. By its nature, the joining process with active brazes is a complex nonequilibrium non-steady state process that couples chemical reaction, reactant and product diffusion to the rheology and wetting behavior of the braze. Most of the these subprocesses are taking place in the interfacial region, most are difficult to access by experiment. To improve the control over the brazing process, one requires a better understanding of the melting of the active braze, rate of the chemical reaction, reactant and product diffusion rates, nonequilibrium composition-dependent surface tension as well as the viscosity. This report identifies ways in which modeling and theory can assist in improving our understanding.

  17. Application of Induction Heating for Brazing Parts of Solar Collectors

    Directory of Open Access Journals (Sweden)

    Kristína Demianová

    2012-01-01

    Full Text Available This paper reports on the application of induction heating for brazing parts of solar collectors made of Al alloys. The tube-flange joint is a part of the collecting pipe of a solar collector. The main task was to design an induction coil for this type of joint, and to select the optimum brazing parameters. Brazing was performed with AlSi12 brazing alloy, and corrosive and non-corrosive flux types were also applied. The optimum brazing parameters were determined on the basis of testing the fabricated brazed joints by visual inspection, by leakage tests, and by macro- and micro-analysis of the joint boundary. The following conditions can be considered to be the best for brazing Al materials: power 2.69 kW,brazing time 24 s, flux BrazeTec F32/80.

  18. Influence of brazing parameters and alloy composition on interface morphology of brazed diamond

    Energy Technology Data Exchange (ETDEWEB)

    Klotz, Ulrich E. [Empa, Swiss Federal Laboratories for Materials Testing and Research, Laboratory for Joining and Interface Technology, Uberlandstrasse 129, CH-8600 Duebendorf (Switzerland)], E-mail: klotz@fem-online.de; Liu Chunlei [Empa, Swiss Federal Laboratories for Materials Testing and Research, Laboratory for Joining and Interface Technology, Uberlandstrasse 129, CH-8600 Duebendorf (Switzerland); Khalid, Fazal A. [Faculty of Metallurgy and Materials Engineering, GIK Institute, Topi, NWFP (Pakistan); Elsener, Hans-Rudolf [Empa, Swiss Federal Laboratories for Materials Testing and Research, Laboratory for Joining and Interface Technology, Uberlandstrasse 129, CH-8600 Duebendorf (Switzerland)

    2008-11-15

    Active brazing is an effective technique for joining diamond or cBN grit to metallic substrates. This technique is currently used to manufacture superabrasive, high-performance tools. The investigation of interface reactions between diamond and active brazing alloys plays an important role in understanding and improving the brazing process and the resultant tool performance. Focused ion beam (FIB) milling enabled the high resolution investigation of these extremely difficult to prepare metal-diamond joints. The interfacial nanostructure is characterized by the formation of two layers of TiC with different morphologies. First a cuboidal layer forms directly on the diamond and reaches a thickness of approximately 70 nm. Then a second layer with columnar TiC crystals grows on the first layer into the brazing filler metal by a diffusion-controlled process. The combined thickness of both TiC layers varies between 50 nm and 600 nm depending on the brazing temperature and holding time.

  19. Brazing of Stainless Steels to Yttria Stabilized Zirconia (YSZ) Using Silver -Base Brazes

    Science.gov (United States)

    Singh, Mrityunjay; Shpargel, Tarah P.; Asthana, Rajiv

    2005-01-01

    Three silver-base brazes containing either noble metal palladium (Palcusil-10 and Palcusil-15) or active metal titanium (Ticusil) were evaluated for high-temperature oxidation resistance, and their effectiveness in joining yttria stabilized zirconia (YSZ) to a corrosion-resistant ferritic stainless steel. Thermogravimetric analysis (TGA), and optical- and scanning electron microscopy (SEM) coupled with energy dispersive spectrometry (EDS) were used to evaluate the braze oxidation behavior and the structure and chemistry of the YSZ/braze/steel joints. The effect of the braze type and processing conditions on the interfacial microstructure and composition of the joint regions is discussed with reference to the chemical changes that occur at the interface. It was found that chemical interdiffusion of the constituents of YSZ, steel and the brazes led to compositional changes and/or interface reconstruction, and metallurgically sound joints.

  20. Influence of brazing parameters and alloy composition on interface morphology of brazed diamond

    International Nuclear Information System (INIS)

    Active brazing is an effective technique for joining diamond or cBN grit to metallic substrates. This technique is currently used to manufacture superabrasive, high-performance tools. The investigation of interface reactions between diamond and active brazing alloys plays an important role in understanding and improving the brazing process and the resultant tool performance. Focused ion beam (FIB) milling enabled the high resolution investigation of these extremely difficult to prepare metal-diamond joints. The interfacial nanostructure is characterized by the formation of two layers of TiC with different morphologies. First a cuboidal layer forms directly on the diamond and reaches a thickness of approximately 70 nm. Then a second layer with columnar TiC crystals grows on the first layer into the brazing filler metal by a diffusion-controlled process. The combined thickness of both TiC layers varies between 50 nm and 600 nm depending on the brazing temperature and holding time

  1. High temperature brazing of diamond tools

    Institute of Scientific and Technical Information of China (English)

    YAO Zheng-jun; SU Hong-hua; FU Yu-can; XU Hong-jun

    2005-01-01

    A new brazing technique of diamond was developed. Using this new technique optimum chemical and metallurgical bonding between the diamond grits and the carbon steel can be achieved without any thermal damages to diamond grits. The results of microanalysis and X-ray diffraction analysis reveal that a carbide layer exists between the diamond and the matrix, which consists of Cr3C2, Cr7C3 and Cr23C6. Performance tests show that the brazed diamond core-drill has excellent machining performance. In comparison with traditional electroplated diamond core-drill, the brazed diamond core-drill manufactured using the new developed technique has much higher machining efficiency and much longer operating life.

  2. Methods to Predict Stresses in Cutting Inserts Brazed Using Iron-Carbon Brazing Alloy

    Science.gov (United States)

    Konovodov, V. V.; Valentov, A. V.; Retuynskiy, O. Yu; Esekuev, Sh B.

    2016-04-01

    This work describes a method for predicting residual and operating stresses in a flat-form tool insert made of tungsten free carbides brazed using iron-carbon alloy. According to the studies’ results it is concluded that the recommendations relating to the limitation of a melting point of tool brazing alloys (950-1100°C according to different data) are connected with a negative impact on tools as a composite made of dissimilar materials rather than on hard alloys as a tool material. Due to the cooling process stresses inevitably occur in the brazed joint of dissimilar materials, and these stresses increase with the higher solidification temperature of the brazing alloy.

  3. Active Metal Brazing and Characterization of Brazed Joints in Titanium to Carbon-Carbon Composites

    Science.gov (United States)

    Singh, M.; Shpargel, T. P.; Morscher, G. N.; Asthana, R.

    2006-01-01

    The Ti-metal/C-C composite joints were formed by reactive brazing with three commercial brazes, namely, Cu-ABA, TiCuNi, and TiCuSiI. The joint microstructures were examined using optical microscopy and scanning electron microscopy (SEM) coupled with energy dispersive spectrometry (EDS). The results of the microstructure analysis indicate solute redistribution across the joint and possible metallurgical bond formation via interdiffusion, which led to good wetting and spreading. A tube-on-plate tensile test was used to evaluate joint strength of Ti-tube/ C-C composite joints. The load-carrying ability was greatest for the Cu-ABA braze joint structures. This system appeared to have the best braze spreading which resulted in a larger braze/C-C composite bonded area compared to the other two braze materials. Also, joint loadcarrying ability was found to be higher for joint structures where the fiber tows in the outer ply of the C-C composite were aligned perpendicular to the tube axis when compared to the case where fiber tows were aligned parallel to the tube axis.

  4. Brazing of photocathode RF gun structures in Hydrogen atmosphere: Process qualification, effect of brazing on RF properties and vacuum compatibility

    International Nuclear Information System (INIS)

    In this paper, we report on the development of a brazing process for an ultra-high vacuum (UHV) compatible photocathode RF gun structure developed at our Centre. The choice of brazing alloy and its form, brazing clearance between parts to be joined and the brazing cycle adopted have been qualified through metallographic examination of identical joints on an OFE copper prototype that was cut open after brazing. The quality of brazed joint not only affects the UHV compatibility of the gun, but also influences the RF parameters finally achieved. A 2-D electromagnetic code, SUPERFISH, was used to predict the variation in RF parameters before and after brazing considering actual brazing clearances provided between the parts to be joined. Results obtained from low power RF measurements on the brazed gun structure confirm the integrity of the brazed joints and show good agreement with those predicted by electromagnetic simulations. The brazed gun structure has been leak-tested and pumped down to a vacuum level limited by the vacuum compatibility of the flange-fittings employed in the setup.

  5. Development of brazing technique for a 1.6 cell BNL/SLAC/UCLA type photocathode guns by hydrogen brazing

    International Nuclear Information System (INIS)

    Two prototypes of a 1.6 cell BNL/SLAC/UCLA type RF photocathode gun, a precision machined RF structure capable of supporting gradients in excess of 80 MV/m, have been successfully brazed and leak rates of 10-10 mbar l/s have been achieved. Brazing, is carried out in two steps in a hydrogen furnace, it involves joining of two RF cavities, 6 cylindrical ports, one rectangular waveguide and one seal plate. The cavities and waveguide are made of copper and the ports and seal plate are of stainless steel. Fixtures were designed and fabricated indigenously to maintain the required assembly tolerances during brazing. This was important for brazing of ports, two of which are brazed to one cavity at an angle of 22.50 at diametrically opposite locations, and the remaining four are brazed to the other cavity in mutually perpendicular orientations. All joints were brazed using copper-silver eutectic (72-28) alloy in foil and wire forms. This paper discusses the brazing requirement, design of fixtures, and the procedure adopted for brazing of the photocathode gun. The paper also discusses results of the tests carried out to qualify the brazed joints. (author)

  6. Brazing of sensors for high-temperature steam instrumentation systems

    International Nuclear Information System (INIS)

    Procedures are developed for brazing a ceramic-to-metal seal and for laser welding of sensor subassemblies into tube walls, induction brazing thermocouples through a tube wall, and furnace brazing triaxial cables, thermocouples, and a vent tube to a guide tube study three-dimensional phenomena in the upper plenum and core of a pressurized water reactor during the reflood stage of a loss-of-coolant accident. 8 refs

  7. Short cycle brazing of an alumina dispersion strengthened copper alloy

    International Nuclear Information System (INIS)

    An alumina dispersion strengthened copper alloy (with 0.07 wt, % alumina) has been proposed for several specialized applications in fusion reactors, such as the stabilizer in superconducting magnets and the structural material for divertors and limiters. In this research, brazed joints of the alumina dispersion strengthened copper alloy were developed using resistance heating brazing. The BCuP-3 brazing alloy was chosen based upon its low activation characteristics. Brazing was conducted using a GLEEBLE 1500 system with which time, temperature, and stress were precisely controlled. Butt-brazed joints with different brazing times were evaluated based on tensile and bending fatigue properties. Results from these tests reveal that the optimum braze time is approximately 1 minute at 8000C with a holding stress of 0.5 MPa. Metallography examinations were conducted on both the as brazed structure and the fracture surfaces. In the former, a transition layer (about 10 μm tick) was formed between the braze metal and the base alloy. Microhardness measurements across the braze did not show any hardening or softening effect due to the brazing process. Metallography of the fractured tensile and fatigue samples showed that cracks always penetrated through the interface between the transition layer and the braze metal. Semiquantitative energy dispersive x-ray spectroscopy (EDS) analysis was also performed across the joint. Profiles of P and Ag showed that P diffused very quickly into base metal along grain boundaries. A strong Al peak (associated with the detection of Al2O3) was found that corresponded with the transition layer. The presence of the alumina particles in the transition zone restricts the grain growth process in this region, resulting in relatively fine grain size

  8. The story of laser brazing technology

    Science.gov (United States)

    Hoffmann, Peter; Dierken, Roland

    2012-03-01

    This article gives an overview on the development of laser brazing technology as a new joining technique for car body production. The story starts with fundamental research work at German institutes in 1993, continues with the first implementations in automobile production in 1998, gives examples of applications since then and ends with an outlook. Laser brazing adapted design of joints and boundary conditions for a safe processing are discussed. Besides a better understanding for the sensitivity of the process against joint irregularities and misalignment, the key to successful launch was an advanced system technology. Different working heads equipped with wire feeding device, seam tracking system or tactile sensors for an automated teaching are presented in this paper. Novel laser heads providing a two beam technology will allow improved penetration depth of the filler wire and a more ecological processing by means of energy consumption.

  9. Study on alumina-alumina brazing for application in vacuum chambers of proton synchrotron

    International Nuclear Information System (INIS)

    The paper describes an experimental study to standardize vacuum brazing process to obtain satisfactory high purity alumina brazed joints for application in rapid cycle proton synchrotron machine. Two different brazing routes, adopted for making alumina-alumina brazed joints, included (i) multi-step Mo-Mn metallization and brazing with BVAg-8 alloy and (ii) advanced single-step active brazing with CuSil-ABA alloy. Brazed alumina specimens, prepared by both the routes, yielded ultra high vacuum compatible, helium leak tight and bakeable joints. Active-brazed specimens exhibited satisfactory strength values in tensile and four-point bend tests. Metallized-brazed specimens, although exhibited relatively lower tensile strength than the targeted value, displayed satisfactory flexural strength in four-point bend test. The results of the study demonstrated that active brazing is the simple and cost effective alternative to conventional metallization route for producing satisfactory brazed joints for application in rapid cycle proton synchrotron machine. (author)

  10. Failure Assessment Diagram for Brazed 304 Stainless Steel Joints

    Science.gov (United States)

    Flom, Yory

    2011-01-01

    Interaction equations were proposed earlier to predict failure in Albemet 162 brazed joints. Present study demonstrates that the same interaction equations can be used for lower bound estimate of the failure criterion in 304 stainless steel joints brazed with silver-based filler metals as well as for construction of the Failure Assessment Diagrams (FAD).

  11. Reactive Boride Brazing on Low-Alloy Automotive Grade Steel

    Science.gov (United States)

    Palanisamy, B.; Upadhyaya, A.

    2011-11-01

    Brazing is a widely used process to improve the performance of steels used in automotive applications. The substrate material is often exposed to harsh conditions in these applications and may affect the service life of the component. Reactive boride brazing aims to improve the mechanical properties of the substrate material by forming a ceramic-metal composite coating in a single-step process in situ. In this study, sintered Ancor 4300 low-alloy steel is used as the substrate with chromium-rich braze and chromium-lean braze materials. The mechanical properties of the brazed samples were studied in detail using microindentation hardness measurements and the transverse rupture test. The results indicate that the brazed superlayer has a 10 times higher hardness. There was a significant improvement in the transverse rupture strength of the steel brazed with the chromium-rich boride as compared to the pure substrate material. In an effort to reduce processing time, green compacts of the substrate were also directly brazed and yielded favorable results.

  12. Brazing of stainless steel; Stainless ko no rozuke

    Energy Technology Data Exchange (ETDEWEB)

    Matsu, T.

    1996-04-01

    This paper explains brazing of stainless steel as to its processing materials, brazing materials, brazing methods, and brazing works. When performing brazing at higher than 800{degree}C on a martensite-based stainless steel represented by the 13Cr steel, attention is required on cracking caused by quenching. When a ferrite-based stainless steel represented by the 18Cr steel is heated above 900{degree}C, crystalline particles grow coarser, causing their tenacity and corrosion resistance to decline. High-temperature long-time heating in brazing in a furnace demands cautions. Austenite-based stainless steel represented by the 18Cr-8Ni steel has the best brazing performance. However, since the steel has large thermal expansion coefficient and low thermal conductivity, attention is required on strain and deformation due to heating, and on localized overheating. Deposition hardened stainless steel made of the Cr-Ni alloy steel added with aluminum and titanium has poor wettability in a brazing work, hence pretreatment is required for the purpose of activation. 9 figs., 7 tabs.

  13. Laser brazing with filler wire for galvanized steel sheets

    Institute of Scientific and Technical Information of China (English)

    Feng Xiaosong; Li Liqun; Chen Yanbin; Zhou Shanbao

    2005-01-01

    The process properties and interface behavior of CO2 laser brazing with automatic wire feed for galvanized steel sheets were investigated , in which the brazing filler metal was CuSi3 and no flux was used. As to the appearance quality of the brazing seams, the roles of the processing parameters, such as brazing speed, wire feeding rate, inclination and feeding direction of the wire, laser power, spot diameter and heating position, were assessed. The further investigation indicates that the behavior of the active elements Si, Mn and Zn are significantly influenced by energy input. At the interface, the microstructure of the base metal was composed of columnar crystals and the acicalar α solid solution was found on the filler metal side.

  14. COMPARATION BETWEEN NONDESTRUCTIVE TESTING METHODS FOR THE ALUMINIUM BRAZED PIECES

    Directory of Open Access Journals (Sweden)

    Dan NIŢOI

    2014-05-01

    Full Text Available Presented paper refers to different control methods used in aluminium brazed joining because of possible defects. Low joining complexity permits exact damages position in relation with materials geometry.

  15. Comparison of brazed joints made with BNi-1 and BNi-7 nickel-base brazing alloys

    Directory of Open Access Journals (Sweden)

    Zorc, Borut

    2000-04-01

    Full Text Available Kinetics of the processes are different with different types of brazing alloys. Precipitation processes in the parent metal close to the brazing gap are of great importance. They control the mechanical properties of the joint area when the brittle eutectic has disappeared from the gap. A comparative study of brazed joints on austenitic stainless alloys made with BNi-7 (Ni-P type and BNi-1 (Ni-Si-B type brazing alloys was made. Brazing alloys containing phosphorus behave in a different manner to those containing boron.

    Las aleaciones de níquel se producen mediante tres sistemas de aleación: Ni-P, Ni-Si y Ni-B. Durante las reacciones metalúrgicas con el metal de base, la eutéctica frágil en la separación soldada puede transformarse en la solución dúctil-sólida con todas aleaciones. La cinética del proceso varía según el tipo de aleación. Los procesos de precipitación en el metal de base cerca de la separación soldada son de mucha importancia, ya que controlan las propiedades mecánicas de la área de unión después de desaparecer la eutéctica frágil de la separación. Se ha hecho un análisis comparativo de uniones soldadas en aleaciones austeníticas inoxidables realizadas con aleaciones BNi-7 (tipo Ni-P y BNi-1 (tipo Ni-Si-B. Las aleaciones que contienen fósforo se comportan de una manera diferente, tanto con el cambio de la eutéctica a la solución sólida, como con los procesos de precipitación en el metal de base cerca de la unión soldada.

  16. Improved Assembly for Gas Shielding During Welding or Brazing

    Science.gov (United States)

    Gradl, Paul; Baker, Kevin; Weeks, Jack

    2009-01-01

    An improved assembly for inert-gas shielding of a metallic joint is designed to be useable during any of a variety of both laser-based and traditional welding and brazing processes. The basic purpose of this assembly or of a typical prior related assembly is to channel the flow of a chemically inert gas to a joint to prevent environmental contamination of the joint during the welding or brazing process and, if required, to accelerate cooling upon completion of the process.

  17. Annular beam shaping system for advanced 3D laser brazing

    Science.gov (United States)

    Pütsch, Oliver; Stollenwerk, Jochen; Kogel-Hollacher, Markus; Traub, Martin

    2012-10-01

    As laser brazing benefits from advantages such as smooth joints and small heat-affected zones, it has become established as a joining technology that is widely used in the automotive industry. With the processing of complex-shaped geometries, recent developed brazing heads suffer, however, from the need for continuous reorientation of the optical system and/or limited accessibility due to lateral wire feeding. This motivates the development of a laser brazing head with coaxial wire feeding and enhanced functionality. An optical system is designed that allows to generate an annular intensity distribution in the working zone. The utilization of complex optical components avoids obscuration of the optical path by the wire feeding. The new design overcomes the disadvantages of the state-of-the-art brazing heads with lateral wire feeding and benefits from the independence of direction while processing complex geometries. To increase the robustness of the brazing process, the beam path also includes a seam tracking system, leading to a more challenging design of the whole optical train. This paper mainly discusses the concept and the optical design of the coaxial brazing head, and also presents the results obtained with a prototype and selected application results.

  18. Brazed aluminum, Plate-fin heat exchangers for OTEC

    Energy Technology Data Exchange (ETDEWEB)

    Foust, H.D.

    1980-12-01

    Brazed aluminum plate-fin heat exchangers have been available for special applications for over thirty years. The performance, compactness, versatility, and low cost of these heat exchangers has been unequaled by other heat exchanger configuration. The application of brazed aluminum has been highly limited because of necessary restrictions for clean non-corrosive atmospheres. Air and gas separation have provided ideal conditions for accepting brazed aluminum and in turn have benefited by the salient features of these plate-fin heat exchangers. In fact, brazed aluminum and cryogenic gas and air separation have become nearly synonymous. Brazed aluminum in its historic form could not be considered for a seawater atmosphere. However, technology presents a new look of significant importance to OTEC in terms of compactness and cost. The significant technological variation made was to include one-piece hollow extensions for the seawater passages. Crevice corrosion sites are thereby entirely eliminated and pitting corrosion attack will be controlled by an integral and sacrificial layer of a zinc-aluminum alloy. This paper on brazed aluminum plate-fin heat exchangers for OTEC will aquaint the reader with the state-of-art and variations suggested to qualify this form of aluminum for seawater use. In order to verify the desirable cost potential for OTEC, Trane teamed with Westinghouse to perform an OTEC system analysis with this heat exchanger. These results are very promising and reported in detail elsewhere.

  19. Brazing of Stainless Steel to Yttria-Stabilized Zirconia Using Gold-Based Brazes for Solid Oxide Fuel Cell Applications

    Science.gov (United States)

    Singh, M.; Shpargel, T. P.; Asthana, R.

    2007-01-01

    Two gold-base active metal brazes (gold-ABA and gold-ABA-V) were evaluated for oxidation resistance to 850 C, and used to join yttria-stabilized zirconia (YSZ) to a corrosion-resistant ferritic stainless steel for possible use in solid oxide fuel cells. Thermogravimetric analysis and optical microscopy and scanning electron microscopy coupled with energy-dispersive spectroscopy were used to evaluate the braze oxidation behavior, and microstructure and composition of the YSZ/braze/steel joints. Both gold-ABA and gold-ABA-V exhibited nearly linear oxidation kinetics at 850 C, with gold-ABA-V showing faster oxidation than gold-ABA. Both brazes produced metallurgically sound YSZ/steel joints due to chemical interactions of Ti and V with the YSZ and steel substrates.

  20. Brazing open cell reticulated copper foam to stainless steel tubing with vacuum furnace brazed gold/indium alloy plating

    Science.gov (United States)

    Howard, Stanley R.; Korinko, Paul S.

    2008-05-27

    A method of fabricating a heat exchanger includes brush electroplating plated layers for a brazing alloy onto a stainless steel tube in thin layers, over a nickel strike having a 1.3 .mu.m thickness. The resultant Au-18 In composition may be applied as a first layer of indium, 1.47 .mu.m thick, and a second layer of gold, 2.54 .mu.m thick. The order of plating helps control brazing erosion. Excessive amounts of brazing material are avoided by controlling the electroplating process. The reticulated copper foam rings are interference fit to the stainless steel tube, and in contact with the plated layers. The copper foam rings, the plated layers for brazing alloy, and the stainless steel tube are heated and cooled in a vacuum furnace at controlled rates, forming a bond of the copper foam rings to the stainless steel tube that improves heat transfer between the tube and the copper foam.

  1. Characterisation of Ga-coated and Ga-brazed aluminium

    Energy Technology Data Exchange (ETDEWEB)

    Ferchaud, E. [Universite de Nantes, Polytech' Nantes, Laboratoire Genie des Materiaux et Procedes Associes, Rue Christian Pauc, 44306 Nantes Cedex 3 (France); Christien, F., E-mail: frederic.christien@univ-nantes.fr [Universite de Nantes, Polytech' Nantes, Laboratoire Genie des Materiaux et Procedes Associes, Rue Christian Pauc, 44306 Nantes Cedex 3 (France); Barnier, V. [Ecole Nationale Superieure des Mines, MPI, CNRS UMR5146, Centre SMS, 158 Cours Fauriel, 42023 Saint Etienne (France); Paillard, P. [Universite de Nantes, Polytech' Nantes, Laboratoire Genie des Materiaux et Procedes Associes, Rue Christian Pauc, 44306 Nantes Cedex 3 (France)

    2012-05-15

    This work is devoted to the brazing of aluminium using liquid gallium. Gallium was deposited on aluminium samples at {approx} 50 Degree-Sign C using a liquid gallium 'polishing' technique. Brazing was undertaken for 30 min at 500 Degree-Sign C in air. EDS (Energy Dispersive X-ray Spectroscopy) and AES (Auger Electron Spectroscopy) characterisation of Ga-coated samples has shown that the Ga surface layer thickness is of ten (or a few tens of) nanometres. Furthermore, aluminium oxide layer (Al{sub 2}O{sub 3}) was shown to be 'descaled' during Ga deposition, which ensures good conditions for further brazing. Cross-section examination of Ga-coated samples shows that liquid gallium penetrates into the aluminium grain boundaries during deposition. The thickness of the grain boundary gallium film was measured using an original EDS technique and is found to be of a few tens of nanometres. The depth of gallium grain boundary penetration is about 300 {mu}m at the deposition temperature. The fracture stress of the brazed joints was measured from tensile tests and was determined to be 33 MPa. Cross-section examination of brazed joints shows that gallium has fully dissolved into the bulk and that the joint is really autogenous. - Highlights: Black-Right-Pointing-Pointer Aluminium can be brazed using liquid gallium deposited by a 'polishing' technique. Black-Right-Pointing-Pointer The aluminium oxide layer is 'descaled' during liquid Ga 'polishing' deposition. Black-Right-Pointing-Pointer EDS can be used for determination of surface and grain boundary Ga film thickness. Black-Right-Pointing-Pointer The surface and grain boundary Ga film thickness is of a few tens of nm. Black-Right-Pointing-Pointer Surface and grain boundary gallium dissolves in the bulk during brazing.

  2. Online monitoring of the laser brazing of titanium overlap joints

    Science.gov (United States)

    Schmitt, R.; Vielhaber, K.; Donst, D.; Klocke, F.

    2007-06-01

    Image processing and thermography for its own are very versatile and established measurement techniques for many years. However, the combination of these two measurement technologies opens a new field of applications. The online monitoring of the laser-brazing of titanium overlap joints is such a new application. The laser brazing process for overlap joining of formed titanium sheets for the production of heat exchangers is presently being investigated at the Fraunhofer IPT. In comparison to conventional furnace brazing the laser brazing technology decreases substantially the heat impact and thus reduces the thermal material damage in the parts due to local selective heating in a laser beam focal spot. Even though the process is stable, errors in the brazing seam such as pores or unacceptable material oxidation can occur. To ensure a high quality an online process monitoring or even process control is necessary. But since the surface remains unchanged during this brazing process no geometrical inspection of the surface can be conducted. Therefore today's quality assurance performs x-ray or destructive testing. This paper demonstrates how the use of thermography in combination with image processing allows a machine integrated online monitoring of the laser brazing process. First the basic principals are presented which cover the fields of heat coupling, heat transmission and heat distribution as well as the temperature emission of light and the spectral properties of the laser beam shaping optic and so lead to the optical set-up. Then analysis algorithms are derived which characterize the process, detect process failures and make a seam tracking possible.

  3. Method of temperature rising velocity and threshold control of electron beam brazing

    Institute of Scientific and Technical Information of China (English)

    Xuedong Wang; Shun Yao

    2005-01-01

    In order to accommodate electron beam to the brazing of the joints with various curve shapes and the brazing of thermo sensitive materials, the method of electron beam scanning and brazing temperature control was developed, in which electron beam was controlled to scan according to predefined scanning track, and the actual temperature rising velocity of the brazed seam was limited in an allowed scope by detecting the brazed seam temperature, calculating the temperature rising velocity and adjusting the beam current during the brazing process; in addition, through the setting of the highest allowed temperature, the actual temperature of the brazed seam could be controlled not exceeding the threshold set value, and these two methods could be employed alone or jointly. It is shown that high precision temperature control in electron beam brazing could be realized and the productivity be increased by the proposed method.

  4. Effects of Rare Earths on Properties of Ti-Zr-Cu-Ni Base Brazing Filler Alloys

    Institute of Scientific and Technical Information of China (English)

    Ma Tianjun; Kang Hui; Wu Yongqin; Qu Ping

    2004-01-01

    The effects of the addition of rare earths on the properties of Ti-Zr-Cu-Ni base brazing filler alloys and the mechanical microstructure and properties were studied for the brazed-joints in the vacuum brazing of TC4 by comparing synthetical properties of two kinds of filler metals.The results indicate that the filler metals added with rare earths have lower melting point, better wettability and higher mechanical properties in the brazing joints.

  5. Microstructural Changes in Brazing Sheet due to Solid-Liquid Interaction

    NARCIS (Netherlands)

    Wittebrood, A.J.

    2009-01-01

    Aluminium brazing sheet is the material of choice to produce automotive heat exchangers. Although in Dutch the official translation of aluminium brazing sheet is “aluminium hardsoldeerplaat” the English name is used in the industry. Aluminium brazing sheet is basically a sandwich material and consis

  6. High-temperature brazing for reliable tungsten-CFC joints

    International Nuclear Information System (INIS)

    The joining of tungsten and carbon-based materials is demanding due to the incompatibility of their chemical and thermophysical properties. Direct joining is unfeasible by the reason of brittle tungsten carbide formation. High-temperature brazing has been investigated in order to find a suitable brazing filler metal (BFM) which successfully acts as an intermediary between the incompatible properties of the base materials. So far only low Cr-alloyed Cu-based BFMs provide the preferential combination of good wetting action on both materials, tolerable interface reactions, and a precipitation free braze joint. Attempts to implement a higher melting metal (e.g. Pd, Ti, Zr) as a BFM have failed up to now, because the formation of brittle precipitations and pores in the seam were inevitable. But the wide metallurgical complexity of this issue is regarded to offer further joining potential

  7. Laser beam active brazing of metal ceramic joints

    Science.gov (United States)

    Haferkamp, Heinz; Bach, Friedrich W.; von Alvensleben, Ferdinand; Kreutzburg, K.

    1996-04-01

    The use of engineering ceramics is becoming more and more important. Reasons for this are the specific properties of these materials, such as high strength, corrosion resistance and wear resistance. To apply the advantages of ceramics, joining techniques of metal ceramic parts are required. In this paper, joining of metal ceramic joints by laser beam brazing is presented. This joining technique is characterized by local heat input, and the minimal thermal stress of the brazed components. During the investigations, an Nd:YAG laser and a vacuum chamber were applied. The advantages of Nd:YAG lasers are the simple mechanical construction, and laser beam guidance via quartz glass fibers, which leads to high handling flexibility. In addition, most of the materials show a high absorption rate for this kind of radiation. As materials, ceramic Al2O3 with a purity of 99.4% and metals such as X5CrNi189 and Fe54Ni29Co17 were used. As a filler material, commercially available silver and silver- copper brazes with chemically active elements like titanium were employed. During this study, the brazing wetting behavior and the formation of diffusion layers in dependence on processing parameters were investigated. The results have shown that high brazing qualities can be achieved by means of the laser beam brazing process. Crack-free joining of metal ceramic parts is currently only possible by the use of metals such as Fe54Ni29Co17 because of its low thermal expansion coefficient, which reduces thermal stresses within the joining zone.

  8. Numerical simulation of filler metal droplets spreading in laser brazing

    Institute of Scientific and Technical Information of China (English)

    Yanbin Chen; Xiaosong Feng; Liqun Li

    2007-01-01

    A finite element model was constructed using a commercial software Fidap to analyze the Cu-base filler metal droplet spreading process in laser brazing, in which the temperature distribution, droplet geometry,and fluid flow velocity were calculated. Marangoni and buoyancy convection and gravity force were considered, and the effects of laser power and spot size on the spreading process were evaluated. Special attention was focused on the free surface of the droplet, which determines the profile of the brazing spot.The simulated results indicate that surface tension is the dominant flow driving force and laser spot size determines the droplet spreading domain.

  9. Numerical simulation of filler metal droplets spreading in laser brazing

    Science.gov (United States)

    Chen, Yanbin; Feng, Xiaosong; Li, Liqun

    2007-11-01

    A finite element model was constructed using a commercial software Fidap to analyze the Cu-base filler metal droplet spreading process in laser brazing, in which the temperature distribution, droplet geometry, and fluid flow velocity were calculated. Marangoni and buoyancy convection and gravity force were considered, and the effects of laser power and spot size on the spreading process were evaluated. Special attention was focused on the free surface of the droplet, which determines the profile of the brazing spot. The simulated results indicate that surface tension is the dominant flow driving force and laser spot size determines the droplet spreading domain.

  10. Investigation of Brazed Plate Heat Exchangers With Variable Chevron Angles

    Directory of Open Access Journals (Sweden)

    S. Muthuraman

    2013-08-01

    Full Text Available - Experiments to measure the condensation heat transfer coefficient and the pressure drop in brazed plate heat exchangers (BPHEs were performed with the refrigerants R410A and R22. Brazed plate heat exchangers with different chevron angles of 45°, 35°, and 20° were used. Varying the mass flux, the condensation temperature, and the vapor quality of the refrigerant, we measured the condensation heat transfer coefficient and the pressure drops. Both the heat transfer coefficient and the pressure drop increased proportionally with the mass flux and the vapor quality and inversely with the condensation temperature and the chevron angle.

  11. Brazing and inertia welding of dissimilar metal tubing

    International Nuclear Information System (INIS)

    A movable pump limiter is currently being built for the Tore Supra tokamak in Cadarace, France. Part of the assembly has dispersion-strengthened Cu cooling tubes joined to an AISI 316L stainless steel transition sleeve. The steel sleeve is subsequently welded into a 315L manifold. This study was made to evaluate the feasibility of brazing or inertia welding the dissimilar metal, tubing-sleeve transition. An alumina-strengthened copper alloy (DSCu) was selected for the module cooling tubes. The 316L transition pieces varied in diameter from the same nominal size as the DSCu pieces when inertial welding, to a 12.7 mm (1/2 in.) O.D. to accommodate a lap joint when brazing. The wall thickness of the inertia welded 316L pieces was varied to determine the overlap effect on the weld quality. Ag-28Cu, Ag-27.6Cu-4.5Ti, Au-37Cu-3In, and Au-18Ni (wt%) filler metals were chosen for brazing and the braze microstructures and strengths were evaluated. The best wetting was achieved with the Au based filler metals. All of the brazed joints were hydrostatically pressure tested to 10.34 MPa (1500 psi) without a failure. In all cases, an excellent metallurgical bond with a relatively small cold worked region was produced. The inertia welded samples were also pressure and tensile tested under the same test conditions that were used to evaluate the brazed samples. The welds passed the 10.34 MPa hydrostatic pressure inspection and failed under a tensile load in the DSCu piece away form the weld interface. Brazing and inertia welding were successfully used to join DSCu to 316L. The Au-based filler metals produced the best brazes with joint strengths of 480 MPa. The inertia welds had slightly higher strengths, but both failed away from the joint in the DSCu tube. All of these samples passed a 10.34 MPa hydrostatic pressure test. These processes allow flexibility in designing and fabricating a dissimilar metal transition joint

  12. Microwave-assisted brazing of alumina ceramics for electron tube applications

    Indian Academy of Sciences (India)

    2016-04-01

    Alumina was joined with alumina using microwave-assisted and conventional brazing methods at 960$^{\\circ}$C for 15 min using TiCuSil (68.8Ag–26.7Cu–4.5Ti in wt.%) as the brazing alloy. The brazed joints were characterizedby X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis, Vickers microhardness evaluation, brazing strength measurement and helium leak test. X-ray diffraction analysis confirmed the formationof Ti-based compounds at the substrate-filler alloy interfaces of the microwave and conventionally brazed joints. The elemental compositions at the joint cross-section were determined by energy dispersive X-ray analysis. Vickers microhardness measurement indicated reliable joint performance for the microwave-assisted brazed joints during actual application in an electron tube. Brazing strength measurement and helium leak test provided the evidence forgood alumina-alumina joint formation.

  13. Field installed brazed thermocouple feedthroughs for high vacuum experiments

    Science.gov (United States)

    Anderson, P. M.; Messick, C.

    1983-12-01

    In order to reduce the occurrence of vacuum leaks and to increase the availability of the DIII vacuum vessel for experimental operation, effort was applied to developing a vacuum-tight brazed feedthrough system for sheathed thermocouples, stainless steel sheathed conductor cables and tubes for cooling fluids. This brazed technique is a replacement for elastomer O ring sealed feedthroughs that have proven vulnerable to leaks caused by thermal cycling, etc. To date, about 200 feedthroughs were used. Up to 91 were grouped on a single conflat flange mounted in a bulkhead connector configuration which facilitates installation and removal. Investigation was required to select a suitable braze alloy, flux and installation procedure. Braze alloy selection was challenging since the alloy was required to have: (1) melting temperature in excess of the 250 C (482 F) bakeout temperature; (2) no high vapor pressure elements; (3) good wetting properties when used in air with acceptable flux; and (4) good wettability to 300 series stainless steel and Inconel.

  14. Enhanced corrosion protection by microstructural control of aluminium brazing sheet

    NARCIS (Netherlands)

    Norouzi Afshar, F.

    2013-01-01

    Aluminium brazing sheet is a sandwich material made out of two aluminium alloys (AA4xxx/AA3xxx) and is widely used in automotive heat exchangers. One of the main performance criteria for heat exchanger units is the lifetime of the product. The lifetime of the heat exchanger units is determined by th

  15. Joining of beryllium by braze welding technique: preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Banaim, P.; Abramov, E. [Ben-Gurion Univ. of the Negev, Beersheba (Israel); Zalkind, S.; Eden, S.

    1998-01-01

    Within the framework of some applications, there is a need to join beryllium parts to each other. Gas Tungsten Arc Braze Welds were made in beryllium using 0.3 mm commercially Aluminum (1100) shim preplaced at the joint. The welds exhibited a tendency to form microcracks in the Fusion Zone and Heat Affected Zone. All the microcracks were backfilled with Aluminum. (author)

  16. Interface characteristics and fracture behavior of brazed polycrystalline CBN grains using Cu-Sn-Ti alloy

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Wen-Feng, E-mail: dingwf2000@vip.163.com [College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); Xu, Jiu-Hua; Chen, Zhen-Zhen; Miao, Qing; Yang, Chang-Yong [College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China)

    2013-01-01

    Polycrystalline CBN grains were brazed onto AISI 1045 steel matrix using Cu-Sn-Ti brazing alloy. Brazing temperature was 880 Degree-Sign C, 900 Degree-Sign C, 920 Degree-Sign C respectively, and the holding time was 8 min. Interface characteristics, elemental distribution and fracture behavior were analyzed in detail by means of scanning electron microscopy, energy dispersive spectroscopy and testing machine for grain compressive strength. The maximum value of the mean compressive strength of brazed PCBN grains reached 879.3 MPa when the brazing temperature was 900 Degree-Sign C. The resultants layer composed of TiN, TiB{sub 2}, TiB and TiAl{sub 3} was formed at grain/alloy interface. Elemental distribution showed that Ti mainly concentrated within the interface zone. The intercrystalline fracture along the CBN/CBN particle boundary was the main fracture modes of brazed polycrystalline CBN grains.

  17. Brazing of AM-350 stainless steel LWBR fuel rod support grids (LWBR Development Program)

    Energy Technology Data Exchange (ETDEWEB)

    Ebejer, L.P.

    1979-02-01

    A brazing process has been developed wherein several hundred stamped AM-350 stainless steel sheet metal components, wire components and machined bar components were simultaneously joined together to fabricate about 400 grids of different sizes for the LWBR fuel rod support system. High temperature (2110F +- 20F) vacuum brazing was employed using Ni--Cr--Si braze alloy filler metal in the form of paste. Techniques employed in the assembly, braze alloy application and fixturing of grids to achieve adequate dimensional control are discussed in detail. The brazing thermal cycle as related to the complex metallurgical process of both AM-350 stainless steel and the Ni--Cr--Si braze alloy is also discussed.

  18. Dissimilar joint characteristics of SiC and WC-Co alloy by laser brazing

    Science.gov (United States)

    Nagatsuka, K.; Sechi, Y.; Nakata, K.

    2012-08-01

    SiC and WC-Co alloys were joined by laser brazing with an active braze metal. The braze metal based on eutectic Ag-Cu alloy with additional Ti as an active element ranging from 0 to 2.8 mass% was sandwiched by the SiC block and WC-Co alloy plate. The brazing was carried out by selective laser beam irradiation on the WC-Co alloy plate. The content of Ti in the braze metal was required to exceed 0.6 mass% in order to form a brazed joint with a measurable shear strength. The shear strength increased with increasing Ti content up to 2.3 mass%Ti and decreased with a higher content.

  19. Effect of Heat Treatment on High Temperature Stress Rupture Strength of Brazing Seam for Nickel-base Superalloy

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In order to enhance the high-temperature stress rupture strength of brazing seam by heat treatment, it was diffusion treated, then solution heat treated, and finally aging treated. The microstructure of brazing seam especially morphology of phase and boride was observed and the strength of brazing seam was measured in this process. The results show that heat treatment can enhance high-temperature stress rupture strength by improving the microstructure of brazing seam. The strength of brazing seam after solution heat treatment decreases in comparison with that only after diffusion treatment while aging treatment after solution heat treatment increases the strength of brazing seam.

  20. Active brazed diamond and cubic boron nitride interfacial nanostructure and application

    International Nuclear Information System (INIS)

    Active brazing is an effective technique for joining diamond or cBN grit onto metallic substrates. Current use of this technique is being made for super abrasive, high performance tools. The lecture will give an overview over different aspects such as (i) tool performance in selected applications, (ii) interfacial nanostructure between super abrasive grit and brazing alloys matrix, (iii) attempts to computer model such interface reactions and (iv) recent improvements of the abrasion resistance of the brazing alloy itself. Super abrasive tools with outstanding performance in applications such as grinding, honing or stone cutting can be manufactured by a single-layer of brazed diamond or cBN grit. A method to obtain regular grit patterns will be presented. Examples of prototype tools and their performance in different applications will be shown. The investigation of interface reactions between diamond and active brazing alloys plays an important role to further improve the brazing process and resulting tool performance. The interfacial nanostructure is characterised by a thin reaction layer of Ti with diamond and cBN, respectively. Results for Ag- and Cu-based brazing alloys will be presented and discussed in view of the influence of brazing process parameters and brazing alloy matrix. Computer modelling of the thermodynamics and kinetics of the interface reactions may allow optimising the process parameters. This requires reliable databases currently being built up. The potential of such methods in ceramic to metal joining will be described. The abrasion resistance of brazing alloys itself plays an important role for tool performance. A new method to achieve a dispersion of nano sized TiC precipitates in the alloy matrix by addition of an organic binder, decomposing during brazing will be presented. In an outlook further applications of brazed diamond grit, such as thermal management materials will be discussed. (author)

  1. Microstructural characteristics of WC-Co and tool steel brazed joint

    Energy Technology Data Exchange (ETDEWEB)

    Young-Sub, K.; Sook-Hwan, K. [Reliability Assessment Team, Research Institute of Industrial Science and Technology, Pohang (Korea)

    2001-07-01

    The current study used Ni base alloys, which reveals the excellent high temperature properties, as filler metals for brazing of WC-Co and tool steel to get the solid joint strength. The strength and the microstructures of brazed joints for different filler metals were examined. The optimum brazing condition and heat treatment condition were obtained through precipitation reaction and microstructural characteristics at the joints. (orig.)

  2. Low vapor pressure braze alloys for thermionic energy converters

    Science.gov (United States)

    Bair, V. L.

    1976-01-01

    Preliminary results in the use of some low-vapor-pressure braze alloys are reported; these are binary alloys of refractory metals (Th, Zr, Hf, Ru, Nb, Ir, Mo, Ta, Os, Re, W) with vapor pressures below 0.1 nanotorr at 1500 K or 10 microtorr at 2000 K. The melting point minima or eutectics of the alloys range from 1510 K to above 3000 K. Melting points and surface wetting on a Ta base are given. Results are presented on brazing of Ir, LaB6, Nb, Re, W, and ZrO2 (with 22 wt % Zr) into a Ta base or a Nb-1% Zr base. The results are applicable in electrode screening programs for thermionic cesium diodes.

  3. An unconventional set-up for fluxless brazing of aluminium

    CERN Document Server

    Loos, Robert

    1999-01-01

    In order to successfully braze aluminium alloy assemblies without the use of oxide-removing fluxes, an evironment with very low contaminant level is mandatory. This is mostly achieved by using a vacuum furnace. Brazing under inert gas of sufficient purity is also possible. The method reported upon here makes use of a stainless steel bag which can enter a traditional air furnace. The bag is evacuated, giving a well distributed mechanical pressure on the parts to join. The intrinsic handicap of poor vacuum is compensated by regular inert gas flushing, even at high temperatures. The set-up works rather well, and the idea is believed to yield a valuable strategic and economic option, for the realization of special equipment as well as for prototyping work. We intend to use the principle for the CMS Preshower cooling screens.

  4. DSC Analysis of LT-3 Aluminum Alloy Vacuum Brazing

    Institute of Scientific and Technical Information of China (English)

    FENG Tao; WU Lu-hai; LOU Song-nian; LI Ya-jiang

    2005-01-01

    LT-3 aluminum alloy is a kind of two-side cladding aluminum special used in vacuum brazing. Differential Scanning Calorimeter (DSC) was used to measure the exothermic and endothermic reaction during the brazing process that the cortex metal and the base metal are melted and re-crystal. The analysis results inidicate that eutectic reaction is the main reaction in the melted cortex metal crystallization process. But the main reaction in the melted base metal crystallization process is the reaction that a-A1 segregated out. According to the experimental details, the critical work of nucleation is 3.82 × 1017J, the critical radius of nucleation is 8.69 × 1010 m, the volume of critical crystal nucleus is 2.75× 10-27 m3 and the per unit cell in critical crystal nucleus is 43.

  5. New hermetic sealing material for vacuum brazing of stainless steels

    Science.gov (United States)

    Hildebrandt, S.; Wiehl, G.; Silze, F.

    2016-03-01

    For vacuum brazing applications such as in vacuum interrupter industry Hermetic Sealing Materials (HSM) with low partial pressure are widely used. AgCu28 dominates the hermetic sealing market, as it has a very good wetting behavior on copper and metallized ceramics. Within recent decades wetting on stainless steel has become more and more important. However, today the silver content of HSMs is more in focus than in the past decades, because it has the biggest impact on the material prices. Umicore Technical Materials has developed a new copper based HSM, CuAg40Ga10. The wettability on stainless steel is significantly improved compared to AgCu28 and the total silver content is reduced by almost 44%. In this article the physical properties of the alloy and its brazed joints will be presented compared to AgCu28.

  6. Welding and brazing of the JET machine components

    International Nuclear Information System (INIS)

    The report covers the techniques used for joining the various parts of the machine. The difficulties encountered during the welding and brazing of similar and dissimilar metals are underlined and the solutions adopted to solve them are indicated. The vast experience gained by those involved in the processes of joining the various parts of the JET machine components, and the lessons learnt are summarized in this report. (author)

  7. Laser Brazing with Beam Scanning: Experimental and Simulative Analysis

    Science.gov (United States)

    Heitmanek, M.; Dobler, M.; Graudenz, M.; Perret, W.; Göbel, G.; Schmidt, M.; Beyer, E.

    Laser beam brazing with copper based filler wire is a widely established technology for joining zinc-coated steel plates in the body-shop. Successful applications are the divided tailgate or the zero-gap joint, which represents the joint between the side panel and the roof-top of the body-in-white. These joints are in direct view to the customer, and therefore have to fulfil highest optical quality requirements. For this reason a stable and efficient laser brazing process is essential. In this paper the current results on quality improvement due to one dimensional laser beam deflections in feed direction are presented. Additionally to the experimental results a transient three-dimensional simulation model for the laser beam brazing process is taken into account. With this model the influence of scanning parameters on filler wire temperature and melt pool characteristics is analyzed. The theoretical predictions are in good accordance with the experimental results. They show that the beam scanning approach is a very promising method to increase process stability and seam quality.

  8. A study on brazing of Glidcop® to OFE Cu for application in Photon Absorbers of Indus-2

    International Nuclear Information System (INIS)

    The paper describes an experimental study aimed at standardizing brazing procedure for joining Glidcop to OFE Cu for its application in upgraded photon absorbers of 2.5 GeV synchrotron radiation source, Indus-2. Two different brazing routes, involving brazing with silver base (BVAg-8) and gold base (50Au/50Cu) alloys, were studied to join Glidcop to OFE Cu. Brazing with both alloys yielded helium leak tight and bakeable joints with acceptable shear strengths.

  9. Interfacial microstructure and performance of brazed diamond grits with Ni-Cr-P alloy

    International Nuclear Information System (INIS)

    The reaction mechanism of the interface among diamond, commercial Ni-Cr-P alloy and steel substrate has been studied by optical microscopy, scanning electron microscope, X-ray diffraction and Raman spectroscopy. The reaction layers formed among diamond, brazing alloy and steel substrate produced good wettability of diamond grits for achieving better quality tools. The reaction layer between diamond and brazing alloy comprised a reaction layer of brazing alloy and a reaction layer of diamond. Cr7C3 and Cr3C2 formed in the reaction layer of brazing alloy was the main reason for improving the bonding strength of Ni-Cr alloy to the diamond grits. A reaction layer of diamond may be a graphitization layer formed on the surface of diamond under high temperature brazing. The reaction layer of brazing alloy and steel substrate was the co-diffusion of Ni, Cr and Fe between the brazing alloy and the steel substrate. The life and sharpness of brazed diamond boring drill bits fabricated in this study were superior to the electroplated one in the market owing to its high protrusion and bonding strength.

  10. Development of brazing foils to join monocrystalline tungsten alloys with ODS-EUROFER steel

    Energy Technology Data Exchange (ETDEWEB)

    Kalin, B.A. [Moscow Engineering Physics Institute (State University), 31 Kashirskoye Sh., Moscow 115409 (Russian Federation)]. E-mail: BAKalin@mephi.ru; Fedotov, V.T. [Moscow Engineering Physics Institute (State University), 31 Kashirskoye Sh., Moscow 115409 (Russian Federation); Sevrjukov, O.N. [Moscow Engineering Physics Institute (State University), 31 Kashirskoye Sh., Moscow 115409 (Russian Federation); Kalashnikov, A.N. [Moscow Engineering Physics Institute (State University), 31 Kashirskoye Sh., Moscow 115409 (Russian Federation); Suchkov, A.N. [Moscow Engineering Physics Institute (State University), 31 Kashirskoye Sh., Moscow 115409 (Russian Federation); Moeslang, A. [Forschungszentrum Karlsruhe, Institut fuer Materialforschung I, 76021 Karlsruhe (Germany); Rohde, M. [Forschungszentrum Karlsruhe, Institut fuer Materialforschung I, 76021 Karlsruhe (Germany)

    2007-08-01

    Results on rapidly solidified filler metals for brazing W with W and monocrystalline W with EUROFER steel (FS) are presented. Rapidly quenched powder-type filler metals based on Ti{sub bal}-V-Cr-Be were developed to braze polycrystalline W with monocrystalline W. In addition, Fe{sub bal}-Ta-Ge-Si-B-Pd alloys were developed to braze monocrystalline W with FS for helium gas cooled divertors and plasma-facing components. The W to FS brazed joints were fabricated under vacuum at 1150 {sup o}C, using a Ta spacer of 0.1 mm in thickness to account for the different thermal expansions. The monocrystalline tungsten as well as the related brazed joints withstood 30 cycles between 750 {sup o}C/20 min and air cooling/3-5 min.

  11. Experimental study of W-Eurofer laser brazing for divertor application

    Energy Technology Data Exchange (ETDEWEB)

    Munez, C.J., E-mail: claudio.munez@urjc.es [Dept. de Tecnologia Mecanica, ESCET, Universidad Rey Juan Carlos, C/Tulipan s/n, Mostoles 28933, Madrid (Spain); Garrido, M.A. [Dept. de Tecnologia Mecanica, ESCET, Universidad Rey Juan Carlos, C/Tulipan s/n, Mostoles 28933, Madrid (Spain); Rams, J.; Urena, A. [Dept. de Ciencia e Ingenieria de Materiales, ESCET, Universidad Rey Juan Carlos, C/Tulipan s/n, Mostoles 28933, Madrid (Spain)

    2011-11-15

    Highlights: > Laser brazing system as a suitable technique to joint W and Eurofer alloys. > High residual stresses at the bonding were produced. > Laser brazing of powder metallurgy W alloys added porosity in the solidified pool. > The CSM methodology as a suitable technique to discriminate zones of welding joints. - Abstract: This work can be considered as a preliminary evaluation of the potential of laser brazing for joining tungsten based alloys to reduced activation ferritic-martensitic steels (Eurofer). Brazing of tungsten and EUROFER alloys using a 55Ni-45Ti alloy as a brazer and a high power diode laser (HPDL) as a power source has been investigated. The brazed joints showed solidified pools with good superficial aspect and a high degree of wettability with the both parent sheets, presumably because of the active effect of titanium. Metallurgical brazeability was investigated and nanoindentation measurements were done to evaluate local hardening and stiffness effects associated to dilution phenomena.

  12. Development of Zn50 Brazing Alloy for Joining Mild Steel to Mild Steel (SAE1018

    Directory of Open Access Journals (Sweden)

    S.C. Nwigbo

    2014-09-01

    Full Text Available This work has developed new brazing alloys for joining mild steel to mild steel (SAE1018 at a lower temperature. The alloys blends and error analysis were done by experimental design software (Design Expert 8.0.7.1. Design of experiments was done by Scheffe quadratic mixture method. The liquidus temperatures were predicted by calculation of phase diagrams of the alloying metals. The brazing alloys were produced by gravity technique and melted using silicon carbide graphite crucible. The quality of the brazing alloys was analyzed by optical microscopy (OM, atomic absorption spectroscopy (AAS and fourier transform infrared spectroscopy (FT-IR. Brazed joints were produced by torch method with a commercial flux. Brazing temperatures (liquidus were tracked by a digital infrared/laser pyrometer. Some mechanical properties studied were tensile strength and hardness. Finally, brazed joints produced from the developed brazing alloys were compared to that produced from muntz brass. Six (6 brazing alloys were successfully developed. Zinc and manganese were the main components, to which were added; 3 to 4 %wt silver and 11 to15 %wt modifying element. The microstructure showed a typical eutectic structure with zinc-rich phase distributed uniformly in the matrix with a combination of different sizes of dendrite, rounded blocks of compounds and hypoeutectic structures. AAS results indicated minimal out-gassing of zinc and FT-IR results indicated very low presence of atmospheric gas. The range of brazing temperature for best results was recorded from 690.90 to 735.10 0C. The joints produced from the developed brazing alloys had acceptable strengths with improved stress-strain behaviour compared to muntz brass.

  13. Microstructure and phase constitution near the interface of Cu/3003 torch brazing using Al Si La Sr filler

    International Nuclear Information System (INIS)

    It has been mainly studied in this paper on brazing of Cu to Al using Al.Si filler metal. The optimized scanning rate of 2.5 mm/s is first obtained through simulating the temperature field of Cu Al brazing process based on ANSYS software. Then the brazing of Cu C11000 to Al 3003 using Al.Si.La.Sr filler is carried out by torch brazing technology. It is found that the brazing seam region is mainly consisted of α Al solid solution and CuAl2 IMC. Further experimental results also show that the rare earth element La in filler metal can not only refine the grain, but also promote the dispersion of intermetallic compounds into the brazing seam, which significantly improves the brazing seam microstructure and mechanical properties of the joints

  14. Microstructure and strength of brazed joints of TiB2 cermet to TiAl-based alloys

    Institute of Scientific and Technical Information of China (English)

    李卓然; 冯吉才; 曹健

    2003-01-01

    In this study, TiB2 cermet and TiAl-based alloy are vacuum brazed successfully by using Ag-Cu-Ti filler metal. The microstructural analyses indicate that two reaction products, Ti(Cu, Al)2 and Ag based solid solution (Ag(s.s)), are present in the brazing seam, and the interface structure of the brazed joint is TiB2/TiB2+ Ag(s.s) /Ag(s.s)+Ti(Cu, Al)2/Ti(Cu, Al)2/TiAl. The experimental results show that the shear strength of the brazed TiB2/TiAl joints decreases as the brazing time increases at a definite brazing temperature. When the joint is brazed at 1 223 K for 5 min, a joint strength up to 173 MPa is achieved.

  15. Braze welding of cobalt with a silver–copper filler

    Directory of Open Access Journals (Sweden)

    Everett M. Criss

    2015-01-01

    Full Text Available A new method of joining cobalt by braze-welding it with a silver–copper filler was developed in order to better understand the residual stresses in beryllium–aluminum/silicon weldments which are problematic to investigate because of the high toxicity of Be. The base and filler metals of this new welding system were selected to replicate the physical properties, crystal structures, and chemical behavior of the Be–AlSi welds. Welding parameters of this surrogate Co–AgCu system were determined by experimentation combining 4-point bending tests and microscopy. Final welds are 5 pass manual TIG (tungsten inert gas, with He top gas and Ar back gas. Control of the welding process produces welds with full penetration melting of the cobalt base. Microscopy indicates that cracking is minimal, and not through thickness, whereas 4-point bending shows failure is not by base-filler delamination. These welds improve upon the original Be–AlSi welds, which do not possess full penetration, and have considerable porosity. We propose that utilization of our welding methods will increase the strength of the Be–AlSi weldments. The specialized welding techniques developed for this study may be applicable not only for the parent Be–AlSi welds, but to braze welds and welds utilizing brittle materials in general. This concept of surrogacy may prove useful in the study of many different types of exotic welds.

  16. Interfacial metallurgy study of brazed joints between tungsten and fusion related materials for divertor design

    International Nuclear Information System (INIS)

    Highlights: • We created brazed joints between tungsten and EUROFER 97, Cu and SS316L with Au80Cu19Fe1 filler. • No elemental transitions were detected between the W and the AuCuFe filler in either direction. • Transition regions between filler to EUROFER97/316L showed similar elastic modulus and hardness to the filler. • Smooth elemental and mechanical properties transition were detected between the filler and Cu. - Abstract: In the developing DEMO divertor, the design of joints between tungsten to other fusion related materials is a significant challenge as a result of the dissimilar physical metallurgy of the materials to be joined. This paper focuses on the design and fabrication of dissimilar brazed joints between tungsten and fusion relevant materials such as EUROFER 97, oxygen-free high thermal conductivity (OFHC) Cu and SS316L using a gold based brazing foil. The main objectives are to develop acceptable brazing procedures for dissimilar joining of tungsten to other fusion compliant materials and to advance the metallurgical understanding within the interfacial region of the brazed joint. Four different butt-type brazed joints were created and characterised, each of which were joined with the aid of a thin brazing foil (Au80Cu19Fe1, in wt.%). Microstructural characterisation and elemental mapping in the transition region of the joint was undertaken and, thereafter, the results were analysed as was the interfacial diffusion characteristics of each material combination produced. Nano-indentation tests are performed at the joint regions and correlated with element composition information in order to understand the effects of diffused elements on mechanical properties. The experimental procedures of specimen fabrication and material characterisation methods are presented. The results of elemental transitions after brazing are reported. Elastic modulus and nano-hardness of each brazed joints are reported

  17. Diffusion bonding and brazing of high purity copper for linear collider accelerator structures

    Science.gov (United States)

    Elmer, J. W.; Klingmann, J.; van Bibber, K.

    2001-05-01

    Diffusion bonding and brazing of high purity copper were investigated to develop procedures for joining precision machined copper components for the Next Linear Collider (NLC). Diffusion bonds were made over a range of temperatures from 400 °C to 1000 °C, under two different loading conditions [3.45 kPa (0.5 psi) and 3.45 MPa (500 psi)], and on two different diamond machined surface finishes. Brazes were made using pure silver, pure gold, and gold-nickel alloys, and different heating rates produced by both radiation and induction heating. Braze materials were applied by both physical vapor deposition (PVD) and conventional braze alloy shims. Results of the diffusion bonding experiments showed that bond strengths very near that of the copper base metal could be made at bonding temperatures of 700 °C or higher at 3.45 MPa bonding pressure. At lower temperatures, only partial strength diffusion bonds could be made. At low bonding pressures (3.45 kPa), full strength bonds were made at temperatures of 800 °C and higher, while no bonding (zero strength) was observed at temperatures of 700 °C and lower. Observations of the fracture surfaces of the diffusion bonded samples showed the effects of surface finish on the bonding mechanism. These observations clearly indicate that bonding began by point asperity contact, and flatter surfaces resulted in a higher percentage of bonded area under similar bonding conditions. Results of the brazing experiments indicated that pure silver worked very well for brazing under both conventional and high heating rate scenarios. Similarly, pure silver brazed well for both the PVD layers and the braze alloy shims. The gold and gold-containing brazes had problems, mainly due to the high diffusivity of gold in copper. These problems led to the necessity of overdriving the temperature to ensure melting, the presence of porosity in the joint, and very wide braze joints. Based on the overall findings of this study, a two-step joining method

  18. Finite element analysis on electron beam brazing temperature and stresses of stainless steel radiator

    Institute of Scientific and Technical Information of China (English)

    Chen Furong; Liu Jun; Xie Ruijun; Liu Fangjun; Hu Gang

    2006-01-01

    Based on thermal-elasto-plastic finite element theory, a two-dimensional finite element model for calculating electron beam brazing temperature and residual stress fields of stainless steel radiator are presented.The distributions of temperature and residual stress are studied.The results showed that temperature distribution on brazing surface is rather uniform, ranging from 1026 ℃ to 1090 ℃.The residual stresses are varied from initial compressive to tensile , and the variation of residual stress is very little in total zone of brazing surface.

  19. Vacuum Brazing of Beryllium Copper Components for the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Tyhurst, C.C.; Cunningham, M.A.

    2002-06-04

    A process for vacuum brazing beryllium copper anode assemblies was required for the Plasma Electrode Pockels Cell System, or PEPC, a component for the National Ignition Facility (NIF). Initial problems with the joint design and wettability of the beryllium copper drove some minor design changes. Brazing was facilitated by plating the joint surface of the beryllium copper rod with silver 0.0006 inch thick. Individual air sampling during processing and swipe tests of the furnace interior after brazing revealed no traceable levels of beryllium.

  20. Brazing technology of Ti alloy/stainless steel dissimilar metal joint at system integrated modular advanced reactor

    International Nuclear Information System (INIS)

    For the technoldogy development of brazing Ti alloy to stainless steel joints used at SMART, the status of brazing technology development, brazing processes, and the brazing technology of Ti alloy and stainless steel are reviewed. Because fusion welding process cannot be applied due to the formation of intermetallic compounds in the weld metal, brazing joint was selected at the design. The joint part is assembled with a thread composed with male part of Ti alloy tube and female part of stainless tube. The gap in the thread will be filled with brazing filler metal. However, brittle Ti-Fe intermetallic compounds are formed at the surface of stainless steel through the diffusion of Ti at the melt. Brazing conditions should be set-up to reduce the formation of intermetallic compounds. For that, 3 kinds of Ag filler metals were selected as the candidates and heating will be done with induction and electric furnaces. Through measuring of joint strength according to the control of pre- and post-braze treatment, heating rate and heating time, optimal brazing method will be fixed. To qualify the brazing procedure and performance and to check defects in final product, the inspection plan will be established according to the req2wuirements of AWS and ASME

  1. Brazing technology of Ti alloy/stainless steel dissimilar metal joint at system integrated modular advanced reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Sang Chul; Kim, Sung Ho; Kim, Yong Wan; Kim, Jong In

    2001-02-01

    For the technoldogy development of brazing Ti alloy to stainless steel joints used at SMART, the status of brazing technology development, brazing processes, and the brazing technology of Ti alloy and stainless steel are reviewed. Because fusion welding process cannot be applied due to the formation of intermetallic compounds in the weld metal, brazing joint was selected at the design. The joint part is assembled with a thread composed with male part of Ti alloy tube and female part of stainless tube. The gap in the thread will be filled with brazing filler metal. However, brittle Ti-Fe intermetallic compounds are formed at the surface of stainless steel through the diffusion of Ti at the melt. Brazing conditions should be set-up to reduce the formation of intermetallic compounds. For that, 3 kinds of Ag filler metals were selected as the candidates and heating will be done with induction and electric furnaces. Through measuring of joint strength according to the control of pre- and post-braze treatment, heating rate and heating time, optimal brazing method will be fixed. To qualify the brazing procedure and performance and to check defects in final product, the inspection plan will be established according to the req2wuirements of AWS and ASME.

  2. Active Metal Brazing and Characterization of Brazed Joints in C-C and C-SiC Composites to Copper-Clad-Molybdenum System

    Science.gov (United States)

    Singh, M.; Asthana, R.

    2008-01-01

    Carbon/carbon composites with CVI and resin-derived matrices, and C/SiC composites reinforced with T-300 carbon fibers in a CVI SiC matrix were joined to Cu-clad Mo using two Ag-Cu braze alloys, Cusil-ABA (1.75% Ti) and Ticusil (4.5% Ti). The brazed joints revealed good interfacial bonding, preferential precipitation of Ti at the composite/braze interface, and a tendency toward delamination in resin-derived C/C composite. Extensive braze penetration of the inter-fiber channels in the CVI C/C composites was observed. The Knoop microhardness (HK) distribution across the C/C joints indicated sharp gradients at the interface, and a higher hardness in Ticusil than in Cusil-ABA. For the C/SiC composite to Cu-clad-Mo joints, the effect of composite surface preparation revealed that ground samples did not crack whereas unground samples cracked. Calculated strain energy in brazed joints in both systems is comparable to the strain energy in a number of other ceramic/metal systems. Theoretical predictions of the effective thermal resistance suggest that such joined systems may be promising for thermal management applications.

  3. Development of Induction Brazing System for Sealing Instrumentation Feed through Part of Nuclear Fuel Test Rig

    International Nuclear Information System (INIS)

    To test the performance of nuclear fuels, coolant needs to be circulated through the test rig installed in the test loop. Because the pressure and temperature of the coolant is 15.5 MPa and 300 .deg. C respectively, coolant sealing is one of the most important processes in fabricating a nuclear fuel test rig. In particular, 15 instrumentation cables installed in a test rig pass through the pressure boundary, and brazing is generally applied as a sealing method. In this study, an induction brazing system has been developed using a high frequency induction heater including a vacuum chamber. For application in the nuclear field, BNi2 should be used as a paste, and optimal process variables for Ni brazing have been found by several case studies. The performance and soundness of the brazed components has been verified by a tensile test, cross section test, and sealing performance test

  4. An Investigation on Corrosion Behavior of a Multi-layer Modified Aluminum Brazing Sheet

    Directory of Open Access Journals (Sweden)

    Liu Wei

    2016-01-01

    Full Text Available The corrosion behavior of a multi-layer modified aluminum brazing sheet (AA4045/3003Mod./AA7072/AA4045 was investigated. The results shows that, the existence of BDP, which forms at the interface between clad and core layer during brazing, changes the corrosion form of the air side of the material from inter-granular corrosion to local exfoliation corrosion. The addition of anti-corrosion layer makes the corrosion form of the water side from inter-granular corrosion into uniform exfoliation corrosion. Compared to the normal triple-layer brazing sheet at the same thickness, the time to perforation of the modified four-layer brazing sheet is increased by more than 200%.

  5. Evaluation of the adhesion strength of diamond films brazed on K-10 type hard metal

    Directory of Open Access Journals (Sweden)

    Sérgio Ivan dos Santos

    2004-06-01

    Full Text Available The coating of cutting tools with diamond films considerably increases the tool performance due to the combination of the unique tribological properties of diamond with the bulk properties of the substrate (toughness. The tool performance, however, is strongly related to the adhesion strength between the film and the substrate. In this work our main goal was to propose and to test a procedure, based on a tensile strength test, to evaluate the adhesion strength of a diamond wafer brazed on a hard metal substrate, taking into account the effect of the brazing temperature and time. The temperature range studied was from 800 to 980 °C and the brazing time ranged from 3 to 40 min. The obtained results could be used to optimize the costs and time required to the production of high performance cutting tools with brazed diamond wafers.

  6. Studies and research on the microstructure of brazed aluminum alloys in the repair process

    Science.gov (United States)

    Dimitescu, A.; Amza, Gh; Niţoi, D. F.; Amza, C. Gh; Apostolescu, Z.

    2016-08-01

    In aeronautical industry, in recent years, brazing joints got a growing spread. Therefore, it is necessary a detailed study on the microstructure of the assembly base and filler material brazed in conditions of reconditioning operation [1]. The methods of destructive examination are not associated with any particular type of test piece but lay down the general principles of the types of testing described. It is emphasized that a satisfactory examination method can only be developed and used after taking into account all the relevant factors regarding the equipment to be used and the characteristics of the test pieces being examined. [1, 2]. Brazing joints are most often systematically designed to be resistant to shearing, and the size of the joint influences the shear strength more than the tensile strength. Studies and researches on the microstructure may be necessary to determine the effects of brazing process or of any subsequent heat treatment on the characteristics of the joint.

  7. Laser fusion-brazing of aluminum alloy to galvanized steel with pure Al filler powder

    Science.gov (United States)

    Liu, Jia; Jiang, Shichun; Shi, Yan; Kuang, Yulin; Huang, Genzhe; Zhang, Hong

    2015-03-01

    The fusion-brazing connection of the dissimilar metal 5052 aluminum alloy/ST07Z steel was achieved by using the Nd:YAG laser with pure Al filler powder, and the effects of the laser power and powder feeding speed on the formation and mechanical properties of the resultant joints were investigated. The experimental results show that melting-brazing connection of 5052 aluminum alloy/galvanized steel can be successfully achieved, and the zinc plating layer has played the role of flux, assuring the brazing properties. The intermetallic compound layer was generated on the welded brazing interface. The joint exhibited a shear strength of 174 N/mm if the thickness of the intermetallic layer at the interface is about 6-7 μm.

  8. Simulation on Thermal Integrity of the Fin/Tube Brazed Joint of Heat Exchangers

    Institute of Scientific and Technical Information of China (English)

    Yiyu QIAN; Feng GAO; Fengjiang WANG; Hui ZHAO

    2003-01-01

    In the applications of heat exchangers, the fin efficiency of heat transfer is the key issue. Thermal distribution withinthe brazed joints in heat exchanger under loading conditions is investigated in this paper. Simulated results showedthat the therma

  9. Braze Welding TIG of Titanium and Aluminium Alloy Type Al – Mg

    Directory of Open Access Journals (Sweden)

    Winiowski A.

    2016-03-01

    Full Text Available The article presents the course and the results of technological tests related to TIG-based arc braze welding of titanium and AW-5754 (AlMg3 aluminium alloy. The tests involved the use of an aluminium filler metal (Al99.5 and two filler metals based on Al-Si alloys (AlSi5 and AlSi12. Braze welded joints underwent tensile tests, metallographic examinations using a light microscope as well as structural examinations involving the use of a scanning electron microscope and an X-ray energy dispersive spectrometer (EDS. The highest strength and quality of welds was obtained when the Al99.5 filler metal was used in a braze welding process. The tests enabled the development of the most convenient braze welding conditions and parameters.

  10. Interface structure and mechanical property of aluminum cooler vacuum brazing joint

    Institute of Scientific and Technical Information of China (English)

    FENG Tao; LOU Song-nian; WU Lu-hai; LI Ya-jiang

    2006-01-01

    A kind of aluminum cooler was manufactured by means of vacuum brazing technique, and the cooler was examined by hydraulic pressure test. The result indicates that the test pressure of the cooler can reach 15 MPa. The fracture of the brazing joint belongs to the mixture type. There are secondary cracks, dimples, cleavage plane and grain-boundary features on the failure surface.The cracking process of aluminum cooler is as follows. The cracks are initiated on the interface, then expand under sub-critical state.When the stress on the remained zone reaches the maximum notch tensile strength of the brazing joint or the crack length reaches the critical value that the brazing joint fracture toughness property permits, the cooler will break sharply.

  11. Researches and studies regarding brazed aluminium alloys microstructure used in aeronautic industry

    Directory of Open Access Journals (Sweden)

    A. Dimitrescu

    2015-04-01

    Full Text Available Brazing is applied to the merge of the pieces which are most required, tensile strength of the solder can reach high values. By brazing there can be assembled pieces of most metals and ferrous and nonferrous alloys, with high melting temperature. This paper presents an analysis of the microstructure of materials from a brazed merge of aluminum alloy L103 which is often used to produce pieces of aeronautical industry. Brazing material was performed using several technologies, and after examination of the microstructure of materials from the merge area it was established as optimal technology the technology which consist of pickling in Aloclene 100 solution with the deposition of filler material on both sides of the base material and the use of spectral acetylene and neutral flame.

  12. Electrochemical depth profiling of multilayer metallic structures: An aluminum brazing sheet

    DEFF Research Database (Denmark)

    Afshar, F. Norouzi; Ambat, R.; Kwakernaak, C.;

    2012-01-01

    Combinatory localized electrochemical cell and glow discharge optical emission spectrometry (GDOES) measurements were performed to obtain a thorough in depth electrochemical characterization of an aluminum brazing sheet. By defining electrochemical criteria i.e. breakdown potential, corrosion pot...

  13. Nano-Phase Powder Based Exothermic Braze Repair Technology For RCC Materials Project

    Data.gov (United States)

    National Aeronautics and Space Administration — MRi is proposing, with its partner, Exotherm Corp (Camden, NJ) to demonstrate the feasibility of using exothermic brazing to join RCC (or C:SiC) composites to...

  14. Nano-Phase Powder Based Exothermic Braze Repair Technology For RCC Materials Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Phase II project will advance innovative, cost effective and reliable nano-phase exothermic RCC joining processes (ExoBrazeTM) in order to be able to reinforce...

  15. Brazing of 14-5 PH steel and WC-Co sinterson considerable dimension surfaces

    Directory of Open Access Journals (Sweden)

    J. Nowacki

    2007-03-01

    Full Text Available Purpose: of this paper is study of structure properties of considerable surfaces vacuum brazed joints of WC-Co sinters and precipitation hardened stainless steel of 14-5 PH using copper and silver-copper as the brazing filler metal.Design/methodology/approach: the joints are used in large dimension spinning nozzles of a die for polyethylene granulation, in that considerable strength and ductility of the joints are required. Structure and mechanical properties of joints have been described. Shear strength Rt and tensile strength Rm of the joints have been defined.Findings: to have been state, that the basic factors decreasing quality of the joint, which can occur during vacuum brazing of the WC-Co ISO K05 sinter – Cu or Ag-Cu brazing filler metal – 14-5 PH steel joints are diffusive processes leading to exchange of elements of cermets and the brazing filler metal and creation of intermetalics in the joint. It can have an unfavourable influence on ductility of sinters and quality of joint. As a result of brazing tests the influence of means and parameters of the brazing on quality of a joint was determined.Research limitations/implications: as a result of the experiments scheme of the joint structure WC-Co ISO K05 sinter – Cu brazing filler metal – 14-5 PH steel joint and WC-Co ISO K05 sinter – Cu brazing filler metal – 14-5 PH have been described.Practical implications: as a result of conducted experiments a production of spinning nozzle of a die for polyethylene granulation with a vacuum-brazed with a WC-Co ISO K05 sinters plates cutting surface of large surfaces on precipitation hardened stainless steel 14-5 PH have been worked out and industrial applied.Originality/value: the basic factors decreasing quality of the joint, which can occur while vacuum brazing of stainless steels and cermets have been determined.

  16. Brazing techniques for side-coupled electron accelerator structures

    International Nuclear Information System (INIS)

    The collaboration between the Los Alamos National Laboratory and the National Bureau of Standards (NBS), started in 1979, has led to the development of an advanced c-w microtron accelerator design. The four 2380-MHz NBS accelerating structures, containing a total of 184 accelerating cavities, have been fabricated and delivered. New fabrication methods, coupled with refinements of hydrogen-furnace brazing techniques described in this paper, allow efficient production of side-coupled structures. Success with the NBS RTM led to Los Alamos efforts on similar 2450-MHz accelerators for the microtron accelerator operated by the Nuclear Physics Department of the University of Illinois. Two accelerators (each with 17 cavities) have been fabricated; in 1986, a 45-cavity accelerator is being fabricated by private industry with some assistance from Los Alamos. Further private industry experience and refinement of the described fabrication techniques may allow future accelerators of this type to be completely fabricated by private industry

  17. Brazing of 14-5 PH steel and WC-Co sinterson considerable dimension surfaces

    OpenAIRE

    J. Nowacki

    2007-01-01

    Purpose: of this paper is study of structure properties of considerable surfaces vacuum brazed joints of WC-Co sinters and precipitation hardened stainless steel of 14-5 PH using copper and silver-copper as the brazing filler metal.Design/methodology/approach: the joints are used in large dimension spinning nozzles of a die for polyethylene granulation, in that considerable strength and ductility of the joints are required. Structure and mechanical properties of joi...

  18. THERMAL FIELD MODELING IN THE MIG / MAG - CMT BRAZE-WELDING PROCESS OF GALVANIZED SHEETS

    OpenAIRE

    GHEORGHE SIMA; ELENA STELA MUNCUT

    2013-01-01

    This paper deals with some technical aspects of the optimization process braze-welding of galvanized steel sheet with a thickness of 0.7-1.5 mm. The braze-welding process is presented systemic, highlighting the input and output variables (of the zinc layer and intermetallic layer characteristics). It is presented the test for statistical analysis performed on a four-level factorial experiment aimed at studying the influence of the main simultaneously welding parameters of the welding technolo...

  19. Strength of vacuum brazed joints for repair; Haallfasthet hos reparationer utfoerda med vakuumloedning

    Energy Technology Data Exchange (ETDEWEB)

    Berglin, Leif [Siemens Industrial Turbomachinery AB, Finspaang (Sweden)

    2005-04-01

    Strength data are missing for braze joints. Repaired components cannot fully make use of the strength of the braze, and lifetime will be underestimated. The goal of the project was to generate material data to be able to prolong the lifetime of the components. Two different material combinations were tested, 12% Chromium steel brazed with BNi-2, and a nickel base alloy, IN792 brazed with BNi-5. Tensile testing at room temperature and elevated temperature was performed in the project. Target group is purchasers and suppliers of repaired components. A tensile test specimen with butt joint was developed in the project. The used test specimen worked well for the 12% Chromium steel. The results from testing show that proof stress and tensile strength are strongly depending on the joint gap, particularly at room temperature. High strength, close to base material strength, was achieved with joint gaps smaller than 50{mu}m. For wider joint gaps, strength was lower. Strength was approximately 25% of base material strength for joint gaps over 100{mu}m. The results can be explained by changes in microstructure. Joint gaps wider than 50{mu}m showed evidence of two-phase structure. At 500 deg C, the results also showed a connection between joint gap, microstructure and strength. The generated strength data can be used for calculations of lifetime for repaired components. Two different process errors were discovered in the manufacturing process of the brazed IN792 test specimens. The generated material data are therefor erroneous. The reason for this was two manufacturing errors. The tack welding was done with too high heat input. The surfaces of the joint gap became oxidised and the oxide hindered wetting of the braze. The second reason was that the brazing was done without the prescribed hold time at maximum temperature. The melting of the braze was therefor not completed when cooling started. As a result, the strength of the IN792 specimens was low at both temperatures.

  20. Tensile fracture characterization of braze joined copper-to-CFC coupon assemblies

    Science.gov (United States)

    Trester, P. W.; Valentine, P. G.; Johnson, W. R.; Chin, E.; Reis, E. E.; Colleraine, A. P.

    1996-10-01

    A vacuum brazing process was used to join a broad spectrum of carbon-fiber reinforced carbon matrix composite (CFC) materials, machined into cylindrical coupons, between coupons of oxygen-free copper, the braze alloy was a copper-base alloy which contained only low activation elements (Al, Si, and Ti) relative to a titanium baseline specification. This demonstration was of particular importance for plasma facing components (PFCs) under design for use in the Tokamak Physics Experiment (TPX); the braze investigation was conducted by General Atomics for the Princeton Plasma Physics Laboratory. A tensile test of each brazed assembly was conducted. The results from the braze processing, testing, and fracture characterization studies of this reporting support the use of CFC's of varied fiber architecture and matrix processing in PFC designs for TPX. Further, the copper braze alloy investigated is now considered to be a viable candidate for a low-activation bond design. The prediction of plasma disruption-induced loads on the PFCs in TPX requires that joint strength between CFC tiles and their copper substrate be considered in design analysis and CFC selection.

  1. JOINING OF MOLYBDENUM DISILICIDE TO STAINLESS STEEL USING AMORPHOUS METAL BRAZES-RESIDUAL STRESS ANALYSIS

    Energy Technology Data Exchange (ETDEWEB)

    VAIDYA, RAJENDRA U [Los Alamos National Laboratory; KAUTZ, DOUGLAS D. [Los Alamos National Laboratory; GALLEGOS, DAVID E. [Los Alamos National Laboratory

    2007-01-30

    Molybdenum disilicide (MoSi{sub 2})/stainless steel 316 L jOints were produced by high temperature brazing using a cobalt-based metallic-glass (METGLAS{trademark} 2714A). Successful joining was completed in two different ways; either by feeding excess braze into the braze gap upon heating or by constraining the MoSi{sub 2}/stainiess steel assembly with an alumina (Al{sub 2}O{sub 3}) fixture during the heating cycle. These steps were necessary to ensure the production of a high quality void free joint. Residual stress measurements were completed on these joints. Indentation results show higher tensile residual stresses in the stainless steel for the joint with the external constraint, in comparison to the unconstrained state. In contrast, the compressive residual stresses In the MoSi{sub 2} (as measured by X-ray diffraction) were lower in the constrained state relative to the unconstrained state. These results and a lack of residual stress balance indicate that the stress state in the braze is significantly different under the two joining conditions and the volume of the braze plays an important role in the development of the residual stresses. Push-out tests carried out on these joints gave higher joint strengths in the unconstrained as compared to the constrained condition. The results of this study have important implications on the selection of the appropriate joining process (use of constraint versus extra braze).

  2. Laser brazing of inconel 718 alloy with a silver based filler metal

    Science.gov (United States)

    Khorram, A.; Ghoreishi, M.; Torkamany, M. J.; Bali, M. M.

    2014-03-01

    In the presented study laser brazing of an inconel 718 alloy with silver based filler metal using 400 W pulsed Nd:YAG laser is investigated. Laser brazing was performed with varying laser frequency, pulse width, process speed and gap distance. The effect of preheating on wetting and spreading also was studied. Brazing geometrical images were observed using an optical microscope. The composition analysis and microstructure of the filler metal and brazed joints were examined using X-ray diffraction analyzer (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). Micro-hardness and tensile test were performed for investigation of mechanical properties. The experimental observations show that filler metal consist of α-Ag solid solution, ά-Cu solid solution surround by the α-Ag solid solution and eutectic structure. Phases of the brazed joint are similar to the filler metal. The results indicate that the filler metal has adequate wetting and spreading on inconel 718 and the wetting angle depends on the heat input significantly. Interdiffusion occurs in laser brazing and the average thickness of reaction layer is approximately 2.5 μm. Whenever the gap is big, it is needed to use longer pulse width in order to have a better melting flow. Preheating has significant influence on wetting and spreading of the filler metal.

  3. MICROSTRUCTURE AND PROPERTIES OF 5A03 AND SUS304 IN TRANSITIONAL BRAZING

    Institute of Scientific and Technical Information of China (English)

    Lu Xueqin; Yang Shanglei; Wu Yixiong

    2005-01-01

    Stainless steel is so different from aluminum alloys in physical and chemical characters.When they are welded directly, there tend to be Al-Fe brittle compounds on the joint. This paper investigates the processing performance, interface microstructures and mechanical properties of aluminum alloys/stainless steel by way of brazing after brush plating a Ni/Cu transitional layer on stainless steel. After the joints are brazed with Al-Si-Cu-Mg~Zn foil brazing filler metal on different brazing parameters, both the mechanical properties and the microstructures are satisfactory for application.And the influence of the brazing parameters on bonding quality of the brazed joints is discussed in detail. The results reveal that no brittle Al-Fe intermetallic Compound is found in the interfaces. The Ni/Cu electroplating layer effectively hinders the diffusion of Fe atoms from SUS304 to 5A03.Though a little AlCu3 brittle compound is produced, its quantity is too small to affect the strength of the joint.

  4. Microstructure, mechanical properties and chemical degradation of brazed AISI 316 stainless steel/alumina systems

    Energy Technology Data Exchange (ETDEWEB)

    Paiva, O.C. [Instituto Superior de Engenharia do Porto (ISEP), Rua Dr. Antonio Bernardino de Almeida 431, 4200-072 Porto (Portugal)], E-mail: omp@isep.ipp.pt; Barbosa, M.A. [Instituto de Engenharia Biomedica (INEB), Rua do Campo Alegre, 823, 4150-180 Porto (Portugal); Faculdade de Engenharia da Universidade do Porto (FEUP), Rua Roberto Frias s/n, 4200-465 Porto (Portugal)

    2008-05-15

    The main aims of the present study are simultaneously to relate the brazing parameters with: (i) the correspondent interfacial microstructure, (ii) the resultant mechanical properties and (iii) the electrochemical degradation behaviour of AISI 316 stainless steel/alumina brazed joints. Filler metals on such as Ag-26.5Cu-3Ti and Ag-34.5Cu-1.5Ti were used to produce the joints. Three different brazing temperatures (850, 900 and 950 deg. C), keeping a constant holding time of 20 min, were tested. The objective was to understand the influence of the brazing temperature on the final microstructure and properties of the joints. The mechanical properties of the metal/ceramic (M/C) joints were assessed from bond strength tests carried out using a shear solicitation loading scheme. The fracture surfaces were studied both morphologically and structurally using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction analysis (XRD). The degradation behaviour of the M/C joints was assessed by means of electrochemical techniques. It was found that using a Ag-26.5Cu-3Ti brazing alloy and a brazing temperature of 850 deg. C, produces the best results in terms of bond strength, 234 {+-} 18 MPa. The mechanical properties obtained could be explained on the basis of the different compounds identified on the fracture surfaces by XRD. On the other hand, the use of the Ag-34.5Cu-1.5Ti brazing alloy and a brazing temperature of 850 deg. C produces the best results in terms of corrosion rates (lower corrosion current density), 0.76 {+-} 0.21 {mu}A cm{sup -2}. Nevertheless, the joints produced at 850 deg. C using a Ag-26.5Cu-3Ti brazing alloy present the best compromise between mechanical properties and degradation behaviour, 234 {+-} 18 MPa and 1.26 {+-} 0.58 {mu}A cm{sup -2}, respectively. The role of Ti diffusion is fundamental in terms of the final value achieved for the M/C bond strength. On the contrary, the Ag and Cu distribution along the

  5. Corrosion Behavior of Aluminum-Steel Weld-Brazing Joint

    Science.gov (United States)

    Shi, Yu; Li, Jie; Zhang, Gang; Huang, Jiankang; Gu, Yufen

    2016-05-01

    Dissimilar metals of 1060 aluminum and galvanized steel were joined with a lap joint by pulsed double-electrode gas metal arc weld brazing with aluminum-magnesium and aluminum-silicon filler metals. The corrosion behavior of the weld joints was investigated with immersion corrosion and electrochemical corrosion tests, and the corrosion morphology of the joints was analyzed with scanning electron microscopy (SEM). Galvanic corrosion was found to occur when the samples were immersed in corrosive media, and the corrosion rate of joints was increased with increased heat input of the workpiece. Comparison of the corrosion properties of weld joints with different filler wires indicated that the corrosion rate of weld joints with aluminum-silicon filler wire was larger than that of weld joints with aluminum-magnesium filler wire. Results also showed that the zinc-rich zone of weld joints was prone to corrosion. The corrosion behavior of zinc-rich zone was analyzed with SEM equipped with an energy-dispersive x-ray spectroscopy analysis system based on the test results.

  6. Impairment induced by chronic occupational cadmium exposure during brazing process

    International Nuclear Information System (INIS)

    Cadmium (CD) is considered a metal of the 20th century to which all inhabitants of develop societies are exposed. Long-term occupational and environmental exposure to CD often results in renal dysfunction as the kidney is considered the critical target organ. The aim of this work was to evalutate both resporatory and renal manifestations induced by occupational exposure to CD compounds during brazing process, and suggesting a protocol for prevention and control for CD- induced health effects. This study was conducted on 20 males occupationally exposed workers. They are divided into two groups: Group-1 included (10) exposed smokers and group-2 included (10) exposed non-smokers. Results of both groups were compared with those of 10 healthy age and sex matched non-smokers. All subjects were subjected to detailed history taking and laboratory investigations including blood and urinary CD, liver profile (SGOT, SGPT and alkline phosphates), kindey function tests (blood urea, creatinine and urinary beta2- microglobulin). The level of Cd in the atmosphere of the work plase air was also assessed to detect the degree of exposure as it was about 6 times greater than thesave level (1 mu /m3).(1) This study demonstrated elevation levels of blood CD, urea, creatinine and urinary CD and beta2 -microglobulin for both exposed worker groups than the controls. In additions no appreciable were noted for liver function tests, although the levels fell within normal range

  7. Brazing of Stainless Steels to Yttria Stabilized Zirconia (YSZ) for Solid Oxide Fuel Cells

    Science.gov (United States)

    Shpargel, Tarah P.; Needham, Robert J.; Singh, M.; Kung, Steven C.

    2005-01-01

    Recently, there has been a great deal of interest in research, development, and commercialization of solid oxide fuel cells. Joining and sealing are critical issues that will need to be addressed before SOFC's can truly perform as expected. Ceramics and metals can be difficult to join together, especially when the joint must withstand up to 900 C operating temperature of the SOFC's. The goal of the present study is to find the most suitable braze material for joining of yttria stabilized zirconia (YSZ) to stainless steels. A number of commercially available braze materials TiCuSil, TiCuNi, Copper-ABA, Gold-ABA, and Gold-ABA-V have been evaluated. The oxidation behavior of the braze materials and steel substrates in air was also examined through thermogravimetric analysis. The microstructure and composition of the brazed regions have been examined by optical and scanning electron microscopy and EDS analysis. Effect of braze composition and processing conditions on the interfacial microstructure and composition of the joint regions will be presented.

  8. Evolution of Surface Oxide Film of Typical Aluminum Alloy During Medium-Temperature Brazing Process

    Institute of Scientific and Technical Information of China (English)

    程方杰; 赵海微; 王颖; 肖兵; 姚俊峰

    2014-01-01

    The evolution of the surface oxide film along the depth direction of typical aluminum alloy under medium-temperature brazing was investigated by means of X-ray photoelectron spectroscopy (XPS). For the alloy with Mg content below 2.0wt%, whether under cold rolling condition or during medium-temperature brazing process, the en-richment of Mg element on the surface was not detected and the oxide film was pure Al2O3. However, the oxide film grew obviously during medium-temperature brazing process, and the thickness was about 80 nm. For the alloy with Mg content above 2.0wt%, under cold rolling condition, the original surface oxide film was pure Al2O3. However, the Mg element was significantly enriched on the outermost surface during medium-temperature brazing process, and MgO-based oxide film mixed with small amount of MgAl2O4 was formed with a thickness of about 130 nm. The alloy-ing elements of Mn and Si were not enriched on the surface neither under cold rolling condition nor during medium-temperature brazing process for all the selected aluminum alloy, and the surface oxide film was similar to that of pure aluminum, which was almost entire Al2O3.

  9. Joining mechanism of Ti/Al dissimilar alloys during laser welding-brazing process

    International Nuclear Information System (INIS)

    Research highlights: → The microstructures of interfacial zones were confirmed in detail by transmission electron microscope (TEM). Interfacial reaction layers of brazing joint were composed of α-Ti, nanosize granular Ti7Al5Si12 and serration-shaped TiAl3. For the first time, obvious stacking fault structure in intermetallic phase TiAl3 was found when the thickness of the reaction layer was very thin (approximately below 1 μm). → Metallurgical characteristics for laser welding-brazing process in the environment of far from equilibrium was expounded by microstructures of the joints, the characteristics of thermal process and element diffusion behavior. - Abstract: Joining mechanism of Ti/Al dissimilar alloys was investigated during laser welding-brazing process with automated wire feed. The microstructures of fusion welding and brazing zones were analysed in details by transmission electron microscope (TEM). It was found that microstructures of fusion welding zone consist of α-Al grains and ternary near-eutectic structure with α-Al, Si and Mg2Si. Interfacial reaction layers of brazing joint were composed of α-Ti, nanosize granular Ti7Al5Si12 and serration-shaped TiAl3. For the first time, apparent stacking fault structure in intermetallic phase TiAl3 was found when the thickness of the reaction layer was very thin (approximately less than 1 μm). Furthermore, crystallization behavior of fusion zone and mechanism of interfacial reaction were discussed in details.

  10. The Integration of Vacuum Brazing into Heat Treatment - A Progressive Combined Process

    Institute of Scientific and Technical Information of China (English)

    Ingo Reinkensmeier; Henkjan Buursen

    2004-01-01

    The continuous constructive challenge to improve the functionality and efficiency of components always results in higher demands on production engineering, against the background of the generally increasing cost pressure. In many cases, you will just succeed in producing competitive and innovative products by combining and coupling of different procedures to an independent (hybrid) technology. The use of hybrid procedures for metal joining and heat treatment of metallic materials finds more and more industrial fields of application. Modern vacuum lines with integrated pressurized gas quenching are considered high-performance and flexible means of production for brazing and heat treatment tasks as well in the turbine industry as in the mould making and tool manufacturing industry. In doing so, the heat treatment is coupled with the brazing cycle in a combined process so that the brazing temperatures and soak times are adapted to the necessary temperatures and times for solution heat treatment and austeniting. This user-oriented article describes on the one hand examples of brazing of turbine components, but above all the practical experience from the plastics processing industry, where the requirement for a high-efficient cooling of injection moulding dies gains more and more importance.The combined procedure "Vacuum Brazing and Hardening" offers plenty of possibilities to produce mould inserts with an efficient tempering system in an economic way.

  11. 75 FR 52037 - Welding, Cutting and Brazing Standard; Extension of the Office of Management and Budget's (OMB...

    Science.gov (United States)

    2010-08-24

    ... Order No. 5-2007 (67 FR 31160). Signed at Washington, DC, on August 16, 2010. David Michaels, Assistant... Occupational Safety and Health Administration Welding, Cutting and Brazing Standard; Extension of the Office of... the information collection requirements contained in the Welding, Cutting and Brazing Standard (29...

  12. Dissimilar laser brazing of h-BN and WC-Co alloy in Ar atmosphere without evacuation process

    Science.gov (United States)

    Sechi, Y.; Nagatsuka, K.; Nakata, K.

    2012-08-01

    Laser brazing with Ti as an active element in Ag-Cu alloy braze metal has been successfully applied to dissimilar joining of h-BN and WC-Co alloy in Ar (99.999% purity) gas flow atmosphere without any evacuation process. Good wettability of the braze metal with h-BN and WC-Co alloy were confirmed by the observation and structural analysis of the interface by electron probe micro-analysis and scanning acoustic microscopy. The oxidation of titanium was not observed and this showed that the laser brazing with titanium as an active element in braze metal could be performed even in an Ar gas flow atmosphere without an evacuation process using a high-vacuum furnace.

  13. Interfacial structure and joint strengthening in arc brazed galvanized steels with copper based filler

    Institute of Scientific and Technical Information of China (English)

    LI Rui-feng; YU Zhi-shui; QI Kai

    2006-01-01

    Galvanized steel sheets were joined by tungsten inert gas(TIG) and metal inert gas(MIG) brazing process using copper based filler. The results show that the joint zone hardness is higher than that of the base material or copper filler from the microhardness tests of TIG brazing specimens, and the fracture spot is at the base materials zone from the tensile tests of MIG brazing specimens. Examination using energy dispersive X-ray analysis reveals the presence of intermetallic compound Fe5Si3(Cu) in the joint. The dispersal of fine Fe5Si3(Cu) particles is the main strengthening factor for the joint. The Fe5Si3(Cu) particles are determined to arise from three sources, namely, spot micro-melt, whisker-like fragmentation and dissolve-separation actions.

  14. Aging Thermal Treatment in the Inconel 725 Brazed Incorporating Tungsten Nanoparticles

    Directory of Open Access Journals (Sweden)

    H. M. Hdz-García

    2016-01-01

    Full Text Available Fractures in blade sections of Inconel 725 were impregnated with tungsten nanoparticles and jointed by the brazing process. In order to evaluate their effect over the microstructure, aging thermal treatments at 750°C for 2, 6, 10, and 14 h were done. BNi-9 was selected as brazing filler metal and was characterized by scanning electron microscopy and X-ray fluorescence. Before brazing, the fractures were impregnated with a mixture of tungsten NPs in ethanol. Measurements of Vickers microhardness showed an increase in the melting zone of samples with aging thermal treatment for 14 h, which is attributed to the precipitation of the γ′ phase with a typical size of ca. 100 nm. Likewise, the tungsten NPs modified the size and morphology of Cr-Ni eutectics into finer and uniformly distributed microstructures.

  15. Design and construction of a 33 GHz brazed accelerator waveguide for high gradient operation

    International Nuclear Information System (INIS)

    This paper discusses design and construction features of a precision machined and brazed traveling wave structure for use as a high gradient 33.3 GHz electron linear accelerator test section in a Two Beam Accelerator. Design emphasis was directed at meeting an RF filling time requirement of 12F<16ns, and at fabricating a test structure that would provide guidelines for demonstrating average accelerating fields of approximately 300 MV/m (maximum surface fields of 650 MV/m). Microwave measurement data, obtained during construction, are described and include a phase dispersion simple cold test technique for accurately predicting the structure filling time. A companion paper discusses plans for high power testing of both this brazed structure and a hybrid brazed/electroformed structure, using the Electron Laser Facility ELF at LLNL

  16. Nondestructive test of brazed cooling tubes of prototype bolometer camera housing using active infrared thermography.

    Science.gov (United States)

    Tahiliani, Kumudni; Pandya, Santosh P; Pandya, Shwetang; Jha, Ratneshwar; Govindarajan, J

    2011-01-01

    The active infrared thermography technique is used for assessing the brazing quality of an actively cooled bolometer camera housing developed for steady state superconducting tokamak. The housing is a circular pipe, which has circular tubes vacuum brazed on the periphery. A unique method was adopted to monitor the temperature distribution on the internal surface of the pipe. A stainless steel mirror was placed inside the pipe and the reflected IR radiations were viewed using an IR camera. The heat stimulus was given by passing hot water through the tubes and the temperature distribution was monitored during the transient phase. The thermographs showed a significant nonuniformity in the brazing with a contact area of around 51%. The thermography results were compared with the x-ray radiographs and a good match between the two was observed. Benefits of thermography over x-ray radiography testing are emphasized. PMID:21280850

  17. Basic principles of creating a new generation of high- temperature brazing filler alloys

    Science.gov (United States)

    Kalin, B. A.; Suchkov, A. N.

    2016-04-01

    The development of new materials is based on the formation of a structural-phase state providing the desired properties by selecting the base and the complex of alloying elements. The development of amorphous filler alloys for a high-temperature brazing has its own features that are due to the limited life cycle and the production method of brazing filler alloys. The work presents a cycle of analytical and experimental materials science investigations including justification of the composition of a new amorphous filler alloy for brazing the products from zirconium alloys at the temperature of no more than 800 °C and at the unbrazing temperature of permanent joints of more than 1200 °C. The experimental alloys have been used for manufacture of amorphous ribbons by rapid quenching, of which the certification has been made by X-ray investigations and a differential-thermal analysis. These ribbons were used to obtain permanent joints from the spacer grid cells (made from the alloy Zr-1% Nb) of fuel assemblies of the thermal nuclear reactor VVER-440. The brazed samples in the form of a pair of cells have been exposed to corrosion tests in autoclaves in superheated water at a temperature of 350 °C, a pressure of 160 MPa and duration of up to 6,000 h. They have been also exposed to destructive tests using a tensile machine. The experimental results obtained have made it possible to propose and patent a brazing filler alloy of the following composition: Zr-5.5Fe-(2.5-3.5)Be-1Nb-(5-8)Cu-2Sn-0.4Cr-(0.5-1.0)Ge. Its melting point is 780 °C and the recommended brazing temperature is 800°C.

  18. THERMAL FIELD MODELING IN THE MIG / MAG - CMT BRAZE-WELDING PROCESS OF GALVANIZED SHEETS

    Directory of Open Access Journals (Sweden)

    GHEORGHE SIMA

    2013-10-01

    Full Text Available This paper deals with some technical aspects of the optimization process braze-welding of galvanized steel sheet with a thickness of 0.7-1.5 mm. The braze-welding process is presented systemic, highlighting the input and output variables (of the zinc layer and intermetallic layer characteristics. It is presented the test for statistical analysis performed on a four-level factorial experiment aimed at studying the influence of the main simultaneously welding parameters of the welding technology CMT (Cold Metal Transfer: determining an optimal welding current IS, welding speed vS, boos current Ina and arc length correction factor l0.

  19. Ultrasonic inspection of the brazed joint and explosive welds used to repair the PFR evaporators

    International Nuclear Information System (INIS)

    A small number of in-service failures associated with the steam-tube to tube-plate welds of the PFR evaporators led to the decision to protect the welds by sleeving. The philosophy was to insert a sleeve through the tube-plate and into the steam tube, thus bridging the existing weld. The top portion of the sleeve was to be explosively welded to the zone adjacent to the top face of the tube-plate and the lower portion brazed into the steam tube. This paper deals with the development and use of ultrasonics to test both the brazed and explosively welded joints

  20. Microstructural Development and Mechanical Properties for Reactive Air Brazing of ZTA to Ni Alloys using Ag-CuO Braze Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Prevost, Erica; DeMarco, A.Joseph; MacMichael, Beth; Joshi, Vineet V.; Meier, Alan; Hoffman, John W.; Walker, William J.

    2014-12-01

    Reactive air brazing (RAB) is a potential joining technique to join metal alloys to ceramics for a variety of applications. In the current study, nickel (Ni) alloys were heat treated to form an oxide layer prior to RAB joining to zirconia toughened alumina (ZTA). The Ni alloys evaluated were Nicrofer 6025 HT, Inconel 600, Inconel 693, Haynes 214 and Inconel 601. The ZTA studied had compositions of 0 to 15 wt% zirconia and 0 to 14 wt% glass. Four point-bend tests were performed to evaluate the joint strength of ZTA/ZTA and ZTA/nickel alloys brazed with Ag-2wt% CuO braze alloys. It was determined that the joint strength is not a function of the ZTA composition, but that the strength is a strong function of the chemistry and microstructure of the oxide layer formed on the nickel alloy. It was determined that an increase in the aluminum content of the Ni alloy resulted in an increase of the thickness of alumina in the oxide layer and was directly proportional to the bond strength with the exception of Inconel 601 which exhibited relatively high joint strengths even though it had a relatively low aluminum content.

  1. Compound characterization of laser brazed SiC-steel joints using tungsten reinforced SnAgTi-alloys

    Science.gov (United States)

    Südmeyer, I.; Rohde, M.; Fürst, T.

    2010-02-01

    With the help of a CO2-laser (λ = 10.64 μm) Silicon carbide (Trade name: Ekasic-F, Comp: ESK Ceramics) has been brazed to commercial steel (C45E, Matnr. 1.1191) using SnAgTi-filler alloys. The braze pellets were dry pressed based on commercially available powders and polished to a thickness of 300 μm. The SnAgTi-fractions were varied with the objective of improving the compound strength. Furthermore, tungsten reinforced SnAgTi-fillers were examined with regard to the shear strength of the ceramic/steel joints. Polished microsections of SnAgTi-pellets were investigated before brazing in order to evaluate the particle distribution and to detect potential porosities using optical microscopy. The brazing temperature and the influence of the reinforcing particles on the active braze filler were determined by measurements with a differential scanning calorimeter (DSC). After brazing. the ceramic-steel joints were characterized by scanning electron micrographs and EDX-analysis. Finally the mechanical strength of the braze-joints was determined by shear tests.

  2. Active vacuum brazing of CNT films to metal substrates for superior electron field emission performance

    Science.gov (United States)

    Longtin, Rémi; Sanchez-Valencia, Juan Ramon; Shorubalko, Ivan; Furrer, Roman; Hack, Erwin; Elsener, Hansrudolf; Gröning, Oliver; Greenwood, Paul; Rupesinghe, Nalin; Teo, Kenneth; Leinenbach, Christian; Gröning, Pierangelo

    2015-02-01

    The joining of macroscopic films of vertically aligned multiwalled carbon nanotubes (CNTs) to titanium substrates is demonstrated by active vacuum brazing at 820 °C with a Ag-Cu-Ti alloy and at 880 °C with a Cu-Sn-Ti-Zr alloy. The brazing methodology was elaborated in order to enable the production of highly electrically and thermally conductive CNT/metal substrate contacts. The interfacial electrical resistances of the joints were measured to be as low as 0.35 Ω. The improved interfacial transport properties in the brazed films lead to superior electron field-emission properties when compared to the as-grown films. An emission current of 150 μA was drawn from the brazed nanotubes at an applied electric field of 0.6 V μm-1. The improvement in electron field-emission is mainly attributed to the reduction of the contact resistance between the nanotubes and the substrate. The joints have high re-melting temperatures up to the solidus temperatures of the alloys; far greater than what is achievable with standard solders, thus expanding the application potential of CNT films to high-current and high-power applications where substantial frictional or resistive heating is expected.

  3. Braze Development of Graphite Fiber for Use in Phase Change Material Heat Sinks

    Science.gov (United States)

    Quinn, Gregory; Beringer, Woody; Gleason, Brian; Stephan, Ryan

    2011-01-01

    Hamilton Sundstrand (HS), together with NASA Johnson Space Center, developed methods to metallurgically join graphite fiber to aluminum. The goal of the effort was to demonstrate improved thermal conductance, tensile strength and manufacturability compared to existing epoxy bonded techniques. These improvements have the potential to increase the performance and robustness of phase change material heat sinks that use graphite fibers as an interstitial material. Initial work focused on evaluating joining techniques from four suppliers, each consisting of a metallization step followed by brazing or soldering of one inch square blocks of Fibercore graphite fiber material to aluminum end sheets. Results matched the strength and thermal conductance of the epoxy bonded control samples, so two suppliers were down-selected for a second round of braze development. The second round of braze samples had up to a 300% increase in strength and up to a 132% increase in thermal conductance over the bonded samples. However, scalability and repeatability proved to be significant hurdles with the metallization approach. An alternative approach was pursued which used a nickel braze allow to prepare the carbon fibers for joining with aluminum. Initial results on sample blocks indicate that this approach should be repeatable and scalable with good strength and thermal conductance when compared with epoxy bonding.

  4. 49 CFR 178.51 - Specification 4BA welded or brazed steel cylinders.

    Science.gov (United States)

    2010-10-01

    ... the thickness of shell metal. (iii) Longitudinal seams in shells must be made by copper brazing... least eight times the thickness of plate, laps being held in position, substantially metal to metal, by... table 1 of appendix A to this part, for the particular material under consideration; (ii) One-half...

  5. Characteristics of dissimilar laser-brazed joints of isotropic graphite to WC–Co alloy

    International Nuclear Information System (INIS)

    Highlights: ► Ti was required in the filler metal for brazing graphite to WC–Co alloy. ► The shear strength of the joint increased with Ti content up to 1.7 mass%. ► Ti concentrated at the interface of graphite/filler metal. ► TiC was formed at the interface of graphite/filler metal. - Abstract: The effect of Ti serving as an activator in a eutectic Ag–Cu alloy filler metal in dissimilar laser-brazed joints of isotropic graphite and a WC–Co alloy on the joint strength and the interface structure of the joint is investigated in this study. To evaluate the joint characteristics, the Ti content in the filler metal was increased from 0 to 2.8 mass%. The laser brazing was carried out by irradiating a laser beam selectively on the WC–Co alloy plate in Ar atmosphere. The threshold content of Ti required to join isotropic graphite to WC–Co alloy was 0.4 mass%. The shear strength at the brazed joint increased rapidly with increasing Ti content up to 1.7 mass%, and a higher Ti content was found to be likely to saturate the shear strength to a constant value of about 14 MPa. The isotropic graphite blocks also fractured at this content. The concentration of Ti observed at the interface between isotropic graphite and the filler metal indicates the formation of an intermetallic layer of TiC.

  6. Penetrating behavior of eutectic liquid during Al/Cu contact reactive brazing

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The behavior of eutectic liquid penetrating into the Al base during Al/Cu contact reactive brazing process was studied. Analysis results show that the eutectic liquid prefers to expand along the grain boundary in the depth direction. Meanwhile, dissolution of solid Al and Cu into the eutectic liquid promotes the eutectic reaction and the continuously formed eutectic liquid leads to the reactive penetrating.

  7. Bonding of Al2O3 ceramic and Nb using transient liquid phase brazing

    Institute of Scientific and Technical Information of China (English)

    于治水; 梁超; 李瑞峰; 吴铭方; 祁凯

    2004-01-01

    The brazing of Al2O3 to Nb was achieved by the method of transient liquid phase (TLP) bonding. Ti foil and Ni-5V alloy foil were used as interlayers for the bonding. The base materials were brazed at 1 423 - 1 573 K for 1-120 min. The results show that the shear strength of the joint first increases and then decreases with increasing holding time and brazing temperature. The joint interface microstructure and elements distribution were investigated. It can be concluded that a composite structure, in which the base metals are solid solution Nb(V) and Nb(Ti)reinforced by Ni2Ti, is formed when the brazing temperature is 1 473 K and holding time 15 min, and a satisfactory joint strength can be achieved. The interaction of Ti foil and Ni-5V foil leads to the formation of liquid eutectic phase with low melting point, at the same time the combination of Ti come from the interlayer with O atoms from Al2O3 results in the bonding of Al2 O3 and Nb.

  8. Effect of holding time on vacuum brazing for a stainless steel plate-fin structure

    International Nuclear Information System (INIS)

    This paper presents a vacuum brazing of 304 stainless steel plate-fin structures with nickel-based BNi-2 filler metal. The effect of brazing holding time on tensile strength and microstructure has been investigated, aiming to obtain the optimal brazing holding time. The microstructure in brazing joint consists of diffusion-affected zone (DAZ), interface reaction zone (IRZ), isothermally solidified zone (ISZ) and athermally solidified zone (ASZ). The structure in the fillet is composed of solid solution, nickel silicon, nickel boron compound and a mixture with nickel silicon and nickel boron. The tensile strength increases along with the increase of holding time, but decreases when the holding time is over 25 min. A maximum tensile strength of 65.1 MPa is obtained with 25 min holding time. Too short holding time will make boron diffuse insufficiently and generate a great deal of brittle boride components, and too long holding time will make the base metal dissolve into the filler metal excessively and creates more corrosion voids.

  9. Micro-nano filler metal foil on vacuum brazing of SiCp/Al composites

    Science.gov (United States)

    Wang, Peng; Gao, Zeng; Niu, Jitai

    2016-06-01

    Using micro-nano (Al-5.25Si-26.7Cu)- xTi (wt%, x = 1.0, 1.5, 2.0, 2.5 and 3.0) foils as filler metal, the research obtained high-performance joints of aluminum matrix composites with high SiC particle content (60 vol%, SiCp/Al-MMCs). The effect of brazing process and Ti content on joint properties was investigated, respectively. The experimental results indicate that void free dense interface between SiC particle and metallic brazed seam with C-Al-Si-Ti product was readily obtained, and the joint shear strength enhanced with increasing brazing temperature from 560 to 580 °C or prolonging soaking time from 10 to 90 min. Sound joints with maximum shear strength of 112.5 MPa was achieved at 580 °C for soaking time of 90 min with (Al-5.25Si-26.7Cu)-2Ti filler, where Ti(AlSi)3 intermetallic is in situ strengthening phase dispersed in the joint and fracture occured in the filler metal layer. In this research, the beneficial effect of Ti addition into filler metal on improving wettability between SiC particle and metallic brazed seam was demonstrated, and capable welding parameters were broadened for SiCp/Al-MMCs with high SiC particle content.

  10. Active Brazing of C/C Composite to Copper by AgCuTi Filler Metal

    Science.gov (United States)

    Zhang, Kexiang; Xia, Lihong; Zhang, Fuqin; He, Lianlong

    2016-05-01

    Brazing between the carbon-fiber-reinforced carbon composite (C/C composite) and copper has gained increasing interest because of its important application in thermal management systems in nuclear fusion reactors and in the aerospace industry. In order to examine the "interfacial shape effect" on the mechanical properties of the joint, straight and conical interfacial configurations were designed and machined on the surface of C/C composites before joining to copper using an Ag-68.8Cu-4.5Ti (wt pct) alloy. The microstructure and interfacial microchemistry of C/C composite/AgCuTi/Cu brazed joints were comprehensively investigated by using high-resolution transmission electron microscopy. The results indicate that the joint region of both straight and conical joints can be described as a bilayer. Reaction products of Cu3Ti3O and γ-TiO were formed near the copper side in a conical interface joint, while no reaction products were found in the straight case. The effect of Ag on the interfacial reaction was discussed, and the formation mechanism of the joints during brazing was proposed. On the basis of the detailed microstructure presented, the mechanical performance of the brazed joints was discussed in terms of reaction and morphology across the joint.

  11. Experimental investigation on both low cycle fatigue and fracture behavior of DZ125 base metal and the brazed joint at elevated temperature

    International Nuclear Information System (INIS)

    Highlights: → Mechanical properties of DZ125 base metal and brazed joint were investigated at 850 deg. C. → The brazed joint has the obvious softening phenomenon at stress range above 640 MPa. → The brazed joint shows lower fatigue life compared with the base metal. → All the brazed joints are fractured in the brazing seam. → The differences of fracture phenomena between two types of specimens were observed. - Abstract: Due to the different low cycle fatigue (LCF) properties and fatigue fracture behavior between DZ125 base metal and the brazed joint, the LCF tests are carried out systematically using tension cycling under stress amplitude control conditions (stress ratio R = 0) at elevated temperature in laboratory air. The present paper sets out to investigate the cyclic deformation response of DZ125 base metal and the brazed joint in two aspects, i.e. fatigue life and fatigue fracture behavior, with the comparative method. Furthermore, the comparative method on the typical fatigue fracture surface features (including fatigue source zone, crack propagation zone and fatigue fracture zone) of DZ125 base metal and the brazed joint cycled to failure is conducted in detail. Based on both the macro mechanical behavior and macro and micro fracture observations, experimental results show that: (1) for the brazed joint, the softening is not obvious at lower stress ranges. But from 640 to 720 MPa, it is very significant; (2) under the same test condition, the brazed joint shows lower fatigue life compared with DZ125 base metal and all brazed joints are fractured in the brazing seam observed by the Scanning Electron Microscope (SEM); and (3) there are many distinctive differences of the fracture phenomena between DZ125 base metal and the brazed joint as follows: (1) the crack initiation mode; (2) the crack propagation behavior; and (3) the morphology of dimple pattern at the fatigue fracture zone.

  12. Pre-qualification of brazed plasma facing components of divertor target elements for ITER like tokamak application

    Energy Technology Data Exchange (ETDEWEB)

    Singh, K.P., E-mail: kpsingh@ipr.res.in [Institute for Plasma Research, Bhat, Gandhinagar, Gujarat (India); Pandya, Santosh P.; Khirwadkar, S.S.; Patel, Alpesh; Patil, Y.; Buch, J.J.U.; Khan, M.S.; Tripathi, Sudhir; Pandya, Shwetang; Govindrajan, J. [Institute for Plasma Research, Bhat, Gandhinagar, Gujarat (India); Jaman, P.M.; Rathore, Devendra; Rangaraj, L.; Divakar, C. [Materials Science Division, National Aerospace Laboratories, CSIR, Bangalore, Karnataka (India)

    2011-10-15

    Qualification of tungsten (W) and graphite (C) based brazed plasma facing components (PFCs) is an important R and D area in fusion research. Pre-qualification tests for brazed joints between W-CuCrZr and C-CuCrZr using NDT (IR thermography and ultrasonic test) and thermal fatigue test are attempted. Mockups having good quality brazed joints of W and C based PFCs were identified using NDT. Subsequently, thermal fatigue test was performed on the identified mockups. All brazed tiles of W based PFC mockups could withstand thermal fatigue test, however, few tiles of C based PFC mockup were found detached. Thermal analyses of mockups are performed using finite element analysis (ANSYS) software to simulate the thermal hydraulic condition with 10 MW/m{sup 2} uniform heat flux. Details about experimental and computational work are presented here.

  13. Interfacial reaction product and mechanical properties of the electron beam brazed K465 Ni-based superalloy joints

    Institute of Scientific and Technical Information of China (English)

    Wang Gang; Zhang Binggang; He Jingshan; Feng Jicai; Wu Yingjie

    2008-01-01

    Ni-based superalloy K465 is brazed with BNi-2 filler metal by vacuum electron beam brazing (VEBB). In process of VEBB, effects of processing primary parameters on shear strength of joints are investigated. Microstructure of the brazed joint with BNi-2 filler metal is studied by means of scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). The results show that the structure of brazed seam consists of a large amount of Ni-based γ solid solution, Ni3Al (γ′), Ni3B, WB, CrB, and a small quantity of WC, NbC. The maximum shear strength of the joint is 398 MPa when the beam current of welding is 2.6 mA, heating time is 480 s and focused current is 1 800 mA.

  14. Microstructure and Strength of Brazed Joints of Ti3Al Base Alloy with Cu-P Filler Metal

    Institute of Scientific and Technical Information of China (English)

    Peng HE; Jicai FENG; Heng ZHOU

    2005-01-01

    Brazing of Ti3Al alloys with the filler metal Cu-P was carried out at 1173~1273 K for 60~1800 s. When products are brazed, the optimum brazing parameters are as follows: brazing temperature is 1215~1225 K; brazing time is 250~300 s. Four kinds of reaction products were observed during the brazing of Ti3Al alloys with the filler metal Cu-P, i.e., Ti3Al phase with a small quantity of Cu (Ti3Al(Cu)) formed close to the Ti3Al alloy; the TiCu intermetallic compounds layer and the Cu3P intermetallic compounds layer formed between Ti3Al(Cu) and the filler metal, and a Cu-base solid solution formed with the dispersed Cu3P in the middle of the joint. The interfacial structure of brazed Ti3Al alloys joints with the filler metal Cu-P is Ti3Al/Ti3Al(Cu)/TiCu/Cu3P/Cu solid solution (Cu3P)/Cu3P/TiCu/Ti3Al(Cu)/Ti3Al, and this structure will not change with brazing time once it forms. The thickness of TiCu+Cu3P intermetallic compounds increases with brazing time according to a parabolic law. The activation energy Q and the growth velocity K0 of reaction layer TiCu+Cu3P in the brazed joints of Ti3Al alloys with the filler metal Cu-P are 286 k J/mol and 0.0821 m2/s, respectively, and growth formula was y2=0.0821exp(-34421.59/T)t.Careful control of the growth for the reaction layer TiCu+Cu3P can influence the final joint strength. The formation of the intermetallic compounds TiCu+Cu3P results in embrittlement of the joint and poor joint properties. The Cu-P filler metal is not fit for obtaining a high-quality joint of Ti3Al brazed.

  15. Fatigue FEM analysis in the case of brazed aluminium alloy 3L59 used in aeronautical industry

    Science.gov (United States)

    Dimitrescu, A.; Amza, Gh; Niţoi, D. F.; Amza, C. Gh; Apostolescu, Z.

    2016-08-01

    The use, on a larger scale, of brazed aluminum alloys in the aerospace industry led to the need for a detailed study of the assemblies behavior. These are built from 6061 aluminum aloy (3L59) brazed with aluminum aloy A103. Therefore, a finit element simulation (FEM) of durability is necessary, that consists in the observation of gradual deterioration until failure. These studies are required and are previous to the stage of the producing the assembly and test it by traditional methods.

  16. 焊料在电子器件中的应用%Application of the Brazing Materials for Electronic Devices

    Institute of Scientific and Technical Information of China (English)

    王恭年; 高陇桥

    2001-01-01

    The compositions and properties of commonly used brazing materials for electonic devices are reviewed in this paper.The problems of the brazing materials at present and its research and development direction are also proposed.%综述了目前在电子器件中常用焊料的组分和性能,指出了该类焊料存在的问题及其今后的研究、发展方向。

  17. The effect of a homogenizing optic on residual stresses and shear strength of laser brazed ceramic/steel-joints

    Science.gov (United States)

    Südmeyer, I.; Rohde, M.; Besser, H.; Grein, M.; Liesching, B.; Schneider, J.

    2011-03-01

    Oxide and non oxide ceramics (Al2O3, SiC) were brazed to commercial steel with active filler alloys using a CO2-laser (l = 10.64 μm). Two different laser intensity profiles were used for heating up the compound: A laser output beam presenting a Gaussian profile and a homogenized, nearly top head profile were applied for joining the compounds in an Argon stream. The temperature distribution with and without the homogenizing optic was measured during the process and compared to the results of a finite element model simulating the brazing process with the different laser intensity profiles. Polished microsections were prepared for characterization of the different joints by scanning electron micrographs and EDXanalysis. In order to evaluate the effects of the different laser intensity profiles on the compound, the shear strengths of the braze-joints were determined. Additionally residual stresses which were caused by the gradient of thermal expansion between ceramic and metal were determined by finite element modeling. The microsections did not exhibit differences between the joints, which were brazed with different laser profiles. However the shear tests proved, that an explicit increase of compound strength up to 34 MPa of the ceramic/metal joints can be achieved with the top head profile, whereas the joints brazed with the Gaussian profile achieved only shear strength values of 24 MPa. Finally tribological pin-on-disc tests proved the capability of the laser brazed joints with regard to the application conditions.

  18. Effect of Processing Parameters on Thermal Cycling Behavior of Al2O3-Al2O3 Brazed Joints

    Science.gov (United States)

    Dandapat, Nandadulal; Ghosh, Sumana; Guha, Bichitra Kumar; Datta, Someswar; Balla, Vamsi Krishna

    2016-10-01

    In the present study, alumina ceramics were active metal brazed at different temperatures ranging from 1163 K to 1183 K (890 °C to 910 °C) using TICUSIL (68.8Ag-26.7Cu-4.5Ti in wt pct) foil as filler alloy of different thicknesses. The brazed joints were subjected to thermal cycling for 100 cycles between 323 K and 873 K (50 °C and 600 °C). The microstructural and elemental composition analysis of the brazed joints were performed by scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) before and after thermal cycling. Helium (He) leak test and brazing strength measurement were also conducted after thermal cycling for 100 cycles. The joint could withstand up to 1 × 10-9 Torr pressure and brazing strength was higher than 20 MPa. The experimental results demonstrated that joints brazed at the higher temperature with thinner filler alloy produced strong Al2O3-Al2O3 joints.

  19. Development of Ag-Cu-Zn-Sn brazing filler metals with a 1 0 weight-% reduction of silver and same liquidus temperature

    Institute of Scientific and Technical Information of China (English)

    Daniel Schnee; Gunther Wiehl; Sebastian Starck; Chen Kevin

    2014-01-01

    With BrazeTec BlueBraze the manufacturers in HVACR industry have an alternative filler metal with 10 weight-%less silver but same brazing temperatures.The performance of these new alloys has been evaluated in several tests.The evaluation included wetting investigations,metallographic examinations,joint strength at different temperatures and pulsation and corrosion resistance.The results ofthese tests will be presented in this paper.

  20. Low activation brazing materials and techniques for SiC f/SiC composites

    Science.gov (United States)

    Riccardi, B.; Nannetti, C. A.; Petrisor, T.; Sacchetti, M.

    2002-12-01

    A low activation brazing technique for silicon carbide fiber reinforced silicon carbide matrix composites (SiC f/SiC) is presented; this technique is based on the use of the 78Si-22Ti (wt%) eutectic alloy. The joints obtained take advantage of a melting point able to avoid composite fibre-interface degradation. All the joints showed absence of discontinuities and defects at the interface and a fine eutectic structure. Moreover, the joint layer appeared well adherent both to the matrix and the fibre interphase and the brazing alloy infiltration looked sufficiently controlled. The joints of SiC f/SiC composites showed 71±10 MPa almost pure shear strength at RT and up to 70 MPa at 600 °C.

  1. Joining of metal bars by a new process of transformation-diffusion brazing

    Institute of Scientific and Technical Information of China (English)

    Zhang Guifeng; Zhang Jianxun; Pei Yi

    2006-01-01

    Within the bonded interface of metal bars joint produced by conventional solid state bonding process (such as flash welding, resistance butt welding, friction welding and so on ), the inclusions are often present, which degrade the ductility of joint. A new process of transformation-diffusion brazing is proposed, in which an amorphous foil containing melting point depressant is preplaced between the interfaces to be joined, and the assembly is repeatedly heated/cooled without holding time at peak temperature. A low carbon steel bars, BNi-2 amorphous foil and resistance butt welding machine were used. The results show that surface contamination can be disrupted by the dissolution of base metal into molten interlayer in comparison with conventional process, and the ductility of joint can be improved by increasing the times of temperature cycles on line. In addition, transformation-diffusion brazing can be done with relatively simple and inexpensive system in comparison with transient liquid phase bonding.

  2. Mechanical and microstructural behavior of brazed aluminum / stainless steel mixed joints

    Science.gov (United States)

    Fedorov, V.; Weis, S.; Wagner, G.

    2016-03-01

    There is a requirement to combine different materials such as aluminum and stainless steel in industrial applications like automotive heat exchangers. Brazing offers the possibility to reduce the joining temperature in comparison to welding due to the lower liquidus temperature of the fillers. In the present work, the mechanical and microstructural behavior of aluminum / stainless steel mixed joints is investigated. The specimens are produced by induction brazing using an AlSi10filler and a non-corrosive flux. To evaluate the mechanical properties of the joints, tensile tests at elevated temperatures are carried out. Additionally, long-term thermal exposure experiments are done in order to investigate the changes in the microstructure.

  3. Topological dependence of mechanical responses of solidification microstructures in aluminum brazed joints

    Institute of Scientific and Technical Information of China (English)

    GAO Feng(高峰); QIAN Yi-yu(钱乙余); D.P.Sekulic; MA Xin(马鑫); F.Yoshida

    2003-01-01

    The main objective is to provide an evidence of spatial dependence of mechanical responses of a heterogeneous aluminum brazed joint re-solidified clad,and to confirm a sufficient sensitivity of a nano-indentation--load curve method for identifying the dependence.Topological features of a network of solidification microstructures(αphase and eutectic),formed during quench in a brazing process of aluminum alloy,influence significantly dynamic mechanical responses of resulting heterogeneous material.Nano/micro indentation depth vs load characteristics of differing phases suggest a spatially sensitive mechanical response of a re-solidified fillet in the joint zone.Hence,a spatial distribution,pattern formations and other morphological characteristics of microstructures have a direct impact on an ultimate joint integrity.Topology-induced variations of indentation-load curves was presented.A hypothesis involving microstructures'spatial distribution vs mechanical response was formulated.

  4. Novel high chromium containing braze filler metals for heat exchanger applications

    Energy Technology Data Exchange (ETDEWEB)

    Rangaswamy, S.; Fortuna, D. [Sulzer Metco, Troy (United States)

    2007-07-01

    A new family of boron-free, high chromium containing braze filler metal compositions were developed (Amdry 105, Amdry 108, Amdry 805). Filler metal properties including metallurgical phases, melting range, flow, corrosion resistance and high temperature oxidation resistance are reported. Additionally, the technical and economical advantages of using these new filler metals in fabricating flat plate type of heat exchangers and metallic catalytic converters is discussed. (orig.)

  5. Evaluation of the adhesion strength of diamond films brazed on K-10 type hard metal

    OpenAIRE

    Sérgio Ivan dos Santos; Carlos Alberto Medeiros Casanova; Cleiton Rodrigues Teixeira; Naira Maria Balzaretti; João Alziro Herz da Jornada

    2004-01-01

    The coating of cutting tools with diamond films considerably increases the tool performance due to the combination of the unique tribological properties of diamond with the bulk properties of the substrate (toughness). The tool performance, however, is strongly related to the adhesion strength between the film and the substrate. In this work our main goal was to propose and to test a procedure, based on a tensile strength test, to evaluate the adhesion strength of a diamond wafer brazed on a ...

  6. Characteristics of dissimilar laser-brazed joints of isotropic graphite to WC-Co alloy

    Energy Technology Data Exchange (ETDEWEB)

    Nagatsuka, Kimiaki, E-mail: nagatuka@jwri.osaka-u.ac.jp [Graduate School of Engineering, Osaka University, Joining and Welding Research Institute, 11-1, Mihogaoka, Ibaraki, Osaka 567-0047 (Japan); Sechi, Yoshihisa, E-mail: sechi@kagoshima-it.go.jp [Kagoshima Prefectural Institute of Industrial Technology, 1445-1 Oda, Hayato-cho, Kirishima, Kagoshima 899-5105 (Japan); Miyamoto, Yoshinari, E-mail: y_miyamoto@toyotanso.co.jp [Toyo Tanso Co., Ltd., 5-7-12 Takeshima, Nishiyodgawa-ku, Osaka 555-0011 (Japan); Nakata, Kazuhiro, E-mail: nakata@jwri.osaka-u.ac.jp [Joining and Welding Research Institute, Osaka University, 11-1, Mihogaoka, Ibaraki, Osaka 567-0047 (Japan)

    2012-04-25

    Highlights: Black-Right-Pointing-Pointer Ti was required in the filler metal for brazing graphite to WC-Co alloy. Black-Right-Pointing-Pointer The shear strength of the joint increased with Ti content up to 1.7 mass%. Black-Right-Pointing-Pointer Ti concentrated at the interface of graphite/filler metal. Black-Right-Pointing-Pointer TiC was formed at the interface of graphite/filler metal. - Abstract: The effect of Ti serving as an activator in a eutectic Ag-Cu alloy filler metal in dissimilar laser-brazed joints of isotropic graphite and a WC-Co alloy on the joint strength and the interface structure of the joint is investigated in this study. To evaluate the joint characteristics, the Ti content in the filler metal was increased from 0 to 2.8 mass%. The laser brazing was carried out by irradiating a laser beam selectively on the WC-Co alloy plate in Ar atmosphere. The threshold content of Ti required to join isotropic graphite to WC-Co alloy was 0.4 mass%. The shear strength at the brazed joint increased rapidly with increasing Ti content up to 1.7 mass%, and a higher Ti content was found to be likely to saturate the shear strength to a constant value of about 14 MPa. The isotropic graphite blocks also fractured at this content. The concentration of Ti observed at the interface between isotropic graphite and the filler metal indicates the formation of an intermetallic layer of TiC.

  7. Oil Circulation Effects on Evaporation Heat Transfer in Brazed Plate Heat Exchanger using R134A

    OpenAIRE

    Jang, Jaekyoo; Chang, Youngsoo; Kang, Byungha

    2012-01-01

    Experimental study was performed for oil circulation effects on evaporation heat transfer in the brazed type plate heat exchangers using R134A. In this study, distribution device was installed to ensure uniform flow distribution in the refrigerant flow passage, which enhances heat transfer performance of plate type heat exchanger. Tests were conducted for three evaporation temperature; 33℃, 37℃, and 41℃ and several oil circulation conditions. The nominal conditions of refrigerant are as follo...

  8. Note: Magnification of a polarization angle with a Littrow layout brazed grating.

    Science.gov (United States)

    Sasao, H; Arakawa, H; Kubo, H; Kawano, Y; Itami, K

    2014-08-01

    A new method to magnify a small polarization angle with brazed gratings has been developed. In the method, difference in diffraction efficiency for S and P polarization components is used. The magnification dependence on the incident angle can be small by arranging the grating in Littrow layout. A magnification with a factor ~2.7 has been demonstrated for a 10.6 μm CO2 laser beam as expected from a calculation. The method is applicable in many polarimetry fields.

  9. Brazing of zirconia to titanium using Ag-Cu and Au-Ni filler alloys

    Directory of Open Access Journals (Sweden)

    Jean S. Pimenta

    2013-12-01

    Full Text Available Advanced ceramic is usually joined to metal by the well-known direct brazing process, where costly active filler alloys can be considered a limitation. Brazing using active-metal-free filler alloy as insert between the joint components is an attempt to overcome it. The active metal diffusion from the titanium member through the bulk of molten filler to the ceramic was responsible to produce an active filler alloy in loco and promote reduction of the zirconium oxide to improve wetting on the ceramic surface. Unalloyed titanium was joined in a high-vacuum furnace (<3x10-5 mbar to yttria-tetragonal zirconia polycristals (Y-TZP and zirconia partially stabilized with magnesia (Mg-PSZ, where commercial fillers Ag-28Cu and Au-18Ni with respective thermal cycles were evaluated. Helium gas leak detection test was performed at the ceramic/metal interface at room temperature; samples from reliable vacuum tight joints were examined by microstructural analysis techniques and energy dispersive X-ray analysis at the joint cross-section. Tight joints were produced with eutectic Ag-Cu filler, revealing an intermetallic layer and a dark reaction layer near the ceramic surface; titanium diffusion was efficient for superficial chemical interactions between individual components. Brazing joints were also tested using three-point flexure testing.

  10. Investigation on laser brazing AA6056 Al alloy to XC18 low-carbon steel

    Institute of Scientific and Technical Information of China (English)

    Jianjun Ding; Feiqun Li; Feng Qu; Patrice Peyre; Remy Fabbro

    2005-01-01

    @@ Based on the studies of influence of YAG laser heating conditions for Al alloy melt and steel on wettability,the mechanics of the laser overlap braze welding of 6056 Al and XC18 steel sheet has been investigated.Under the temperature range which is above the melting point of the Al alloy and below the melting point of the steel, two dissimilar metals can be joined by means of laser braze welding. There is no crack observed in the joining area, i.e. Al-Fe intermetallic phase (Fe3Al/FeAl/FeAl3/Fe2Al5) layer formed by solution and diffusion between liquid-solid interface. The temperature range can be defined as the process temperatures of laser braze welding of Al-Fe materials. Selecting a higher laser heating temperature can improve the wettability of Al melt to steel surface, but the intermetallic phase layer is also thicker. When the laser heating temperature is so high that the joining surface of steel is melted, there is a crack trend in the joining area.

  11. Dissimilar metals TIG welding-brazing of aluminum alloy to galvanized steel

    Institute of Scientific and Technical Information of China (English)

    San-bao LIN; Jian-ling SONG; Guang-chao MA; Chun-li YANG

    2009-01-01

    Dissimilar metals TIG welding-brazing of aluminum alloy to galvanized steel was investigated, and the wettability and spreadability of aluminum filler metal on the steel surface were analyzed. The resultant joint was characterized in order to determine the brittle intermetallic compound (IMC) in the interfacial layer, and the mechan-ical property of the joint was tested. The results show that the zinc coated layer can improve the wettability and spreadability of liquid aluminum filler metal on the surface of the steel, and the wetting angle can reach less than 20°. The lap joint has a dual characteristic and can be divided into a welding part on the aluminum side and a brazing part on the steel side. The interfacial IMC layer in the steel side is about 9.0 μm in thickness, which transfers from (α-Al + FeAl3) in the welded seam side to (Fe2Al5+ FeAl2) and (FeAl2+ FeAl) in the steel side. The crystal grain of the welded seam is obviously larger in size in the aluminum side. The local incomplete brazing is found at the root of the lap joint, which weakens the property of the joint. The fracture of the joint occurs at the root and the average tensile strength reaches 90 MPa.

  12. Novel Approach to Increase the Energy-related Process Efficiency and Performance of Laser Brazing

    Science.gov (United States)

    Mittelstädt, C.; Seefeld, T.; Radel, T.; Vollertsen, F.

    Although laser brazing is well established, the energy-related efficiency of this joining method is quite low. That is because of low absorptivity of solid-state laser radiation, especially when copper base braze metals are used. Conventionally the laser beam is set close to the vertical axis and the filler wire is delivered under a flat angle. Therefore, the most of the utilized laser power is reflected and thus left unexploited. To address this situation an alternative processing concept for laser brazing, where the laser beam is leading the filler wire, has been investigated intending to make use of reflected shares of the laser radiation. Process monitoring shows, that the reflection of the laser beam can be used purposefully to preheat the substrate which is supporting the wetting and furthermore increasing the efficiency of the process. Experiments address a standard application from the automotive industry joining zinc coated steels using CuSi3Mn1 filler wire. Feasibility of the alternative processing concept is demonstrated, showing that higher processing speeds can be attained, reducing the required energy per unit length while maintaining joint properties.

  13. Residual Stress in Brazing of Submicron Al2O3 to WC-Co

    Science.gov (United States)

    Grunder, T.; Piquerez, A.; Bach, M.; Mille, P.

    2016-07-01

    This study evaluated the residual stresses induced by brazing and grinding submicron Al2O3, using different methods. Energy dispersive x-ray spectrometry analysis (EDX) of 72Ag-Cu filler and filler/WC-Co interface showed evidence of atomic diffusion and possible formation of titanium oxide layers between the joint and the bonding materials. An analytical model supported by the finite element method (FEM) based on strain determination due to the difference in variation of thermal expansion was used to assess the stress distribution at the coupling interface and in bulk materials. The model took into account the evolution of the Young's modulus and of the thermal expansion with temperature. The model could be used to follow strain and stress evolutions of the bonded materials during the cooling cycle. The maximum stress rose above -300 MPa at the center of the 100 × 100 × 3 mm ceramic plates. The residual stresses on the external surface of ceramic were investigated by x-ray diffraction (XRD) and indentation fracture method (IFM). After brazing and grinding the plate, the principal stresses were 128.1 and 94.9 MPa, and the shear stress was -20.1 MPa. Microscopic examination revealed grain pull-out promoted by the global residual stresses induced by the brazing and grinding processes. The surface stresses evaluated by the different methods were reasonably correlated.

  14. Mechanical Design, Brazing and Assembly Procedures of the LINAC4 RFQ

    CERN Document Server

    Mathot, S; Briswalter, A; Callamand, Th; Carosone, J; Favre, N; Geisser, J M; Lombardi, A; Maire, V; Malabaila, M; Pugnat, D; Richerot, Ph; Riffaut, B; Rossi, C; Timmins, M; Vacca, A; Vandoni, G; Vretenar, M

    2010-01-01

    The Linac4 RFQ will accelerate the H- beam from the ion source to the energy of 3 MeV. The RFQ is composed of three sections of one meter each, assembled by means of ultra high vacuum flanges and adjustable centring rings. The complete 3-m long RFQ will be supported isostatically over 3 points like a simple beam in order to minimise the maximum deflection. The ridge line, used to feed the RF power into the RFQ, will be supported via springs and its position adjusted in such way that no strain is introduced into the RFQ at the moment of its connection. The mechanical design has been done at CERN where the modules are completely manufactured, heat treated and brazed also. In that way, all of the processes are carefully controlled and the influence, notably of the heat treatments, has been understood in a better way. Since 2002 several four vanes RFQ modules have been brazed at CERN for the TRASCO and IPHI projects. A two-step brazing procedure has been tested. This technique is actually used for the assembly of...

  15. Improving interfacial reaction nonhomogeneity during laser welding-brazing aluminum to titanium

    International Nuclear Information System (INIS)

    Highlights: → Interfacial reaction nonhomogeneity of laser welding-brazing was improved. → The process window was extended by rectangular spot combined with V-shaped groove. → Mechanical property and its stability of Ti/Al dissimilar joint were enhanced. -- Abstract: Heterogeneous interfacial reactions were easily found along the Ti/Al interface due to high temperature gradient during laser welding-brazing of Ti/Al dissimilar alloys. To improve the nonhomogeneity, relative uniform energy distribution of laser beam and appropriate groove were attempted. The effects of these attempts on the nonhomogeneity of interfacial reactions were investigated by finite element method (FEM) numerical simulation and experimental validation. The results indicate that the V-shaped groove can make the interface roughly parallel to the isotherm of the temperature field. Moreover, the rectangular spot laser can further improve homogenization of the interfacial reaction along the interface in comparison with circular spot laser. Tensile test results show that the combination of rectangular spot laser welding-brazing and V-shaped groove can effectively control the fracture of Ti/Al joints in the seam in a wide processing parameters window, and the average tensile strength reaches 278 MPa.

  16. Nickel-coated Steel Stud to Aluminum Alloy Joints Made by High Frequency Induction Brazing

    Institute of Scientific and Technical Information of China (English)

    GE Jiaqi; WANG Kehong; ZHANG Deku; WANG Jian

    2015-01-01

    Nickel-coated 45 steel studs and 6061 aluminum alloy with 4047 Al alloy foil asfi ller metal were joined by using high frequency induction brazing. The microstructure of Fe/Al brazed joint was studied by means of optical microscopy (OM), scanning electron microscope (SEM), energy dispersive X-ray (EDX), and X-ray diffraction (XRD). Results showed that 45 steel stud and 6061 aluminum alloy could be successfully joined by high frequency induction brazing with proper processing parameters. The bonding strength of the joint was of the order of 88 MPa. Ni coating on steel stud successfully avoided the generation of Fe-Al intermetallic compound which is brittle by blocking the contact between Al and Fe. Intermetallic compounds, i e,Al3Ni2, Al1.1Ni0.9 and Al0.3Fe3Si0.7 presented in Al side, FeNi and Fe-Al-Ni ternary eutectic structure were formed in Fe side. The micro-hardness in intermetallic compound layer was 313 HV. The joint was brittle fractured in the intermetallic compounds layer of Al side, where plenty of Al3Ni2 intermetallic compounds were distributed continuously.

  17. Production of robust contours with braze coatings for cylinder head gaskets; Erzeugung konturgenauer Auftragsschichten fuer Zylinderkopfdichtungen

    Energy Technology Data Exchange (ETDEWEB)

    Cierocki, K.; Heilig, M. [Goetze Payen GmbH, Herford (Germany); Koch, J.; Koschlig, M. [Degussa AG, Hanau (Germany)

    1998-12-01

    Multilayer gaskets made of steel for cylinder heads are state of the art at the automotive industry. To simplify the construction by replacing one layer a precise braze coating of the gasket contour was developed (BrazeSkin-Process). The used filler metal consists of a Ni-based filler suspension, which is applied by a serigraphy process. Within this work the development up to now and the potential in the near future are described. (orig.) [Deutsch] In der Automobilindustrie werden auf heutigem Stand der Technik Mehr-Lagen-Dichtungen (MLS) als Zylinderkopf-Dichtung eingesetzt. Hierbei kommen den einzelnen Lagen unterschiedliche Funktionen zu. Die Aufgaben einer Vereinfachung des Aufbaus durch Einsparung einer Lage wurde durch die Erzeugung einer konturgenauen Beschichtung auf einer der Zwischenlagen um die Zylinderbohrung herum geloest. Zur Erzeugung dieser Beschichtung wurde eine Lotsuspension entwickelt, die einer Produktgruppe mit dem Begriff BrazeSkin zugerechnet wird. Diese Lotsuspension besteht aus einem gefuellten Ni-Basis-Lot, das mittels Siebdruck aufgetragen wird. Im Durchlaufofen werden die aufgedruckten Flaechen unter Schutzgas geloetet. Aufgrund der Fuellung mit einem hochschmelzenden Zusatz entsteht im Loetprozess eine Legierung, die gleichermassen die Grundzuege eines Verbundwerkstoffes und eines Reaktionslotes beinhaltet. Hierdurch wird auch die Forderung nach einer mass- und konturgenauen Schichtdicke erfuellt. Der Grad der Serienreife fuer die erste Anwendung wurde jetzt erreicht. Eine Beschreibung der Entwicklung sowie zukuenftige Entwicklungsmoeglichkeiten werden aufgezeigt. (orig.)

  18. Fabrication and Characterization of Brazed Joints for SiC-Metallic Systems Utilizing Refractory Metals

    Science.gov (United States)

    Coddington, Bryan; Asthana, Rajiv; Halbig, Michael C.; Singh, M.

    2011-01-01

    Metal to ceramic joining plays a key role for the integration of ceramics into many nuclear, ground and aero based technologies. In order to facilitate these technologies, the active metal brazing of silicon carbide (CVD beta-SiC, 1.1 mm thick, and hot-pressed alpha-SiC, 3 mm thick) to the refractory metals molybdenum and tungsten using active braze alloys was studied. The joint microstructure, composition, and microhardness were evaluated by optical microscopy (OM), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and Knoop hardness testing. The braze alloys, Cusil-ABA, Ticusil and Copper-ABA, all formed sound joints with excellent wetting and chemical bonding with the SiC substrate. Despite the close thermal expansion match between the metal substrates and SiC, hairline cracks formed in alpha-SiC while beta-SiC showed no signs of residual stress cracking. The use of ductile interlayers to reduce the effect from residual stresses was investigated and joints formed with copper as an interlayer produced crack free systems utilizing both CVD and hot-pressed SiC.

  19. Detached Melt Nucleation during Diffusion Brazing of a Technical Ni-based Superalloy: A Phase-Field Study

    Science.gov (United States)

    Böttger, B.; Apel, M.; Laux, B.; Piegert, S.

    2015-06-01

    Advanced solidification processes like welding, soldering, and brazing are often characterized by their specific solidification conditions. But they also may include different types of melting processes which themselves are strongly influenced by the initial microstructures and compositions of the applied materials and therefore are decisive for the final quality and mechanical properties of the joint. Such melting processes are often not well- understood because - compared to other fields of solidification science - relatively little research has been done on melting by now. Also, regarding microstructure simulation, melting has been strongly neglected in the past, although this process is substantially different from solidification due to the reversed diffusivities of the involved phases. In this paper we present phase-field simulations showing melting, solidification and precipitation of intermetallic phases during diffusion brazing of directionally solidified and heat-treated high-alloyed Ni- based gas turbine blade material using different boron containing braze alloys. Contrary to the common belief, melting of the base material is not always planar and can be further accompanied by detached nucleation and growth of a second liquid phase inside the base material leading to polycrystalline morphologies of the joint after solidification. These findings are consistent with results from brazed laboratory samples, which were characterized by EDX and optical microscopy, and can be explained in terms of specific alloy thermodynamics and inter-diffusion kinetics. Consequences of the gained new understanding for brazing of high- alloyed materials are discussed.

  20. Development of rapidly quenched nickel-based non-boron filler metals for brazing corrosion resistant steels

    Science.gov (United States)

    Ivannikov, A.; Kalin, B.; Suchkov, A.; Penyaz, M.; Yurlova, M.

    2016-04-01

    Corrosion-resistant steels are stably applied in modern rocket and nuclear technology. Creating of permanent joints of these steels is a difficult task that can be solved by means of welding or brazing. Recently, the use rapidly quenched boron-containing filler metals is perspective. However, the use of such alloys leads to the formation of brittle borides in brazing zone, which degrades the corrosion resistance and mechanical properties of the compounds. Therefore, the development of non-boron alloys for brazing stainless steels is important task. The study of binary systems Ni-Be and Ni-Si revealed the perspective of replacing boron in Ni-based filler metals by beryllium, so there was the objective of studying of phase equilibrium in the system Ni-Be-Si. The alloys of the Ni-Si-Be with different contents of Si and Be are considered in this paper. The presence of two low-melting components is revealed during of their studying by methods of metallography analysis and DTA. Microhardness is measured and X-ray diffraction analysis is conducted for a number of alloys of Ni-Si-Be. The compositions are developed on the basis of these data. Rapidly quenched brazing alloys can be prepared from these compositions, and they are suitable for high temperature brazing of steels.

  1. Laser Brazing of Aluminum with a New Filler Wire AlZn13Si10Cu4

    Science.gov (United States)

    Tang, Z.; Seefeld, T.; Vollertsen, F.

    Laser brazing processes of aluminum with both single beam and double beam techniques were developed using a new AlZn13Si10Cu4 filler wire which has a lower solidification range comparing to normal AlSi12 filler wire and the base material. Brazing experiments on both bead on plate and flange joints showed that the new wire has a very good wettability on the aluminum samples. Comparing to the AlSi12 wire one needs a lower heat input (in some cases 73% less heat input) for joining the same samples with the new filler wire and reaches a high hardness value in the joint. In addition, brazing with double beam technique showed its potential to increase the joint quality.

  2. An Ag based brazing system with a tunable thermal expansion for the use as sealant for solid oxide cells

    Science.gov (United States)

    Kiebach, Ragnar; Engelbrecht, Kurt; Grahl-Madsen, Laila; Sieborg, Bertil; Chen, Ming; Hjelm, Johan; Norrman, Kion; Chatzichristodoulou, Christodoulos; Hendriksen, Peter Vang

    2016-05-01

    An Ag-Al2TiO5 composite braze was developed and successfully tested as seal for solid oxide cells. The thermo-mechanical properties of the Ag-Al2TiO5 system and the chemical compatibility between this composite braze and relevant materials used in stacks were characterized and the leak rates as a function of the operation temperature were measured. The thermal expansion coefficient in the Ag-Al2TiO5 system can be tailored by varying the amount of the ceramic filler. The brazing process can be carried out in air, the joining partners showed a good chemical stability and sufficient low leak rates were demonstrated. Furthermore, the long-term stability of the Ag-Al2TiO5 composite braze was studied under relevant SOFC and SOEC conditions. The stability of brazed Crofer/Ag-Al2TiO5/NiO-YSZ assemblies in reducing atmosphere and in pure oxygen was investigated over 500 h at 850 °C. Additionally, a cell component test was performed to investigate the durability of the Ag-Al2TiO5 seal when exposed to dual atmosphere. The seals performed well over 900 h under electrolysis operation conditions (-0.5 A cm2, 850 °C), and no cell degradation related to the Ag-Al2TiO5 sealing was found, indicating that the developed braze system is applicable for the use in SOFC/SOEC stacks.

  3. Potential and limitations of microanalysis SEM techniques to characterize borides in brazed Ni-based superalloys

    International Nuclear Information System (INIS)

    Brazed Ni-based superalloys containing complex phases of different Boron contents remain difficult to characterize at the micrometer scale. Indeed Boron is a light element difficult to measure precisely. The state-of-the-art microanalysis systems have been tested on a single crystal MC2 based metal brazed with BNi-2 alloy to identify boride precipitates. Effort has been made to evaluate the accuracy in Boron quantitation. Energy-dispersive and wavelength-dispersive X-ray spectroscopy attached to a Scanning Electron Microscope have first been used to determine the elemental composition of Boron-free phases, and then applied to various types of borides. Results have been compared to the ones obtained using a dedicated electron probe microanalysis, considered here as the reference technique. The most accurate method to quantify Boron using EDS is definitely by composition difference. A precision of 5 at.% could be achieved with optimized data acquisition and post-processing schemes. Attempts that aimed at directly quantifying Boron with various standards using EDS or coupled EDS/WDS gave less accurate results. Ultimately, Electron Backscatter Diffraction combined with localized EDS analysis has proved invaluable in conclusively identifying micrometer sized boride precipitates; thus further improving the characterization of brazed Ni-based superalloys. - Highlights: • We attempt to accurately identify Boron-rich phases in Ni-based superalloys. • EDS, WDS, EBSD systems are tested for accurate identification of these borides. • Results are compared with those obtained by electron probe microanalysis. • Boron was measured with EDS by composition difference with a precision of 5 at. %. • Additional EBSD in phase identification mode conclusively identifies the borides

  4. Effect of interlayer on the mechanical properties of YG8 hard carbide/40Cr steel brazed joints

    Institute of Scientific and Technical Information of China (English)

    Wu Mingfang; Pu Juan; Chen Jian

    2009-01-01

    The effects of Cu foil and Ni foil on the mechanical properties of YG8 hard carbide/4OCr steel brazed joints were investigated. The results show that both Cu foil and Ni foil were beneficial to decrease the residual stress and enhance the joint strength. Moreover, Ni foil exhibited the better impact on enhancing the joint strength relative to Cu foil. When Cu foil was used as interlayer material, the key factor to restrain the joint strength was the massive and quick dissolution of Cu. Therefore, in order to prevent the excessive dissolution of Cu foil, the process parameter should be controlled strictly in the brazing process.

  5. Phase analysis of fume during arc weld brazing of steel sheets with protective coatings

    Directory of Open Access Journals (Sweden)

    J. Matusiak

    2016-04-01

    Full Text Available The article presents the results of research of the phase identification and of the quantitative phase analysis of fume generated during Cold Metal Transfer (CMT, ColdArc and Metal Inert Gas / Metal Active Gas (MIG / MAG weld brazing. Investigations were conducted for hot - dip coated steel sheets with zinc (Zn and zinc-iron (Zn - Fe alloy coatings. Arc shielding gases applied during the research-related tests were Ar + O2, Ar + CO2, Ar + H2 and Ar + CO2 + H2 gas mixtures. The analysis of the results covers the influence of the chemical composition of shielding gas on the chemical composition of welding fume.

  6. Numerical simulation of copper based filler metal droplets spreading under arc brazing

    Institute of Scientific and Technical Information of China (English)

    YU Zhi-shui; LI Rui-feng; QI Kai; ZHOU Fang-ming

    2005-01-01

    The spreading behavior of copper filler metal droplets under arc brazing was studied by numerical simulation method using Surface Evolver software. The mathematical model in which arc pressure force acceleration was added to the droplet microelement as the form of gravity acceleration was used in numerical simulation. Then the 3D filler metal droplet profile for different welding currents was simulated. The results show that the simulation results and the experimental results are in good accordance. And it can be seen that the spreading height decreases and diameter increases with the increasing welding current in an approximate linear relation.

  7. Note: Magnification of a polarization angle with a Littrow layout brazed grating

    Science.gov (United States)

    Sasao, H.; Arakawa, H.; Kubo, H.; Kawano, Y.; Itami, K.

    2014-08-01

    A new method to magnify a small polarization angle with brazed gratings has been developed. In the method, difference in diffraction efficiency for S and P polarization components is used. The magnification dependence on the incident angle can be small by arranging the grating in Littrow layout. A magnification with a factor ˜2.7 has been demonstrated for a 10.6 μm CO2 laser beam as expected from a calculation. The method is applicable in many polarimetry fields.

  8. Mechanical characteristics of laser braze-welded aluminium-copper connections

    Science.gov (United States)

    Solchenbach, Tobias; Plapper, Peter

    2013-12-01

    The mechanical characteristics of dissimilar Al-Cu connections, joined by a novel, robust laser braze-welding process are reported. A fiber laser is used in combination with a 2D galvoscanner to provide spatial power modulation by superposed circular beam oscillation. With the help of statistical experimental design, a broad range of processing parameters has been investigated in order to understand their effects on the joint characteristics. A maximum shear strength of 121 MPa has been detected within the scope of the experiments.

  9. Control of microstructure in soldered, brazed, welded, plated, cast or vapor deposited manufactured components

    Science.gov (United States)

    Ripley, Edward B.; Hallman, Russell L.

    2015-11-10

    Disclosed are methods and systems for controlling of the microstructures of a soldered, brazed, welded, plated, cast, or vapor deposited manufactured component. The systems typically use relatively weak magnetic fields of either constant or varying flux to affect material properties within a manufactured component, typically without modifying the alloy, or changing the chemical composition of materials or altering the time, temperature, or transformation parameters of a manufacturing process. Such systems and processes may be used with components consisting of only materials that are conventionally characterized as be uninfluenced by magnetic forces.

  10. Melting Point Depression and Fast Diffusion in Nanostructured Brazing Fillers Confined Between Barrier Nanolayers

    Science.gov (United States)

    Kaptay, G.; Janczak-Rusch, J.; Jeurgens, L. P. H.

    2016-08-01

    Successful brazing using Cu-based nanostructured brazing fillers at temperatures much below the bulk melting temperature of Cu was recently demonstrated (Lehmert et al. in, Mater Trans 56:1015-1018, 2015). The Cu-based nano-fillers are composed of alternating nanolayers of Cu and a permeable, non-wetted AlN barrier. In this study, a thermodynamic model is derived to estimate the melting point depression (MPD) in such Cu/AlN nano-multilayers (NMLs) as function of the Cu nanolayer thickness. Depending on the melting route, the model predicts a MPD range of 238-609 K for Cu10nm/AlN10nm NMLs, which suggests a heterogeneous pre-melting temperature range of 750-1147 K (476-874 °C), which is consistent with experimental observations. As suggested by basic kinetic considerations, the observed Cu outflow to the NML surface at the temperatures of 723-1023 K (450-750 °C) can also be partially rationalized by fast solid-state diffusion of Cu along internal interfaces, especially for the higher temperatures.

  11. Phase constitution in the interfacial region of laser penetration brazed magnesium–steel joints

    International Nuclear Information System (INIS)

    The phase constitution in the interfacial region of laser penetration brazed magnesium–steel joints was investigated using electron microscopy. From the distribution of elements, the transition zone was mainly composed of elements Mg and Fe along with some Al and O. Furthermore, the transition layer consisted mainly of intermetallic compounds and metal oxides. The compounds were identified as Al-rich phases, such as Mg17Al12, Mg2Al3, FeAl and Fe4Al13. More noteworthy was that the thickness of the transition layer was determined by Fe–Al compounds. The presence of FeAl and Fe4Al13 was a result of the complex processes that were associated with the interfacial reaction of solid steel and liquid Mg–Al alloy. - Highlights: • A technology of laser penetration brazed Mg alloy and steel has been developed. • The interface of Mg/Fe dissimilar joints was investigated using electron microscopy. • The transition layer consisted of intermetallic compounds and metal oxides. • Moreover, the thickness of transition layer was determined by Fe/Al compounds. • The presence of FeAl and Fe4Al13 was associated with the interfacial reaction

  12. Some properties of low-vapor-pressure braze alloys for thermionic converters

    Science.gov (United States)

    Bair, V. L.

    1978-01-01

    Density, dc electrical resistivity, thermal conductivity, and linear thermal expansion are measured for arc-melted rod-shaped samples of binary eutectics of Zr, Hf, Ru, Nb, Ir, Mo, Ta, Os, Re, and W selected as very-low-pressure braze fillers for thermionic converters. The first two properties are measured at 296 K for Zr-21.7 at% Ru, Zr-13 wt% W, Zr-19 wt% W, Zr-22.3 at% Nb, Nb-66.9 at% Ru, Hf-25.3 wt% Re, Zr-25.7 at% Ta, Hf-22.5 at% W, and Nb-35 wt% Mo. The last property is measured from 293 K to 2/3 melting point for specified alloys of different compositions. Resistivities of 0.000055 to 0.000181 ohm-cm are observed with the alloys having resistivities about ten times that of the less resistive constituent metal and about three times that of the more resistive constituent metal, except for Zr-19 wt% W and Nb-35 wt% Mo (greater resistivities). Thermal expansion coefficients vary from 0.000006 to 0.0000105/K. All brazes exhibit linear thermal expansion near that of their constituent metals.

  13. Brazing characteristics of a Zr–Ti–Cu–Fe eutectic alloy filler metal for Zircaloy-4

    International Nuclear Information System (INIS)

    A Zr–Ti–Cu–Fe quaternary eutectic alloy was employed as a new Be-free brazing filler metal for Zircaloy-4 to supersede physically vapor-deposited Be coatings used conventionally with several disadvantages. The quaternary eutectic composition of Zr58Ti16Cu10Fe16 (at.%) showing a low melting temperature range from 832 °C to 853 °C was designed by a partial substitution of Zr with Ti based on a Zr–Cu–Fe ternary eutectic system. By applying an alloy ribbon with the determined composition, a highly reliable joint was obtained with a homogeneous formation of predominantly grown α-Zr phases owing to a complete isothermal solidification, exhibiting strength higher than that of Zircaloy-4. The homogenization of the joint was rate-controlled by the diffusion of the filler elements (Ti, Cu, and Fe) into the Zircaloy-4 base metal, and the detrimental segregation of the Zr2Fe phase in the central zone was completely eliminated by an isothermal holding at a brazing temperature of 920 °C for 10 min

  14. Brazing characteristics of a Zr–Ti–Cu–Fe eutectic alloy filler metal for Zircaloy-4

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jung G.; Lim, C.H. [Nuclear Materials Development Division, Korea Atomic Energy Research Institute (KAERI), Yuseong, Daejeon 305-353 (Korea, Republic of); Kim, K.H. [University of Science and Technology, Nuclear Materials Development Division, Korea Atomic Energy Research Institute (KAERI), Yuseong, Daejeon 305-353 (Korea, Republic of); Park, S.S. [School of Mechanical and Advanced Materials Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798 (Korea, Republic of); Lee, M.K., E-mail: leeminku@kaeri.re.kr [Nuclear Materials Development Division, Korea Atomic Energy Research Institute (KAERI), Yuseong, Daejeon 305-353 (Korea, Republic of); Rhee, C.K. [Nuclear Materials Development Division, Korea Atomic Energy Research Institute (KAERI), Yuseong, Daejeon 305-353 (Korea, Republic of)

    2013-10-15

    A Zr–Ti–Cu–Fe quaternary eutectic alloy was employed as a new Be-free brazing filler metal for Zircaloy-4 to supersede physically vapor-deposited Be coatings used conventionally with several disadvantages. The quaternary eutectic composition of Zr{sub 58}Ti{sub 16}Cu{sub 10}Fe{sub 16} (at.%) showing a low melting temperature range from 832 °C to 853 °C was designed by a partial substitution of Zr with Ti based on a Zr–Cu–Fe ternary eutectic system. By applying an alloy ribbon with the determined composition, a highly reliable joint was obtained with a homogeneous formation of predominantly grown α-Zr phases owing to a complete isothermal solidification, exhibiting strength higher than that of Zircaloy-4. The homogenization of the joint was rate-controlled by the diffusion of the filler elements (Ti, Cu, and Fe) into the Zircaloy-4 base metal, and the detrimental segregation of the Zr{sub 2}Fe phase in the central zone was completely eliminated by an isothermal holding at a brazing temperature of 920 °C for 10 min.

  15. Melting Point Depression and Fast Diffusion in Nanostructured Brazing Fillers Confined Between Barrier Nanolayers

    Science.gov (United States)

    Kaptay, G.; Janczak-Rusch, J.; Jeurgens, L. P. H.

    2016-05-01

    Successful brazing using Cu-based nanostructured brazing fillers at temperatures much below the bulk melting temperature of Cu was recently demonstrated (Lehmert et al. in, Mater Trans 56:1015-1018, 2015). The Cu-based nano-fillers are composed of alternating nanolayers of Cu and a permeable, non-wetted AlN barrier. In this study, a thermodynamic model is derived to estimate the melting point depression (MPD) in such Cu/AlN nano-multilayers (NMLs) as function of the Cu nanolayer thickness. Depending on the melting route, the model predicts a MPD range of 238-609 K for Cu10nm/AlN10nm NMLs, which suggests a heterogeneous pre-melting temperature range of 750-1147 K (476-874 °C), which is consistent with experimental observations. As suggested by basic kinetic considerations, the observed Cu outflow to the NML surface at the temperatures of 723-1023 K (450-750 °C) can also be partially rationalized by fast solid-state diffusion of Cu along internal interfaces, especially for the higher temperatures.

  16. Induction brazing of 6063/3 A21 aluminum alloy%6063和3A21铝合金的感应钎焊应用研究

    Institute of Scientific and Technical Information of China (English)

    杨林

    2013-01-01

    介绍了感应钎焊技术在雷达产品常用钎焊铝合金上的应用,通过对铝合金感应加热的感应器优化设计技术和精密温控技术的研究,实现了铝合金感应钎焊的精密控温,进行了管与管、管与法兰异型接头的感应器设计,开展了铝合金的感应硬钎焊工艺研究,分析了铝合金感应钎焊工件的钎焊缝和钎焊圆角、尺寸变形精度、表面氧化和微观组织等.文中实现了铝合金复杂结构的感应钎焊,并应用于铝合金6063法兰和3A21方型波导管接头的钎焊,为此类结构提供一种新的焊接方法.%The application of induction brazing to aluminum alloy composite in radar was introduced. The induction brazing temperature was precisely controlled by the optimization of induction coil and the research on temperature - control technology. The induction coil used in brazing tube/tube or tube/flange joint was design, and the induction brazing process was also studied. The brazed joint, brazing deformation, surface oxidation, and microstructure of the aluminum alloy were analyzed. This study realizes the induction brazing of aluminum alloy composite with complicate structure, and this technology was applied to braze 6063 aluminum alloy flange and 3A21 aluminum alloy rectangle wave guide, which provided a new method to braze aluminum alloy composite with similar structure.

  17. An Ag based brazing system with a tunable thermal expansion for the use as sealant for solid oxide cells

    DEFF Research Database (Denmark)

    Kiebach, Wolff-Ragnar; Engelbrecht, Kurt; Grahl-Madsen, Laila;

    2016-01-01

    as a function of the operation temperature were measured. The thermal expansion coefficient in the Ag-Al2TiO5 system can be tailored by varying the amount of the ceramic filler. The brazing process can be carried out in air, the joining partners showed a good chemical stability and sufficient low leak rates...

  18. Issues of low activation brazing of SiC f/SiC composites by using alloys without free silicon

    Science.gov (United States)

    Riccardi, B.; Nannetti, C. A.; Petrisor, T.; Woltersdorf, J.; Pippel, E.; Libera, S.; Pilloni, L.

    2004-08-01

    The paper presents a novel low activation brazing technique for SiC f/SiC composites. The brazing alloy does not contain free silicon and is based on the use of a Si-44Cr at.% eutectic and the intermetallic CrSi 2 (melting temperatures 1390 and 1490 °C, respectively). These are advantageous because the melting point is low enough to avoid degradation of the advanced fibres and of the interphases in the composite, and the Si-Cr intermetallics are chemically compatible with silicon carbide. Both the eutectic and the intermetallic were prepared before brazing operations by melting a Si-Cr mixture. The joining was performed under vacuum (about 10 -4 Pa). Systematic investigations of the microstructure and of the nanochemistry (TEM, EELS, ELNES) of the Si-Cr joints reveal that direct chemical Si-Si, Cr-C and Si-Cr bonds across the interface are responsible for the adhesion: the interfaces were proved to be nearly atomically sharp and adhesive. Altogether, this brazing procedure enables joints with sufficient strength and with a microstructure comparable with that of the starting powders to be obtained.

  19. Microstructure and Mechanical Properties of Plasma Arc Brazed AISI 304L Stainless Steel and Galvanized Steel Plates

    Science.gov (United States)

    Jin, Yajuan; Li, Ruifeng; Yu, Zhishui; Wang, Yu

    2016-04-01

    Plasma arc brazing is used to join the AISI 304L stainless steel and galvanized steel plate butt joints with the CuSi3Mn1 filler wire. The effect of parameters on weld surface appearance, interfacial microstructure, and composition distribution in the joint was studied. The microhardness and mechanical tests were conducted to determine the mechanical properties of the welded specimens. The results indicated that good appearance, bead shape, and sufficient metallurgical bonding could be obtained when the brazing process was performed with a wire feeding speed of 0.8 m/min, plasma gas flow rate of 3.0 l/min, welding current of 100 A, and welding speed of 27 cm/min. During plasma arc brazing process, the top corner of the stainless steel and galvanized steel plate were heated and melted, and the melted quantity of stainless steel was much more than that of the galvanized steel due to the thermal conductivity coefficient difference between the dissimilar materials. The microhardness test results shows that the microhardness value gradually increased from the side of the galvanized steel to the stainless steel in the joint, and it is good for improving the mechanical properties of joint. The tensile strength was a little higher than that of the brazing filler, and the fracture position of weld joint was at the base metal of galvanized steel plate.

  20. Metallurgical reactions in the coalescence zone between a reinforcement and a base metal in reinforced brazed joints

    Directory of Open Access Journals (Sweden)

    Zorc, B.

    2004-12-01

    Full Text Available A reinforcement wire added to a brazed joint strongly improves the properties of the joint, i.e., its strength, toughness and resistance to crack initiation and propagation. This effect, however, can be achieved only if the reinforcement wire is of a suitable shape, from an appropriate material as regards the base metal and the brazing alloy and it coalesces strongly and toughly with the base metal. The properties of such a joint depend on the reinforcement wire and not on the brazing alloy. The most favourable reinforcement shape was determined. Metallurgical reactions among the base metal, the brazing alloy, and the reinforcement were studied.

    La armadura, añadida a las uniones fuertemente soldadas, mejora considerablemente las características de la unión, es decir, su dureza, tenacidad y resistencia frente a la formación y propagación de la grieta separada. Se puede alcanzar dicho resultado solamente si el alambre de la armadura tiene la forma apropiada, está formado con el material adecuado (acorde al material de base y la unión y se funde de manera fuerte y tenaz con el material de base. Las propiedades de la unión mencionada, dependen del alambre de la armadura y no de la soldadura. Se determina la forma más ventajosa de la armadura y se investigan las reacciones metalúrgicas entre el material de base, la soldadura y la armadura.

  1. Influence of laser energy input mode on joint interface characteristics in laser brazing with Cu-base filler metal

    Institute of Scientific and Technical Information of China (English)

    LI Li-qun; FENG Xiao-song; CHEN Yan-bin

    2008-01-01

    The flange butt joints of 1 mm-thick galvanized steel sheets were brazed with CuSi3 as filler metal at different laser heating modes. The microstructures and element distributions of joint interface were investigated by SEM and EDS. The results show that there is no obvious interface layer with the circular individual beam heating and lamellar Fe-Si intermetallic compound layer is found with dual-beam laser spot heating. With the irradiation of rectangular laser spot, the joint interface layer is also formed. The layer thickness is larger than that of dual-beam brazing and the layer shape is fiat so that intermetallic compounds trend to grow into cellular crystals. Moreover, the interface layer shape also depends on its position in the joint. Under the high heat input, dendritic or granular intermetallic compounds dispersively distribute in brazing seam adjacent to the interface, which is caused by the melting or dissolving of the base metal. According to the results, the brazing quality can be controlled by laser heating mode and processing parameters.

  2. Joining of CBN abrasive grains to medium carbon steel with Ag-Cu/Ti powder mixture as active brazing alloy

    Energy Technology Data Exchange (ETDEWEB)

    Ding, W.F. [College of Mechanical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China)]. E-mail: dingwf2000@vip.163.com; Xu, J.H. [College of Mechanical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); Shen, M. [College of Mechanical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); Su, H.H. [College of Mechanical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); Fu, Y.C. [College of Mechanical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); Xiao, B. [College of Mechanical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China)

    2006-08-25

    In order to develop new generation brazed CBN grinding wheels, the joining experiments of CBN abrasive grains and medium carbon steel using the powder mixture of Ag-Cu alloy and pure Ti as active brazing alloy are carried out at elevated temperature under high vacuum condition. The relevant characteristics of the special powder mixture, the microstructure of the interfacial region, which are both the key factors for determining the joining behavior among the CBN grains, the filler layer and the steel substrate, are investigated extensively by means of differential thermal analysis (DTA), scanning electron microscope (SEM) and energy dispersion spectrometer (EDS), as well X-ray diffraction (XRD) analysis. The results show that, similar to Ag-Cu-Ti filler alloy, Ag-Cu/Ti powder mixture exhibits good soakage capability to CBN grains during brazing. Moreover, Ti in the powder mixture concentrates preferentially on the surface of the grains to form a layer of needlelike Ti-N and Ti-B compounds by chemical metallurgic interaction between Ti, N and B at high temperature. Additionally, based on the experimental results, the brazing and joining mechanism is deeply discussed in a view of thermodynamic criterion and phase diagram of Ti-B-N ternary system.

  3. 78 FR 53159 - Standard for Welding, Cutting, and Brazing; Extension of the Office of Management and Budget's...

    Science.gov (United States)

    2013-08-28

    ... Paperwork Reduction Act of 1995 (44 U.S.C. 3506 et seq.) and Secretary of Labor's Order No. 1-2012 (77 FR... Occupational Safety and Health Administration Standard for Welding, Cutting, and Brazing; Extension of the... Budget's (OMB) approval of the information collection requirements contained in the Standard for...

  4. Compressive Strength Evaluation in Brazed ZrO2/Ti6Al4V Joints Using Finite Element Analysis

    Science.gov (United States)

    Sharma, Ashutosh; Kee, Se Ho; Jung, Flora; Heo, Yongku; Jung, Jae Pil

    2016-05-01

    This study aims to synthesize and evaluate the compressive strength of the ZrO2/Ti-6Al-4V joint brazed using an active metal filler Ag-Cu-Sn-Ti, and its application to dental implants assuring its reliability to resist the compressive failure in the actual oral environment. The brazing was performed at a temperature of 750 °C for 30 min in a vacuum furnace under 5 × 10-6 Torr atmosphere. The microstructure of the brazed joint showed the presence of an Ag-rich matrix and a Cu-rich phase, and Cu-Ti intermetallic compounds were observed along the Ti-6Al-4V bonded interface. The compressive strength of the brazed ZrO2/Ti-6Al-4V joint was measured by EN ISO 14801 standard test method. The measured compressive strength of the joint was ~1477 MPa—a value almost five times that of existing dental cements. Finite element analysis also confirmed the high von Mises stress values. The compressive strains in the samples were found concentrated near the Ti-6Al-4V position, matching with the position of the real fractured sample. These results suggest extremely significant compressive strength in ZrO2/Ti-6Al-4V joints using the Ag-Cu-Sn-Ti filler. It is believed that a highly reliable dental implant can be processed and designed using the results of this study.

  5. Manufacturing and High Heat Flux Testing of Brazed Flat-Type W/CuCrZr Plasma Facing Components

    Science.gov (United States)

    Lian, Youyun; Liu, Xiang; Feng, Fan; Chen, Lei; Cheng, Zhengkui; Wang, Jin; Chen, Jiming

    2016-02-01

    Water-cooled flat-type W/CuCrZr plasma facing components with an interlayer of oxygen-free copper (OFC) have been developed by using vacuum brazing route. The OFC layer for the accommodation of thermal stresses was cast onto the surface of W at a temperature range of 1150 °C-1200 °C in a vacuum furnace. The W/OFC cast tiles were vacuum brazed to a CuCrZr heat sink at 940 °C using the silver-free filler material CuMnSiCr. The microstructure, bonding strength, and high heat flux properties of the brazed W/CuCrZr joint samples were investigated. The W/Cu joint exhibits an average tensile strength of 134 MPa, which is about the same strength as pure annealed copper. High heat flux tests were performed in the electron beam facility EMS-60. Experimental results indicated that the brazed W/CuCrZr mock-up experienced screening tests of up to 15 MW/m2 and cyclic tests of 9 MW/m2 for 1000 cycles without visible damage. supported by National Natural Science Foundation of China (No. 11205049) and the National Magnetic Confinement Fusion Science Program of China (No. 2011GB110004)

  6. Influence of the brazing parameters on microstructure and mechanical properties of brazed joints of Hastelloy B2 nickel base alloy; Influencia de los parametros de soldeo fuerte en la microestructura y propiedades mecanicas de la union de la aleacion base niquel Hastelloy B2

    Energy Technology Data Exchange (ETDEWEB)

    Sotelo, J. C.; Gonzalez, M.; Porto, E.

    2014-07-01

    A study of the high vacuum brazing process of solid solution strengthened Hastelloy B2 nickel alloy has been done. A first stage of research has focused on the selection of the most appropriate brazing filler metal to the base material and vacuum furnace brazing process. The influence of welding parameters on joint microstructure constituents, relating the microstructure of the joint to its mechanical properties, has been evaluated. Two gaps of 50 and 200 micrometers, and two dwell times at brazing temperature of 10 and 90 minutes were studied. The braze joint mainly consists of the nickel rich matrix, nickel silicide and ternary compounds. Finally, the results of this study have shown the high bond strength for small gaps and increased dwell times of 90 minutes. (Author)

  7. Al2O3/Al2O3 Joint Brazed with Al2O3-particulate-contained Composite Ag-Cu-Ti Filler Material

    Institute of Scientific and Technical Information of China (English)

    Jianguo YANG; Hongyuan FANG; Xin WAN

    2005-01-01

    Microstructure and interfacial reactions of Al2O3 joints brazed with Al2O3-particulate-contained composite Ag-Cu-Ti filler material were researched by scanning electron microscopy (SEM), electron probe microscopy analysis (EPMA),energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). The interfacial reaction layer thickness of joints brazed with conventional active filler metal and active composite filler materials with different volume fraction of Al2O3 particulate was also studied. The experimental results indicated although there were Al2O3 particulates added into active filler metals, the time dependence of interfacial layer growth of joints brazed with active composite filler material is t1/2 as described by Fickian law as the joints brazed with conventional active filler metal.

  8. ON FABRICATION AND BRAZING OF 15A, 120 keV CONTINUOUS DUTY ACCELERATOR GRID ASSEMBLIES

    Energy Technology Data Exchange (ETDEWEB)

    Biagi, L.A.; Koehler, G.W.; Paterson, J.A.

    1980-05-01

    The development of high intensity neutral beam injectors at the Lawrence Berkeley Laboratory has progressed from relatively low duty cycle, low energy devices to the next generation of continuous duty high energy units. The earlier pulsed versions were designed with edge cooled grid structures described ·in a previous publication. The prerequisites set by the higher duty cycle devices no longer allow the edge cooling methods to be employed. Hollow molybdenum grid rails with deionized cooling water flowing at pressures of approximately 1.73 x 10{sup 6}Pa (250 PSI) at from 1.135 to 1.89 liters per minute (.3 to .5 GPM) are brazed to Type 304L stainless steel rail holders.

  9. Evaluation of Laser Braze-welded Dissimilar Al-Cu Joints

    Science.gov (United States)

    Schmalen, Pascal; Plapper, Peter

    The thermal joining of Aluminum and Copper is a promising technology towards automotive battery manufacturing. The dissimilar metals Al-Cu are difficult to weld due to their different physicochemical characteristics and the formation of intermetallic compounds (IMC), which have reduced mechanical and electric properties. There is a critical thickness of the IMCs where the favored mechanical properties of the base material can be preserved. The laser braze welding principle uses a position and power oscillated laser-beam to reduce the energy input and the intermixture of both materials and therefore achieves minimized IMCs thickness. The evaluation of the weld seam is important to improve the joint performance and enhance the welding process. This paper is focused on the characterization and quantification of the IMCs. Mechanical, electrical and metallurgical methods are presented and performed on Al1050 and SF-Cu joints and precise weld criteria are developed.

  10. Rapidly solidified surface melts of Ni-B-Si-Cr brazing alloy

    Science.gov (United States)

    Tucker, T. R.; Ayers, J. D.

    1981-10-01

    Sintered powder layers of a Ni-based brazing alloy were consolidated by scanned electron beam radiation to produce a continuous fused coating. The surface of this coating was then remelted by laser and electron beams under differing conditions, resulting in a variety of resolidification structures. Alloy BNi2 was chosen for these studies because it exhibits substantial hardening on grain refinement and because it can be prepared in the glassy state relatively easily. Surface microhardness for BNi2 reaches a maximum of about 1200 DPH at a cooling rate approaching 105 K/s. For higher quench rates, hardness decreases and ductility increases. As the cooling rate approaches 107 k/s, overlapping beam scans produce an extended amorphous surface. A solidification rate higher than that needed to produce an amorphous structure in a single melt pass is necessary to avoid surface cracking or crystallization when overlapping melt passes are employed.

  11. Structural Design and Preliminary Evaluation of a Lightweight, Brazed, Air-Cooled Turbine Rotor Assembly

    Science.gov (United States)

    Meyer, Andre J., Jr.; Morgan, William C.

    1958-01-01

    A lightweight turbine rotor assembly was devised, and components were evaluated in a full-scale jet engine. Thin sheet-metal airfoils were brazed to radial fingers that were an integral part of a number of thin disks composing the turbine rotor. Passages were provided between the disks and in the blades for air cooling. The computed weight of the assembly was 50 percent less than that of a similar turbine of normal construction used in a conventional turbojet engine. Two configurations of sheet-metal test blades simulating the manner of attachment were fabricated and tested in a turbojet engine at rated speed and temperature. After 8-1/2 hours of operation pieces broke loose from the tip sections of the better blades. Severe cracking produced by vibration was determined as the cause of failure. Several methods of overcoming the vibration problem are suggested.

  12. Microstructure and mechanical properties of MoSi2–MoSi2 joints brazed by Ag–Cu–Zr interlayer

    International Nuclear Information System (INIS)

    Highlights: ► Brazing of MoSi2–MoSi2 using Ag–Cu–Zr interlayer at different temperatures. ► Investigation of shear strength and microstructure of the joint by SEM and XRD. ► Formation of Ag-rich solid solution and various Cu–Zr–Si intermetallic compounds. ► Maximum shear strength for the sample with 830 °C brazing temperature. ► Various fracture path and morphology at different brazing temperatures. - Abstract: The present work investigates joining of two MoSi2 parts through Cusil/Zr/Cusil interlayer with Cusil being a commercial eutectic of Cu–Ag alloy. The joining operation was implemented in an inert gas tube furnace by brazing. The brazing temperature ranged from 800 to 930 °C while the operation lasted for 60 min. Evaluation of joints strength through shear loading identified the maximum strength 60.31 MPa for the brazed sample at 830 °C. Interfacial microstructure was studied by Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS) and X-ray Diffraction (XRD) techniques. Applying the temperature of 830 °C was led to a uniform dense joint consisting of various phases with excellent bonding within the interfaces. XRD and EDS results revealed different phases such as Mo5Si3, Ag-rich solid solution and Cu10Zr7 at the interface. At higher brazing temperatures the amount of intemetallic compounds and residual stresses increased and therefore, mechanical properties of the joint degraded. The fracture analysis by SEM revealed various fracture path and morphology for different brazing temperatures

  13. 珩磨工具用中温钎焊材料的研制%Development of moderate temperature brazing filler metals for honing tools

    Institute of Scientific and Technical Information of China (English)

    杨继东; 裴夤崟; 龙伟民; 钟素娟

    2011-01-01

    For the present brazing problems on the honing segments, joining experiment on the honing segments was conducted by moderate temperature brazing. The compositions of moderate temperature brazing filler metals were adjusted, melting temperature of filler metals, wettability of filler metals on the honing segments and the tensile strength of brazing joints were tested. The deformation amount of brazed honing segments with different filler metals was compared. The research results showed that the moderate temperature brazing technology had small deformation and high tensile strength, and it was a feasible mode for joining of honing segments.%针对目前珩磨条钎焊存在的问题,采用中温钎焊对珩磨工具进行了连接试验,对中温钎焊用钎料的化学成分进行了调整,测试了钎料的熔化温度、钎料对珩磨条的润湿性以及钎焊接头的抗拉强度,并比较了不同钎料钎焊后珩磨工具的变形量.研究表明:中温钎焊工艺变形小,强度较高,是珩磨条连接的可行方式.

  14. Interlayer design to control interfacial microstructure and improve mechanical properties of active brazed Invar/SiO2–BN joint

    International Nuclear Information System (INIS)

    Ag–Cu/Cu/Ag–Cu–Ti composite interlayer was successfully designed to braze Invar alloy and SiO2–BN ceramic. The effect of Cu-foil thickness on the microstructure and mechanical properties of the brazed joints was investigated. The results showed that, compared with single Ag–Cu–Ti brazing foil, the formation of brittle Fe2Ti and Ni3Ti compounds detrimental to the joint strength was greatly inhibited by using composite interlayer. The active Ti atoms in the liquid filler reacted with SiO2–BN ceramic to form a TiN–TiB2 fine-grain layer. The desired interfacial microstructure composed of layered Ag- and Cu-based solid solutions was obtained, which was beneficial for the joint strength. The shear strength of brazed joints was 207% higher than the joints brazed with single Ag–Cu–Ti foil when a 100 μm thick Cu interlayer was used. The inhibition of brittle compounds formation was attributed to the control of reaction sequences during brazing and to the addition of Cu barrier layer

  15. Interface Behavior of Mg alloy Eutectic Brazing%镁合金共晶钎焊界面行为

    Institute of Scientific and Technical Information of China (English)

    白莉

    2012-01-01

    Magnesium alloy was bonded by eutectic contacting reaction brazing using pure silver interlayer, and the microstructure, interface diffusion behavior of elements of the welded joint was studied. The results from the experiment show that the eutectic contacting reaction brazing can achieve effective connection of magnesium alloy, and the interface has relatively higher content of silver, which has the obvious trend of diffusion for both sides of magnesium alloy.%采用纯银做中间层共晶钎焊工艺对镁合金进行连接,研究了接头微观组织及界面元素扩散行为.结果表明,采用共晶钎焊可以实现镁合金的有效连接,结合界面银元素相对含量较高,有着明显的向两边镁合金扩散的趋势.

  16. Cold metal transfer welding–brazing of pure titanium TA2 to magnesium alloy AZ31B

    Energy Technology Data Exchange (ETDEWEB)

    Cao, R., E-mail: caorui@lut.cn; Wang, T.; Wang, C.; Feng, Z.; Lin, Q.; Chen, J.H.

    2014-08-25

    Highlights: • Mg–Ti joints can be successfully performed at suitable welding variables by CMT. • Typical brazing–welding joints can be formed for Mg–Ti joint and Ti–Mg joint. • The brazing interface is mainly composed of Ti{sub 3}Al, Mg{sub 17}Al{sub 12} and Mg{sub 0.97}Zn{sub 0.03}. • Elements Al and Zn are crucial to join successfully Mg and Ti base metals. - Abstract: Pure titanium TA2 was joined to Mg AZ31B by cold metal transfer (CMT) welding–brazing method in the form of two lap-shear joints (Mg–Ti joint and Ti–Mg joint) with Mg AZ61 wire. The microstructure of Ti/Mg CMT joints was identified and characterized by means of optical microscopy (OM), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). The mechanical properties of various welding parameters were compared and analyzed. Desired Ti/Mg CMT joints with satisfied weld appearances and mechanical properties were achieved at suitable welding variables. The Ti/Mg CMT joints had dual characteristics of a welding joint at the Mg side and a brazing joint at the Ti side. Moreover, for two joints, the brazing interfaces were composed of an intermetallic compounds (IMCs) layer including Ti{sub 3}Al, Mg{sub 17}Al{sub 12} and Mg{sub 0.97}Zn{sub 0.03} phases. Mg–Ti joint had the higher tensile load of 2.10 kN, and Ti–Mg joint had the tensile load of 1.83 kN.

  17. Two-beam Laser Brazing of Thin Sheet Steel for Automotive Industry Using Cu-base Filler Material

    Science.gov (United States)

    Mittelstädt, C.; Seefeld, T.; Reitemeyer, D.; Vollertsen, F.

    This work shows the potential of two-beam laser brazing for joining both Zn-coated steel and 22MnB5. Brazing of Zn-coated steel sheets using Cu-Si filler wire is already state of the art in car manufacturing. New press-hardened steels like 22MnB5 are more and more used in automotive industry, offering high potential to save costs and improve structural properties (reduced weight / higher stiffness). However, for joining of these ultra-high strength steels investigations are mandatory. In this paper, a novel approach using a two-beam laser brazing process and Cu-base filler material is presented. The use of Cu-base filler material leads to a reduced heat input, compared to currently applied welding processes, which may result in benefits concerning distortion, post processing and tensile strength of the joint. Reliable processing at desired high speeds is attained by means of laser-preheating. High feed rates prevent significant diffusion of copper into the base material.

  18. The Role of Zinc Layer During Wetting of Aluminium on Zinc-coated Steel in Laser Brazing and Welding

    Science.gov (United States)

    Gatzen, M.; Radel, T.; Thomy, C.; Vollertsen, F.

    The zinc layer of zinc-coated steel is known to be a crucial factor for the spreading of liquid aluminium on the coated surface. For industrial brazing and welding processes these zinc-coatings enable a fluxless joining between aluminium and steel in many cases. Yet, the reason for the beneficial effect of the zinc to the wetting process is not completely understood. Fundamental investigations on the wetting behaviour of single aluminium droplets on different zinc-coated steel surfaces have revealed a distinct difference between coated surfaces at room temperature and at elevated temperature regarding the influence of different coating thicknesses. In this paper the case of continuous laser brazing and welding processes of aluminium and commercial galvanized zinc-coated steel sheets are presented. It is shown that in the case of bead-on-plate laser beam brazing, the coating thickness has a measureable effect on the resulting wetting angle and length but does not have a significant impact in case of overlap laser beam welding. This might be linked to different heat transfer conditions. The results also strongly indicate that proper initialbreakup of oxide layers is still required to accomplish good wetting on zinc-coated surfaces.

  19. Controlling phase formation during aluminium/steel Nd:YAG laser brazing

    Directory of Open Access Journals (Sweden)

    Rodriguez, L.

    2006-12-01

    Full Text Available The reduction of fuel consumption of internal combustion motors, imposed by the new anti-pollution and energy saving laws may be attained by reducing the weight of vehicles, introducing, for example, aluminium sections into the main steel car-body. Laser brazing is a process which can be used to perform such a junction. The main problem of welding this kind of materials combination with conventional processes is the potential formation of inter-metallic phases, which reduces the good performance of the joint. Laser brazing allows a very good control of the thermal development of the joint, with a limited precipitation of these brittle phases. This paper presents the results of a feasibility study made with ZnAl-30 as filler metal. The study shows that the type of configuration used for the assembly has a particular influence on the formation of brittle phases and consequently on the mechanical performance of the joint.

    La reducción en el consumo de combustibles fósiles y las emergentes leyes mundiales anti-contaminación, obligan a prever una reducción en el peso de los vehículos de transporte. Esta condición se puede cumplir por ejemplo, introduciendo componentes de Aluminio en el cuerpo de la carrocería principal de acero de los mencionados vehículos. El principal problema que se presenta al realizar este tipo de ensamblaje es la formación de fases íntermetálicas frágiles que pueden comprometer el buen desenvolvimiento de la unión. La soldadura con rayo láser permite un buen control de calor aportado y una formación muy limitada de este tipo de fases. Este trabajo presenta los resultados preliminares de los estudios realizados en uniones soldadas con ZnAl-30 como material de aportación. El estudio muestra que el tipo de configuración utilizada para realizar la soldadura tiene una influencia importante sobre la posibilidad de formación de estas fases ínter-metálicas.

  20. 一种新型钎料的成型方法及应用%Forming method and its application of a novel brazing filler metal

    Institute of Scientific and Technical Information of China (English)

    王星星; 龙伟民; 于新泉; 裴夤崟; 孙华为; 程亚芳

    2013-01-01

    主要设计了一种新型钎料的成型模具——三叶内摆线形滚动拉丝模,对其结构特征给以描述,通过算例将新型钎料与棒状钎料进行对比,详细介绍新型三叶内摆线形钎料的实现过程.结果表明,与棒状钎料相比,新型三叶内摆线形钎料与三钢球的接触面积大,增加幅度为15%~50%.在拉拔长度一定的条件下,与等横截面积的棒状钎料相比,三叶内摆线形钎料的横截面周长及体表面积较大.设计的新型钎料成型模具可有效减少能耗,提高拉拔效率,实现三叶内摆线形新型钎料的产业化.%A wire drawing dies of new brazing filler metal was designed.The structure feature of this wire drawing dies was described,and the body surface area of the new brazing filler metal was compared with rod-like brazing filler metal through examples,the process of trefoil hypocycloid brazing filler metal was introduced in detail.The results indicate that the contact area of trefoil hypocycloid brazing filler metal and three steel ball is larger about 15%~50% than the rod-like brazing filler metal.As compared to general trod-like brazing filler metal,the cross-sectional perimeter and body surface area of trefoil hypocycloid brazing filler metal is also larger under the same drawing length.The novel wire drawing dies can effectively reduce energy consumption and improve the drawing efficiency.Industrialization of trefoil hypocycloid new brazing filler metal would be realized in future.

  1. Behavior of Brazed W/Cu Mockup Under High Heat Flux Loads

    Science.gov (United States)

    Chen, Lei; Lian, Youyun; Liu, Xiang

    2014-03-01

    In order to transfer the heat from the armor to the coolant, tungsten has to be connected with a copper heat sink. The joint technology is the most critical issue for manufacturing plasma facing components. Consequently, the reliability of the joints should be verified by a great number of high-heat-flux (HHF) tests to simulate the real load conditions. W/Cu brazed joint technology with sliver free filler metal CuMnNi has been developed at Southwestern Institute of Physics (SWIP). Screening and thermal fatigue tests of one small-scale flat tile W/CuCrZr mockup were performed on a 60 kW electron-beam Material testing scenario (EMS-60) constructed recently at SWIP. The module successfully survived screening test with the absorbed power density (Pabs) of 2 MW/m2 to 10 MW/m2 and the following 1000 cycles at Pabs of 7.2 MW/m2 without hot spots and overheating zones during the whole test campaign. Metallurgy and SEM observations did not find any cracks at both sides and the interface, indicating a good bonding of W and CuCrZr alloy. In addition, finite element simulations by ANSYS 12.0 under experimental load conditions were performed and compared with experimental results.

  2. Critical Issues for Producing UHTC-Brazed Joints: Wetting and Reactivity

    Science.gov (United States)

    Passerone, A.; Muolo, M. L.; Valenza, F.

    2016-08-01

    A brief survey is presented of the most important interaction phenomena occurring at the solid-liquid interfaces in metal-ceramic systems at high temperatures, with special attention to the most recent developments concerning wetting and joining transition metals diborides. These phenomena are described and discussed from both the experimental and theoretical points of view in relation to joining ceramic and metal-ceramic systems by means of processes in the presence of a liquid phase (brazing, TLPB etc.). It is shown that wetting and the formation of interfacial dissolution regions are the results of the competition between different phenomena: dissolution of the ceramic in the liquid phase, reaction and formation of new phases at the solid-liquid interface, and drop spreading along the substrate surface. We emphasize the role of phase diagrams to support both the design of the experiments and the choice of active alloying elements, and to interpret the evolution of the system in relation to temperature and composition. In this respect, the sessile-drop technique has been shown to be helpful in assessing critical points of newly calculated phase diagrams. These studies are essential for the design of joining processes, for the creation of composite materials, and are of a particular relevance when applied to UHTC materials.

  3. Effect of Temperature and Sheet Temper on Isothermal Solidification Kinetics in Clad Aluminum Brazing Sheet

    Science.gov (United States)

    Benoit, Michael J.; Whitney, Mark A.; Wells, Mary A.; Winkler, Sooky

    2016-09-01

    Isothermal solidification (IS) is a phenomenon observed in clad aluminum brazing sheets, wherein the amount of liquid clad metal is reduced by penetration of the liquid clad into the core. The objective of the current investigation is to quantify the rate of IS through the use of a previously derived parameter, the Interface Rate Constant (IRC). The effect of peak temperature and initial sheet temper on IS kinetics were investigated. The results demonstrated that IS is due to the diffusion of silicon (Si) from the liquid clad layer into the solid core. Reduced amounts of liquid clad at long liquid duration times, a roughened sheet surface, and differences in resolidified clad layer morphology between sheet tempers were observed. Increased IS kinetics were predicted at higher temperatures by an IRC model as well as by experimentally determined IRC values; however, the magnitudes of these values are not in good agreement due to deficiencies in the model when applied to alloys. IS kinetics were found to be higher for sheets in the fully annealed condition when compared with work-hardened sheets, due to the influence of core grain boundaries providing high diffusivity pathways for Si diffusion, resulting in more rapid liquid clad penetration.

  4. Vacuum brazing of OFE Copper-316L stainless steel transition joints without electroplating stainless steel part for application in particle accelerators

    International Nuclear Information System (INIS)

    Brazed transition Joints between OFE copper and type 316L austenitic stainless steel (SS) find extensive applications in particle accelerators all over the world. In contrast to excellent wettability of OFE copper, austenitic SS is well known for its poor wettability for BVAg-8 (72Ag/28Cu; melting point: 1052 K) braze filler metal (BFM). High surface wettability is believed to be necessary to drag molten BFM into the capillary gap between mating metallic surfaces. Therefore, the widely accepted practice for vacuum brazing of such transition joints involves electroplating of SS parts with nickel or copper to enhance its wettability. A recently concluded in-house study, involving Nb to Ni-plated 316L SS brazing, has demonstrated that satisfactory ingress of BFM into a capillary joint between two dissimilar metals is possible if the poor wettability of one of the mating surfaces is compensated by good wettability of its counterpart. In the light of these observations, the present study was undertaken to explicitly evaluate the requirement of electroplating the SS part for establishment of sound OFE copper-316L SS brazed joints suitable for service in ultra-high vacuum (UHV) of particle accelerators

  5. Effects of Al2O3 Particulates on the Thickness of Reaction Layer of Al2O3 Joints Brazed with Al2O3-Particulate-Contained Composite Filler Materials

    Institute of Scientific and Technical Information of China (English)

    Jianguo YANG; Jingwei WU; Hongyuan FANG

    2003-01-01

    In order to understand the rate-controlling process for the interfacial layer growth of brazing joints brazed with activecomposite filler materials, the thickness of brazing joints brazed with conventional active filler metal and activecomposite filler materials with different volume fraction of Al2O3 particulate was studied. The experimental resultsindicate although there are Al2O3 particulates added into active filler metals, the time dependence of interfacial layergrowth is t2 as described by Fickian law for the joints brazed with conventional active filler metal. It also shows thatthe key factor affecting the interfacial layer growth is the volume fraction of alumina in the composite filler materialcompared with the titanium weight fraction in the filler material.

  6. Silicon high vacuum brazing study and microstructural analysis of the joint formation; Estudo da brasagem de silicio em alto vacuo e analise microestructural da juncao

    Energy Technology Data Exchange (ETDEWEB)

    Santana, E.C.A. [Universidade Estadual Paulista - UNESP, Campus de Guaratingueta, SP (Brazil); Francisco, F.R.; Bagnato, O.R. [Laboratorio Nacional de Luz Sincrotron - LNLS, Campinas, SP (Brazil)], e-mail: erika.santana@lnls.br

    2010-07-01

    On the project of Synchrotron Light Source, silicon-crystal are often used as monochromator and mirrors, to reflect the electrons beam. Silicon is known as a very fragile material, and its optical elements must be designed carefully. Usually, it is bonded in a cooling support made by copper. Thermal contact between the crystal plate and cooling support is made of In-Ga liquid alloy. Due to the difficult of this bonding, brazing tests are being taken with Fe-Ni alloy, in order to improve the silicon mirrors application and performance. Wet ability tests were performed between the silicon plate and commercial fillers. A brazing test was made of silicon and Al12Si, as filler, with Fe-Ni, as base material. Results of microstructure analysis indicated that the braze of a silicon plate is quite promissory. (author)

  7. Microstructure and Mechanical Performance of Cu-Sn-Ti-Based Active Braze Alloy Containing In Situ Formed Nano-Sized TiC Particles

    Science.gov (United States)

    Leinenbach, Christian; Transchel, Robert; Gorgievski, Klea; Kuster, Friedrich; Elsener, Hans Rudolf; Wegener, Konrad

    2015-05-01

    A Cu-Sn-Ti-based active brazing filler alloy was in situ reinforced with nanosized TiC particles by adding different amounts of a cellulose nitride-based binder. The TiC particles emanate from a reaction of the Ti within the filler alloy with the carbon from the binder that does not decompose completely during heating. The correlation between the microstructure and mechanical performance was studied. In addition, the effect of different binder amounts on the shear strength and cutting performance of brazed diamond grains was studied in shear tests and single grain cutting tests. The results clearly show that the mechanical performance of the brazed diamond grains can be improved by the formation of TiC particles. This is attributed to particle strengthening of the filler alloy matrix as well as to the decreasing grain size and more homogeneous distribution of the (Cu,Sn)3Ti5 phase with increasing amount of binder.

  8. Application of Be-free Zr-based amorphous sputter coatings as a brazing filler metal in CANDU fuel bundle manufacture

    International Nuclear Information System (INIS)

    Amorphous sputter coatings of Be-free multi-component Zr-based alloys were applied as a novel brazing filler metal for Zircaloy-4 brazing. By applying the homogeneous and amorphous-structured layers coated by sputtering the crystalline targets, the highly reliable joints were obtained with the formation of predominantly grown α-Zr grains owing to a complete isothermal solidification, exhibiting high tensile and fatigue strengths as well as excellent corrosion resistance, which were comparable to those of Zircaloy-4 base metal. The present investigation showed that Be-free and Zr-based multi-component amorphous sputter coatings can offer great potential for brazing Zr alloys and manufacturing fuel rods in CANDU fuel bundle system. (author)

  9. Response to high heat fluxes and metallurgical examination of a brazed carbon-fiber-composite/refractory-metal divertor mock-up

    International Nuclear Information System (INIS)

    As a feasibility-study an actively cooled divertor mock-up has been subjected to high heat flux loading in electron beam simulation. The divertor design concept is based on a carbon-fiber-composite material (Aerolor 05) brazed onto a TZM/Mo41Re heat sink. The plasma facing carbon armor is divided in seven tiles to allow variable loading parameters - and repeated destructive tests. The mock-up has survived high heat flux loading up to about 12 MW/m2 surface heat flux in steady-state conditions. One armor tile showed no change in the thermal response even after 500 s at ∝14 MW/m2. To estimate the general thermal response of the mock-up design, numerical methods were applied. The predicted behavior was confirmed by the experimental results. The loading experiments were followed by a detailed metallurgical investigation of the loaded sample regions and the braze joints. The typical damages after high heat flux testing and cycling were failure (i.e. detachment) in the Zr brazed carbon/TZM joint, and failure in the CuPd bonded TZM/TZM joint due to an excess of the melting temperature of the brazes. The microstructural changes in the braze regions and the recrystallization behavior of the refractory alloys are discussed. Only in one case the loaded surface of the carbon armor shows considerable erosion, caused by a partial detachment along a braze joint and thus loss of the good thermal contact during the last applied loading shots. The thermal analyses and high heat flux performance of the Aerolor-05 armored mock-up are compared to the thermal response of a previously tested mock-up of corresponding geometry with armor tiles of isotropic graphite. (orig.)

  10. Tensile Strength of Welded Joint of 1Cr18Ni9 Stainless Steel and Nb-1Zr Alloy Jointed by Electron Beam Self-material Brazing

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Compared with Nb-1Zr alloy stainless steels have a quite difference in melting point, thermalphysical and electromagnetism properties etc.. Therefore, it is very difficulty to joint by melting weldingmethod. Electron beam self-brazing method is an accepted method to use for this kind of welding. Make

  11. Brazing of aluminium assemblies under nitrogen convection in a charge furnace; Brasage d'assemblages en aluminium sous convection d'azote dans un four a charge

    Energy Technology Data Exchange (ETDEWEB)

    Faure, D.; Perez, G. [BMI Fours Industriels, 38 - Saint Quentin Fallavier (France)

    2006-03-15

    The research of a weight saving has led to the use of aluminium in the automotive industry, which has been innovation instigator for a lot of industries. The brazing under vacuum of aluminium, even if it presents a lot of advantages, is inadequate to the mass production because it is too difficult for the quality of the preliminary assembly to the brazing. It is rather reserved to the advance technology industries such as the aeronautics or the power electronics. A lot of aluminium heat exchangers are mass manufactured and brazed by the Nocolok process. (O.M.)

  12. 中国古青铜器表面富锡铜鎏镀及鎏焊的工艺探索第三部分——鎏焊%Technological study on amalgam coating and brazing of tin-rich copper on surface of bronze wares of ancient China——Part Ⅲ.Amalgam brazing

    Institute of Scientific and Technical Information of China (English)

    吴元康; 储荣邦

    2012-01-01

    Amalgam brazing is derived from amalgam coating. The definition, characteristics, application, and significance of amalgam brazing were expatiated. A process of amalgam brazing for producing combined bronze wares was developed. The compositions of brazing material and flux were given. The operations of pretreatment, mercury removal by heating, and post-treatment were described. The implementation of amalgam coating and brazing processes was introduced taking the Western Han Dynasty's bronze cowry container with tribute-paying figures excavated in Yunnan as an example. The method for distinguishing whether an antique bronze ware is produced by cast welding after lost-wax casting or by copper brazing with separated small cast parts was presented.%鎏焊是从鎏镀衍生而来的.阐述了鎏焊的定义、特点、应用和意义.设计了用于制作组合青铜器的鎏焊工艺,给出了焊料、焊剂配方,说明了前处理、加热驱汞及后处理的操作方法.以西汉云南纳贡场面青铜贮贝器为例,介绍了鎏镀与鎏焊工艺的具体实施过程.提出了鉴别古青铜器是由失蜡铸造后铸焊而成还是由分铸小件铜焊而成的方法.

  13. 多元平行流式冷凝器炉中钎焊工艺研究%Study on Brazing Process for Condenser in Controlled Atmosphere Brazing Furnace

    Institute of Scientific and Technical Information of China (English)

    郭艳; 凌泽民; 李金阁

    2011-01-01

    The optimum technological parameters of brazing condenser in controlled atmosphere brazing(CAB) furnace were obtained by simulating 3-D temperature distribution of micro-joint between fin and flat tube of the condenser using ANSYS software. The process experiment, temperature measurement and properties testing were carried out. The results show that the real thermal cycle curve fits well with the initial simulation one. The morphology of the welded joint has no defects and the microstructure is dense and mainly a(Al)+Al-Si. The leaking has no slightly leaking. It can be obtained that it is a meaningful method to put FEM employ into the process design.%采用ANSYS软件,通过对温度场的模拟,确定了较佳的工艺参数,并进行了工艺实验、温度检测及相关性能测试.温度检测结果表明,模拟曲线与实测曲线吻合较好,说明模拟的温度场是正确的.通过对钎焊接头显微组织分析表明,接头无缺陷,组织致密,显微组织主要以a(Al)+Al-Si共晶组织为主;相关性能测试表明,接头无微漏,达到了使用要求.说明采用有限元软件进行工艺指导是可行的.

  14. Numerical Simulation of Brazing TiC Cermet to Iron with TiZrNiCu Filler Metal

    Institute of Scientific and Technical Information of China (English)

    Lixia ZHANG; Jicai FENG

    2004-01-01

    The maximum thermal stress and stress concentration zones of iron/TiC cermet joint during cooling were studied in this paper. The results showed that the shear stress on iron/TiC cermet joint concentrates on the interface tip and the maximum shear stress appears on the left tip of iron/TiZrNiCu interlace. Positive tensile stress on TiC cermet undersurface concentrates on both sides of TiC cermet and its value decreases during cooling. Negative tensile stress on TiC cermet undersurface concentrates on the center of TiC cermet and its value increases during cooling. Brazing temperature has little effect on the development and maximum thermal stress.

  15. In situ synthesis of TiB whisker reinforcements in the joints of Al2O3/TC4 during brazing

    International Nuclear Information System (INIS)

    Research highlights: → Al2O3 ceramic and TC4 alloy were successfully brazed by Ag-Cu-Ti-B mixed powder. → TiBw was in situ synthesized during the brazing process. → TiBw not only refined the microstructure of the joint but also alleviated the joint stress. → The effect of the volume fraction of in situ TiBw on the microstructure of joints was studied. → The effect of the volume fraction of in situ TiBw on the shear strength of joints was researched. - Abstract: Al2O3 ceramic has been successfully joined to Ti-6Al-4V alloy with Ag-Cu-Ti-B mixed powder. The TiB whiskers in the brazing layer were in situ synthesized during brazing. The effects of B content in reactant on the phase composition, microstructure and shear strength of the joints were investigated using SEM, EDS, and shear test. Results indicate that B content in the filler has a great impact upon the microstructure of the joints via exerting an influence on the volume fraction of in situ synthesized TiB whiskers. When the TiB content is 40 vol.%, the shear strength reaches the maximum value of 77.9 MPa. The higher content of TiB (≥40 vol.%) depresses the shear strength of the joints due to the interfacial thermal stress cannot be relaxed. Reaction phases (Ti3Cu2AlO, Ti2Cu, Ti2(Cu, Al), Ti(Cu, Al) and Ti3Al) appear in the joint, moreover, as the volume fraction of TiB increase, Ag (s.s) and Ti(Cu, Al) distribute more uniform and fine in the brazing layer, as well as TiB whiskers mainly distribute in them. Eventually, Ti3Cu2AlO, TiB and TiB2 firstly generate based on the thermodynamic analysis, and in excessive Ti circumstances, TiB whiskers remain in the brazing alloy.

  16. Effect of bonding time on joint properties of vacuum brazed WC - Co hard metal/carbon steel using stacked Cu and Ni alloy as insert metal

    Energy Technology Data Exchange (ETDEWEB)

    Lee, W.B.; Jung, S.B. [Sungkyunkwan Univ., Dept. of Advanced Materials Engineering, Suwon, Kyounggi-do (Korea); Kwon, B.D. [Seoul Technical High School, Dept. of Metallurgy, Seoul (Korea)

    2004-11-15

    Hard metal WC - Co and carbon steel were successfully joined using double layered Cu alloy and amorphous Ni alloy as inert metal and an oil cooling method after brazing. Defects such as cracks and voids were not formed near the bonded zone. This result means that double layered insert metals and oil cooling minimised the residual stress near the bonded zone after brazing. The shear strength of the joints decreased with increasing bond time. The reasons why the shear strength decreased as bond time increased could be many, including shape of the interface, formation and growth of brittle intermetallic compounds, and coarsening of WC particles near the bond zone. The maximum shear strength of the joints was 310 MPa under conditions 0.6 ks bond time and 8 wt-%Co content in the WC hard alloy. (Author)

  17. Phase-dependent corrosion of titanium-to-stainless steel joints brazed by Ag–Cu eutectic alloy filler and Ag interlayer

    International Nuclear Information System (INIS)

    The electrochemical corrosion properties of Ti–STS dissimilar joints brazed by a 72Ag–28Cu alloy filler and an Ag interlayer were studied in a 3.5% NaCl solution using potentiodynamic polarization and ac impedance spectroscopy. For a joint with a layered structure of Ti(base)/TiAg/Ag solid solution/Ag–Cu eutectic/STS(base), galvanic corrosion mostly occurred in the TiAg phase with a severe material loss, indicating that the TiAg layer acted as an anode in the galvanic couple in the layered joint. The Ag-rich solid solution layer was also corroded to a certain extent, but the corrosion in this layer was dominated by the selective pitting corrosion of the eutectic Cu-rich phase. With an increase in the brazing temperature, the Cu-rich phases disappeared owing to the enhanced isothermal solidification effect, leading to an improvement of the corrosion resistance

  18. Phase-dependent corrosion of titanium-to-stainless steel joints brazed by Ag–Cu eutectic alloy filler and Ag interlayer

    Energy Technology Data Exchange (ETDEWEB)

    Lee, M.K.; Park, J.J.; Lee, J.G., E-mail: jglee88@kaeri.re.kr; Rhee, C.K.

    2013-08-15

    The electrochemical corrosion properties of Ti–STS dissimilar joints brazed by a 72Ag–28Cu alloy filler and an Ag interlayer were studied in a 3.5% NaCl solution using potentiodynamic polarization and ac impedance spectroscopy. For a joint with a layered structure of Ti(base)/TiAg/Ag solid solution/Ag–Cu eutectic/STS(base), galvanic corrosion mostly occurred in the TiAg phase with a severe material loss, indicating that the TiAg layer acted as an anode in the galvanic couple in the layered joint. The Ag-rich solid solution layer was also corroded to a certain extent, but the corrosion in this layer was dominated by the selective pitting corrosion of the eutectic Cu-rich phase. With an increase in the brazing temperature, the Cu-rich phases disappeared owing to the enhanced isothermal solidification effect, leading to an improvement of the corrosion resistance.

  19. Nd:YAG Laser Melting-Brazing Welding Between 5052 Aluminum and Galvanized Steel%5052铝/镀锌钢Nd:YAG激光熔-钎焊

    Institute of Scientific and Technical Information of China (English)

    石岩; 邝玉林; 刘佳; 张宏

    2012-01-01

    利用Nd:YAG激光器实现了5052铝/镀锌钢异种金属板材之间的熔-钎焊连接,并对焊缝成形、接头性能及微观形貌做了分析.分析结果表明,合适的热输入能够有效实现5052铝/镀锌钢异种金属之间的熔-钎焊连接,焊接接头中铝合金母材发生熔化与镀锌钢形成钎焊连接,镀锌钢母材并未发生熔化;焊接接头的抗拉强度为128 N/mm;微观形貌分析表明,在焊缝钎接界面处生成了一层薄金属间化合物层,金属间化合物层的厚度为3~4 μm.%The melting-brazing connection of the dissimilar metal 5052 aluminum alloy/galvanized steel was achieved by using the Nd:YAG laser, and the weld formation, joint performance and microstructure of joint was analyzed. The analysis result indicates that, it can achieve successful melting-brazing connection of 5052 aluminum alloy/galvanized steel, the aluminum in the joint melted and formed a brazed joint with galvanized steel, the galvanized steel hadn't melt; tensile strength of welded joint can be high as 128 N/mm; the microstructure showed that, a thin intermetallic compound layer is generated on the welded brazing interface, its thickness is 3~4 μm.

  20. 硬质合金刀具钎焊后性能变化的研究%Changes in properties of carbide cutting tools after being brazed

    Institute of Scientific and Technical Information of China (English)

    赵丽杰; 王贵成; 王冬

    2001-01-01

    对硬质合金刀具钎焊前后的硬度、裂纹形成及变化、焊缝质量和切削性能等进行了大量的试验研究.结果表明:硬质合金刀具钎焊后硬度下降范围在HRA1以内;采用延长钎焊后保温时间和增加补偿垫片均可以减少或避免刀具表面裂纹的产生;对18CrMnTi渗碳淬火齿轮(HRC55~58)单齿侧刃铣削中钎焊刀具的切削性能同机夹刀具相比无明显差异.它为硬质合金钎焊刀具在精密切削FMS和其他自动化加工中的广泛应用提供了实验和理论依据.%Presents the experimental tests run on hardness of carbide cutting tools before and after being brazed, initiation and propagation of cracks in them, quality of weld and cutting performance of these cutting tools, and the experimental test results which show that the reduction in hardness of carbide cutting tools after being brazed is within HRA1, the initiation of cracks in the surface of cutting tools can be reduced or eliminated by prolonging the holding time for the cutting tools after being brazed and adding shims, and the cutting performance of brazed cutting tools with single cutting edge made of 18CrMnTi is similar to that of fixed machining cutting tool.

  1. Microstructure and mechanical properties of active brazed SiO{sub 2}--BN ceramic modified by electron-beam evaporated Ti

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Z.W., E-mail: hityangzhenwen@163.com [State Key Lab of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Zhang, L.X., E-mail: hitzhanglixia@163.com [State Key Lab of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Ren, W.; Xue, Q.; He, P.; Feng, J.C. [State Key Lab of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China)

    2013-01-10

    SiO{sub 2}--BN ceramic surface modified by electron-beam evaporated Ti was brazed to itself using an inactive Ag--Cu eutectic alloy at 840 Degree-Sign C for 10 min. The effect of Ti content on the microstructure and mechanical properties of the joints was investigated by scanning and transmission electron microscopy and shear test. The results showed that the evaporated Ti layer dissolved into the liquid Ag--Cu alloy rapidly and reacted with SiO{sub 2}--BN ceramic to form a TiN--TiB{sub 2} fine-grain layer. Ag--Cu eutectic structure in the center of the joint was gradually taken place by Ti--Cu compounds with the increase of the Ti content. This microstructure evolution remarkably affected the shear strength of the joint. The highest shear strength of 39.2 MPa was obtained when the Ti content in the brazing alloy was 2.0 wt%. The joint strength was clearly improved when a soft Cu interlayer was inserted between two Ag--Cu brazing foils. The effect of Cu-foil thickness on the microstructure and the shear strength of the joint was studied.

  2. 异种合金激光熔钎焊研究进展%Progress in Laser Fusion Welding-Brazing of Dissimilar Alloys

    Institute of Scientific and Technical Information of China (English)

    肖荣诗; 董鹏; 赵旭东

    2011-01-01

    激光熔钎焊是利用两种合金熔点的差异,通过激光加热使低熔点材料(母材和填充材料)熔化,在接头界面与固态高熔点母材相互作用达到冶金结合的异种合金连接方法.按激光能量吸收机制对激光熔钎焊进行了分类,并结合所做工作,阐述了激光熔钎焊方法的发展及研究进展.%Laser fusion welding-brazing processes are methods to metallurgically join dissimilar alloys with different melting points by laser heating to melt materials (substrate and filler material) with lower melting point, and by the interaction between the weld pool and the solid substrate with higher melt point at the joint interface. Laser fusion welding-brazing processes of dissimilar alloys are classified according to the laser energy absorption mechanisms. The development and state of the art of laser fusion welding-brazing processes are reviewed.

  3. Microstructure and fracture behavior of SiO_2 glass ceramic and TC4 alloy joint brazed with TiZrNiCu alloy

    Institute of Scientific and Technical Information of China (English)

    LIU Duo; ZHANG Li-xia; FENG Ji-cai; LIU Hong-bin; HE Peng

    2009-01-01

    Vacuum brazing of SiO_2 glass ceramic and TC4 alloy using a commercially available TiZrNiCu foil was investigated. The interfaciai microstructure and the fractures were examined with an optical microscope (OM) and an S-4700 scanning electron microscope (SEM) equipped with an energy dispersive spectrometer (EDS) and an electron probe X-ray microanalyzer (EPMA). The structure of joint interface was identified by XRD (JDX-3530M). Meanwhile, the fracture paths of the joints were comprehensively studied. The results show that processing parameters, especially the brazing temperature, have a significant effect on the microstructurc and mechanical properties of joints. The typical interface structure is SiO_2/Ti_2O+Zr_3Si_2+Ti_5Si_3/(Ti,Zr)+Ti_2O+ TiZrNiCu/Ti(s.s)/TiZrNiCu+Ti(s.s)+Ti_2(Cu,Ni)/TC4 from SiO_2 glass ceramic to TC4 alloy side. Based on the mechanical property tests, the joints brazed at 880℃ for 5 min has the maximum shear strength of 23 MPa.

  4. Fatigue properties of laser-brazed joints of Dual Phase and TRansformation Induced Plasticity steel with a copper-aluminium consumable

    International Nuclear Information System (INIS)

    High strength steels combine good formability with excellent mechanical properties and have developed continuously in recent years. Joining these materials is however increasingly difficult as fusion joining processes destroy the carefully constructed microstructure. To counteract this problem, joining processes which require less heat input have been investigated. Laser brazing is a relatively new technique and a potential candidate which has found application in the automotive industry. In this paper the fatigue lifetime properties of laser-brazed Dual Phase (DP600) and TRansformation Induced Plasticity (TRIP700) steel joints made with a copper-aluminium consumable are reported. Joints created with DP600 steel showed fracture through the steel due to a brass present in the stress concentration region at the edge of the reinforcement. TRIP700 steels show similar results if the applied maximum stress is in excess of 280 MPa. However, at maximum stresses of 230 MPa, failure occurred across the interface between the braze metal and the steel. A basic fatigue crack path model is presented for the two competing failure mechanisms.

  5. Analysis on interfacial layer of aluminum alloy and non-coated stainless steel joint made by TIG welding-brazing

    Institute of Scientific and Technical Information of China (English)

    Song Jiaaling; Lin Sanbao; Yang Chunli; Ma Guangchao; Wang Yinjie

    2009-01-01

    Dissimilar metals TIG welding-brazing of aluminum alloy and non-coated stainless steel was investigated. The resultant joint was characterized in order to identify the phases and the brittle intermetaUic compounds (IMCs) in the interfacial layer by optical metalloscope (OM), wanning electron microscopy (SEM) and energy dispersive spectrometer (EDS), and the cracked joint was analyzed in order to understand the cracking mechanism of the joint. The results show that the microfusion of the stainless steel can improve the wetting and spreading of liquid aluminum base filler metal on the steel surface and the melted steel accelerates the formation of mass of brittle IMCs in the interracial layer, which causes the joint cracking badly. The whole interfacial layer is 5 - 7 μm thick and comprises approximately 5 μm-thickness reaction layer in aluminum side and about 2 μm-thickness diffusion layer in steel side. The stable Al-rich IMCs are formed in the interfaciallayer and the phases transfer from (Al + FeAl3) in aluminum side to (FeAl3+ Fe2Al5) and (α-Fe + FeAl) in steel side.

  6. Dissimilar Laser Welding/Brazing of 5754 Aluminum Alloy to DP 980 Steel: Mechanical Properties and Interfacial Microstructure

    Science.gov (United States)

    Yang, Jin; Li, Yulong; Zhang, Hua; Guo, Wei; Weckman, David; Zhou, Norman

    2015-11-01

    A diode laser welding/brazing technique was used for lap joining of 5754 aluminum alloy to DP 980 steel with Al-Si filler metal. The correlation between joint interfacial microstructure, wettability of filler metal, and mechanical properties was systematically investigated. At low laser power (1.4 kW), a layer of intermetallic compounds, composed of θ-Fe(Al,Si)3 and τ 5 -Al7.2Fe1.8Si, was observed at the interface between fusion zone and steel. Because of the poor wettability of filler metal on the steel substrate, the joint strength was very low and the joint failed at the FZ/steel interface. When medium laser power (2.0 kW) was applied, the wettability of filler metal was enhanced, which improved the joint strength and led to FZ failure. With further increase of laser power to 2.6 kW, apart from θ and τ 5, a new hard and brittle η-Fe2(Al,Si)5 IMC with microcracks was generated at the FZ/steel interface. The formation of η significantly degraded the joint strength. The failure mode changed back to interfacial failure.

  7. Effects of machining parameters on tool life and its optimization in turning mild steel with brazed carbide cutting tool

    Science.gov (United States)

    Dasgupta, S.; Mukherjee, S.

    2016-09-01

    One of the most significant factors in metal cutting is tool life. In this research work, the effects of machining parameters on tool under wet machining environment were studied. Tool life characteristics of brazed carbide cutting tool machined against mild steel and optimization of machining parameters based on Taguchi design of experiments were examined. The experiments were conducted using three factors, spindle speed, feed rate and depth of cut each having three levels. Nine experiments were performed on a high speed semi-automatic precision central lathe. ANOVA was used to determine the level of importance of the machining parameters on tool life. The optimum machining parameter combination was obtained by the analysis of S/N ratio. A mathematical model based on multiple regression analysis was developed to predict the tool life. Taguchi's orthogonal array analysis revealed the optimal combination of parameters at lower levels of spindle speed, feed rate and depth of cut which are 550 rpm, 0.2 mm/rev and 0.5mm respectively. The Main Effects plot reiterated the same. The variation of tool life with different process parameters has been plotted. Feed rate has the most significant effect on tool life followed by spindle speed and depth of cut.

  8. The Study Of The Impact Of Surface Preparation Methods Of Inconel 625 And 718 Nickel-Base Alloys On Wettability By BNi-2 And BNi-3 Brazing Filler Metals

    Directory of Open Access Journals (Sweden)

    Lankiewicz K.

    2015-06-01

    Full Text Available The article discusses the impact of surface preparation method of Inconel 625 and 718 nickel-base alloys in the form of sheets on wettability of the surface. The results of the investigations of surface preparation method (such as nicro-blasting, nickel plating, etching, degreasing, abrasive blasting with grit 120 and 220 and manually grinding with grit 120 and 240 on spreading of BNi-2 and BNi-3 brazing filler metals, widely used in the aerospace industry in high temperature vacuum brazing processes, are presented. Technological parameters of vacuum brazing process are shown. The macro- and microscopic analysis have shown that nicro-blasting does not bring any benefits of wettability of the alloys investigated.

  9. Interfacial microstructure and mechanical property of SiO{sub 2}-BN ceramics and Invar joint brazed with Ag-Cu-Ti active filler metal

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Z.W. [State Key Lab of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Zhang, L.X., E-mail: hitzhanglixia@163.com [State Key Lab of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Xue, Q.; He, P.; Feng, J.C. [State Key Lab of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China)

    2012-02-01

    Highlights: Black-Right-Pointing-Pointer The diffusion of Fe and Ni from Invar has great influence on joint microstructure. Black-Right-Pointing-Pointer Shear strength depends heavily on Ni{sub 3}Ti and Fe{sub 2}Ti brittle compounds. Black-Right-Pointing-Pointer Formation mechanism of the composite TiN-TiB{sub 2} fine-grain layer was discussed. Black-Right-Pointing-Pointer TiN-TiB{sub 2} fine-grain layer was the key factor in achieving a good bonding. - Abstract: SiO{sub 2}-BN ceramics and Invar alloy were jointed by active brazing using Ag-21Cu-4.5Ti (wt.%) filler at 1113-1173 K for 5-30 min. Scanning and transmission electron microscopy studies revealed that the amorphous SiO{sub 2} was not reacted during brazing while h-BN had strong tendency to react with Ti to formation a fine-grain layer adjacent to SiO{sub 2}-BN ceramic. The composite TiN-TiB{sub 2} fine-grain layer with the thickness of 100-150 nm was the key factor in achieving a good bond between SiO{sub 2}-BN ceramic and Invar. Invar alloy dissolved into the molten filler and reacted with Ti to form Fe{sub 2}Ti and Ni{sub 3}Ti, which dispersed in Ag- and Cu-based solid solution. The shear strength of the joint decreases with the increase of Fe{sub 2}Ti and Ni{sub 3}Ti brittle compounds. The maximum shear strength reached 32 MPa when the joint brazed at 1153 K for 10 min. Cracks primarily propagated in the SiO{sub 2}-BN ceramic and partially along the reaction layer.

  10. Research on Treatment of Diamond Surface by Film Deposition and Induction Brazing%金刚石表面的膜层沉积处理及其感应钎焊的研究

    Institute of Scientific and Technical Information of China (English)

    马伯江; 蔡啸; 于庆先

    2012-01-01

    Diamond grits were deposited by hot filament chemical vapor deposition (HFCVD) and they were used to fabricate the brazed diamond tools by induction brazing. The gas ratio (H2/CH4) used was 100 : 1.5(standard cubic--centimetres per minute), the total gas pressure was maintained at about 2.0 kPa, and the substrate temperature was heated to 700℃ for 45 minutes during HFCVD. As a result, amorphous carbon film is deposited on the diamond surface. The diamond edges exposed out of the filler alloy keeps good sharpness after induction brazing of HFCVD deposited diamond. Chro- mium- carbides with uniform porosity and irregular shapes were formed on the diamond grits im mersed into the brazing filler alloy. The liquid brazing filler metal filled in porosity can enhance the bonding strength between the brazing filler metal and the diamond grits. The heavy--load grinding tests of the brazed diamond wheels fabricated by three kinds of diamond grits show that there is a low percentage of pullout from matrix and whole grain fracture for the deposited diamond grits brazed by induction heating.%将热丝化学气相沉积(HFCVD)处理的金刚石作为磨料感应钎焊制作金刚石工具。HFCVD处理试验中,混合气为H2和CH4(体积流量比为100∶1.5),炉内压力为2.0kPa,700℃下处理45min后,在金刚石表面沉积了一层非晶碳膜。感应钎焊HFCVD处理的金刚石显示,出露部分的金刚石棱边能保持良好的锋利性;浸没在钎料层下面的金刚石表面形成了有均匀孔隙且形状不规则的铬碳化合物,液态钎料充填这些化合物孔隙之间,能够增强钎料对金刚石的把持强度。3种金刚石磨料感应钎焊制作的金刚石磨盘的高效重负荷石材磨削试验显示,HFCVD处理的金刚石的整体破碎率和脱落率最低。

  11. Ni-Cr-B-Si+Cu-P-Sn复合钎料真空钎焊金刚石%Vacuum brazing diamond with Ni-Cr-B-Si+Cu-P-Sn composite filler metal

    Institute of Scientific and Technical Information of China (English)

    卢金斌; 贺亚勋; 张旺玺; 刘磊; 李华

    2016-01-01

    采用在镍基钎料中分别添加3%、5%和7%(质量分数)Cu-P-Sn组成新型复合钎料,并进行金刚石磨粒的钎焊实验,利用SEM、EDS和XRD对金刚石焊后的界面碳化物形貌及钎料组织进行测试分析。结果表明:添加5%Cu-P-Sn的复合钎料进行金刚石钎焊时,钎焊温度有所下降,金刚石表面碳化物较规整,并且数量有所下降,降低金刚石的热损伤。新型钎料中形成树枝晶α-Ni基固溶体和枝晶间Ni 31 Si 12、Cr 7 C 3等化合物的组织,不同含量Cu-P-Sn与Ni-Cr-B-Si合金可以较大程度互溶,可以实现钎料性能的调控,降低金刚石的热损伤。%A series of new composite brazing fillers metal were got by adding 3%, 5% or 7% (mass fraction) Cu-P-Sn in the primary brazing filler metal Ni-Cr-B-Si, respectively, then, they were used to braze diamond particles. The interface morphology of diamond carbide and the microstructure of brazing filler metal were tested by SEM, EDS and XRD. The results show that, when the composite brazing filler metal containing 5% Cu-P-Sn alloy, the carbide on the surface of the diamond is more regular and less with brazing temperature decreases, which decreases the thermal damage to the diamond. In the brazing filler alloy, the microstructures, such as dentrite included solid solution of Ni with some carbides like Ni31Si12 and Cr7C3, are formed. As the added component, Cu-P-Sn at different proportions can be dissolved into the primary brazing filler Ni-Cr-B-Si in large degree, which can adjust the properties of the filler and reduce the heat damage to the diamond.

  12. The effect of different crystal conditions of filler metal on vacuum brazing of TiAl alloy and 42CrMo

    Institute of Scientific and Technical Information of China (English)

    Zhu Ying; Zhang Mo; Wang Guojian; Li Wenyi; Kang Hui; Qu Ping

    2007-01-01

    Ti-based filler metals made by transient solidification and normal crystallization were selected for the vacuum brazing of the TiAl alloy and 42CrMo under different processing parameters. The results show that the tensile strength of the joint of transient solidified filler metal is higher than that of normal crystallized filler metal under the same processing parameters. By the analysis of scanning electron microscope(SEM) and X-ray diffracting (XRD) , it is found that the higher strength maybe caused by the generating of TiAl , TiNi and TiCu at the interface of joint made by transient solidified filler metal.

  13. The quality evaluation of the end-plate welds and brazed joints for CANDU nuclear fuel by an ultrasonic imaging method

    International Nuclear Information System (INIS)

    This paper describes a method for the quality evaluation of spot welds and brazed joints by analysing ultrasonic images (C-scan). A present, the quality control for these joints is made by destructive methods. The authors present the most frequent types of flaw met in their investigations. They have attempted to obtain a dependence of torsion moment, measured by a destructive method against the polar inertia moment, obtained from parameters measured on ultrasound images. The ultrasonic images were analysed off-line using a dedicated software. (author)

  14. A contribution to the study of metal-ceramic bonding by direct vacuum brazing with reactive metals

    International Nuclear Information System (INIS)

    Wettability and bonding tests were utilized to evaluate the behaviour of various specials alloys, for work at high temperature under vacuum, for the inter-bonding of silicon carbide, alumina ceramic, graphite (for electrical applications) and petroleum coke and their joining with themselves as the metals titanium, molybdenum, nickel and copper. The joints exhibiting effective bonding were investigated by means of optical microscopy, scanning electron microscopy and X-rays diffraction. Elemental mapping of the constituents and quantitative chemical microanalysis were also undertaken, via the energy dispersive analysis of X-rays (SEM/EDS). On the basis of the results the possible mechanisms of bond-formation have been discussed. It was verified that: a) of the filler metals studied, those which exhibited effective wettability on all the above materials were: 49Cu-49Ti-2Be, Zircaloy4-5Be and a commercial alloy Ticusil, which consisted of a Cu-Ag eutectic with a small addition of pure Ti, of nominal composition 26.7Cu-68.8Ag-4.5Ti; b) the alloys with high levels of reactive metals such as Ti and Zr tended to form low ductility bonds due to the formation of hard, brittle phases; c) the copper suffered pronounced erosion when in direct contact with alloys of high Ti and Zr contents, due to the formation of phases whose melting points were below the brazing temperature of those materials; e) the compounds detected as reaction products were identified as, TiC in the samples rich in carbon, such as the SiC ceramic and graphite joints, or the oxides Cu2Ti2O5 and Cu3TiO4 in the bonding of alumina to alloys including Ti in their composition or in that of the filler metal, proving that the effectiveness of the bond is dependent upon an initial and indispensable chemical bonding. (author)

  15. Laser-MIG Arc Hybrid Brazing-Fusion Welding of Al Alloy to Galvanized Steel with Different Filler Metals

    Institute of Scientific and Technical Information of China (English)

    Shujun WANG; Guoliang QIN; Yuhu SU

    2013-01-01

    Aluminum alloy plates were joined to galvanized steel sheets with lap joint by laser-MIG arc hybrid brazingfusion welding with AlSi5,AlSi12,AlMg5 filler wires,respectively.The influences of Si and Mg on the microstructure and mechanical properties of the brazed-fusion welded joint were studied.The increase of Si element in the fusion weld can make the grain refined,and increase the microhardness of the fusion weld.Therefore,the microhardness in fusion weld made from AlSi12 and AlSi5 filler wires can be up to 98.4 HV0.01and 96.8 HV0.01,which is higher than that from AlMg5 filler wire of 70.4 HV0.01.The highest tensile strength can reach 178.9 MPa made with AlMg5 filler wire.The tensile strength is 172.43 MPa made with AlSi5 filler wire.However,the lowest tensile strength is 144 MPa made with AlSi12 filler wire.The average thicknesses of the intermetallic compounds (IMCs) layer with AlSi5,AlSi12,AlMg5 filler wires are 1.49-2.64 μm.The lMCs layer made from AlSi5,AlSi12 filler wires are identified as FeAl2,Fe2Als,Fe4Al13 and Al0.5Fe3Si0.5,that from AlMg5 filler wire are identified as FeAl2,Fe2Al5 and Fe4Al13.

  16. Brazing of Ti- Ni Coated Diamonds%复合镀覆Ti-Ni金刚石的钎焊应用

    Institute of Scientific and Technical Information of China (English)

    王艳辉; 臧建兵; 王明智

    2001-01-01

    Latest developments of coating technology show that, when diamond crystal or PCD is coated with Ti or W by vacuum slow vapor deposition process, it can be further coated with Ni, Co or Cr by electroless plating or electroplating so as to form a composite coating on its surface. Due to the strong metallurgical adhesion between diamond and coating, diamond is easily brazed onto different metal substrate. Composite-coated diamond is mainly used for making surface-set tool to obrain high protrusion height of diamond grit and strong interface adhesion. Thus tool's lifetime and efficiency are improved greatly.%镀覆技术的研究进展表明:经过真空微蒸发镀钛、钨的金刚石单晶或聚晶,可以采用化学镀或电镀的方法在钛或钨镀层上进一步镀覆镍、钴、铬等金属,这种复合镀层与金刚石界面强力冶金结合,并且可以采用各种钎焊方法实现金刚石与多种金属基体的焊接。复合镀覆的金刚石可用于各类表镶工具的制造,获得高出刃、高磨粒结合强度,使金刚石表镶工具的使用寿命和加工效率大幅度提高。

  17. Vacuum brazing of TiAl48Cr2Nb2 casting alloys based on TiAl (γ intermetallic compound

    Directory of Open Access Journals (Sweden)

    Z. Mirski

    2010-01-01

    Full Text Available A growing interest in modern engineering materials characterised by increasingly better operational parameters combined with a necessity to obtain joints of such materials representing good operation properties create important research and technological problems of today. These issues include also titanium joints or joints of titanium alloys based on intermetallic compounds. Brazing is one of the basic and sometimes even the only available welding method used for joining the aforesaid materials in production of various systems, heat exchangers and, in case of titanium alloys based on intermetallic compounds, turbine elements and space shuttle plating etc. This article presents the basic physical and chemical properties as well as the brazability of alloys based on intermetallic compounds. The work also describes the principle and mechanisms of diffusion-brazed joint formation as well as reveals the results of metallographic and strength tests involving diffusion-welded joints of TiAl48Cr3Nb2 casting alloy based on TiAl (γ phase with the use of sandwich-type layers of silver-based parent metal (grade B- Ag72Cu-780 (AG 401 and copper (grade CF032A. Structural examination was performed by means of light microscopy, scanning electron microscope (SEM and energy dispersion spectrometer (EDS. Furthermore, the article reveals the results of shear strength tests involving the aforementioned joints.

  18. Manufacturing and high heat-flux testing of brazed actively cooled mock-ups with Ti-doped graphite and CFC as plasma-facing materials

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Rosales, C; Ordas, N; Lopez-Galilea, I [CEIT and Tecnun (University of Navarra), 20018 San Sebastian (Spain); Pintsuk, G; Linke, J [Forschungszentrum Juelich GmbH, EURATOM Association, 52425 Juelich (Germany); Gualco, C; Grattarola, M; Mataloni, F [Ansaldo Ricerche S.p.A., I-16152 Genoa (Italy); Ramos Fernandez, J M; MartInez Escandell, M [Departamento de Quimica Inorganica, University of Alicante, E-03690 Alicante (Spain); Centeno, A; Blanco, C [Instituto Nacional del Carbon (CSIC), Apdo. 73, E-33080 Oviedo (Spain)], E-mail: cgrosales@ceit.es

    2009-12-15

    In the frame of the EU project ExtreMat new Ti-doped isotropic graphites and carbon fibre-reinforced carbons (CFCs) with high thermal conductivity and reduced chemical erosion were brazed to a CuCrZr heat-sink to produce flat-tile actively cooled mock-ups (MUs). Brazing was done using a low CTE interlayer to shift the stresses to the metal-metal interface. These MUs were exposed to high heat-fluxes in the electron beam facility JUDITH. Screening tests were conducted increasing the heat load stepwise up to 15 MW m{sup -2}, followed by 100 cycles at 15 MW m{sup -2}, subsequent screening up to 20 MW m{sup -2} and 100 cycles at 20 MW m{sup -2}. All MUs withstood screening at 15 MW m{sup -2} and most of them survived screening at 20 MW m{sup -2}. Ti-doped CFC MUs showed a significant improvement compared with the undoped reference CFC, surviving several cycles at 20 MW m{sup -2} on all tiles. One of the Ti-doped graphite MUs withstood 100 cycles at 20 MW m{sup -2} on one tile, representing a promising result.

  19. Active brazing of ceramic inlays for the application in wear critical areas of forging dies; Aktivloeten von keramischen Segmenten fuer den Einsatz in verschleisskritischen Bereichen von Schmiedegesenken

    Energy Technology Data Exchange (ETDEWEB)

    Bach, Fr.W.; Doege, E.; Kutlu, I.; Huskic, A. [Institut fuer Umformtechnik und Umformmaschinen, Universitaet Hannover, Welfengarten 1A, 30167 Hannover (Germany)

    2002-11-01

    The use of reinforcing ceramic segments in forging tools is investigated and has been successfully tested with model of dies recently. With reinforcing ceramic segments, however, the thermal widening of the steel tool is a major problem for forging dies. Further, only rotationally symmetrical ceramic inserts can be used as reinforcements which restricts the shape capabilities in tool design significantly. A considerably greater design flexibility is possible if the ceramic segments are brazed into the die body material. To this end, reactively brazed ceramic-metal composites are to be developed and tested for feasibility in the forging process. (Abstract Copyright [2002], Wiley Periodicals, Inc.) [German] Der Einsatz durch thermisches Schrumpfen gefuegter keramischer Segmente in Schmiedewerkzeugen wird seit einiger Zeit untersucht und erfolgreich an Modellgesenken erprobt. Hier zeigt sich die Gefahr der thermischen Aufweitung des Schrumpfverbandes als Hauptproblem bei Schmiedegesenken mit eingeschrumpften keramischen Segmenten. Weiterhin lassen sich nur rotationssymmetrische keramische Segmente einschrumpfen, was eine erhebliche Einschraenkung der Gestaltungsmoeglichkeiten in der Werkzeugkonstruktion bedeutet. Deutlich groessere Gestaltungsmoeglichkeiten bietet das Aktivloeten keramischer Segmente in Gesenkgrundkoerper. Hierfuer sollen aktivgeloetete Keramik-Metall-Verbunde entwickelt und auf Einsatzfaehigkeit im Schmiedeprozess ueberprueft werden. (Abstract Copyright [2002], Wiley Periodicals, Inc.)

  20. 浅论铝合金真空钎焊机箱的应用和加工%Elementary Discussion on the Application and Processing of Vacuum Brazing Aluminum Alloy Chassis

    Institute of Scientific and Technical Information of China (English)

    王飚; 李卫民

    2014-01-01

    本文阐述了真空钎焊技术的优点及铝合金真空钎焊机箱的应用和加工的重要性,突出了机载装备中真空钎焊的必要性。其次,本文以某型号机箱为例,围绕着铝合金真空钎焊机箱加工的四个方面详细地加以介绍、描述和总结了加工工艺及要点。最后,本文指出了铝合金真空钎焊机箱能够提升航空电子系统的整体效能,只有通过提高工艺水平,规范生产流程,才能确保机载电子设备机箱的生产和质量稳定,提高生产效益。%Firstly, this paper expounded on the advantages of vacuum brazing technology and the importance of application and processing of vacuum brazing aluminum alloy chassis, with the emphasis on the necessity of vacuum brazing in airborne equipment. Secondly, taking a certain type of chassis as an example, this paper introduced, described and summarized the processing technology and key point of vacuum brazing process of aluminum alloy chassis in four aspects. Finally, it was pointed out that vacuum brazing aluminum alloy chassis was able to improve the overall effectiveness of avionics system, only by improving the technological level , and standardizing the production process, in order to ensure the production and quality of airborne electronic equipment chassis, and improve production efficiency.

  1. 铝钢异种材料电弧熔钎焊接技术的研究%Investigation on Arc Brazing Technology of Aluminum and Steel

    Institute of Scientific and Technical Information of China (English)

    尹兰礼; 雷永平; 林健; 王培中; 钟毅

    2011-01-01

    为了减轻车身重量,铝合金正被广泛的应用到汽车车身用中.而铝合金与汽车用钢板的连接问题是铝合金得以广泛应用的关键.本研究通过钨极氩弧焊和冷金属过渡焊两种电弧熔钎焊接方法实现铝合金与低碳钢的连接,研究了两种焊接方法的焊缝成型、接头拉剪强度以及金属间化合物的成分差异,并与传统的铆接接头进行比较.研究表明,电弧熔钎焊具有较高的接头拉剪强度和较小的接头重量.由于冷金属过渡焊的热输入量低,使得其焊缝成型相对较好,且其接头拉剪强度值已达到母材强度的85%.%Aluminum is being widely applied to automobile body to reduce the weight The key problem is connecting aluminum alloy to steel of car-body. In this paper, aluminum and steel are connected by Tungsten Inert Gas (TIG) arc brazing and Cold Metal Transfer (CMT) arc brazing. The weld formation of the two welding methods and component of intermetallic compounds (IMC) are investigated, and compared the joint's tensile-shear strength with traditional Self-piercing riveting. The results show that the joints made by arc brazing have higher tensile-shear strength and lighter weight. Due to the low welding heat input, the weld formation of CMT is better than that of TIG. And the tensile-shear strength of CMT joint has reached 85% of the base metal strength.

  2. Torch Brazing Methods for Cast Iron QT500-7 and Its Influence on Performance of Brazed Joints%QT500—7铸铁火焰钎焊方法及其对接头性能的影响

    Institute of Scientific and Technical Information of China (English)

    王振波; 陈春焕

    2012-01-01

    Using B-Ag40CuZnCdNi alloy as filler metal, cast iron QT500 7 was connected by torch brazing. The effect of filler metal placement method and heating time on the shear strength of the brazed joints was studied by shear test and microstructure observation. The results showed that when sandwich method was used to place the filler metal, the joint was likely to cause welding defects, and the carrying capacity of the joint was lower than that of base metal. When capillary method was used in enough heating time, the filling process of the liquid metal had also played a role of cleaning the gap of brazing seam, which was helpful to get the joint with thin and straight brazing seam and less defects, so the shear strength had been improved, when the heating time was more than 5 min, the carrying capacity of the joint was higher than that of base metal, but it will be not as good as sandwich method if the heating time was insufficient.%以B-Ag40CuZnCdNi合金为钎料,采用火焰钎焊方法实现了QT500—7铸铁的连接。研究了“三明治”法和毛细法两种钎料放置方式及不同加热时间对钎焊接头抗剪强度的影响,并对连接界面的微观组织进行了分析。结果表明:用“三明治”法放置钎料时,接头容易产生焊接缺陷,接头的承载能力低于母材;用毛细法放置钎料时,在足够长的加热时间条件下,液态钎料的填缝过程同时具有清洁钎缝间隙的作用,有利于得到钎缝细小平直且缺陷少的接头,因此抗剪强度得到提高,加热时间大于5min时,接头承载能力高于母材,但加热时间不足时反而不如“三明治”法的施焊效果。

  3. Interfacial microstructure and mechanical property of Ti6Al4V/A6061 dissimilar joint by direct laser brazing without filler metal and groove

    Energy Technology Data Exchange (ETDEWEB)

    Song, Zhihua, E-mail: zhsong@jwri.osaka-u.ac.jp [Joining and Welding Research Institute, Osaka University, Osaka, Ibaraki 567-0047 (Japan); Department of Mechanical Engineering, Tsinghua University, Beijing 100084 (China); Key Laboratory for Advanced Materials Processing Technology, Ministry of Education (China); Nakata, Kazuhiro [Joining and Welding Research Institute, Osaka University, Osaka, Ibaraki 567-0047 (Japan); Wu, Aiping [Department of Mechanical Engineering, Tsinghua University, Beijing 100084 (China); Key Laboratory for Advanced Materials Processing Technology, Ministry of Education (China); Liao, Jinsun [Kurimoto Ltd., Osaka 559-0021 (Japan)

    2013-01-10

    Laser brazing of Ti6Al4V and A6061-T6 alloys with 2 mm thickness was conducted by focusing laser beam on aluminum alloy side, and the effect of laser offset distance on microstructure and mechanical properties of the dissimilar butt joint was investigated. Laser offset has a great influence on the thickness of interfacial intermetallic compound (IMC) layer and the mechanical property of joint. The thickness of interfacial IMC layer is less than 500 nm, and the average tensile strength of the joint reaches 64% of aluminum base material strength, when suitable welding conditions are used. The interfacial IMC is TiAl{sub 3}. The formation of interfacial IMC layer and its effect on mechanical property of the joint are discussed in the present study.

  4. Effect of Silver Content on Microstructure and Properties of Brass/steel Induction Brazing Joint Using Ag-Cu-Zn-Sn Filler Metal

    Institute of Scientific and Technical Information of China (English)

    J. Cao; L.X. Zhang; H.Q. Wang; L.Z. Wu; C. Feng

    2011-01-01

    The induction brazing of brass to steel using Ag-Cu-Zn-Sn filler metal was investigated in this study. The influence of Ag content on the microstructure and properties were analyzed by means of optical microscopy, scanning electron microscopy and electron probe microanalysis. Defect free joint was achieved using Ag-Cu-Zn-Sn filler metal. The microstructure of the joint was mainly composed of Ag-based solid solution and Cu-based solid solution. The increase of Ag content and the cooling rate both led to the increase of the needle like eutectic structure. The tensile strength decreased with the increase of Ag content. The tensile strength at room temperature using Ag25CuZnSn filler metal reached 445 MPa. All fractures using Ag-Cu-Zn-Sn filler metal presented ductile characteristic.

  5. Comparison of Microstructure and Mechanical Properties of Induction and Vacuume Brazed Joint of Titanium Via Copper and Ag-Cu Eutectic Filler Metal / Mikrostruktura I Właściwości Mechaniczne Połączeń Tytanu Lutowanych Indukcyjnie I Próżniowo Z Użyciem Spoiwa Miedzianego I Eutektycznego Ag-Cu

    Directory of Open Access Journals (Sweden)

    Różański M.

    2015-12-01

    Full Text Available This study presents the basic physico-chemical properties and describes the brazeability of titanium. The work contains the results of macro and microscopic metallographic examination as well as the results of strength-related tests of vacuum and induction brazed joints made of Grade 2 technical titanium using the Cu 0.99 and Ag 272 filler metal interlayers and F60T flux intended for titanium brazing in the air atmosphere.

  6. Study of Process on Brazing Diamond/CBN Grinding Wheel Matrix Technology%钎焊金刚石/CBN砂轮基体工艺方法初探

    Institute of Scientific and Technical Information of China (English)

    袁建新; 王永强; 马家稑

    2012-01-01

    According to several process methods on manufacturing the brazing diamond/CBN grinding wheel in the domestic market currently, the advantages and disadvantages of these methods are analyzed. In accordance with the actual problem occurred during factory tests: the welding temperature affects severely hardness of the grinding wheel matrix, and accordingly affects the accuracy consistency, a method for finding out a suitable matrix material is presented in this thesis, and thus a better sample is offered to solve the effect problem of the high - temperature brazing on the matrix. The conclusion is; to meet the dynamic performance requirements of CBN/diamond grinding wheel matrix, the 40Mn2 material is recommended for a grinding wheel matrix, its hardness can reach around HRC38 after temper at a temperature of around 700℃ , and thus can meet the requirements of high - speed grinding and high - precision grinding.%针对目前国内制作钎焊金刚石/CBN砂轮的几种工艺方法,分析了存在的优缺点.根据工厂试验中出现的实际问题,指出了寻找到合适基体材料的方法,为解决高温钎焊对基体的影响提供了一个较好的样本.为了满足CBN/金刚石砂轮基体的力学性能需要,建议砂轮基体采用40Mn2这种材料,在700℃左右回火,其硬度可以达到38HRC左右,能够满足高速磨削和高精度磨削的要求.

  7. 铝制冷却器真空钎焊接头界面结构及断口分析%Interface Structure and Fracture Analysis of Aluminum Cooler Vacuum Brazing Joint

    Institute of Scientific and Technical Information of China (English)

    许敬年; 曹秀丽; 冯涛

    2012-01-01

    采用真空钎焊技术研制了一种用于高级轿车的铝制冷却器.采用LT-3铝复合板材进行了焊接试验,分析了钎焊接头的组织,并对所试制的铝制板翅式冷却器进行了水压试验及其断口分析.结果表明,钎焊接头中生成了网状共晶组织,接头中生成了金属间化合物.焊接完成的板翅式冷却器水压试验压力可达到15 kg/cm2以上,钎焊接头断口属于混合断裂,断口表面分布有二次裂纹、韧窝、解理面、沿晶断裂等断裂特征.%A kind of aluminum cooler used for advanced car by adopting vacuum brazing technology was developed. Welding test was conducted by Utilizing LT-3 aluminum composite plate. The structure of brazing joint was analyzed, and hydrostatic test and fracture analysis on fin type cooler of trial produced aluminum composite plate were carried out. The results showed that there are some reticular eutectic structures and intermetallic compound in the brazing joint. The hydrostatic test pressure of fine type cooler can reach more than 15 kg/cm2, the fracture type of the brazing joint is mixed fracture, and secondary cracks, dimples, cleavage planes and intergranular fracture etc. distribute on the surface of the fracture.

  8. Review Article: recent advances in metal-ceramic brazing Artigo Revisão: avanços recentes em brasagem metal-cerâmica

    Directory of Open Access Journals (Sweden)

    R. M. do Nascimento

    2003-12-01

    Full Text Available Metal-ceramic joining has slowly but steadily become an important manufacturing step. The evolution of joining processes has allowed ceramics to be used in combination with metals in a number of hybrid devices from traditional light bulbs and seals to improved cutting tools and modern monitoring and measuring electronic devices. New joining methods and newer approaches to conventional methods have been developed aiming at joints characterized by improved reliability, and interfaces capable of withstanding high-temperature resistance with minimum residual stresses. A summary of recent improvements on alternative approaches to ceramic-metal joining as well as new developments on brazing are presented herein. The present review also focuses on recent advances towards brazing metallized ceramics and the selection of filler alloys, since in a scenario that includes joining by laser and direct bonding with liquid transient phases, brazing continues to be by far the most widely used approach to joining as a result of its low-cost and possibility to join intricate geometries for large-scale production. Finally, methods to evaluate the mechanical strength and residual thermal stresses are presented in addition to alternative approaches to minimize residual stresses and, consequently, improve joint reliability.O interesse no estudo de métodos de junção-cerâmica para aplicações industriais tem crescido gradativamente ao longo dos anos. A evolução dos processos de união tem permitido a utilização de cerâmicas em conjunto com metais na fabricação de diversos componentes híbridos incluindo lâmpadas tradicionais, juntas para vácuo, ferramentas de corte de alto desempenho e modernos dispositivos eletrônicos de medição e monitoramento. Novos métodos de união e aprimoramentos de métodos convencionais têm sido estudados com o intuito de produzir-se juntas com alta confiabilidade e interfaces capazes de suportar altas temperaturas de

  9. SiCp/2024Al铝基复合材料表面颗粒暴露及真空钎焊分析%Analysis on SiCp/2024 aluminum matrix composites surface reinforcements exposing and vacuum brazing

    Institute of Scientific and Technical Information of China (English)

    冯涛; 王引真; 楼松年; 张蒙蒙; 李春鹏

    2011-01-01

    Using the particle exposing and surface alloying technique of aluminum matrix composite, taking M6 and BAI88Si as the filler metal, the SiCp/2024Al aluminum matrix composite was brazed. The metallographic analysis, tensile test and Xray diffraction experiment were done. The test results indicate that the surface reinforcements are partly exposed by ( NaOH+HNO3 ) solution. The brazing joint combination state could be improved by depositing Cu element with M6 filler metal. The brazing joint and the base metal combined well with no obvious boundary. The reinforced composite solder joints with SiC particle are formed. There is no SiC particle agglomerated in the brazing joint. The tensile strength of the welded joint can reach 202 MPa. There is no Al4C3 brittleness phase formed in the brazing joint.%采用复合材料表面颗粒暴露及表面合金化工艺,利用M6和BAI88Si钎料对SiCp/2024Al铝基复合材料进行钎焊试验,并进行金相分析、拉伸试验和X射线衍射试验.结果表明:采用(NaOH+HNO3)工艺能将复合材料表面颗粒部分暴露出来;采用表面沉积Cu,使用M6钎料,能改善钎缝的结合状态;钎缝与铝基复合材料间无明显界限,结合良好,并形成了有SiC颗粒增强的复合钎缝,SiC颗粒在钎缝中无团聚现象;钎焊接头强度能达到202 MPa;在钎缝中无Al4C3脆性相生成.

  10. 镀膜CBN珩轮激光钎焊基础工艺研究%Basic Process Research on Laser Brazing Film CBN on the Gear-honing-tool

    Institute of Scientific and Technical Information of China (English)

    梁国星; 吕明; 李文斌; 马麟

    2012-01-01

    完成镀膜CBN珩轮激光钎焊需要1套完整的工艺,包括珩轮基体钎焊前清洗、镀膜CBN粗化、黏结剂涂覆、钎料及磨粒固着、激光钎焊等.任意1项出现纰漏,都会对镀膜CBN钎焊连接质量造成一定的影响,降低钎焊后珩轮精度.本文在总结以往试验的基础上,对镀膜CBN珩轮激光钎焊工艺进行了基础性研究,制定出1套激光钎焊镀膜CBN珩轮制作工艺,并对激光钎焊过程中常见的镀膜CBN磨粒缺陷进行了分析,阐述了产生缺陷的原因,提出避免缺陷产生的方法,为珩轮的制备提供了新的方法,对于加快新型珩轮的开发和推动珩齿工艺的发展提供了有益的帮助.%Laser brazing on the film CBN gear-honing matrix was achieved,a perfect technology must be provided including cleaning honing matrix,CBN grit roughening treatment,coating binder on the matrix,fixing spelter and grits,laser brazing process and so on. Going awry either segment, the laser brazing connection quality among the CBN grit, gear-honing matrix and spelter would be affected to certain extent. The precision of gear-honing-tool would be decreased. Based on summarizing the experiments results,the basic technology of laser brazing the film CBN on the gear-honing matrix was studied in this paper. The defects in the process of laser brazing CBN had been analyzed,and the generated reason and solution were explained, then a new method for manufacturing gear-honing-tool is put forward. It is benefit to speeding up gear-honing-tool developing and promoting the process of honing gear.

  11. Mg/Cu异种材料共晶反应钎焊连接研究%Dissimilar Metals Between Copper and Magnesium Alloy in Eutectic Contacting Reaction Brazing

    Institute of Scientific and Technical Information of China (English)

    王怀建; 袁苗达; 白莉

    2012-01-01

    Magnesium alloy (AZ31B) and Copper (T2) were bonded by eutectic contacting reaction brazing. The microstructural features and mechanical properties of the welded joint was studied by scanning electron microscopy (SEM), energy dispersive spectrometer (EDS). The results show that when the welding process is at 500 °C for 5 min, under the pressure of 2MPa, the tensile strength of the welded joint reaches 42MPa.%采用共晶钎焊工艺对Mg/Cu异种材料进行连接,焊后利用扫描电镜和EDS对焊接接头的微观组织及元素扩散行为进行了研究.在焊接温度为500℃,焊接时间为5min,焊接压力为2MPa的工艺下,焊接接头最高抗拉强度为42 MPa.

  12. Condensation heat transfer and pressure drop of R-134a saturated vapour inside a brazed compact plate fin heat exchanger with serrated fin

    Science.gov (United States)

    Ramana Murthy, K. V.; Ranganayakulu, C.; Ashok Babu, T. P.

    2016-05-01

    This paper presents the experimental heat transfer coefficient and pressure drop measured during R-134a saturated vapour condensation inside a small brazed compact plate fin heat exchanger with serrated fin surface. The effects of saturation temperature (pressure), refrigerant mass flux, refrigerant heat flux, effect of fin surface characteristics and fluid properties are investigated. The average condensation heat transfer coefficients and frictional pressure drops were determined experimentally for refrigerant R-134a at five different saturated temperatures (34, 38, 40, 42 and 44 °C). A transition point between gravity controlled and forced convection condensation has been found for a refrigerant mass flux around 22 kg/m2s. In the forced convection condensation region, the heat transfer coefficients show a three times increase and 1.5 times increase in frictional pressure drop for a doubling of the refrigerant mass flux. The heat transfer coefficients show weak sensitivity to saturation temperature (Pressure) and great sensitivity to refrigerant mass flux and fluid properties. The frictional pressure drop shows a linear dependence on the kinetic energy per unit volume of the refrigerant flow. Correlations are provided for the measured heat transfer coefficients and frictional pressure drops.

  13. Development of a brazing process for the production of water- cooled bipolar plates made of chromium-coated metal foils for PEM fuel cells

    Science.gov (United States)

    Mueller, M.; Hoehlich, D.; Scharf, I.; Lampke, T.; Hollaender, U.; Maier, H. J.

    2016-03-01

    Beside lithium batteries, PEM fuel cells are the most promising strategy as a power source to achieve the targets for introducing and increasing the usage of electric vehicles. Due to limited space and weight problems, water cooled, metallic bipolar plates in a fuel cell metal stack are preferred in motor vehicles. These plates are stamped metal sheets with a complex structure, interconnected media-tight. To meet the multiple tasks and requirements in use, complex and expensive combinations of materials are currently in use (carbon fiber composites, graphite, gold-plated nickel, stainless and acid resistant steel). The production of such plates is expensive as it is connected with considerable effort or the usage of precious metals. As an alternative, metalloid nitrides (CrN, VN, W2N, etc.) show a high chemical resistance, hardness and a good conductivity. So this material category meets the basic requirements of a top layer. However, the standard methods for their production (PVD, CVD) are expensive and have a slow deposition rate and a lower layer thicknesses. Because of these limitations, a full functionality over the life cycle of a bipolar plate is not guaranteed. The contribution shows the development and quantification of an alternative production process for bipolar plates. The expectation is to get significant advantages from the combination of chromium electrodeposition and thermochemical treatment to form chromium nitrides. Both processes are well researched and suitable for series production. The thermochemical treatment of the chromium layer also enables a process-integrated brazing.

  14. Interfacial microstructure and strength of diffusion brazed joint between Al2O3–TiC and 9Cr1MoV steel

    Indian Academy of Sciences (India)

    Wang Juan; Li Yajiang; S A Gerasimov

    2007-08-01

    Joining of composite, Al2O3–TiC, with heat-resistant 9Cr1MoV steel, was carried out by diffusion brazing technology, using a combination of Ti, Cu and Ti as multi-interlayer. The interfacial strength was measured by shear testing and the result was explained by the fracture morphology. Microstructural characterization of the Al2O3–TiC/9Cr1MoV joint was investigated by X-ray diffraction (XRD) and scanning electron microscope (SEM) with energy-dispersion spectroscopy (EDS). The results indicate that a Al2O3–TiC/9Cr1MoV joint with a shear strength of 122 MPa can be obtained by controlling heating temperature at 1130°C for 60 min with a pressure of 12 MPa. Multi-interlayer Ti/Cu/Ti was fused fully and diffusion occurred to produce interfacial layer between Al2O3–TiC and 9Cr1MoV steel. The total thickness of the interfacial layer is about 100 m and Ti3AlC2, TiC, Cu and Fe2Ti are found to occur in the interface layer.

  15. Microstructure characteristic of SS304/BNi-2/SS304 butt joint by high temperature brazing%SS304/BNi-2/SS304高温钎焊对接接头微观结构特征

    Institute of Scientific and Technical Information of China (English)

    竺国荣; 陈虎; 祝金丹; 巩建鸣

    2011-01-01

    通过试验手段研究了SS304/BNi-2/SS304钎焊对接接头微观结构特征,使用能谱分析结合合金三元相图研究了接头区域典型的微观结构形貌和特征相变化规律,讨论了降熔元素在接头等温凝固连接过程中所起的关键作用。结果表明,在钎焊温度时,B从液相钎料向固相母材的快速扩散控制了接头的等温凝固过程,也因此决定了接头的微观结构相特征;钎焊接头通常会存在4种典型的相特征区域;钎角质量对于整个钎焊接头性能有重要影响。%The microstructure characteristic of SS304/Bni -2/SS304 butt joint was analyzed by high temperature brazing through the experimental research. Some typical microstructural morphologies and phase transition feature of the butt joint were studied by using ternary phase diagrams and EDS analysis. The critical effect of element diffusion on isothermal solidification of brazed joint was also discussed by analyzing the microstructural evolution. The results showed that the quick diffusing of boron from the liquid filler alloy into solid base metal controlled the isothermal solidification process as well as the joint microstructure. Four typical characteristic zones could be observed for the whole brazed joint. The fillet quality played a very important role in the whole joint performance.

  16. Research of Electrochemical Corrosive Characteristics of Zn-Al Solders for Cu/Al Brazing%铜/铝钎焊用Zn-Al钎料的电化学腐蚀性能研究

    Institute of Scientific and Technical Information of China (English)

    王凯; 刘正林; 杨凯珍

    2011-01-01

    Zn-Al solders used for Cu/Al brazing were prepared by ingot metallurgy method in high frequency induction furnace. The anti-corrosive properties of Zn-Al solders added with Mg were evaluated and analyzed by immersion tests, electrochemical corrosion measurements, and the corrosive mechanism was discussed. The results show that the electrode potential of the solders substrates can be significantly improved by the addition of Mg to greatly improve the anti-corrosive properties of solders, while it will not significantly reduce the shear strength of welding joint. Using the Zn-Al solder added with Mg and CsF-AlF3 flux, Al and Cu tubes can be brazed by high frequency brazing method without air leaking at high air pressure even after immersion tests.%采用铸锭冶金法,在高频感应炉中制备了铜/铝钎焊用Zn-22Al钎料,通过浸泡腐蚀试验、电化学腐蚀试验对添加Mg元素的钎料的耐蚀性能进行了评价分析,并探讨了其腐蚀机理.研究结果表明,添加Mg元素可显著提高钎料基体的电极电位,从而显著提高钎料本身的耐腐蚀性能,并不会显著降低铜/铝接头的强度.加入Mg元素的Zn-22Al钎料,配合CsF-AlF3无腐蚀中温钎剂,采用高频感应加热钎焊连接铜/铝管,通过浸泡腐蚀试验后,仍可获得高剪切强度的接头.

  17. Vacuum brazing of 1Cr18Ni9Ti stainless steelusing new Ni55Fe35Si10filler%新型Ni55Fe35Si10钎料对1Cr18Ni9Ti不锈钢的真空钎焊

    Institute of Scientific and Technical Information of China (English)

    祁凯; 张明铭; 于治水; 李瑞峰

    2011-01-01

    A new kind of ternary Ni55Fe35Si10 brazing filler without element B included is developed to join lCrl8Ni9Ti stainless steel by vacuum brazing method. Wetting and lap joining process are all done to study the properties of the brazing alloy with brazing parameters 1 180 t and 1 220 t, respectively, for 10 min. Wetting angles are measured after brazing. The interfacial structure and element distribution behavior are also studied. The results show that the brazing filler has a good wetting property on the lCrl8Ni9Ti stainless steel surface, and the wetting angles are 14.8°at 1 180 t and 13. L°at 1 220 ℃. The increasing of brazing temperature leads to the decreasing of formation of intermetallic compound, which may improve the joint property. The intermetallic compound indicates a higher microhardness in the brazing seam.%采用新型三元不含B元素的Ni55Fe35Si10钎料对1Cr18 Ni9Ti不锈钢进行润湿试验及搭接钎焊试验研究.试验在真空钎焊炉中进行,保温温度分别为1 180℃和1 220℃,保温时间为10 min.对所得润湿试样进行润湿角测量,并用扫描电镜和能谱对钎焊试样微观组织和元素分布行为进行观察和分析.最后,采用显微硬度计测量搭接试样界面硬度的分布趋势.研究结果表明:钎料在1Cr1 8Ni9Ti不锈钢表面具有良好的润湿能力,在1 180℃和1 220℃时润湿角分别为14.8°和13.1°.钎焊温度增加时,界面金属间化合物数量减少,改善了接头组织,金属间化合物表现出较高的显微硬度值.

  18. Design of Fully Automatic Nitrogen Protection Brazing Furnace of Automotive Air Conditioning Radiator%汽车空调散热器全自动氮气保护钎焊炉的研制

    Institute of Scientific and Technical Information of China (English)

    陈明非; 汪娜

    2012-01-01

    全自动氮气保护钎焊炉是汽车空调散热器铝材焊接的关键设备.钎焊的工艺是将装配好的汽车空调散热器的芯体送入钎焊炉,经喷淋焊剂、干燥炉烘干、加热炉进行焊接,然后通过水冷室、风冷室进行冷却完成散热器的钎焊.技术关键是加热炉钎焊温度和含氧量的控制.通常采用在钎焊过程中向炉内充氮气,使炉内含氧量控制在70ppm以下.加热炉的进出口设置前室和后室,内置不锈钢幕帘阻挡空气的混入.介绍该设备的结构、部件、主要技术参数以及调试办法等.%The NB type entire automatic nitrogen protection brazing furnace is the essential equipment in aluminum welding. The brazing process includes sending the core of the assembled automotive air conditioning radiator into the brazing furnace, through being sprayed the flux,dried in the drying oven and heating furnace to weld, and then the welding is completed after being cooled in the cooling room and air cooling room.The key technology is the control of the temperature and the oxygen content of furnace braz ing.lt is commonly used to aerate nitrogen during the brazing process into the furnace,to guarantee oxygen content in the furnace is controlled below 70ppm.The import and export of the furnace is set with the front room and after room,with built—in stainless steel curtain to block the air.The structure of the equipment, components, main technical parameters as well as debugging approach is introduced.

  19. 高硅铝合金真空钎焊接头组织与性能测试研究%Microstructure and Properties" Testing of Hypereutectic Si-A1 Alloy Vacuum Brazed Joint

    Institute of Scientific and Technical Information of China (English)

    陈潇潇; 侯玲; 徐道荣

    2012-01-01

    选用Cu箔、Zn及BA188SiMg片状钎料作为填充金属,采用真空加热方法进行高硅铝合金的钎焊连接,并对接头进行光学金相、显微硬度、扫描电子显微等测试、分析、研究。结果表明:3种钎料钎焊高硅铝合金,通过凝固、结晶等过程形成冶金结合,生成共晶体和固溶体组织,形成可靠的连接接头,外观良好。%Hypereutectic Si A1 Alloys were connected by vacuum soldering with the filler of BAI88SiMg, pure copper and zinc, and the joints of brazing were analyzed and researched by optical microscope,Vickers and scanning electron microscopy. The results show that hypereutectic Si-A1 alloys can be connected hard with the solid solution and eutectic by the process of solidification and crystallization with three brazing filler metals, and reliable joints with good surface are formed.

  20. Cu/Al管气体火焰钎焊接头特征及热力学分析%Characteristics and thermodynamics analysis of oxyacetylene flame brazing joint of Cu/Al tubes

    Institute of Scientific and Technical Information of China (English)

    罗键; 赵国际; 王向杰; 孙玉

    2011-01-01

    Entropy changes in chemical reaction of Cu/Al intermetallic compounds formation in Cu/Al oxyacetylene flame brazing are calculated, and the tendency of Cu/Al intermetallic compounds form and transform to CuAl2 is analyzed with the method of chemical thermodynamics. The microstructure and characteristics of elements distribution and diffusion of the Cu/Al oxyacetylene flame brazing joint are analyzed by XRD, SEM and EDS. Results show that, under the condition of Cu/Al oxyacetylene flame brazing, the CuAl2 intermetallic compounds formed by the direct reaction of Cu&Al atoms and the sustained reaction of Cu/Al intermetallic compounds with Al atoms. CuAl has relatively strong independent transformation trend. The results of thermodynamics analysis and calculation are consistent with the XRD of joint. Brazing joint can be divided into three feature regions: the a-Al and binary eutectic (α-Al+CuAl2) region is near Al side with the width of about 30 μm; the fine multiple eutectic structure is formed in brazing seam center near Al side with the width of about 150 μm; and the region near Cu substrate with the width of about 120 μm, where Cu diffuses largely and reacts richly with Al and massive CuAl2 is formed like corals.%通过计算Cu/Al管氧乙炔气体火焰钎焊条件下形成金属间化合物的各化学反应的熵变,对Cu/Al金属间化合物的形成及向CuAl2转化的趋势进行了化学热力学分析;结合XRD、SEM、EDS研究了Cu/Al管氧乙炔气体火焰钎焊接头组织与元素分布特征.结果表明,Cu/Al管氧乙炔气体火焰钎焊条件下,接头中脆性金属间化合物CuAl2由Cu、Al原子的直接结合和其他Cu/Al金属间化合物与Al原子的继续反应生成,其中CuAl自主转化趋势较强;热力学计算分析与接头XRD分析结果一致.钎焊接头可分为3个特征区域:靠近Al基体侧形成了宽度约30μm的α-Al与α-Al+CuAl2二元共晶区;钎缝中心偏Al基体一侧形成了宽度约150

  1. Furnace Brazing of Diamond Grinding Wheel with Ni-Cr Alloy under Vacuum Atmosphere%Ni-Cr合金真空单层钎焊金刚石砂轮

    Institute of Scientific and Technical Information of China (English)

    肖冰; 徐鸿钧; 武志斌; 徐西鹏

    2001-01-01

    单层高温钎焊超硬磨料砂轮具有传统电镀砂轮无法比拟的优异磨削性能,国内应及早研制开发应用此种砂轮。本文利用真空炉中钎焊的方法,用Ni-Cr合金钎料,适当控制钎焊温度、保温时间和冷却速度,实现了金刚石与钢基体间的高强度连接。扫描电镜X射线能谱,结合金相及试样逐层的X射线结构分析,剖析了Ni-Cr合金与金刚石和钢基体钎焊界面的微区组织结构;揭示了Ni-Cr合金对金刚石和钢基体表面的浸润和钎焊机理。即在钎焊过程中会在金刚石界面形成富Cr层并与金刚石表面的C元素反应生成Cr7C3,在钢基体结合界面上Ni-Cr合金和钢基体中的元素相互扩散形成冶金结合,这是实现合金层与金刚石和钢基体都有高结合强度的主要因素。最后重负荷磨削试验表明金刚石为正常磨损,没有整颗金刚石脱落,说明金刚石确有高的把持强度。%The brazing of a monolayer diamond grinding wheel with active filler metals can show distinct advantages over conventional electroplated diamond grinding wheel in terms of faster cutting and longer life.The present study has shown that a commercially available Ni-Cr alloy can be used as an active filler material for brazing diamond grit.Furnace brazing is carried out in a current of vacuum.SEM-EDS microanalyses have shown that during brazing the chromium present in the alloy segregated preferentially to the surface of the diamond to form a chromium-rich reaction product.X-ray diffraction reveals that the wetting and bonding behaviour on diamond surface by Ni-Cr alloy melt is realized through Cr7C3 which is produced by interaction between Cr atoms of Ni-Cr alloy and C atoms of diamond surface at elevated temperatures.The analyses also indicate that the bond between the alloy and the steel substrate is established through a cross-difusion of iron and chromium.Finally,a grinding test shows that the wear modes

  2. 不锈钢真空钎焊管板连接微观特征及残余应力有限元分析%Microstructure Characteristics and Finite Element Analysis for Welding Residual Stress of Vacuum Brazed of Stainless Steel Tube Sheet Joint

    Institute of Scientific and Technical Information of China (English)

    吕彪; 熊缨

    2011-01-01

    采用拉伸试验机对304不锈钢管板结构真空钎焊强度进行了试验,运用金相和EDS方法分析了钎焊接头的微观组织特征.运用有限元ANSYS软件对微小尺寸不锈钢管板结构在真空钎焊过程中产生的残余应力进行了模拟.结果表明,应力集中出现在管板连接钎焊接头处,有限元分析获得了该处的残余应力分布规律.%The intensity of vacuum brazed of 304 stainless steel tube sheet structure has been tested with the tensile testing machine. This paper presented the microstructure characters of brazed joint with metallographic analysis and EDS analysis,studied the residual stress of vacuum brazed of the small size stainless steel tube sheet structure with finite element software ANSYS. The experimental results show that the stress concentration occurs at the joint of the brazed tube sheet, finite element analysis obtains the distribution of the residual stress. [ Ch,7 fig. 4 tab. 10 ref.

  3. 镁/镀锌钢异种合金单、双光束激光熔钎焊特性%Single and dual beam laser welding-brazing characteristics of magnesium/zinc-coated steel dissimilar alloys

    Institute of Scientific and Technical Information of China (English)

    檀财旺; 梅长兴; 李俐群; 戴景民; 郭伟

    2012-01-01

    以镁焊丝为填充材料,对镁/镀锌钢异种合金进行单、双光束激光熔钎焊试验研究,分析不同工艺参数对焊缝成形的影响规律,获得不同热源作用方式下的界面形态规律及其对界面强度的影响.结果表明:采用单、双光束进行填丝熔钎焊均可获得较满意的外观成形:单光束容易存在未钎合现象,焊接过程不够稳定,而双光束具有更好的温度分布,容易提高润湿铺展能力.剪切强度测试结果表明,单、双光束最大的接头效率分别达到30.9%和42.4%,焊趾处裂纹的存在是导致接头失效的主要原因.%The single and dual laser welding-brazing of AZ31 Mg alloy to DP980 galvanized steel was conducted with Mg filler wire. The effect of different parameters on the weld appearance was analyzed. Moreover, the interfacial pattern under different heat sources and its influence on the interfacial strength were obtained. The results indicate that good weld appearance can be achieved using both single and dual laser beam welding-brazing as filler wire. It tends to produce the lack of fusion defect by single-beam welding and the welding process is unstable. The dual-beam welding has much more uniform temperature distribution, so, the spreading-wetting ability is better than the former. The shear test results show that the highest joint efficiency of single-beam and dual-beam welding are 30.9% and 42.4%, respectively. The crack produced at the toe of weld after laser welding-brazing is the main reason for joint failure.

  4. 保温时间对Mg/Cu共晶反应钎焊连接的影响%Effects of Holding Time on Eutectic Contacting Reaction Brazing of Mg/Cu

    Institute of Scientific and Technical Information of China (English)

    王怀建; 白莉

    2012-01-01

    Magnesium alloy and copper were bonded by eutectic contacting reaction brazing, and the effects of holding time on the microstructure and tensile properties were studied. The results from the experiment show that when the welding process is 500℃ keeping for 30 min, welding pressure is 2MPa, the tensile strength can reach 54MPa.%采用共晶钎焊工艺对Mg/Cu异种材料进行连接,研究了不同保温时间对接头微观组织及力学性能的影响.结果表明,在焊接温度为500℃、保温时间为30 min、焊接压力为2MPa的工艺下,焊接接头最高抗拉强度为54 MPa.

  5. Wetting evaluation of silver based braze alloys onto zirconia metalized with reactive elements for application in oil well drill bots; Avaliacao do molhamento de ligas de adicao a base de prata sobre zirconia polida e metalizada com elementos ativos para aplicacao em brocas de perfuracao de pocos de petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, J.C.; Silva, J.M.; Santos, P.R.F.; Nascimento, R.M.; Martinelli, A.E. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil). Dept. de Engenharia de Materiais], Email: jocabuzo@gmail.com; Pimenta, J.S. [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil). Dept. de Engenharia Mecanica

    2010-07-01

    Drill bits with hard ceramic inserts are often used on drilling operations. The cutting and crushing action of rocks will produce failures in the tricone bits, which are related to wear; total or partial rupture of the drill bit body or even the inserts; thermal shock and corrosion. The research of better drill bits with ceramic inserts thermally more stable and mechanically stronger, will lead to an increase of their lifetime, and so reducing costs of substitution and maintenance. In the present work, some silver based braze alloys were melted onto zirconia YSZ substrates metallized or not with active metals. inside a furnace with vacuum of 10{sup -5} mbar to evaluate the wetting behavior. The system with AgCuTi and the non metallized YSZ ceramic, showed low contact angles and stable interfaces, which may be appropriate for brazing metal/ceramic parts. (author)

  6. Study on Influence Factors of Transient Behavior of Laser Brazing Weld Pool of Beryllium%铍材钎焊熔池动态行为的影响因素研究

    Institute of Scientific and Technical Information of China (English)

    史平安; 赵朋成; 莫军; 武传松; 郝志明

    2011-01-01

    With considering the geometry characteristic of laser brazing and analyzing the action features of heat source in laser brazing, a transient three-dimensional model of laser welding-brazing weld pool for beryllium is established on the basis of theories of fluid dynamics and heat transfer, in which a composite heat source constituted by double-ellipsoidal area heat source and Rotary-Gaussian body heat source along the z-direction is used to describe the heat flux source of a moving laser. Many factors are considered in the model including the convective heat transfer of liquid metal, solid heat conduction of workpiece outside the weld pool, latent heat in welding process, side assist gas orientation, the structure and properties of bonding interface, material thermo-physical properties as the function of temperature and so on. The program to simulate the transient variations of temperature field and flow field in laser brazing weld pool is developed by using Fortran language, and the effects of latent heat, the pattern of side assist gas and butt gap on fluid flow and heat transfer of weld pool are studied. The results show that the effects of the latent heat of phase change are not always negligible. In particular, the influence of the latent heat is more violent under moving laser beam action than under stationary laser beam. The gas flow rate and direction has an important effect on flow style and shape of weld pool, and the selection of side assist gas orientation can enhance the stability of laser brazing process and increase the depth of weld pool. The existence of gap makes the temperature field uneven and it is the decisive reason that the shape of weld pool looks like a nailhead. If the gap is taken into account, the shape of weld pool obtained from calculation will be in better agreement with the test result.%在综合分析激光钎焊的焊缝形状特征和热源作用特点的基础上,根据流体力学和传热学原理,建立瞬态熔池三维数

  7. Multiple-unit implant frames: one-piece casting vs. laser welding and brazing Sobre estruturas de implantes múltiplos: fundição em monobloco versus soldagem a laser e brasagem

    Directory of Open Access Journals (Sweden)

    Elza Maria Valadares da Costa

    2004-09-01

    Full Text Available The linear distortion of prostheses over implants, one-piece casting and cast in sections followed by laser welding by laser and brazing was evaluated in an edentulous mandibular model with five parallel abutments, with a distance of 10mm from center to center. Seventy five gold cylinders were tightened with screws on the abutments with 10Ncm torque. The cylinder/analogue assemblies were measured by microscopic examination (0.001mm accuracy and the obtained results were compared with the GC (control group. Fifteen metal frames were waxed and cast in a gold alloy (Stabilor, Degussa Hulls, Brazil and divided into three groups with five elements each, as followed: GM (one-piece casting, GB (section and brazing and GL (section and laser welding. In all groups, measurements were taken at the right, left, buccal and lingual sides of the cylinder/analogue interface and the results were submitted to analysis of variance (ANOVA and to the Tukey test (5%. The smallest amount of distortion was seen in the laser group (GL with a mean value of 13.58, followed by the brazing group (GB with a mean value of 24.33 and one-piece (GM with a mean value of 40.00. The greatest distortion was found in the one-piece group (GM.A distorção linear das próteses sobre implantes, fundidas em monobloco e fundidas em secções e soldadas a laser e por brasagem foi avaliada em um modelo de uma mandíbula edêntula com cinco análogos de pilares de implantes, paralelos entre si com distância de 10mm medidos de centro a centro. Sobre estes foram parafusados novos cilindros de ouro, com torque de 10N/cm. Então foram executadas 15 sobre-estruturas metálicas que foram divididas: GC - Adaptação passiva dos cilindros de ouro; GM - monobloco, GB - segmentos soldados por brasagem e, GL - segmentos soldados a laser. Observaram-se as estruturas fixadas com parafusos novos sob microscópio de mensuração. A medição foi realizada na vestibular direita e esquerda e da mesma forma

  8. MIG Arc Brazing of Dissimilar Metals between Pure Aluminum and Zinc-Coated Steel%纯铝与镀锌钢板MIG熔-钎焊工艺研究

    Institute of Scientific and Technical Information of China (English)

    国旭明; 汪建梅; 徐荣正

    2013-01-01

    MIG arc brazing of dissimilar metals between pure aluminum and zinc-coated steel in a lap joint was investigated using Al-Mg,Al-Si filler wires.The interface structure and the mechanical properties of the fusion-brazing joint were characterized.The results show that the high quality welded joint is successfully achieved with Al-Mg,Al-Si filler wire in the suitable welding parameters.The intermetallic compound layer (IMC) is composed of θ-Al3Fe,η-Al5Fe2 and AlFeSi phases by using Al-Si filler wire.It is thinner and denser than that obtained by using Al-Mg filler wire.The growth of IMC layer is suppressed due to the addition of Si element.The shear strength of welded joint nearly reaches that of pure aluminum.The cracking position occurs in weld zone.%采用Al-Mg,Al-Si两种填充焊丝,研究了纯铝与镀锌钢板异种金属材料的MIG熔-钎焊工艺,分析了焊接接头的界面结构特征及其力学性能.研究结果表明:在合适的焊接参数下,选用两种填充焊丝可以实现纯铝板(1060)与镀锌钢板的MIG熔-钎焊.与添加Al-Mg焊丝相比,填充Al-Si焊丝,界面反应层由θ-Al3 Fe,η-Al5 Fe2和AlFeSi相组成,且反应层较薄,焊缝中加入Si元素有效地抑制了金属间化合物层的生长,此时所获得的拉剪强度较大,接近纯铝板(1060)的抗拉强度,接头断裂发生在焊缝位置.

  9. 1Cr18Ni9Ti/6A02 Dissimilar Metal Braze Welding Head Structure Analysis%1Cr18Ni9Ti/6A02异种金属钎焊接头结构分析

    Institute of Scientific and Technical Information of China (English)

    孙秀京; 马广超; 马丽翠; 孔兆财; 范波; 柳玲; 陈志凯

    2014-01-01

    The morphology and the microstruc-ture of 1Cr18Ni9Ti stainless steel and 6A02 aluminum alloy dissimilar metal joints obtained by the crucible fur-nace brazing process are analysis in this paper. The macro morphology and the microstructure characteristics of the joints were expounded through metallographic examina-tion;Scanning electron microscopy is used to observe the microstructure and measure the energy spectrum, thus the steel/aluminum dissimilar metal interface layer structure is further analyzed, and the typical defect of the joint is de-scribed and analyzed.%本文针对采用坩锅炉钎焊工艺获得的1Cr18Ni9Ti不锈钢与6A02铝合金异种金属钎焊接头进行了接头形貌及微观组织分析。通过金相检查的方法阐述了接头宏观形貌及界面组织特点;使用扫描电镜进行了高倍组织观察及能谱测量,从而进一步分析了钢/铝异种金属界面层结构,并对接头典型缺陷进行了描述和分析。

  10. Mg/Cu共晶反应钎焊微观组织及力学特性分析%Microstructure and properties of welded joints of Mg/Cu by eutectic reaction brazing

    Institute of Scientific and Technical Information of China (English)

    王怀建; 白莉

    2013-01-01

    Magnesium alloy (AZ31B) and copper (T2) were bonded by eutectic reaction brazing technology, and effects of temperature on microstructures, tensile properties were studied. The microstructures of joints were investigated using scanning electron microscopy (SEM). And tensile strength test was performed on universal tensile testing machine. Results from the experiment show that when the welding temperature is 500 °C , its tensile strength can reach the maximum of 54 MPa, and the joint shows. brittle fracture.%采用共晶反应钎焊连接工艺对Mg/Cu异种材料进行连接,研究不同温度对接头微观组织及力学特性的影响.采用扫描电镜对焊接接头的微观组织进行研究,采用拉伸试验机研究接头的力学特性.研究表明:在焊接温度为500℃,焊接接头强度最高,最高抗拉强度为54 MPa,断口呈现脆性断裂特性.

  11. 单层钎焊CBN成型砂轮磨削钛合金的温度研究%Temperature research of profile grinding on titanium alloy by monolayer brazed CBN forming grinding wheels

    Institute of Scientific and Technical Information of China (English)

    白永明; 童圣亭

    2014-01-01

    Because of its special properties , titanium alloy has been widely used in the aerospace field , but how to efficiently process is a difficult problem in current research .Designed a monolayer brazing CBN forming grinding wheel , and using it in straight groove grinding of titanium alloy TC 4 material .Through a series of temperature tests by different grinding conditions ,stud-ying the grinding characteristics of the wheel in grinding TC 4 titanium alloy materials .%钛合金因其具备的特殊性能而使其在航空航天领域得到了广泛的应用,但是钛合金的高效加工一直是当前研究的难点。设计一种单层钎焊CBN成型砂轮,用于TC4钛合金材料的直槽磨削加工。通过开展一系列不同磨削条件下的温度试验,研究所设计的砂轮磨削TC4钛合金材料的磨削性能。

  12. 钛合金喷注器扩散钎焊失效分析与改进研究%Failure analysis and improvement on diffusion brazing of titanium alloy injector

    Institute of Scientific and Technical Information of China (English)

    刘彦杰; 杨俊; 吴建军; 刘涛; 朱铭德

    2012-01-01

    Because the diffusion brazing invalidation of the titanium alloy injector occurred in an engine hot test, an improvement research of the injector welding configuration and parameters was performed based on the failure analysis by scanning electron micrograph, metallographic analysis and XPS methods. The results of simulation and test show that intensity and consistency of the improved diffusion welding are evidently enhanced.%某次试车中发动机喷注器出现扩散钎焊失效故障,根据失效焊缝的扫描电镜断口观察、X射线光电子能谱和金相分析结果对喷注器焊接结构、工艺参数等进行了改进研究。仿真、试件试验和热试车结果表明,改进后喷注器扩散钎焊强度和一致性明显提高。

  13. Study of No Corrosion Aluminum Fluxes on Brazing Aluminum Heat Exchanger%钎焊铝制热交换器用无腐蚀铝钎剂的研究

    Institute of Scientific and Technical Information of China (English)

    刘宏江; 曾燕; 蔡志红; 蔡沛沛; 贺军四; 胡泽宇; 李世婕; 黄烨

    2014-01-01

    Based on the AlF3 -KF eutectic compound fluxes, under the circumstances of not changing the non-corrosive nature, by adding additives, the eutectic compound fluxes are modified. By adding inorganic additives, the abilities of removing the oxide film and solderability are improved;And through adding organic additives, the settling property in water is improved, the purpose of efficient use in brazing aluminum heat exchanger is achieved.%以AlF3-KF共晶化合物钎剂为基础,在不改变其无腐蚀性质的情况下,通过添加助剂,对其进行改性。添加无机助剂,提高了钎剂的去膜能力和助焊性;添加有机助剂,提高了钎剂在水中的抗沉降性能,从而达到能高效应用于钎焊铝制热交换器的目的。

  14. Brasagem da zircônia metalizada com titânio à liga Ti-6Al-4V Brazing of metalized zirconia with titanium to Ti-6Al-4V alloy

    Directory of Open Access Journals (Sweden)

    J. S. Pimenta

    2012-06-01

    Full Text Available Zircônia tetragonal estabilizada com ítria foi mecanicamente metalizada com titânio e a condição de molhamento avaliada com as ligas convencionais Ag-28Cu e Au-18Ni. Estas dissolveram o revestimento de titânio para uma completa distribuição deste metal ativo na superfície cerâmica, gerando uma liga ativa in situ e possibilitando adequadas ligações químicas ao metal base na temperatura de união. Os melhores resultados de molhamento foram selecionados para brasagem indireta em forno de alto-vácuo nas juntas ZrO2/Ti-6Al-4V. Testes de detecção de vazamento de gás hélio foram realizados na interface de união das juntas; amostras removidas na seção transversal de juntas estanques foram examinadas por técnicas de análise microestrutural. Formou-se uma camada escura adjacente à cerâmica metalizada, responsável pelo molhamento ocasionado pela liga Ag-28Cu. Entretanto, o uso da liga Au-18Ni resultou em precipitação de intermetálicos e microtrincamento interfacial. Perfis de microdureza através da interface resultante até onde a zircônia mostrou típico escurecimento não indicaram alternância significativa entre medições consecutivas; os resultados dos ensaios de resistência mecânica à flexão-3p foram considerados satisfatórios.Yttria tetragonal zirconia polycrystal was mechanically metallized with titanium and the wetting behavior on the ceramic surface was analyzed using the conventional fillers Ag-28Cu and Au-18Ni. These alloys had dissolved the active metal coating, which acts to zirconia reduction on its surface and promoting suitable chemical bonding to the metallic member. Better wetting results were selected for indirect brazing in a high-vacuum furnace for ZrO2/Ti-6Al-4V simple butt joints. Helium gas leak detection was made at the joints interface; samples were removed from the tight joints cross-section and examined by microstructural analysis techniques and EDX analysis. There was formation of a dark

  15. Fluxless Joining between Aluminium Alloy and Galvanized Steel by Fiber Laser Fusion Welding-Brazing with Filler Powder%铝/钢异种金属无钎剂激光填粉熔钎焊接

    Institute of Scientific and Technical Information of China (English)

    赵旭东; 肖荣诗

    2012-01-01

    The fluxless fusion welding-brazing result between 6061 aluminum alloy and galvanized steel with filler material is studied by using rectangular laser beam. The dependence of the mechanical properties on solidification behavior is established based on the joint formation and the weld microstructure. The results indicate that a fusion welding-brazing weld of AA6061 and galvanized steel without flux can be achieved using the welding with filler powder. By optimizing the welding parameters, the favorable weld without crack and porosity can be achieved. The weld width and the thickness of intermetallic compounds layer increase with laser energy input increasing. The intermetallic in the weld is composed of Al-Fe and Al-Fe-Si system phases. Specimens are fractured at the weld/steel interface with the brittle characteristic during tensile test. The weakness of the joint is the weld interface. The maximum intensity of 152. 5 N/mm is obtained. Al6Fe2Zn0.4 and α-Al are found in the fracture surface on the aluminum side. The intensity of joint is both determined by weld width and the thickness of intermetallic compound layer.%采用宽带激光光斑和填粉焊接技术,在不使用钎剂的情况下进行6061铝合金/镀锌钢板的熔钎焊接实验.分析测试了接头成形、焊缝组织和接头强度,并探讨了影响接头强度的因素.结果表明,采用此方法可实现6061铝合金/镀锌钢板的熔钎焊连接.选用优化的焊接工艺参数获得了成形饱满,无裂纹、气孔等缺陷的焊缝.焊缝熔宽和金属间化合物层厚度随焊接热输入量的增加而增大.熔钎焊缝中金属间化合物由AFFe和Al-Fe-Si系统化合物组成.拉伸试样均断裂在钎料/镀锌钢界面,接头最大机械抗力为152.5 N/mm,断口呈脆性断裂特征,钎料/镀锌钢界面为接头的薄弱环节.拉伸试样铝一侧断裂面由Al5 Fe2 Zno.4和α-Al组成.焊缝熔宽、金属间化合物层厚度共同决定了接头的机械抗力水平.

  16. 金刚石/铜基钎料粉末注射成型工艺参数的优化%Optimization of Parameters in Diamonds/Copper Based Brazing Filler Metal Powders Injection Molding Process

    Institute of Scientific and Technical Information of China (English)

    伍俏平; 邓朝晖; 潘占; 张荣辉; 张正

    2012-01-01

    通过正交试验对金刚石/铜基钎料粉末小型薄壁件的注射成型工艺参数进行了优化。结果表明:当模具温度为40℃,注射压力为12MPa,注射温度为150℃,注射流量为20cm^3·S^-1,为最佳工艺参数组合,能获得表面光整、组织均匀的注射生坯;随着注射压力的增大,注射生坯密度增大;注射温度升高,生坯密度降低;注射流量增大,生坯密度先升后降。%Optimization of parameters in the injection molding process of diamonds/copper based brazing niter metal powders was investigated by orthogonal experiments. Results indicate that the optimized combination of parameters was given as following: the mould temperature was 40 ℃; injection pressure was 12 MPa; injection temperature was 150 ℃ and injection flow rate was 20 cm^3 . s 1. And a molded specimen with a smooth surface, uniform microstructure could be achieved under the optimized condition. The density of molded specimens increased with increase of injection pressure, but decreased with increase of injection temperature, and the density increased first and decreased afterwards when the iniection flow rate increased.

  17. Experimental Investigation on Induction Brazing of Monolayer Diamond Grinding Wheel with Ni-CrAlloy under vacuum Atmosphere%真空感应钎焊单层金刚石砂轮的实验研究

    Institute of Scientific and Technical Information of China (English)

    武志斌; 肖冰; 徐鸿钧

    2001-01-01

    An experimental investigation is made on induction brazing ofmonolayer diamond grinding wheel with Ni-Cr alloy as solder under vacuum atmosphere.As a result,the strong bonding between diamond and steel is obtained,while the filled intermediate layer material is reactive Ni-Cr alloy slice.With the observation by scanning microscope,the composition analysis by X-ray energy spectrum and the structure analysis by X-ray diffractometer,it is shown that it is the continuous stable chromium carbide film formed on the interface between the diamond and the filled intermediate layer,and the (FexCry) C layer on the interface between steel surface and the filled intermediate layer that cause the better bonding strength.Finally,a grinding test proves the correctness of the investigation result.%在真空条件下用Ni-Cr合金做钎料进行了钎焊单层金刚石砂轮的实验研究,实现了金刚石与钢基体间的牢固化学冶金结合。通过扫描电镜X射线能谱,结合X射线衍射结构分析,发现Ni-Cr合金中的Cr原子与金刚石表面的碳原子反应生成稳定连续的Cr3C2膜,在钢基体结合界面上生成(FexCry)C,这是实现合金层与金刚石及钢基体之间都有较高结合强度的主要因素。通过磨削实验验证了金刚石确实有较高的把持强度。

  18. How braze flaws affect the thermal-hydraulic performance of the Tore Supra Phase-III outboard pump limiter. A case study of the effects of nonuniform thermal resistance on the peak heat flux to the coolant for tubes with one-sided heating

    International Nuclear Information System (INIS)

    The phase-III Outboard Pump Limiter is a heat sink made of pyrolytic graphite armor brazed to water-cooled copper tubes. Around the inner wall of the tube wall, some of the water can be in the subcooled boiling regime. The central issue analyzed here is how the heat flow in the tube changes when the thermal resistance along the heated portion of the tube is redistributed. Cracks or braze flaws in the joint between the tile and tube cause this redistribution. Severe cracks or flaws reduce the power-handling capability of this assembly because the local peak heat fluxes increase and, for a given critical heat flux (CHF), the safety margin decreases. There were some surprises. The increase in local peak heat flux for the most common type of flaw encountered in the fabrication of this limiter was negligible up to a flaw size of nearly 50%. The examples presented are intended as a case study that illuminates the more general problem of how correlations for heat transfer and for CHF developed for uniform circumferential heating are applied to a case of one-sided heating. 17 refs., 19 figs., 1 tab

  19. 防锈铝板/镀锌钢板异种金属冷金属过渡熔钎焊接头的组织与抗拉强度%Microstructure and Tensile Strength of Rust-Proof Aluminum Plate and Zinc-Coated Steel Plates Braze-Weld Joint Prepared by Cold Metal Transfer

    Institute of Scientific and Technical Information of China (English)

    冯曰海; 王克鸿; 高飞; 杜刚

    2013-01-01

    The cold metal transfer (CMT) brazing-welding process was used to weld dissimilar metals of LF21 rust-proof aluminum plate and DD51D+Z zinc-coated steel plate,and the microstructure and tensile strength of the joint were studied.The results show that the compound layer of middle interface zone of the braze-weld joint was intermetallic compound FeAla with thickness of 4-6 μm.The average transverse tensile strength of the joint was up to 77 MPa and strength coefficient was 0.6.%采用冷金属过渡(CMT)熔钎焊接工艺,对LF21防锈铝板和DD51D+Z镀锌钢板进行了异种金属的连接,对接头的显微组织和抗拉强度进行了研究.结果表明:防锈铝板和镀锌钢板的熔钎焊接头的中间界面区化合物为4~6 μm厚的FeAl3金属间化合物,接头的平均横向抗拉强度为77MPa,接头的强度系数为0.6.

  20. Laser welding-brazing and numerical simulation of zinc-coated steel and 6016 aluminum alloy%镀Zn钢-6016铝合金异种金属的激光熔钎焊及数值模拟

    Institute of Scientific and Technical Information of China (English)

    周惦武; 吴平; 彭利; 张屹; 陈根余

    2012-01-01

    熔钎焊是抑制或减少钢/铝异种金属激光焊接过程中FeAl脆性金属间化合物产生的有效工艺方法.采用光纤激光器,不添加任何钎料,对1.2 mm厚DC56D+ZF镀锌钢和6016铝合金平板试件进行激光搭接焊试验,利用MATLAB软件,针对焊接过程的实际情况,在一定的基本假设下建立准稳态下钢/铝异种金属激光焊接熔池形状的数学模型,基于准稳态形状控制方程数值计算获得的熔池几何形状分布,结合试验来调整焊接工艺参数,获得最佳焊接成形,利用卧式金相显微镜、扫描电镜和X射线衍射仪等手段研究焊接接头各区域的金相组织、主要元素分布与物相组成.结果表明:焊接激光束照射搭接在钢板上的铝板对接焊缝时,焊接功率和焊接速度对熔池几何形状的影响较大,随着激光功率的增大,熔深增加;而随着焊接速度的增加,熔深却变浅.当焊接功率为1 600~1 800W、焊接速度v=30 mm/s、离焦量D=0 mm时,焊缝成形性良好,无明显裂纹、气孔等缺陷,焊接接头区域存在一个台阶状结构,在平台区域,钢/铝两钟金属存在明显的界限,界面结合依靠液态的铝在钢母材表面上的润湿、填充和铺展等作用;下凹区域,钢/铝熔合较好,Fe和Al元素的混合区宽度较大,未形成明显的FeAl脆性金属间化合物,Fe和Al的热扩散是该区域界面结合的主要原因.%The laser welding-brazing is an effective process to inhibit or reduce FeAl brittle intermetallic compound produced during laser welding-brazing of steel and aluminum alloy. The laser lap welding test was carried out based on the DC56D+ZF galvanized steel with thickness of 1.2 mm and the 6016 aluminum alloy with the fiber laser. The Matlab software was used, according to the actual situation of welding process, the steel and aluminum dissimilar metal laser welding pool shapes of the mathematical model in the flight quasi-steady state was established under

  1. MICROSTRUCTURE ANALYSIS OF INTERFACIAL LAYER WITH TUNGSTEN INERT GAS WELDING-BRAZING JOINT OF ALUMINUM ALLOY/STAINLESS STEEL%铝合金/不锈钢钨极氩弧熔-钎焊接头界面层的微观结构分析

    Institute of Scientific and Technical Information of China (English)

    林三宝; 宋建岭; 杨春利; 马广超

    2009-01-01

    Against the background of the required weight reduction in transportation through lightweight construction, the application of hybrid structures, where aluminum alloy and steel are jointed together, has a high technical and economical potential. But jointing of material combinations of aluminum alloy and steel is problematic by fusion welding since brittle intermetallic compounds (IMCs) are formed between aluminum alloy and steel. Nowadays, tungsten inert gas (TIG) welding-brazing offers a great potential for aluminum alloy and steel jointing. In this process, the sheet and filler metal are heated or melted by TIG heat, and the joint has a dual characteristic: in aluminum alloy side it is a welding joint, while in steel side it is a brazing joint. However, in the dynamic heating process, the heating temperature changes so quickly and the reaction time between the liquid filler metal and solid steel is so short that it is more difficult to control the IMC layer's growth, predominantly its thickness and microstructures. Most of past reports about the brazing of aluminum alloy and steel indicate Al-Fe binary IMC layers, e.g., Fe_2Al_5 and FeAl_3, formed in the brazing joint, which are detrimental to the mechanical properties of the joint. Si additions are used to limit the growth of the brittle Al-Fe IMC layer between aluminum alloy and steel by replacing Al-Fe phases with less detrimental Al-Fe-Si phases in aluminizing and furnace brazing of aluminum alloy and steel. By now, there have been few reports of investigating the interfacial layer of TIG welding-brazing joint of aluminum alloy and stainless steel. In this paper, a butt TIG welding-brazing joint of aluminum alloy/stainless steel was formed using Al-Si eutectic filler wire with modified Noclock flux precoated on a steel surface. The microstructure characteristics of the welded seam-steel interfacial layer were analyzed by OM, SEM and EDS and its mechanical properties were measured by dynamic ultra

  2. Effect of grit spacing on hole diameter precision and hole wall roughness of CFRP laminate drilled with brazed diamond core drill%钎焊金刚石套料钻磨粒间距对碳纤维增强树脂基复合材料(CFRP)制孔直径和孔壁粗糙度的影响

    Institute of Scientific and Technical Information of China (English)

    王伟锋; 陈燕; 徐九华; 牟娟

    2012-01-01

    Carbon fiber reinforced plastics ( CFRP) laminate was drilled with brazed diamond core drill under no cooling condition. The effect of grit spacing of diamond on hole diameter precision and hole wall roughness in drilling CFRP at different feed speed was studied. A heat affected simulation model of CFRP hole diameter drilled with brazed diamond core drill was established. The results indicated that expanding factor oi hole diameter decreased with the increase of grit spacing and feed speed, and grit spacing had a relatively larger effect on expanding factor. The surface roughness of hole wall increased with the increase of grit spacing and feed speed. When grit spacing of brazed diamond core drill was 1. 6 mm and feed speed was 150 mm/min, the hole quality of CFRP laminate was perfect.%在无冷却润滑条件下,采用钎焊金刚石套料钻对CFRP层合板进行钻削加工试验,研究了不同进给速度条件下钎焊金刚石套料钻的磨粒间距对CFRP层合板制孔直径精度和孔壁粗糙度的影响,建立了钎焊金刚石套料钻钻削CFRP的温度场仿真模型.研究结果表明:制孔直径的扩孔因子随着磨粒间距和进给速度的增加而减小,磨粒间距对扩孔因子的影响程度较大;孔壁相同位置处的粗糙度随着磨粒间距和进给速度的增加而增加;采用磨粒间距为1.6 mm的80/100金刚石磨粒的套料钻,在进给速度为150mm/min时钻削CFRP层合板制孔效果好.

  3. 铝/镀锌钢薄板异种金属CMT熔钎焊接头组织与力学性能%Microstructure and Mechanical Properties of CMT Welding-brazing Joint for Dissimilar Materials between Aluminums and Galvanized Steels

    Institute of Scientific and Technical Information of China (English)

    余刚; 曹睿; 陈剑虹

    2012-01-01

    The dissimilar materials, aluminum alloys and galvanized steels were joined by CMT welding -brazing method. Analyzing the macro feature of cross -section, microstructure, the defects and mechanical properties of welding-brazing joints with SEM, EDAX, tension text, it is shown that the lap joints with better properties and better weld appearance are formed between the aluminum alloys and galvanized steels. From the microstructure and formation of weld metal, the cross-section of the joint can be divided into four zones; weld metal, middle interface, transitional interface and zinc - rich zone. There is a continuous and compact inter -metallic compound layers with a thickness of 3~4μm, which is formed in the brazing interface zone between the weld metal and the galvanized steel sheet. The main components of the layer are Fe3 Al, FeAl2, Fe2 Al5 and FeAl3,then, the zinc-rich zone is mainly composed of aluminum -rich solid solution and residue of Zn. Tensile strength tests show that the joint is fractured in the aluminum heat affect zone, and the joint strength with 204MPa is obtained.%采用冷金属过渡方法对铝合金和镀锌钢板进行了熔钎焊连接,使用扫描电镜、能谱分析和拉伸试验分析了接头的截面形貌、组织特征、焊接缺陷及力学性能.试验结果表明,铝合金和镀锌钢能得到成形美观、性能良好的搭接接头.对焊缝金属的组织特征分析表明,焊接接头由熔化区、中心界面区、过渡界面区和富锌区组成,在焊缝金属和镀锌板的界面区形成厚度为3~4μm的金属间化合物层(主要成分为Fe3Al、FeAl2、Fe2Al5和FeAl3),富锌区由富铝的固溶体和残留的锌组成.在进行拉伸试验时,断裂发生在热影响区,接头强度为204MPa.

  4. AZ31B镁合金/不锈钢异种合金双光束激光熔钎焊接特性%Welding Characteristics of AZ31B Magnesium Alloy/Stainless Steel Dissimilar Alloys by Dual Beam Laser Welding-Brazing Process

    Institute of Scientific and Technical Information of China (English)

    李俐群; 郭伟; 檀财旺

    2012-01-01

    以镁基焊丝为填充材料,采用双光束激光熔钎焊的方法对AZ31B镁合金/不锈钢的焊接特性进行了研究.分析了不同工艺参数对焊缝成形、接头力学性能和断裂行为的影响.结果表明,采用双光束进行填丝熔钎焊能够获得较满意的外观成形,无明显缺陷,焊接工艺范围较宽.接头拉伸均断裂于熔化焊的镁侧焊缝及热影响区(HAZ),最大剪切强度为193 MPa,达到镁合金母材强度的71%.组织分析发现焊缝和HAZ的晶粒粗大,成为接头的薄弱部位,是接头失效的主要原因.钎焊侧界面发生了冶金反应,界面处生成1~2 μm的反应层.%AZ31B magnesium alloys and 201 stainless steel are joined by laser welding-brazing process with Mg based filler. The welding characteristics including influence of processing parameters on weld appearance, mechanical properties and fracture behavior are studied- Results indicate that satisfactory appearance of welds without evident defects can be achieved by dual beam laser-brazing process with filler. A wide processing window is obtained. The tensile-shear test shows that fracture occurred at two places, weld seam and heat affect zone (HAZ) at the welding side of Mg alloys. The maximum shear strength can reach 193 Mpa, which is 71% of that of Mg base metal. The microstructure observed indicates that seam and HAZ are weak parts, which results in failure of joint due to presence of coarse grains. Metallurgical reaction occurs at the brazing side, where reaction layer with thickness of 1~2 μm forms.

  5. 超声时间和预留间隙对超声波辅助钎焊镁合金钎料填缝性能的影响%Influence of ultrasonic time and pre-clearance on gap-filling behavior of filler metal during ultrasonic-assisted brazing of magnesium alloy

    Institute of Scientific and Technical Information of China (English)

    李红; 耿园月; 闫久春; 栗卓新

    2013-01-01

    In order to investigate the influence of ultrasonic on flow behavior of filler metal when the filler metal propagates on the solid/liquid surface in brazing process, the gap-filling behavior of the molten filler metal during ultrasonic-assisted brazing of magnesium alloy was in-situ observed by high-speed video camera. Besides, the gap-filling behavior in unparalleled gaps and brazed joint properties were investigated. When the filler metal fills the gap in the direction parallel to the ultrasonic energy propagation, the dynamic curve of filling-gap distance appears linear relation with the ultrasonic time. And it shows that at the same ultrasonic time, good pre-clearance results in low filling velocity. Along the filler flow direction, the thickness of brazed joint decreases gradually. The filling-gap distance decreases as ultrasonic time increases when filler metal is placed at large gap side. The compactness of the joint is general. The filling-gap distance increases firstly and then decreases with the ultrasonic time increasing when the filler metal is placed at small gap side. In this case, the defects appear in the whole joint. The analysis indicates that the flow behavior of filler metal in unparalleled clearance is influenced by the combined effect of ultrasonic induced gap-filling action and capillary action.%采用高速摄影对超声波辅助钎焊镁合金过程熔态钎料的填缝行为进行了实时观察,并研究了不等间隙中钎料的填缝行为及接头性能.结果表明,超声波在钎焊固/液界面传播对钎料填缝行为有显著的影响.钎料在平行于超声波能量传播方向上填缝,填缝长度和超声时间的动力学曲线呈直线型.超声时间相同时,预留间隙越大,钎料的填缝速度越低.在大间隙端加钎料,随超声时间增加,填缝长度减小,钎缝致密性较好;小间隙端加钎料,随超声时间增加,填缝长度先增大后减小,整个钎缝均存在缺陷.认为钎料在不等

  6. Characteristics of precoating TIG welding-brazing joint of aluminum alloy to stainless steel%铝合金/不锈钢预涂层钨极氩弧熔钎焊接头的特性

    Institute of Scientific and Technical Information of China (English)

    宋建岭; 林三宝; 杨春利; 马广超

    2009-01-01

    通过在不锈钢表面预涂钎剂层,采用铝硅共晶钎料实现铝合金/不锈钢TIG熔钎焊连接,获得具有熔焊与钎焊双重性质的对接接头,运用OM、SEM、EDS分析接头的微观组织及成分,通过拉伸实验评定接头的力学性能.结果表明:铝母材局部熔化,与液态钎料混合后凝固形成焊缝,焊缝组织主要由α(Al)基体和在晶界析出的Al-Si共晶相组成;不锈钢不发生熔化,液态钎料与不锈钢在界面反应形成不均匀分布的金属间化合物层,最大厚度不超过10 μm,界面上部金属间化合物较厚,呈锯齿状,主要相成分为α(τ5)-Al7.4Fe2Si;界面下部金属间化合物较薄,呈细须状,由α(τ5)-Al7.4Fe2Si+α(Al)混合相构成;接头的平均抗拉强度为90.6 MPa,焊缝/不锈钢界面下部为连接的薄弱环节,成为断裂的起始位置.%Dissimilar metals TIG welding-brazing of aluminum alloy to stainless steel was conducted using Al-Si eutectic wire with precoating special flux layer on the steel surface. The microstructure characteristics of aluminum alloy/stainless steel butt joint were analyzed by OM, SEM and EDS, and the tensile strength of the joint was measured by instron-testing machine. The results show that the aluminum base material is melted and mixed with the liquid filler metal to form the welded seam, which consists of α(Al) matrix and Al-Si eutectic phases in the intergranular. The stainless steel is not melted and reacts with the melted metal to form nonuniform intermetallic compound (IMC) at the welded seam/steel interfacial layer, of which the thickness is less than 10 μm. At the upper part of the layer, the IMC is thick and presents serrated-shape and consists of α(τ5)-Al7.4Fe2Si phase, while at the lower part, the IMC is thinner than the upper part and presents thin whiskered-shape and consists of α(τ5)-Al7.4Fe2Si+α(Al) mixed phases. The average tensile strength of joints is 90.6 MPa and the fracture starts at the lower part of

  7. 石墨自润滑钎焊CBN砂轮磨削镍基高温合金温度的试验研究%Experimental study on grinding temperature of nickel-based superalloy with graphite self-lubrication brazed CBN wheel

    Institute of Scientific and Technical Information of China (English)

    黄加林; 傅玉灿; 赵立; 陈路; 陈珍珍

    2012-01-01

    Grinding comparative experiments of nickel-based superalloy GH4169 with both graphite self-lubrication brazed CBN wheel and vitrified CBN counterpart were carried out. Grinding temperatures of the workpiece surface were measured with semi-manual thermocouple method. The morphology of the grains on the surface of the wheel and the distribution of element were detected using scanning electron microscope ( SEM) and energy dispersion spectrometer (EDS). The results showed that the grinding temperature of graphite self-lubrication brazed CBN wheel was 100 ℃ lower than that of vitrified CBN wheel under the same grinding parameters. Moreover, a layer of graphite film was formed on the surface of the CBN grits after grinding, which indicated that the lubricant graphite could spread over the wheel surface during the grinding process and decreased the friction between the grinding wheel and the workpiece in contact zone, thus decreased the grinding temperature.%利用石墨自润滑钎焊CBN砂轮和陶瓷CBN砂轮进行了高温合金GH4169磨削对比试验,采用夹丝半人工热电偶方法测量工件表面磨削温度,并运用扫描电镜、能谱仪对砂轮表面磨粒的微观形貌及元素分布情况进行分析.结果表明:在相同磨削条件下,多层自润滑钎焊CBN砂轮磨削GH4169高温合金的磨削温度比陶瓷结合剂CBN砂轮低100℃左右;砂轮表层的磨粒表面形成一层石墨薄膜,有助于减小摩擦,从而降低磨削温度.

  8. Step brazing a multi-target TRAX

    International Nuclear Information System (INIS)

    Fabrication of a target holder for a multi-target transmission anode x-ray tube (TRAX) involved joining of five different materials. The TRAX will generate a nearly mono-energetic x-ray beam useful for instrument calibration and dosimetry studies. Each of three different targets will provide a different energy. The design will allow the experimenter to place a different target in front of the electron beam without breaking vacuum each time. The procedure is described for attaching three 12.7 mm (1/2 in.) diameter targets - made of tungsten, gold and uranium 238 (D-38) - to an OFHC copper support bar. The joining of the copper bar to a welded stainless steel bellows and flange is also described

  9. 电感耦合等离子体原子发射光谱法测定镍基钎焊料中铬和硅%Determination of chromium and silicon in nickel-based brazing material by inductively coupled plasma atomic emission spectrometry

    Institute of Scientific and Technical Information of China (English)

    杨丽; 王金阳; 张庸

    2013-01-01

    The analysis conditions of chromium and silicon in nickel-based brazing material by inductively coupled plasma atomic emission spectrometry (ICP-AES) were discussed.After the nickelbased brazing material was dissolved with aqua regia-hydrofluoric acid mixed acid,and matrix effect was reduced by matrix matching,chromium and silicon in the sample were determined by ICP-AES with spectral line of 267.716(125) nm and 251.612(133) nm as the analytical lines for chromium and silicon respectively.This proposed method was applied to the determination of chromium and silicon in actual samples and the results were consistent with those obtained by ammonium persulfate oxidization titration method and perchloric acid dehydration method.The relative standard deviation (RSD,n =6) of chromium and silicon was 0.55%-0.73% and 0.71%-1.0%,respectively.The recoveries were 100%-101% and 99%-100%,respectively.%探讨了电感耦合等离子体原子发射光谱法(ICP-AES)测定镍基钎焊料中铬和硅的分析条件.试样经王水和氢氟酸混合酸溶解,选择267.716(125) nm和251.612(133) nm的光谱线分别作为铬和硅的分析线,并采用基体匹配法降低了基体效应,ICP-AES测定了镍基钎焊料中铬和硅含量.实际样品中铬和硅的测定结果与过硫酸铵氧化滴定法和高氯酸脱水法相符,铬和硅的相对标准偏差(n=6)分别为0.55%~0.73%和0.71%~1.0%,加标回收率分别为100%~101%和99%~100%.

  10. 46 CFR 56.30-30 - Brazed joints.

    Science.gov (United States)

    2010-10-01

    ... be sufficient to fill completely the annular clearance between the socket and the pipe or tube. (b.... in boiler steam air heaters provided the requirements of UB-12 of section VIII ASME Boiler and Pressure Vessel Code (incorporated by reference; see 46 CFR 56.01-2) are satisfied at the...

  11. Inert Welding/Brazing Gas Filters and Dryers

    Science.gov (United States)

    Goudy, Jerry

    2009-01-01

    The use of hybridized carbon/silicon carbide (C/SiC) fabric to reinforce ceramic matrix composite face sheets and the integration of such face sheets with a foam core creates a sandwich structure capable of withstanding high-heat-flux environments (150 W/sq cm) in which the core provides a temperature drop of 1,000 C between the surface and the back face without cracking or delamination of the structure. The composite face sheet exhibits a bilinear response, which results from the SiC matrix not being cracked on fabrication. In addition, the structure exhibits damage tolerance under impact with projectiles, showing no penetration to the back face sheet. These attributes make the composite ideal for leading-edge structures and control surfaces in aerospace vehicles, as well as for acreage thermal protection systems and in high-temperature, lightweight stiffened structures. By tailoring the coefficient of thermal expansion (CTE) of a carbon fiber containing ceramic matrix composite (CMC) face sheet to match that of a ceramic foam core, the face sheet and the core can be integrally fabricated without any delamination. Carbon and SiC are woven together in the reinforcing fabric. Integral densification of the CMC and the foam core is accomplished with chemical vapor deposition, eliminating the need for bond-line adhesive. This means there is no need to separately fabricate the core and the face sheet, or to bond the two elements together, risking edge delamination during use. Fibers of two or more types are woven together on a loom. The carbon and ceramic fibers are pulled into the same "pick" location during the weaving process. Tow spacing may be varied to accommodate the increased volume of the combined fiber tows while maintaining a target fiber volume fraction in the composite. Foam pore size, strut thickness, and ratio of face sheet to core thickness can be used to tailor thermal and mechanical properties. The anticipated CTE for the hybridized composite is managed by the choice of constituents, varying fiber tow sizes and constituent part ratios. This structural concept provides high strength and stiffness at low density 1.06 g/cu cm in panels tested. Varieties of face sheet constructions are possible, including variations in fiber type and weave geometry. The integrated structures possible with this composite could eliminate the need for non-load-bearing thermal protection systems on top of a structural component. The back sheet can readily be integrated to substructures through the incorporation of ribs. This would eliminate weight and cost for aerospace missions.

  12. 双光束激光钎焊工艺%Dual laser beam brazing process

    Institute of Scientific and Technical Information of China (English)

    封小松; 陈彦宾; 倪加明; 林尚阳

    2006-01-01

    以CO2激光为热源,镀锌钢板为母材,CuSi3焊丝为钎料,进行了双光束激光自动填丝钎焊工艺试验.通过对比单、双光束钎焊特点及改变双光束钎焊工艺参数,分析了双光束激光功率、离焦方式、双束激光能量配比、焦点间距等对接头质量的影响.结果表明,双光束钎焊对激光功率的变化具有更大的适应性;当采用负离焦并行双光束、2 mm 焦点距离的串行双光束且前束激光功率大于后束激光时,可以获得更好的钎缝质量,钎焊过程更具灵活性、适应性.在此基础上,借助金相显微镜、SEM和EDX能谱分析,对接头组织及界面元素分布规律进行了分析.结果表明,双光束钎缝附近母材晶粒更细小,粗晶区更窄;在界面处有Fe-Si金属间化合物生成.

  13. Combined Laser Beam Welding and Brazing Process for Aluminium Titanium Hybrid Structures

    Science.gov (United States)

    Möller, F.; Grden, M.; Thomy, C.; Vollertsen, F.

    The current state of the art in light-weight construction is - for the case of aircraft structures - the use of either aluminium or titanium. Whereas aluminium is light-weight and less expensive, titanium offers superior corrosion properties at higher cost. In order to combine the advantages of both materials, a hybrid Ti-Al structure is proposed for e.g. seat-track application. In this paper, an overview of the results from this research work and the accompanying thermo-mechanical simulations will be reported and discussed. On the basis of the development of an appropriate system technology, the process development will be described, focusing on the main influencing parameters of the process on joint properties.

  14. Low-Temperature Interface Reaction between Titanium and the Eutectic Silver-Copper Brazing Alloy

    OpenAIRE

    Andrieux, J; Dezellus, Olivier; Bosselet, F.; Viala, J.C.

    2009-01-01

    Reaction zones formed at 790 °C between solid titanium and liquid Ag-Cu eutectic alloys (pure and Ti-saturated) have been characterized. When pure Ag-Cu eutectic alloy with 40 at.% Cu is used, the interface reaction layer sequence is: alpha-Ti / Ti2Cu / TiCu / Ti3Cu4 / TiCu4 / L. Because of the fast dissolution rate of Ti in the alloy, the reaction zone remains very thin (3-6 µm) whatever the reaction time. When the Ag-Cu eutectic alloy is saturated in titanium, dissolution no longer proceeds...

  15. Ultrasonic C-scan inspection of brazed joint in thin panel honeycomb structure

    Institute of Scientific and Technical Information of China (English)

    刘斌; 刚铁

    2014-01-01

    The non-destructive testing ofbrazed joint in honeycomb structure with thin panel(thickness:0.2 mm)was studied by ultrasonic C-scan method.Samples with different types ofartificial defect were designed;the characteristic signal and the main parameters ofthe test were determined by the pre-experiment,and then parameters were optimized by orthogonal design, finally the optimum process was verified by a single panel sample. The multiple reflection echoes were chosen as the characteristic signal.The optimal C-scan results were achieved when the 20 MHz focus probe was used,and the pass band range for received signal were selected as 8-17.5 MHz.The defects such as incomplete penetration and core damage can be detected with ultrasonic C-scan,and the detection accuracy can reach to 1 mm.

  16. 49 CFR 178.50 - Specification 4B welded or brazed steel cylinders.

    Science.gov (United States)

    2010-10-01

    ... calculated shear strength at least 10 times the test pressure of the cylinder; gaskets required, adequate to... as the finished cylinder. (k) Physical test. A physical test must be conducted to determine yield strength, tensile strength, elongation, and reduction of area of material as follows: (1) The test...

  17. 49 CFR 178.55 - Specification 4B240ET welded or brazed cylinders.

    Science.gov (United States)

    2010-10-01

    ... tight fit and calculated shear strength at least 10 times the test pressure of the cylinder; gaskets... between knife edges, wedge shaped, 60° angle, rounded to 1/2 inch radius. (k) Physical test. A physical test must be conducted to determine yield strength, tensile strength, elongation, and reduction of...

  18. Corrosion behaviour of Ti/Al2O3 interfaces produced by an active metal brazing methodology

    OpenAIRE

    Ariza, E.; Rocha, L. A.; Paiva, O. C.

    2004-01-01

    Metal/ceramic joints are used in a broad range of applications in biomedicine, such as the encapsulation of implantable telemetric devices, the fabrication of crowns and bridges for dental restoration, or the production of drug delivery systems, biomedical sensors and electrodes. Apart of other characteristics, the corrosion resistance of metal/ceramic interfaces is of prime importance when biomedical applications are considered. Most of metal/ceramic joints are produced by the active meta...

  19. Numerical simulation of iron/TiC ceramic tappet brazed with TiZrNiCu filler metal

    Institute of Scientific and Technical Information of China (English)

    张丽霞; 冯吉才; 李卓然

    2003-01-01

    Maximum value of thermal stress and stress concentration zones of iron/TiC ceramic tappet during cooling were studied.The results show that when the temperature is 300 K,the maximum values of shear stress and tensile stress on iron/TiC ceramic interface both appear on the tip of TiZrNiCu/iron interface,so cracks always originate from TiZrNiCu/iron interface.Positive tensile stress on iron undersurface relaxes to the inner of iron and negative tensile stress on iron undersurface concentrates on the side of iron as the temperature declines,which leads to the origination of cracks on iron undersurface because of the alternation between positive and negative tensile stress.

  20. 铜散热器高频感应钎焊专机的研制%Development of special machine of high frequency induction brazing for copper radiator

    Institute of Scientific and Technical Information of China (English)

    刘淑健; 李凌宇

    2002-01-01

    @@高频感应钎焊专机是为钎焊铜散热器的干管和两端的封堵而专门设计的半自动钎焊专机,被焊工件(见图1)是壁厚为1.5mm的异型铜管与壁厚为12mm的黄铜管端封堵,两者同为导师热性能极好的铜材料,但壁厚相差7倍,原采用手工火焰钎焊方法,由于加热温度难于控制且无法有效地保证管与封堵同时均匀地升温,再加上手工送钎料和焊缝的形状异型,因此不可避免地出现钎焊接头的质量问题,如钎焊强度不高,致密性不好,且由于火焰钎焊是一个局部加热过程,易产生应力和变形。

  1. 铍环激光束钎焊过程的数值模拟%NUMERICAL SIMULATION ON LASER BEAM BRAZE WELDING OF BERYLLIUM RING

    Institute of Scientific and Technical Information of China (English)

    董平; 陈裕泽; 邹觉生; 李盛和

    2002-01-01

    采用MARC软件对铍环激光束钎焊过程的温度场和应力场进行了有限元分析.温度场分析得到与铍环实际激光束钎焊基本一致的焊缝形状.应力场分析表明,焊接后轴向应力和环向应力在焊缝中心的钎料上为压应力,在铍环外表面热影响区和内表面均为拉应力,径向应力为压应力,焊接残余应力主要分布在离焊缝2 mm的范围内,焊接后铍环内外表面发生径向收缩.将有限元分析得到的铍环外表面的轴向残余应力结果与实测结果进行了比较,二者所反映的应力变化趋势基本一致.

  2. Research on the Welding Technology for Flame Brazing of Dissimilar Materials%异种材料火焰钎焊焊接工艺研究

    Institute of Scientific and Technical Information of China (English)

    熊亚

    2016-01-01

    The welding of dissimilar materials involves the welding structure of red copper and mild steel, and it adopts high silver welding flux, 37B, which silver content is 37 %. Because it contains very high proportion of pre-cious metal, silver, it is very costly. In order to solve this problem, this paper researches the welding material. On the condition of guaranteeing the quality, cost reduction is realized.%异种材料焊接,涉及到的紫铜和低碳钢的焊接结构,采用高银焊料37B(含银量37%)焊接,因其含有贵重金属银且占比极高,导致成本极其高昂。为解决此问题,本文对焊接材料进行研究,在保证产品质量的前提下,降低成本。

  3. Microstructures characteristics and properties of solidified aluminum alloy brazed joint%铝合金钎焊凝固接头的组织特征和性能

    Institute of Scientific and Technical Information of China (English)

    高峰; 钱乙余; D.P.Sekulic; 马鑫; F.Yoshida

    2003-01-01

    研究了钎焊温度对钎焊接头微观组织的影响, 并利用图像软件Image-Pro Plus确定了不同初始凝固温度下α-(Al)相在钎焊接头中的体积分数. 结果表明: 随着初始凝固温度增加, α-(Al)相所占的比例增大. 通过成分分析(EPMA)和硬度测试, 分析了硅扩散层的特征. 压痕法测试结果表明: 不同初始凝固温度下获得的同种组织, 其力学和物理等综合性能不同, 从而造成整个钎焊接头力学性能的差异.

  4. Sputter target

    Science.gov (United States)

    Gates, Willard G.; Hale, Gerald J.

    1980-01-01

    The disclosure relates to an improved sputter target for use in the deposition of hard coatings. An exemplary target is given wherein titanium diboride is brazed to a tantalum backing plate using a gold-palladium-nickel braze alloy.

  5. 78 FR 75947 - Agency Information Collection Activities; Submission for OMB Review; Comment Request; Welding...

    Science.gov (United States)

    2013-12-13

    ...; Welding, Cutting, and Brazing Standard ACTION: Notice. SUMMARY: The Department of Labor (DOL) is... (ICR) titled, ``Welding, Cutting, and Brazing Standard,'' to the Office of Management and Budget (OMB... the Welding, Cutting, and Brazing Standard, regulations 29 CFR part 1910, subpart Q. More...

  6. Thermal cycling tests of actively cooled beryllium copper joints

    Energy Technology Data Exchange (ETDEWEB)

    Roedig, M.; Duwe, R.; Linke, J.; Schuster, A.; Wiechers, B. [Forschungszentrum Juelich GmbH (Germany)

    1998-01-01

    Screening tests (steady state heating) and thermal fatigue tests with several kinds of beryllium-copper joints have been performed in an electron beam facility. Joining techniques under investigation were brazing with silver containing and silver-free braze materials, hot isostatic pressing (HIP) and diffusion bonding (hot pressing). Best thermal fatigue performance was found for the brazed samples. (author)

  7. Advance in study on fusion-brazing welding of dissimilar metals between Al alloy and steel%铝合金/钢异种金属熔-钎焊技术研究进展

    Institute of Scientific and Technical Information of China (English)

    苏玉虎; 秦国梁; 位延堂

    2011-01-01

    文中分析了铝及铝合金与钢异种金属焊接时存在的问题,认为铝合金/钢熔-钎焊接是最适合铝合金/钢复合结构制造的焊接技术.介绍了熔-钎焊接的概念及特点,综述了国内外激光熔-钎焊、TIG熔-钎焊、MIG熔-钎焊、CMT熔-钎焊以及激光+MIG电弧复合熔-钎焊等焊接工艺方法在铝合金与钢异种金属连接中的研究现状,并对比了各种工艺方法的优缺点.最后指出,合适的填充材料和钎剂的开发以及焊接热输入的精确控制是实现铝及铝合金与钢异种金属优质高效连接的关键.

  8. 铝/镀锌钢板CMT熔钎焊界面区组织与接头性能%Interface microstructure and mechanical property of CMT welding-brazed joint between aluminum and galvanized steel sheet

    Institute of Scientific and Technical Information of China (English)

    石常亮; 何鹏; 冯吉才; 张洪涛

    2006-01-01

    采用冷金属过渡方法(CMT)对铝和镀锌钢板异种材料进行了熔钎焊连接.使用扫描电镜(SEM)、能谱分析(EDAX)和拉伸试验对焊接接头界面区显微组织及接头性能进行研究.试验结果表明,铝和镀锌钢能得到成形良好的搭接接头.在CMT熔钎焊的方法下,形成了中间厚两边薄的界面区,并且在熔化区一侧边缘形成了富锌区,界面区组织成分也由致密的FeAl3金属间化合物层变为α固溶体和FeAl3化合物混合层,而富锌区是由富铝的α固溶体和残留的铝组成.在进行拉伸试验时,断裂发生在铝母材的热影响区,接头强度为72.09MPa.

  9. Influence of filler wire on copper/steel dissimilar metals CMT welding-brazing%铜/钢异种金属CMT熔钎焊填充材料影响分析

    Institute of Scientific and Technical Information of China (English)

    杨卫鹏; 李双吉; 朱笑睿; 陈树海; 林三宝

    2015-01-01

    采用S201和S211两种焊丝对铜/钢异种金属CMT熔钎焊特性进行比较研究,发现在相同(或相近)的CMT焊接工艺条件下,S211焊丝在母材上的铺展性明显优于S201焊丝;虽然采用S211焊丝的焊缝抗拉强度有所提高,但是在某些条件下容易产生焊接热裂纹,而使用S201焊丝的焊缝具有较高的抗热裂性;综合考虑,S201焊丝更加适合铜/钢异种金属CMT熔钎焊.

  10. Numerical simulation of influence of process on stress field of electron beam brazing radiator%工艺过程对散热器电子束钎焊残余应力影响的数值模拟

    Institute of Scientific and Technical Information of China (English)

    李军民; 陈芙蓉

    2008-01-01

    利用ANSYS软件,建立二维有限元模型,分析了两种不同钎焊工艺对1Cr18Ni9Ti不锈钢散热器电子束钎焊接头残余应力的影响,旨在筛选出一种合适的工艺及参数.结果表明,对于径向残余应力,采用直接加热钎焊工艺,钎焊面上出现明显的应力集中区域;而采用分阶段加热钎焊工艺,钎焊面上没有应力集中区出现,且应力变化曲线比直接加热钎焊工艺平缓得多;对于周向残余应力,分阶段加热与直接加热钎焊工艺相比,拉应力峰值减小了11.2%.两种钎焊工艺的周向残余拉应力峰值均大于径向残余拉应力,钎焊面的危险部位沿圆周方向,即电子束扫描加热的方向.

  11. 钎焊式空冷系统用嵌入式冷轧铝-钢复合带材的开发%Development of Embedded Aluminum-Steel Cladding Strip for Brazed Air Cooling System by Cold Rolling Bonding

    Institute of Scientific and Technical Information of China (English)

    李龙; 张小军; 曾祥勇; 陈鑫; 高闯; 周德敬

    2015-01-01

    通过“表面处理+冷轧复合+退火处理”三步法,即先采用钢丝刷对4 mm 08A1钢(/%:0.01C,0.018A1)和0.23 mm 4A60铝带表面进行处理,然后在前张力30 kN下利用高精度Φ420 mm四辊轧机对铝-钢进行60%的单道次冷轧复合,并于罩式退火炉进行520℃24 h的退火处理,开发出了极薄复层(80~90 μm)冷轧4A60铝/08A1钢1.7mm复合带材.复合带材中08A1钢的组织为平均晶粒尺寸15μm的等轴铁素体,抗拉强度≥320MPa,伸长率≥28%,弯曲性能也符合指标要求.复合带材在(600±10)℃钎焊后铝钢界面未发现金属间化合物,铝钢界面未发现分层现象.

  12. 铝/钢异种金属激光填丝熔-钎焊连接工艺研究%Wire Feeding Laser Brazing and Fusion for Al-Fe Dissimilar Metal

    Institute of Scientific and Technical Information of China (English)

    张冬云; 高双欣; 高海芸; 赵建哲

    2011-01-01

    采用板条CO2激光器对铝-钢异种金属搭接接头进行激光填丝焊接试验研究.分析了不同热输入量对焊缝成形质量的影响以及不同热输入量对焊缝显微组织、焊缝物相及力学性能的影响.实验结果表明,与低能量密度参数下的焊接接头相比高能量密度参数下的焊缝内部组织将不再均匀,而是出现了条状或块状金属间化合物FeAl,铝-铁界面产生的金属间化合物厚度增加,钢板熔化区主要物相也由低能量密度时的FeAl和Al与α-Fe形成的固溶体转变为Fe3Al和Al与α-Fe形成的固溶体,从而降低了焊缝的力学性能.拉剪结果显示,高能量密度焊接参数下的焊缝抗拉(剪)强度仅为低能量密度下的72.9%.%Dissimilar metal joining of steel/aluminum alloy by slab CO2 laser beam welding with filling wire is investigated and the influence of different heat input on the weld formation quality is introduced. The influence of different heat input on microstructure, phase and mechanical properties of joints are analyzed. The experimental results show that microstructure in the joints with higher heat input parameters compared with lower heat input parameters is no longer homogenous, Fe-A1 intermetallic phase with the shape of strip and lump can be found in the joints, the thickness of the intermetallics layer increases in the interface of aluminum/steel joints, and the main phase in the melts of joints transforms from FeAl and solid solution of A1 in α-Fe to Fe3A1 and solid solution of Al in α-Fe. Mechanical properties deteriorate with the increase of the intermetallics layer. Tensile test shows that tensile (or shear) strength with high heat input parameters is 72.9 % of that with low heat input parameters.

  13. 铝-镀锌钢板异种金属Pulsed DE-MIG熔钎焊方法研究%Pulsed DE-MIG brazing-welding method of aluminum-galvanized steel dissimilar metals

    Institute of Scientific and Technical Information of China (English)

    顾玉芬; 邵玲; 石玗; 黄健康

    2014-01-01

    A new, high efficiency and low heat input method of Pulsed DE-MIG was put forward to control welding heat input precisely and growth of intermetallic compounds in interface of aluminum-steel. Pulsed DE-MIG process parameters were optimized by plate welding of aluminum alloy welding wire ER5356 welded on galvanized steel. The total current of welding wire remained constant, and Pulsed DE-MIG of aluminum-galvanized steel dissimilar metals was carried out at different Pulsed DE-MIG welding parameters. It indicated that the weld seam width decreased significantly but bead height increased obviously when bypass current increased gradually. OM, SEM and EDS were adopted to observe and characterize the interface microstructures of the joints. Two intermetallic compounds layers of Fe2 Al5 and FeAl3 formed along the interface. When the heat input of base metal was large, many FeAl3 precipicated, and when the heat input of base metal was decreased gradually, the amount of FeAl3 decreased until without FeAl3 .%为精确控制焊接热输入,从而控制铝钢异种金属界面区金属间化合物生长,提出一种新型高效低热输入的脉冲旁路耦合电弧MIG焊(Pulsed DE-MIG)方法,用ER5356铝合金焊丝在镀锌钢板上利用平板堆焊实验对工艺参数进行优化。在焊丝总电流保持不变,不同的Pulsed DE-MIG焊接参数下焊接,结果表明随着旁路电流的增大,焊缝宽度显著变小,且焊缝堆高明显变高。采用OM、SEM、EDS等测试手段观察和分析连接界面区的微观组织,发现在连接界面区形成Fe2 Al5、FeAl3金属间化合物层,且母材热输入大时,FeAl3析出得多,随着母材热输入的减小,FeAl3析出逐步减少直至FeAl3无析出。

  14. Effect of brazing residual stress on creep for stainless steel plate-fin structure%不锈钢板翅结构钎焊残余应力对蠕变的影响

    Institute of Scientific and Technical Information of China (English)

    蒋文春; 巩建鸣; 涂善东; 陈虎

    2007-01-01

    利用有限元法,对微小尺寸的镍基钎焊不锈钢板翅结构进行600 ℃下的蠕变有限元分析,讨论钎焊残余应力对蠕变变形的影响.结果表明,由于镍基钎料BNi-2和不锈钢母材SS304力学性能的差异以及钎焊夹具的约束作用,钎焊后在接头处产生了较大的残余应力,对不锈钢板翅结构高温下的蠕变行为产生很大影响,在强度设计中不能忽略.初始应力和蠕变应变的分布规律具有一致性.隔板和翅片具有不同的应力应变分布特征,隔板侧的蠕变开裂的倾向比翅片大.钎角处蠕变应力和应变集中,易萌生蠕变裂纹.研究结果为不锈钢板翅结构钎焊接头的高温强度设计提供参考.

  15. 46 CFR 56.75-30 - Pipe joining details.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Pipe joining details. 56.75-30 Section 56.75-30 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PIPING SYSTEMS AND APPURTENANCES Brazing § 56.75-30 Pipe joining details. (a) Silver brazing. (1) Circumferential pipe joints...

  16. 46 CFR 56.75-25 - Detail requirements.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Detail requirements. 56.75-25 Section 56.75-25 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PIPING SYSTEMS AND APPURTENANCES Brazing § 56.75-25 Detail requirements. (a) Pipe may be fabricated by brazing when the...

  17. 46 CFR 57.05-3 - Limited space qualifications.

    Science.gov (United States)

    2010-10-01

    ... Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING WELDING AND BRAZING.... EC01FE91.028 Figure 57.05-3(a)—Limited space restriction for pipe welding performance qualification EC01FE91.029 Figure 57.05-3(b)—Limited space restriction for pipe brazing performance qualification...

  18. Broadband, High-Temperature Ultrasonic Transducer

    Science.gov (United States)

    Parker, F. Raymond; Winfree, William P.; Barrows, Danny A.

    1995-01-01

    Materials chosen for endurance at high temperatures and acoustic coupling and damping. Acoustic transducer designed to exhibit broad frequency response and to survive temperatures close to melting points of brazing alloys. Attached directly and continuously to hot object monitored ultrasonically: for example, it can be attached to relatively cool spot on workpiece during brazing for taking ultrasonic quality-control measurements.

  19. 75 FR 74083 - Agency Information Collection Activities; Submission for OMB Review; Comment Request; Welding...

    Science.gov (United States)

    2010-11-30

    ... ] additional information, see the related notice published in the Federal Register on August 24, 2010 (75 FR...; Welding, Cutting and Brazing ACTION: Notice. SUMMARY: The Department of Labor (DOL) hereby announces the... request (ICR) titled, ``Welding, Cutting and Brazing,'' to the Office of Management and Budget (OMB)...

  20. The accelerator driven transmutation technology - A study on the linac for proton accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Han, Bum Soo; Joh, Ki Hun; Kim, Sung Myun; Park, Heung Gyu; Park, Jong Pil; Kang, Bo Sun [Samsung Heavy Industries, Taejon (Korea)

    1999-04-01

    The purpose of this study is to investigate the manufacturing technology of proton accelerators, and to find the adequate manufacturing technique for construction of such proton accelerators. Review of manufacturing technology for RFQ has been carried out - RFQ machine of other country has been reviewed on the aspects of manufacturing, - Machining of engineering mock-up has been performed based on the designed data, - Brazing technology for RFQ, and brazing test and analysis of Copper specimen. Adequate brazing conditions for RFQ - 1st brazing (vane to section, 950 deg C), Filler metal composition: Cu-20Sn, Brazing conditions: peak temp. 950 deg C (holding time 20min, rising rate 7 deg C/min), Atmosphere: H{sub 2}. - 2nd brazing (section to section, 850 deg C or less), Filler metal: Cu-Sn4%-P7.5%-Ag6%, Brazing conditions: peak temp. 750 deg C (holding time 20min, rising rate 7 deg C/min), Atmosphere: H{sub 2}. 8 refs., (author). 31 figs., 6 tabs.

  1. Ultrasonic testing technology development for pressure retaining Ti alloy-stainless steel dissimilar metal joint of SMART steam generator

    International Nuclear Information System (INIS)

    The steam generator for the Integral reactor SMART has module feed water (FW) pipe and module steam pipe which consist of Ti-alloy and STS321 called dissimilar metal joint. These brazed joints are classified as a class 1 boundary component being needed inservice inspection according to ASME Sec. XI. But inspecting the thread part of brazed joint is really difficult due to geometrical condition. For this reason, various NDT methods have been investigated. In this paper, the ultrasonic inspection was recommended to evaluate the integrity of brazed dissimilar metal joint, and representative UT results of specimens are presented

  2. LIFE CYCLE DESIGN OF AIR INTAKE MANIFOLDS; PHASE I: 2.0 L FORD CONTOUR AIR INTAKE MANIFOLD

    Science.gov (United States)

    The project team applied the life cycle design methodology to the design analysis of three alternative air intake manifolds: a sand cast aluminum, brazed aluminum tubular, and nylon composite. The design analysis included a life cycle inventory analysis, environmental regulatory...

  3. 40 CFR 433.10 - Applicability; description of the metal finishing point source category.

    Science.gov (United States)

    2010-07-01

    ..., Electrochemical Machining, Electron Beam Machining, Laser Beam Machining, Plasma Arc Machining, Ultrasonic... Deformation, Pressure Deformation, Shearing, Heat Treating, Thermal Cutting, Welding, Brazing, Soldering... apply and the following regulations shall apply: Nonferrous metal smelting and refining (40 CFR part...

  4. Bonding of Cf/SiC composite to Invar alloy using an active cement, Ag-Cu eutectic and Cu interlayer

    Science.gov (United States)

    Lei, Zhao; Xiaohong, Li; Jinbao, Hou; Qiang, Sun; Fuli, Zhang

    2012-10-01

    The interfacial microstructures and mechanical properties of the joints formed by active cement added brazing in vacuum of Cf/SiC composite to Invar alloy, using Ag-Cu eutectic alloy and pure copper foil as braze alloy and interlayer respectively, were investigated. CuTi, Cu4Ti3, Fe2Ti and the reaction layer of TiC and Si were the predominant components at the joint interface. The maximum shear strength of the joint was 77 MPa for brazing at 850 °C for 15 min. The results show that active cement added brazing in vacuum using Ag-Cu eutectic alloy and Cu interlayer can be used successfully for joining Cf/SiC composites to Invar alloy.

  5. An investigation on the effects of phase change material on material components used for high temperature thermal energy storage system

    Science.gov (United States)

    Kim, Taeil; Singh, Dileep; Zhao, Weihuan; Yua, Wenhua; France, David M.

    2016-05-01

    The latent heat thermal energy storage (LHTES) systems for concentrated solar power (CSP) plants with advanced power cycle require high temperature phase change materials (PCMs), Graphite foams with high thermal conductivity to enhance the poor thermal conductivity of PCMs. Brazing of the graphite foams to the structural metals of the LHTES system could be a method to assemble the system and a method to protect the structural metals from the molten salts. In the present study, the LHTES prototype capsules using MgCl2-graphite foam composites were assembled by brazing and welding, and tested to investigate the corrosion attack of the PCM salt on the BNi-4 braze. The microstructural analysis showed that the BNi-4 braze alloy can be used not only for the joining of structure alloy to graphite foams but also for the protecting of structure alloy from the corrosion by PCM.

  6. Numerical Modelling of Indution Heating - Fundamentals

    DEFF Research Database (Denmark)

    Zhang, Wenqi

    Induction heating is extensively used for brazing and heat treatment of materials to produce consumer and industrial products; structural assemblies; electrical and electronic products; mining, machine, and hand tools; ordnance equipment; and aerospace assemblies. It is often applied when rapid...

  7. Improved method for the preparation of TiN-coated WC-Co-based samples for cross-sectional AEM investigation.

    Science.gov (United States)

    Hefter, J; Ostreicher, K; Sung, C

    1992-11-01

    An improved method for the preparation of cross-sectional thin foils of coated WC-Co samples for studies by analytical electron microscopy is described. A braze alloy is used to join the sections of the sample together and the resulting sample is stable during subsequent grinding, dimpling, and milling operations. Cross-sectional micrographs provide examples of the efficacy of this method. No microstructural alteration associated with the brazing operation was observed. PMID:1472751

  8. 46 CFR 56.75-5 - Filler metal.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Filler metal. 56.75-5 Section 56.75-5 Shipping COAST... Brazing § 56.75-5 Filler metal. (a) The filler metal used in brazing must be a nonferrous metal or alloy having a melting point above 1,000 °F. and below that of the metal being joined. The filler metal...

  9. A Study of Deposition Coatings Formed by Electroformed Metallic Materials

    OpenAIRE

    Hayashi, Shoji; Sugiyama, Shuta; Shimura, Kojiro; Tobayama, Go; Togashi, Toshio

    2016-01-01

    Major joining methods of dental casting metal include brazing and laser welding. However, brazing cannot be applied for electroformed metals since heat treatment could affect the fit, and, therefore, laser welding is used for such metals. New methods of joining metals that do not impair the characteristics of electroformed metals should be developed. When new coating is performed on the surface of the base metal, surface treatment is usually performed before re-coating. The effect of surface ...

  10. High temperature thermoelectrics

    Science.gov (United States)

    Moczygemba, Joshua E.; Biershcenk, James L.; Sharp, Jeffrey W.

    2014-09-23

    In accordance with one embodiment of the present disclosure, a thermoelectric device includes a plurality of thermoelectric elements that each include a diffusion barrier. The diffusion barrier includes a refractory metal. The thermoelectric device also includes a plurality of conductors coupled to the plurality of thermoelectric elements. The plurality of conductors include aluminum. In addition, the thermoelectric device includes at least one plate coupled to the plurality of thermoelectric elements using a braze. The braze includes aluminum.

  11. 镀锌层对铝/镀锌钢板CMT熔-钎焊电弧加热行为的影响%Effect of zinc coating on arc heating behavior for joining Al and zinc coated steel by welding-brazing process

    Institute of Scientific and Technical Information of China (English)

    张洪涛; 冯吉才; 何鹏; 赵洪运

    2009-01-01

    通过建立的电弧形态视觉传感系统以及电流电压波形采集系统研究了镀锌层对铝/镀锌钢板CMT熔-钎焊电弧加热行为的影响.结果表明,小电流焊接时,镀锌层可以作为等离子体阴极,起到稳定电弧的作用,而在无镀锌层条件下,电弧的阴极斑点不停地跳跃,电弧极其不稳;随着焊接电流的增大,在镀锌钢板上焊接时,由于镀锌层的蒸发变得十分剧烈,这种蒸发行为也使得在镀锌钢板上焊接时的电弧的边缘上翘,减小了电弧与工件的接触面积,进而降低了焊接热输入,减小了界面脆性化合物层的厚度.

  12. Study on Microstructure and Mechanical Property of Welding-brazing Joints of Aluminum Alloy to Galvanized Steel by CMT%铝合金/镀锌钢CMT熔钎焊接头显微组织与力学性能研究

    Institute of Scientific and Technical Information of China (English)

    郭鑫; 赵悦; 何忝锜

    2015-01-01

    分别使用ER4043铝硅焊丝和ER5183铝镁焊丝为填充金属,对5083铝合金和EH36镀锌钢进行CMT焊接,使用万能试验机测试接头拉伸强度;用SEM和EDS对接头的显微组织进行分析.结果表明,两种焊丝都可得到成形良好的焊缝,但使用ER5183焊丝得到的焊缝比使用ER4043焊丝的焊缝润湿角大,且接头强度要低很多.

  13. Analysis of Poor Factor for Brazed Car Condenser by 434-0 Aluminium Alloy Composite Plate%434-O铝合金复合板制成汽车冷凝器真空钎焊不良因素分析

    Institute of Scientific and Technical Information of China (English)

    陈丽君

    2010-01-01

    铝合金汽车冷凝器真空钎焊打压试验后出现起鼓、鼓暴现象,对零件中434复合板材料做了成分、热差、金相分析系统的对比试验.结果表明,冷凝器钎焊良好和钎焊不良中434复合板材成分、晶粒度、熔化温度等均无明显差异.打压起鼓、鼓暴现象应与冷凝器装配、翅片强度等因素有关,并提出了相应的工艺措施.

  14. Analysis of Poor Factor for Brazed Car Condenser by 434-O Aluminum Alloy Composite Plate%434-O铝合金复合板制成汽车冷凝器真空钎焊不良因素分析(续)

    Institute of Scientific and Technical Information of China (English)

    陈丽君

    2010-01-01

    @@ 由表1、表2显示:原始复合板材1#、2#两个试样芯层3003、皮层4004合金化学成分均合格,符合GB/T3190-2008的要求. 2.2 热差分析 制备热差分析试样,利用综合热差分析仪测定434-O合金的熔化温度,1#、2#两批试样热差分析结果见图3所示.

  15. Microstructure and properties of dissimilar metals TIG welding-brazing joint of aluminum alloy to stainless steel using Al-Si flux-cored wire%铝合金与不锈钢异种金属铝硅药芯焊丝TIG熔钎焊接头组织及性能

    Institute of Scientific and Technical Information of China (English)

    林三宝; 宋建岭; 马广超; 杨春利

    2009-01-01

    采用铝硅药芯焊丝进行了铝合金与不锈钢异种金属无镀层TIG熔钎焊试验,运用OM,SEM,EDS及XRD分析了接头微观组织,研究了界面层及焊缝中金属间化合物种类,分析了药芯钎剂的作用,并测试了接头力学性能.结果表明,药芯钎剂能够促进铝硅钎料在不锈钢表面润湿铺展,获得的润湿角小于30°,钎剂挥发不完全,在接头中产生许多气孔;接头中钢侧界面层由[Al,Fe,Si]相和Fe_4Al_(13)构成,焊缝由α-Al基体、汉字状α铁相(Fe_2SiAl_8)以及细长板条状混合相(β铁相FeSiAl_5及少量Al-Si共晶相)构成;剪切试验中接头均断裂在钢侧界面层,接头抗剪强度仅为55MPa,断裂面由[Al,Fe,Si]相、Fe_4Al_(13)以及少量的Fe_2Si,Al_5Cr相构成.

  16. 不锈钢板翅结构钎焊残余应力及其高温蠕变松弛行为三维有限元分析%3-D finite element analysis of residual stress and its creep relaxation at high temperature for stainless steel brazed plate-fin structure

    Institute of Scientific and Technical Information of China (English)

    蒋文春; 巩建鸣; 陈虎; 涂善东

    2007-01-01

    利用有限元软件ABAQUS,对不锈钢板翅结构在钎焊过程中产生的残余应力及其高温下的蠕变松弛行为进行三维有限元分析,得到了残余应力的变化规律.结果表明,由于镍基钎料BNi-2和不锈钢母材304力学性能的差异以及夹具的约束作用,钎焊后在接头处产生了较大的残余应力.在高温环境下,由于蠕变松弛,残余应力大幅度下降.在蠕变稳态阶段,钎缝处仍然存在一定的残余应力;钎角处蠕变应力和应变集中,易萌生裂纹,成为最薄弱环节.研究结果为板翅结构的高温强度设计提供参考.

  17. Improved Blackbody Temperature Sensors for a Vacuum Furnace

    Science.gov (United States)

    Farmer, Jeff; Coppens, Chris; O'Dell, J. Scott; McKechnie, Timothy N.; Schofield, Elizabeth

    2009-01-01

    Some improvements have been made in the design and fabrication of blackbody sensors (BBSs) used to measure the temperature of a heater core in a vacuum furnace. Each BBS consists of a ring of thermally conductive, high-melting-temperature material with two tantalum-sheathed thermocouples attached at diametrically opposite points. The name "blackbody sensor" reflects the basic principle of operation. Heat is transferred between the ring and the furnace heater core primarily by blackbody radiation, heat is conducted through the ring to the thermocouples, and the temperature of the ring (and, hence, the temperature of the heater core) is measured by use of the thermocouples. Two main requirements have guided the development of these BBSs: (1) The rings should have as high an emissivity as possible in order to maximize the heat-transfer rate and thereby maximize temperature-monitoring performance and (2) the thermocouples must be joined to the rings in such a way as to ensure long-term, reliable intimate thermal contact. The problem of fabricating a BBS to satisfy these requirements is complicated by an application-specific prohibition against overheating and thereby damaging nearby instrumentation leads through the use of conventional furnace brazing or any other technique that involves heating the entire BBS and its surroundings. The problem is further complicated by another application-specific prohibition against damaging the thin tantalum thermocouple sheaths through the use of conventional welding to join the thermocouples to the ring. The first BBS rings were made of graphite. The tantalum-sheathed thermocouples were attached to the graphite rings by use of high-temperature graphite cements. The ring/thermocouple bonds thus formed were found to be weak and unreliable, and so graphite rings and graphite cements were abandoned. Now, each BBS ring is made from one of two materials: either tantalum or a molybdenum/titanium/zirconium alloy. The tantalum

  18. Robust Joining Technology for Solid Oxide Fuel Cells Applications

    Science.gov (United States)

    Shpargel, Tarah P.; Needham, Robert J.; Singh, M.; Kung, S. C.

    2004-01-01

    Recently there has been a great deal of interest in research development and commercialization of solid oxide fuel cells (SOFCs). Joining and sealing are critical issues that will need to be addressed before SOFCs can truly perform as expected. Ceramics and metals can be difficult to join together, especially when the joint must withstand up to 900 C operating temperature of the SOFCs. The goal of the present study is to find the most suitable braze material for joining of yttria stabilized zirconia (YSZ) to stainless steel. A number of commercially available braze materials TiCuSil, TiCuNi, Copper-ABA, Gold-ABA and Gold-ABA-V have been evaluated. The oxidation behavior of the braze materials and steel substrates in air was also examined through thermogravimetric analysis. The microstructure and composition of the brazed regions have been examined by optical and scanning electron microscopy and eDS analysis. Effect of braze composition and processing conditions on the interfacial microstructure and composition of the joint regions will be presented.

  19. 汽车空调压缩机吸入管钎焊工艺设计%Design of soldering process for suction pipe in automobile air conditioning compressor

    Institute of Scientific and Technical Information of China (English)

    王红宾; 白钢; 付春坤

    2012-01-01

    吸入管与压缩机连接处的制冷剂泄漏是汽车空调系统的常见问题,制冷剂泄漏严重影响压缩机效率,并增加能耗、污染环境.在现有钎焊工艺的基础上,结合生产实际,设计和优化钎焊工艺参数,改善钎焊接头性能,提高焊接质量,解决汽车空调压缩机吸入管的泄漏问题.利用UG三维软件设计效率更高、更便捷的钎焊工装夹具,以提高生产效率.%The leakage of refrigerants which seriously impact on the compressor efficiency and increase energy consumption and environmental pollution is the common problems of automotive air conditioning system in the place that the suction pipe and compressor connection.Based on the existing brazing process,combining with practices,this paper designs and optimizes brazing process parameters to improve the performance of brazing joint and brazing quality and solve problems that the suction pipe of automobile air-conditioner compressor leaks.Using UG 3D software,designs brazing jig that is more efficient and convenient to improve production efficiency.

  20. NEW HIGH STRENGTH AND FASTER DRILLING TSP DIAMOND CUTTERS

    Energy Technology Data Exchange (ETDEWEB)

    Robert Radtke

    2006-01-31

    The manufacture of thermally stable diamond (TSP) cutters for drill bits used in petroleum drilling requires the brazing of two dissimilar materials--TSP diamond and tungsten carbide. The ENDURUS{trademark} thermally stable diamond cutter developed by Technology International, Inc. exhibits (1) high attachment (shear) strength, exceeding 345 MPa (50,000 psi), (2) TSP diamond impact strength increased by 36%, (3) prevents TSP fracture when drilling hard rock, and (4) maintains a sharp edge when drilling hard and abrasive rock. A novel microwave brazing (MWB) method for joining dissimilar materials has been developed. A conventional braze filler metal is combined with microwave heating which minimizes thermal residual stress between materials with dissimilar coefficients of thermal expansion. The process results in preferential heating of the lower thermal expansion diamond material, thus providing the ability to match the thermal expansion of the dissimilar material pair. Methods for brazing with both conventional and exothermic braze filler metals have been developed. Finite element modeling (FEM) assisted in the fabrication of TSP cutters controllable thermal residual stress and high shear attachment strength. Further, a unique cutter design for absorbing shock, the densification of otherwise porous TSP diamond for increased mechanical strength, and diamond ion implantation for increased diamond fracture resistance resulted in successful drill bit tests.

  1. Fabrication of High-Temperature Heat Exchangers by Plasma Spraying Exterior Skins on Nickel Foams

    Science.gov (United States)

    Hafeez, P.; Yugeswaran, S.; Chandra, S.; Mostaghimi, J.; Coyle, T. W.

    2016-06-01

    Thermal-sprayed heat exchangers were tested at high temperatures (750 °C), and their performances were compared to the foam heat exchangers made by brazing Inconel sheets to their surface. Nickel foil was brazed to the exterior surface of 10-mm-thick layers of 10 and 40 PPI nickel foam. A plasma torch was used to spray an Inconel coating on the surface of the foil. A burner test rig was built to produce hot combustion gases that flowed over exposed face of the heat exchanger. Cooling air flowed through the foam heat exchanger at rates of up to 200 SLPM. Surface temperature and air inlet/exit temperature were measured. Heat transfer to air flowing through the foam was significantly higher for the thermally sprayed heat exchangers than for the brazed heat exchangers. On an average, thermally sprayed heat exchangers show 36% higher heat transfer than conventionally brazed foam heat exchangers. At low flow rates, the convective resistance is large (~4 × 10-2 m2 K/W), and the effect of thermal contact resistance is negligible. At higher flow rates, the convective resistance decreases (~2 × 10-3 m2 K/W), and the lower contact resistance of the thermally sprayed heat exchanger provides better performance than the brazed heat exchangers.

  2. Study on Interface Structure and Bond Properties between Cemented Carbide and Tool Steel Blazing with amorphous alloy

    Institute of Scientific and Technical Information of China (English)

    Bao Ming-dong; Xu Jin-fu; Xu Xue-bo; Zou Gui-sheng; Huang Geng-hua

    2004-01-01

    Cemented Carbide YG11C and Tool Steel Crl2MoV was blazed with Ni-base amorphous alloys, QG-1011,MBF-20 and MBF-75, using dynamics thermodynamics analogue testing machine Gleeble 1500D. The effects of brazing temperature, holding time and holding pressure on micro-structure and bond strength were investigated. Results showed that YG11C and Cr12MoV were all wetted well by these three Ni-base alloys, and the bond strength was as high as 220MPa,320MPa, 320MPa respectively. When the blazing temperature was at the point over the melting point 60-70℃ of Ni-base alloy, the holding time was about 2-10min, the suitable pressure was benefit for improving the brazing quality.Microanalysis showed Co in cemented carbide diffused into liquid brazing alloy and formed the Fe-Co solid .solution.

  3. Manufacturing of indigenous RF cavity for Indus-2

    International Nuclear Information System (INIS)

    At present four, 505.8 MHz, imported copper RF cavities are being used in Indus-2 synchrotron radiation source. These cavities are used to impart energy to the electron beam to attain the required energy level and also maintain it. From first stage of accelerator i.e booster synchrotron the electron beam is injected into Indus-2 ring where the beam energy is increased from 550 MeV to 2.5 GeV using these cavities. Indigenous developmental work is initiated to fabricate RF cavities using in-house manufacturing facilities. For fabrication of this cavity various innovative tasks were executed which includes, development of forming tools, optimization of machining parameters, development of cutting tools, various brazing trials, brazing procedure qualification, design and development of machining and brazing fixtures, optimization of chemical cleaning procedure etc. The paper also discusses about specifications of the cavity, its vacuum testing and RF testing results. (author)

  4. Development of laser welded appendages to Zircaloy-4 fuel tubing (sheath/cladding)

    International Nuclear Information System (INIS)

    Highlights: • Examines feasibility of laser welding appendages to Zr-4 tubing. • Laser welding minimizes the HAZ and removes toxic Be. • Mechanical properties of laser welds appear competitive with induction brazed joints. • Work appears promising and lays the foundation for further investigations. - Abstract: Laser welding is a potential alternative to the induction brazing process commonly used for appendage attachment in CANDU® fuel fabrication that uses toxic Be as a filler metal, and creates multiple large heat affected zones in the sheath. For this work, several appendages were laser welded to tubing using different laser heat input settings and then examined with a variety of techniques: visual examination, metallography, shear strength testing, impact testing, and fracture surface analysis. Where possible, the examination results are contrasted against production induction brazed joints. The work to date looks promising for laser welded appendages. Further work on joint optimization, corrosion testing, irradiation testing, and post-irradiation examination will be performed in the future

  5. Thermo-mechanical tests of a CFC divertor mock-up

    Science.gov (United States)

    Cardella, A.; Akiba, M.; Duwe, R.; Di Pietro, E.; Suzuki, S.; Satoh, K.; Reheis, N.

    1994-04-01

    Thermo-mechanical tests have been performed on a divertor mock-up consisting of a metallic tube armoured with five carbon fibre composite tiles. The tube is inserted inside the tiles and brazed with TiCuSil braze (monoblock concept). The tube material is TZM, a molybdenum alloy, and the armour material is SEP CARB N112, a high conductivity carbon-carbon composite. Using special surface preparation consisting of laser drilling, small (˜- 500 μm) holes in the composite have been made to increase the surface wetted by the braze and the resistance. The mock-up has been tested at the JAERI 400 kW electron beam test facility JEBIS. The aim of the test was to assess the performance of the mock-up in screening and thermal fatigue tests with particular attention to the behaviour of the armour to heat sink joint.

  6. Effects of Al2O3-Particulate-Contained Composite Filler Materials on the Shear Strength of Alumina Joints

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    All2O3/Al2O3 joints were brazed with a new kind of filler materials, which were formed by adding Al2O3 particulates into Ag-Cu-Ti active filler metal. The results showed that the material parameters (the Ti content, Al2O3 particulate volume fraction) of the composite filler materials affected the shear strength of brazed joints. When the Ti content was 2 wt pct in the filler metal, the shear strength of brazing joints decreased with the increasing the volume ratio of Al2O3 particulate. When the Ti content was 3 wt pct in the filler metal, the shear strength of joints increased from 93.75 MPa(Al2O3p 0 vol. pct) to 135.32 MPa(Al2O3p 15 vol. pct).

  7. Effect of La2O3 Nanoparticles on the Brazeability, Microstructure, and Mechanical Properties of Al-11Si-20Cu Alloy

    Science.gov (United States)

    Sharma, Ashutosh; Roh, Myung Hwan; Jung, Jae Pil

    2016-06-01

    The Al-11Si-20Cu brazing alloy and its ex situ composite with the content ranging from 0.01 to 0.05 wt.% of La2O3 are produced by electromagnetic induction-cum-casting route. The brazeability of the alloy and composite samples are tested using the spreading technique according to JIS Z-3197 standard. The mechanical properties such as filler microhardness, tensile shear strength, and elongation of the brazed joints are evaluated in the as-brazed condition. It is reported that incorporation of an optimal amount of 0.05 wt.% of hard La2O3 nanoparticles in the Al-Si-Cu matrix inhibits the growth of the large CuAl2 intermetallic compounds (IMCs) and Si particles. As a consequence, the composite filler brazeability, microhardness, joint tensile shear strength, and elongation are improved significantly compared to those of monolithic Al-11Si-20Cu alloy.

  8. Ultrasonic Spectroscopy of Stainless Steel Sandwich Panels

    Science.gov (United States)

    Cosgriff, Laura M.; Lerch, Bradley A.; Hebsur, Mohan G.; Baaklini, George Y.; Ghosn, Louis J.

    2003-01-01

    Enhanced, lightweight material systems, such as 17-4PH stainless steel sandwich panels are being developed for use as fan blades and fan containment material systems for next generation engines. In order to improve the production for these systems, nondestructive evaluation (NDE) techniques, such as ultrasonic spectroscopy, are being utilized to evaluate the brazing quality between the 17-4PH stainless steel face plates and the 17-4PH stainless steel foam core. Based on NDE data, shear tests are performed on sections representing various levels of brazing quality from an initial batch of these sandwich structures. Metallographic characterization of brazing is done to corroborate NDE findings and the observed shear failure mechanisms.

  9. Joining of SiC Fiber-Bonded Ceramics using Silver, Copper, Nickel, Palladium, and Silicon-Based Alloy Interlayers

    Energy Technology Data Exchange (ETDEWEB)

    Asthana, Rajiv [University of Wisconsin-Stout, Menomonie; Singh, Mrityunjay [NASA-Glenn Research Center, Cleveland; Lin, Hua-Tay [ORNL; Matsunaga, Kenji [Ube Industries, Ltd.; Ishikawa, Toshihiro [Ube Industries, Ltd.

    2013-01-01

    SiC fiber-bonded ceramics, SA-Tyrannohex, (SA-THX) with perpendicular and parallel fiber orientations were brazed using Ag-, Ni- and Pd-base brazes, and four Si X (X: Ti, Cr, Y, Ta) eutectics. Outcomes were variable, ranging from bonded joints through partially bonded to un-bonded joints. Prominent Ti- and Si-rich interfaces developed with Cusil-ABA, Ticusil, and Copper-ABA and Ni- and Si-rich layers with MBF-20. Stress rupture tests at 650 and 750 C on Cusil-ABA-bonded joints revealed a temperature-dependent behavior for the perpendicular joints but not for the parallel joints with failure occurring at brazed interface. Higher-use temperatures can be targeted with eutectic Si Ti and Si Cr alloys.

  10. Electrochemical profiling of multi-clad aluminium sheets used in automotive heat exchangers

    DEFF Research Database (Denmark)

    Bordo, Kirill; Ambat, Rajan; Peguet, Lionel;

    2014-01-01

    a localized electrochemical cell and GDOES sputtering. Galvanic corrosion behaviour of individual cladding lay-ers was studied by ZRA in a conventional electrochemical cell. The changes in the microstructure of the material caused by the brazing process were investigated by scanning electron microscopy (SEM...... was profiled using a combination of glow dis-charge optical emission spectroscopy (GDOES) sputtering, localized potentiodynam-ic polarization and zero resistance ammetry (ZRA) measurements. Multi-clad struc-ture used was a four layer sandwich consisting of a copper-containing AA3xxx long-life core alloy, AA......4343 brazing clad on both sides and a copper-free AA3xxx interlay-er on the air-side of the sandwich sheet. The polarization behaviour of both as-rolled and brazed materials (i.e. corrosion potential, pitting potential, cathodic and anodic reactivities) was determined as a function of depth using...

  11. Material studies in the frame of CLIC Accelerating structures production conducted within the Mechanics program together with Metso Oy

    CERN Document Server

    Nurminen, Janne

    2012-01-01

    MeChanICs (Marie Curie Linking Industry to CERN) is an Industry to Academia Partnership and Pathways (IAPP) platform for precision manufacturing knowledge exchange bringing together five Finnish manufacturing companies with Helsinki Insitute of Physics (HIP) and CERN. The scientific objective of MeChanICs project is to contribute to the manufacturing RTD of CLIC enabling technologies. The focus is on the design, materials, machining, brazing and assembly of A CLIC accelerating structure. This study deals with the materials work package of the program and wants to explore the following items: 1) producing copper accelerating structures for CLIC from raw copper powder by near net shape hot isostatic pressing (HIP). 2) The feasibility to use HIP diffusion bonding of the accelerator structures as a function of surface quality and applied temperature and pressure. 3) Brazing for CLIC AS auxiliary systems, like water cooling or damping manifolds, to the disc stack by coating one of the brazing partners with an enab...

  12. 中国古青铜器表面富锡铜鎏镀及鎏焊的工艺探索第二部分——鎏镀的原理及工艺设计%Technological study on amalgam coating and brazing of tin-rich copper on surface of bronze wares of ancient China—Part Ⅱ.Principle and process design of amalgam coating

    Institute of Scientific and Technical Information of China (English)

    吴元康; 储荣邦

    2012-01-01

    The major roles of Cu, Sn, Pd, and Hg in amalgam coating material, the principle of metallurgical reactions between the elements, and the phase transformation involved in the process of removing mercury by heating were described. Three formulations of Sn-rich copper powder for amalgam coating were designed to reproduce antique bronze mirrors. The pretreatment of bronze wares, the preparation of amalgam coating material and its coating method, and the operation procedure of mercury removal by heating were introduced. The reasons why the Sn-rich coatings on ancient bronze wares are produced by amalgam coating of Sn-rich copper were presented.%阐述了鎏镀料中铜、锡、铅、汞的主要作用,以及加热驱汞时各元素之间冶金反应的原理和物相变化.以仿古青铜镜为例,设计了3种鎏镀用富锡铜粉的配方,介绍了青铜件的镀前处理,汞齐涂料配制和涂抹的方法,以及加热驱汞的操作步骤.指出了古青铜器表面富锡镀层为鎏镀富锡铜的依据.

  13. 中国古青铜器表面富锡铜鎏镀及鎏焊的工艺探索 第一部分——富锡铜鎏镀在古青铜器中的应用%Technological study on amalgam coating and brazing of tin-rich copper on surface of bronze wares of ancient China—Part Ⅰ.Application of amalgam coating of tin-rich copper in ancient bronze wares

    Institute of Scientific and Technical Information of China (English)

    吴元康; 储荣邦

    2012-01-01

    The ancient bronze wares with Sn-rich copper coatings on their surfaces were introduced based on the archaeological findings in China. The definition and classification of amalgam coating were described. It is pointed out that most ancient bronze wares were treated by amalgam coating of Sn-rich copper, not by hot-dip plating or other processes. The removal of Hg by heating after amalgam coating and the decomposition of Sn7-9Hg in soil lead to the fact that Hg is undetectable on the surface of ancient bronze wares.%根据出土文物的情况,介绍了表面具有富锡铜层的古青铜器.阐述了鎏镀的定义及分类.指出古青铜器大多经过富锡铜鎏镀工艺处理,而不是热浸镀或其他工艺.认为鎏镀后加热驱汞及Sn7-9Hg在土壤环境中分解,是导致古青铜器表面测不出汞的原因.

  14. BNL 56 MHz HOM damper prototype fabrication at JLAB

    Energy Technology Data Exchange (ETDEWEB)

    Huque, N.; McIntyre, G.; Daly, E. F.; Clemens, W.; Wu, Q.; Seberg, S.; Bellavia, S.

    2015-05-03

    A prototype Higher-Order Mode (HOM) Damper was fabricated at JLab for the Relativistic Heavy-Ion Collider’s (RHIC) 56 MHz cavity at Brookhaven National Laboratory (BNL). Primarily constructed from high RRR Niobium and Sapphire, the coaxial damper presented significant challenges in electron-beam welding (EBW), brazing and machining via acid etching. The results of the prototype operation brought about changes in the damper design, due to overheating braze alloys and possible multi-pacting. Five production HOM dampers are currently being fabricated at JLab. This paper outlines the challenges faced in the fabrication process, and the solutions put in place.

  15. Discipline report on thermal analyses of M551, M552, and M553 experiments. [on gravity and heat conduction

    Science.gov (United States)

    Muraki, T.; Masubuchi, K.

    1974-01-01

    Reduced gravity does not significantly affect the thermal histories in the M551 specimen, even if molten metal flow pattern is different from that in terrestrial conditions. Thermal histories corresponding to terrestrial experimental conditions were calculated by use of the computer programs. Heat conduction through brazing alloy (M552 experiment) is improved in the Skylab conditions, because of the increased extent, rate and uniformity of braze spreading in space. Effects of reduced gravity on heat flow in the M553 specimen are insignificant, because convection effects appear instantaneously and conduction is a governing factor on the heat flow.

  16. Assessing the influence of heat treatments on γ-TiAl joints

    OpenAIRE

    Guedes, A.; Pinto, A. M. P.; Vieira, M F; Viana, Filomena

    2006-01-01

    The heat treatment of γ-TiAl alloy (Ti-47Al-2Cr-2Nb (at.%)) diffusion brazed joints was investigated. Joining was performed using a Ti/Ni/Ti clad-laminated braze alloy foil at 1050 and 1150ºC with a dwell time of 10 minutes. The joints were subsequently heat treated at 1250 and 1350ºC for 240 and 30 minutes, respectively. The microstructure and the chemical composition of the interfaces were analysed by scanning electron microscopy (SEM) and by energy dispersive X-ray spectroscopy (EDS), r...

  17. BNL 56 MHz HOM Damper Prototype Fabrication at JLab

    Energy Technology Data Exchange (ETDEWEB)

    Huque, Naeem A. [Jefferson Lab., Newport News, VA (United States); Daly, Edward F. [Jefferson Lab., Newport News, VA (United States); Clemens, William A. [Jefferson Lab., Newport News, VA (United States); McIntyre, Gary T. [Brookhaven National Lab. (BNL), Upton, NY (United States); Wu, Qiong [Brookhaven National Lab. (BNL), Upton, NY (United States); Seberg, Scott [Brookhaven National Lab. (BNL), Upton, NY (United States); Bellavia, Steve [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-09-01

    A prototype Higher-Order Mode (HOM) Damper was fabricated at JLab for the Relativistic Heavy-Ion Collider's (RHIC) 56 MHz cavity at Brookhaven National Laboratory (BNL). Primarily constructed from high RRR Niobium and Sapphire, the coaxial damper presented significant challenges in electron-beam welding (EBW), brazing and machining via acid etching. The results of the prototype operation brought about changes in the damper design, due to overheating braze alloys and possible multi-pacting. Five production HOM dampers are currently being fabricated at JLab. This paper outlines the challenges faced in the fabrication process, and the solutions put in place.

  18. Fracture analysis of Ag nanobrazing of NiTi to Ti alloy

    Energy Technology Data Exchange (ETDEWEB)

    Quintino, L., E-mail: lquirino@ist.utl.pt [Universidade Tecnica de Lisboa (IST/UTL) (Portugal). Instituto Superior Tecnico. Dept. de Engenharia Mecanica; Liu, L., E-mail: ray.plasma@gmail.com [Tsinghua Univ., Beijing (China). Dept. of Mechanical Engineering; Hu, A.; Zhou, Y., E-mail: anming.hu@uwaterloo.ca, E-mail: nzhou@uwaterloo.ca [University of Waterloo, Ontario (Canada). Dept. of Mechanical Engineering; Miranda, R.M., E-mail: rmiranda@fct.unl.pt [Universidade Nova de Lisboa (UNIDEMI), Caparica (Portugal). Dept. de Engenharia Mecanica e Industrial

    2013-07-15

    Dissimilar joining of shape memory alloys to Ti alloys has long been attempted by several research groups due to the foreseen potential industrial applications. However, the very dissimilar thermo-physical properties of both materials place several difficulties. Brazing can be a solution since the base materials are subjected to a less sharp thermal cycle. In the present study brazed overlap joints of 1 mm thick plates of equiatomic Ni Ti and Ti6Al4V were produced using nano silver based filler materials. Surfaces were analyzed to asses the type of fracture and the capability of achieving bonding and involved mechanisms are discussed. (author)

  19. Tensile, Fatigue and Creep Properties of Aluminum Heat Exhanger Tube Alloys for Temperatures from 293 K to 573 K (20°C to 300°C)

    OpenAIRE

    Kahl, Sören; Ekström, Hans-Erik; Mendoza, Jesus

    2014-01-01

    Since automotive heat exchangers are operated at varying temperatures and under varying pressures, both static and dynamic mechanical properties should be known at different temperatures. Tubes are the most critical part of the most heat exchangers made from aluminum brazing sheet. We present tensile test, stress amplitude-fatigue life, and creep–rupture data of six AA3XXX series tube alloys after simulated brazing for temperatures ranging from 293 K to 573 K (20 °C to 300 °C). While correlat...

  20. Joining of ceramic Ba0.5Sr0.5Co0.8Fe0.2O3 membranes for oxygen production to high temperature alloys

    DEFF Research Database (Denmark)

    Kiebach, Wolff-Ragnar; Engelbrecht, Kurt; Kwok, Kawai;

    2016-01-01

    The possibility of joining dense ceramic BCSF tubular membranes to metal alloys using a silver braze was investigated. Four different alloys (Crofer 22 APU (R), Kanthal APM (R), Haynes 214 (R) and EN 1.4841) were considered and the influence of their oxide scale stability/reactivity and their the......The possibility of joining dense ceramic BCSF tubular membranes to metal alloys using a silver braze was investigated. Four different alloys (Crofer 22 APU (R), Kanthal APM (R), Haynes 214 (R) and EN 1.4841) were considered and the influence of their oxide scale stability...

  1. Titanium honeycomb structure. [for supersonic aircraft wing structure

    Science.gov (United States)

    Davis, R. A.; Elrod, S. D.; Lovell, D. T.

    1972-01-01

    A brazed titanium honeycomb sandwich system for supersonic transport wing cover panels provides the most efficient structure spanwise, chordwise, and loadwise. Flutter testing shows that high wing stiffness is most efficient in a sandwich structure. This structure also provides good thermal insulation if liquid fuel is carried in direct contact with the wing structure in integral fuel tanks.

  2. USE OF A COBALT BASED METALLIC-GLASS IN JOINING MOSI2 TO STAINLESS STEEL

    Energy Technology Data Exchange (ETDEWEB)

    R. VAIDYA; P. RANGASWAMY; ET AL

    2001-04-01

    The successful use of a cobalt-based metallic-glass in joining molybdenum disilicide (MoSi{sub 2}) to stainless steel 316L was demonstrated. Such joints are being investigated for sensor tube applications in glass melting operations. The cobalt-based metallic-glass (METGLAS{trademark} 2714A) was found to wet the MoSi{sub 2} and stainless steel surfaces and provide high quality joints. Joining was completed at 1050 C for 60 minutes in two different ways; either by feeding excess braze into the braze gap upon heating or by constraining the MoSi{sub 2}/stainless steel assembly with an alumina (Al{sub 2}O{sub 3}) fixture during the heating cycle. These steps were necessary to ensure the production of a high quality void free joint. Post-brazing metallographic evaluations coupled with quantitative elemental analysis indicated the presence of a Co-Cr-Si ternary phase with CoSi and CoSi{sub 2} precipitates within the braze. The residual stresses in these molybdenum disilicide (MoSi{sub 2})/stainless steel 316 L joints were evaluated using X-ray diffraction and instrumented indentation techniques. These measurements revealed that significant differences are induced in the residual stresses in MoSi{sub 2} and stainless steel depending on the joining technique employed. Push-out tests were carried out on these joints to evaluate the joint strength.

  3. Use of a cobalt-based metallic glass for joining MoSi{sub 2} to stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Vaidya, R.U.; Rangaswamy, P.; Misra, A.; Gallegos, D.E.; Castro, R.G.; Petrovic, J.J. [Los Alamos National Lab., NM (United States). Materials Science and Technology Div.; Butt, D.P. [Florida Univ., Gainesville, FL (United States). Dept. of Materials Science and Engineering

    2002-07-01

    The successful use of a cobalt-based metallic glass in joining molybdenum disilicide (MoSi{sub 2}) to stainless steel 316L was demonstrated. Such joints are being investigated for sensor tube applications in glass melting operations. The cobalt-based metallic-glass (METGLAS{sup TM} 2714A) was found to wet the MoSi{sub 2} and stainless steel surfaces and provide high quality joints. Joining was completed at 1050 C for 60 minutes in two different ways; either by feeding excess braze into the braze gap upon heating or by constraining the MoSi{sub 2}/stainless steel assembly with an alumina (Al{sub 2}O{sub 3}) fixture during the heating cycle. These steps were necessary to ensure the production of a high quality void free joint. Post-brazing metallographic evaluations coupled with quantitative elemental analysis indicated the presence of a Co-Cr-Si ternary phase with CoSi and CoSi{sub 2} precipitates within the braze. The residual stresses in these molybdenum disilicide (MoSi{sub 2})/stainless steel 316 L joints were evaluated using X-ray diffraction and instrumented indentation techniques. These measurements revealed that significant differences are induced in the residual stresses in MoSi{sub 2} and stainless steel depending on the joining technique employed. Push-out tests were carried out on these joints to evaluate the joint strength. (orig.)

  4. Fabrication and characterization of tungsten and graphite based PFC for divertor target elements of ITER like tokamak application

    Energy Technology Data Exchange (ETDEWEB)

    Khirwadkar, S.S., E-mail: sameer@ipr.res.in [Institute For Plasma Research, Bhat, Gandhinagar, Gujarat (India); Singh, K.P.; Patil, Y.; Khan, M.S.; Buch, J.J.U.; Patel, Alpesh; Tripathi, Sudhir [Institute For Plasma Research, Bhat, Gandhinagar, Gujarat (India); Jaman, P.M.; Rangaraj, L.; Divakar, C. [Materials Science Division, National Aerospace Laboratories, CSIR, Bangalore, Karnataka (India)

    2011-10-15

    The development of the fabrication technology of macro-brush configuration of tungsten (W) and carbon (graphite and CFC) plasma facing components (PFCs) for ITER like tokamak application is presented. The fabrication of qualified joint of PFC is a requirement for fusion tokamak. Vacuum brazing method has been employed for joining of W/CuCrZr and C/CuCrZr. Oxygen free high conductivity (OFHC) copper casting on W tiles was performed followed by machining, polishing and ultrasonic cleaning of the samples prior to vacuum brazing. The W/CuCrZr and graphite/CuCrZr based test mockups were vacuum brazed using silver free alloys. The mechanical shear and tensile strengths were evaluated for the W/CuCrZr and graphite/CuCrZr brazed joint samples. The micro-structural examination of the joints showed smooth interface. The details of fabrication and characterization procedure for macro-brush tungsten and carbon based PFC test mockups are presented.

  5. Transient thermal behavior of multilayer media: Modeling and application to stratified moulds

    Science.gov (United States)

    Lazard, M.

    2006-07-01

    Transient and steady-state heat transfer in multilayer media is investigated by the thermal quadrupole method. A semi-analytical solution is proposed for the cases of layers parallel or orthogonal to the main heat-flux direction. The principal application is the study of the effect of the brazing metal used in stratified steel moulds.

  6. 29 CFR 1910.252 - General requirements.

    Science.gov (United States)

    2010-07-01

    ... atmospheres penetrated by the ultraviolet radiation of gas-shielded welding operations. (12) Cutting of... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Welding, Cutting and Brazing § 1910.252 General requirements. (a) Fire... contractors) and those in management on whose property cutting and welding is to be performed, see...

  7. Bibliography of the technical literature of the Materials Joining Group, Metals and Ceramics Division, 1951 through June 1987

    International Nuclear Information System (INIS)

    This document contains a listing of the written scientific information originating in the Materials Joining Group (formerly the Welding and Brazing Group), Metals and Ceramics Division, Oak Ridge National Laboratory during 1951 through June 1987. It is a registry of about 400 documents as nearly as possible in the order in which they were issued

  8. Standard marking system for valves, fittings, flanges and unions

    International Nuclear Information System (INIS)

    The marking system described applies to valves, fittings, flanges and unions used in piping connections which include flanged, soldered, brazed, threaded or welded joints. These specified markings serve to identify the manufacturer, rating designation, materials of construction, and special service limitations imposed by the manufacturer

  9. Effect of welding processes on corrosion resistance of UNS S31803 duplex stainless steel

    International Nuclear Information System (INIS)

    An attractive combination of corrosion resistance and mechanical properties in the temperature range -50 to 250 .deg. C is offered by duplex stainless steel. However, undesirable secondary precipitation phase such as σ, γ2 and Cr2N may taken place at the cooling stage from the welding processes. Therefore, this paper describes the influence of different welding procedures such as manual metal arc welding (MMA), tungsten inert gas welding (TIG) and vacuum brazing on corrosion resistance of the welded joint for UNS S31803 duplex stainless steel. Microstructure and chemical compositions of the welded joint were examined. The weight loss of specimens immersed in 6% FeCl3 solution at 47.5 .deg. C for 24-hours was determined and used to evaluate the pitting resistance of duplex stainless steel and their welds. The region of heat-affected zone of specimen obtained by the MMA is much wider than that resulted from TIG, therefore, the weight loss of welds by MMA was larger than that of weld by TIG. The weight loss of brazed specimens cooled from slow cooling rate was larger than those of specimens cooled from high cooling rate, because the precipitation of σ phase. Beside that, the weight loss of brazed specimen is greater than those of the welded specimens. The galvanic corrosion was observed in brazed duplex stainless steel joints in the chloride solution

  10. 29 CFR 1910.253 - Oxygen-fuel gas welding and cutting.

    Science.gov (United States)

    2010-07-01

    ... accordance with the regulations of the U.S. Department of Transportation, 49 CFR parts 171-179. (ii... reach them, or fire-resistant shields shall be provided. (J) Cylinders shall not be placed where they...) Joints in brass or copper pipe shall be welded, brazed, threaded, or flanged. If of the socket type,...

  11. Vocabulary Does Not Complicate the Simple View of Reading

    Science.gov (United States)

    Braze, David; Katz, Leonard; Magnuson, James S.; Mencl, W. Einar; Tabor, Whitney; Van Dyke, Julie A.; Gong, Tao; Johns, Clinton L.; Shankweiler, Donald P.

    2016-01-01

    Gough and Tunmer's (1986) simple view of reading (SVR) proposed that reading comprehension (RC) is a function of language comprehension (LC) and word recognition/decoding. Braze et al. (2007) presented data suggesting an extension of the SVR in which knowledge of vocabulary (V) affected RC over and above the effects of LC. Tunmer and Chapman…

  12. 76 FR 45655 - Airworthiness Directives; Superior Air Parts and Lycoming Engines (Formerly Textron Lycoming...

    Science.gov (United States)

    2011-08-01

    ... Policies and Procedures (44 FR 11034, February 26, 1979), (3) Will not affect intrastate aviation in Alaska...). Diaphragms produced from specific lot numbers could have stud threads that don't meet design, incomplete braze between the stud and hub, and studs made from lower temper material. Diaphragms from these...

  13. Production of ceramic-metal joints for high-vacuum applications and development of simulation program for discharge tube

    Energy Technology Data Exchange (ETDEWEB)

    Kang, S. H.; Chung, K. H. [Seoul National University, Seoul (Korea)

    2000-04-01

    To develop a ceramic-metal jointed tube for high-vacuum applications, metalizing process and active metal brazing were investigated. Active metal brazing was adopted as a joining process to produce a high-vacuum tube which had high joint strength and reliability. A possibility for the development of new composition of Mo-Mn paste was studied. Also, to improve the strength and reliability of active metal brazed joint, TiN coating was introduced as a diffusion barrier. It was revealed that TiN coating could improve the joint strength and reliability. 100mm {phi} tube joint was produced using incusil ABA brazing alloy. The strength and reliability of manufactured tube showed higher value than commercial one. The electric field distribution in ceramic tube under high voltage was analyzed. Two dimensional electric field distribution was investigated under the existence of charged particles. From this result, electric field distribution at the surface of ceramic tube and the location of high electric field was predicted. Finally, Arc discharge was simulated to analyze the effect of arc discharge on the discharge tube wall. The maximum temperature of arc was 12000-13000K. The wall temperature was increased 100-170K by the arc discharge. 45 refs., 57 figs., 4 tabs. (Author)

  14. Progress in Joining Ceramics to Metals

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The research and development of joining methods of ceramics to metals, especially brazing, diffusion bonding and partial transition liquid phase bonding, were introduced. Some opinions were put forward. For new composites emerging, it is necessary to develop new joining methods, particularly in the field of high temperature technique for joining ceramics to superalloys.

  15. 化学镀

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    3D Stacked Packages With Bumpless Interconnect Technology;?AActive brazing alloy produced by electroless plating technique; Additional effect of electroless plating fihn (damping capacity improvelnent; Adsorbates formed on non-conducting substrates by two-step catalyzation pretreatment for electroless plating;Deposition of Through-Hole Metal Fihn Oll Glass with Electroless Plating

  16. 29 CFR 1910.255 - Resistance welding.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 5 2010-07-01 2010-07-01 false Resistance welding. 1910.255 Section 1910.255 Labor... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Welding, Cutting and Brazing § 1910.255 Resistance welding. (a.... Ignitron tubes used in resistance welding equipment shall be equipped with a thermal protection switch....

  17. Soldadura (Welding). Spanish Translations for Welding.

    Science.gov (United States)

    Hohhertz, Durwin

    Thirty transparency masters with Spanish subtitles for key words are provided for a welding/general mechanical repair course. The transparency masters are on such topics as oxyacetylene welding; oxyacetylene welding equipment; welding safety; different types of welds; braze welding; cutting torches; cutting with a torch; protective equipment; arc…

  18. Energy absorption of andwiched honeycombs with facesheets under in-plane crushing

    NARCIS (Netherlands)

    Atli-Veltin, B.; Gandhi, F.

    2013-01-01

    The in-plane crushing and energy absorption of sandwiched honeycomb cores with facesheets are examined through finite element simulations. Assuming no debonding between the facesheet and honeycomb core (which would be the case if manufacturing techniques such as brazing are used to produce very stro

  19. Improved Air-Treatment Canister

    Science.gov (United States)

    Boehm, A. M.

    1982-01-01

    Proposed air-treatment canister integrates a heater-in-tube water evaporator into canister header. Improved design prevents water from condensing and contaminating chemicals that regenerate the air. Heater is evenly spiraled about the inlet header on the canister. Evaporator is brazed to the header.

  20. Research progress of composite fillers

    Directory of Open Access Journals (Sweden)

    Yixuan ZHAO

    2015-08-01

    Full Text Available Using composite filler is a very potential way to braze dissimilar material, especially braze metals with ceramics. The composite filler which is added varieties of high temperature alloy, carbon fiber and ceramic particles has a suitable coefficient of thermal expansion. The application of composite filler can release the residual stress caused by mismatch of thermal expansion coefficient in the brazing joints and improve the overall performance significantly. According to the traditional classification method of composite materials, the composite filler is divided into micron-reinforced composite filler and nano-reinforced composite filler, of which the feature and research status are discussed in this text. According to the influence of different size reinforced phases on microstructure and mechanical property of the brazing joints, nano-reinforced composite filler has more uniform and better structure compared with micron-reinforced composite filler, and higher joint strengh can be obtained by using it. However, the reinforced mechanism is still an open question, and will become the key area of the future research work.

  1. Preparing for CLIC tests

    CERN Multimedia

    Laurent Guiraud

    1999-01-01

    The Canon 5 undergoes first brazing for preparation in the CLIC study at the CLIC Test Facility 2 (CTF2). This will test injection for a proposed linear collider that will further explore discoveries made at the LHC. Electric fields in the canon will boost electrons into the acceleration fields of the collider.

  2. CW RFQ fabrication and engineering

    International Nuclear Information System (INIS)

    The design and fabrication of a four-vane RFQ to deliver a 100 mA CW proton beam at 6.7 MeV is described. This linac is an Oxygen-Free Electrolytic (OFE) copper structure 8 m in length and was fabricated using hydrogen furnace brazing as the joining technology

  3. 46 CFR 57.05-5 - Low temperature application.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Low temperature application. 57.05-5 Section 57.05-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING WELDING AND BRAZING Performance Qualifications § 57.05-5 Low temperature application. For low temperature application, each...

  4. Energy and technology review

    International Nuclear Information System (INIS)

    Research programs at LLNL are reviewed. This issue discusses validation of the pulsed-power design for FXR, the NOVA plasma shutter, thermal control of the MFTF superconducting magnet, a low-energy x-ray spectrometer for pulsed-source diagnostics, micromachining, the electronics engineer's design station, and brazing with a laser microtorch

  5. Bibliography of the technical literature of the Materials Joining Group, 1951--1991

    Energy Technology Data Exchange (ETDEWEB)

    David, S.A.; Goodwin, G.M.; Gardner, K. [comps.

    1991-12-01

    This document contains a listing of the written scientific information originating in the Materials Joining (formerly the Welding and Brazing Group), Metals and Ceramics Division, Oak Ridge National Laboratory during 1951 through June 1991. This registry of documents is as much as possible, in the order of issue date.

  6. Bibliography of the technical literature of the Materials Joining Group, Metals and Ceramics Division, 1951 through June 1987

    Energy Technology Data Exchange (ETDEWEB)

    David, S.A.; Goodwin, G.M.; Gardner, K. (comps.)

    1987-08-01

    This document contains a listing of the written scientific information originating in the Materials Joining Group (formerly the Welding and Brazing Group), Metals and Ceramics Division, Oak Ridge National Laboratory during 1951 through June 1987. It is a registry of about 400 documents as nearly as possible in the order in which they were issued.

  7. 向 NI-Cr 合金中添加 Ni/C 制备自润滑金刚石工具%Manufacturing of self-lubricating diamond tools with Ni-Cr alloy adding with Ni/C

    Institute of Scientific and Technical Information of China (English)

    孟普; 甘瑞霞

    2015-01-01

    Ni-Cr alloy adding with Ni /C of 3%,5% was utilized to braze diamond grains in protective furnace with the temperature 1 050 ℃ and holding time 5 min,respectively.Diamond morphology and the brazed joint mi-crostructure were analyzed with the help of scanning electron microscope;the brazed joint hardness was measured by Vickers.The results show that Ni-Cr alloy adding with Ni /C has good wettability with diamond;it could a-chieve high strength bonding between diamond and brazing layer.Carbide crystallizes and nucleates on the surface of diamond has an orientation relationship with diamond surface.The Cr7 C3 morphology is hollow and clusters eu-tectic graphite forms in the brazing layer,which has a relationship with the adding Ni /C.There is small amount of Ni /C within brazing layer,the brazed joint hardness falls from 830 HV0.2 to 700 HV0.2,this is benefit to de-crease the thermal stress and improve the protrusion of diamond in the later grinding.%利用添加3%、5%的 Ni-Cr 合金在保护气氛炉中制备金刚石试样,钎焊温度为1050℃,保温5 min。采用扫描电镜分析钎焊金刚石形貌和钎缝的微观组织,维氏硬度计测量接头的硬度。结果表明:添加 Ni /C 的 Ni-Cr 合金对金刚石具有较好的润湿性,可以实现高强度连接,碳化物在金刚石表面形核和结晶长大,与金刚石表面的原子分布具有一定位向关系。钎缝中形成的空心 Cr7C3和簇状共晶石墨与添加的 Ni /C 有关,钎焊层中有少量 Ni /C剩余,硬度从830HV0.2降低到700HV0.2,这有利于降低钎焊热应力和金刚石后期的出露高度。

  8. Joining techniques for core flow test loop fuel rod simulators

    International Nuclear Information System (INIS)

    Laser welding and furnace brazing techniques have been developed to join subassemblies for fuel rod simulators (FRSs) that have survived up to 1000-h steady-state operation at 700 to 11000C cladding temperatures and over 5000 thermal transients, ranging from 10 to 500C/s. A pulsed-laser welding procedure uses small diameter filler wire to join one end of a resistance heating element to a tubular conductor. The other end of the heating element is laser welded to an end plug, which in turn is welded to a central conductor. Before these welding operations, the intermediate material conductors (either tubular or rod) are vacuum brazed to matching copper leads. On room temperature tensile testing, 10 of 11 brazements between copper and nickel rods failed in the copper rather than the brazement. The thin walls and ductility of the copper and nickel tubular conductors caused joint machining and fitup problems. Accordingly, it has not been possible to consistently produce tensile test samples of brazed dissimilar metal tubular conductors that will fail outside the joint area. A unique tubular electrode carrier has also been developed for gas tungsten arc welding FRSs to the tubesheet of a test assembly. Two seven-rod mockups of the simulator-to-tubesheet joint area were welded and successfully cycled 500 times from 3700C (6980F) down to 1000C (2120F) with an internal pressure of 11.72 MPa (1700 psi). No leakage was detected by helium mass spectrometry, either before or after testing. Modified versions of the electrode carrier were developed for brazing electrical leads to the upper ends of the FRSs. Satisfactory brazes have been made on both single-rod mockups and arrays of simulators

  9. Influencia de los parámetros de soldeo fuerte en la microestructura y propiedades mecánicas de la unión de la aleación base níquel Hastelloy B2

    Directory of Open Access Journals (Sweden)

    Sotelo, José Carlos

    2014-09-01

    Full Text Available A study of the high vacuum brazing process of solid solution strengthened Hastelloy B2 nickel alloy has been done. A first stage of research has focused on the selection of the most appropriate brazing filler metal to the base material and vacuum furnace brazing process. The influence of welding parameters on joint microstructure constituents, relating the microstructure of the joint to its mechanical properties, has been evaluated. Two gaps of 50 and 200 micrometers, and two dwell times at brazing temperature of 10 and 90 minutes were studied. The braze joint mainly consists of the nickel rich matrix, nickel silicide and ternary compounds. Finally, the results of this study have shown the high bond strength for small gaps and increased dwell times of 90 minutes.Se realizó un estudio pormenorizado del proceso de soldeo fuerte en horno de alto vacío de la aleación base níquel Hastelloy B2 fortalecida por solución sólida. En una primera fase del trabajo se seleccionó el material de aporte acorde al material objeto de unión y a la fuente de calentamiento seleccionada. Posteriormente, se evaluó la influencia del gap (50 y 200 micrómetros y tiempo de permanencia a temperatura de soldeo (10 y 90 minutos sobre los microconstituyentes de la unión, relacionando la microestructura con las propiedades mecánicas de la junta. Los análisis metalográficos mostraron una unión constituida por una matriz rica en níquel, siliciuros de níquel y compuestos ternarios. Finalmente, los resultados de los ensayos mecánicos a esfuerzos cortantes mostraron una elevada resistencia para gaps de 50 micrómetros y tiempos de permanencia de 90 minutos.

  10. Current state-of-the-art manufacturing technology for He-cooled divertor finger

    International Nuclear Information System (INIS)

    A divertor concept for DEMO has been investigated at Karlsruhe Institute of Technology (KIT) which has to withstand a heat flux of 10 MW/m2. The design utilizes small finger module composed of a small tungsten tile brazed on a thimble made from tungsten alloy. The divertor finger is cooled by helium jet impingement at 10 MPa and 600 deg. C. The subject of this paper is technological studies on machining and braze joining the divertor components. Goal of this task, which is considered an important R and D issue, is to find out appropriate manufacturing methods to ensure high functionality and high reliability of the divertor as well as to meet the economic aspect. One of the major requirements for manufacturing is micro-crack-free surface of tungsten parts, since crack propagations in tungsten were observed in the previous high-heat-flux tests at Efremov. Different manufacturing methods and the corresponding results are discussed in the following report.

  11. Microstructural Characteristics of a Stainless Steel/Copper Dissimilar Joint Made by Laser Welding

    Science.gov (United States)

    Chen, Shuhai; Huang, Jihua; Xia, Jun; Zhang, Hua; Zhao, Xingke

    2013-08-01

    The microstructures and its formation mechanism of a stainless steel/copper dissimilar joint by laser welding were investigated. It was found that the two modes of joining, i.e., welding-brazing and fusion welding, depend on different processing parameters. In the welding-brazing mode, the interface between copper and the fusion zone has scraggy morphology because the molten pool is frozen by solid copper with high thermal conductivity. The interdiffusion of elements occurs in the neighborhood of the interface, which leads to the metallurgy bond of the mode. In the fusion welding mode, the liquid phase in the fusion zone undergoes not only primary but also secondary liquid separation due to the high cooling rate and high supercooling level of laser welding. Some microcracks generated in the fusion zone by thermal stress mismatch are healed by liquid copper filling.

  12. Dissimilar material joining using laser (aluminum to steel using zinc-based filler wire)

    Science.gov (United States)

    Mathieu, Alexandre; Shabadi, Rajashekar; Deschamps, Alexis; Suery, Michel; Matteï, Simone; Grevey, Dominique; Cicala, Eugen

    2007-04-01

    Joining steel with aluminum involving the fusion of one or both materials is possible by laser beam welding technique. This paper describes a method, called laser braze welding, which is a suitable process to realize this structure. The main problem with thermal joining of steel/aluminum assembly with processes such as TIG or MIG is the formation of fragile intermetallic phases, which are detrimental to the mechanical performances of such joints. Braze welding permits a localized fusion of the materials resulting in a limitation on the growth of fragile phases. This article presents the results of a statistical approach for an overlap assembly configuration using a filler wire composed of 85% Zn and 15% Al. Tensile tests carried on these assemblies demonstrate a good performance of the joints. The fracture mechanisms of the joints are analyzed by a detailed characterization of the seams.

  13. Study on Potassium Fluoaluminate Eutectic Flux

    Institute of Scientific and Technical Information of China (English)

    张韻慧; 尹淑梅; 肖莉; 李宁; 张则甡

    2004-01-01

    In this study, Nocolok eutectic flux,used widely in the process of the brazing of aluminum and its alloy, was prepared by the reaction between Al(OH)3/KOH resolution and HF. A series of KF-AlF3 eutectic productions at various reaction temperatures were prepared. The melting points of the products were measured by differential thermal analysis (DTA), and the composites were characterized by X-ray diffraction (XRD). The results suggest that the temperature control is important to produce an ideal flux consisting of K2AlF5, H2O and KAlF4, with a low melting point of 560 ℃,which is suitable for the brazing of aluminum and its alloy as the aluminum fluxes.

  14. Accelerator structure work for NLC

    Energy Technology Data Exchange (ETDEWEB)

    Miller, R.H.; Adolphsen, C.; Bane, K.L.F.; Deruyter, H.; Farkas, Z.D.; Hoag, H.A.; Holtkamp, N.; Lavine, T.; Loew, G.A.; Nelson, E.M.; Palmer, R.B.; Paterson, J.M.; Ruth, R.D.; Thompson, K.A.; Vlieks, A.; Wang, J.W.; Wilson, P.B. [Stanford Linear Accelerator Center, Menlo Park, CA (United States); Gluckstern, R. [Maryland Univ., College Park, MD (United States); Ko, K.; Kroll, N. [Stanford Linear Accelerator Center, Menlo Park, CA (United States)]|[California Univ., San Diego, La Jolla, CA (United States). Dept. of Physics

    1992-07-01

    The NLC design achieves high luminosity with multiple bunches in each RF pulse. Acceleration of a train of bunches without emittance growth requires control of long range dipole wakefields. SLAC is pursuing a structure design which suppresses the effect of wakefields by varying the physical dimensions of successive cells of the disk-loaded traveling wave structure in a manner which spreads the frequencies of the higher mode while retaining the synchronism between the electrons and the accelerating mode. The wakefields of structures incorporating higher mode detuning have been measured at the Accelerator Test Facility at Argonne. Mechanical design and brazing techniques which avoid getting brazing alloy into the interior of the accelerator are being studied. A test facility for high-power testing of these structures is complete and high power testing has begun.

  15. TWTs and klystrons for satellite relay telecommunications systems

    Science.gov (United States)

    Pujes, J. P.

    Earth-station power amplifiers can be equipped with either klystrons or TWTs. Improvements in the field of klystrons has been continuous but not spectacular. Brazed-helix technology enables broadband helix TWTs to operate at high power levels. A 1.5-kW, 6-GHz brazed-helix TWT has achieved an average operating life of 15,000 hours. A 3-kW, 6-GHz tube is being developed, as well as 160-W and 750-W 14-GHz tubes. Coupled-cavity power TWTs are still used at frequencies of 14 GHz and higher. A 1-kW, 30-GHz TWT is being prepared. In the future, gyrotrons might be used at frequencies higher than 30 GHz.

  16. The jointing stress analysis of one-shot seal-off high-voltage vacuum interrupters

    Institute of Scientific and Technical Information of China (English)

    Zhao Zhizhong; Zou Jiyan; Cong Jiyuan; Wen Huabin; Sun Hui

    2006-01-01

    The free shrinkage of ceramic or metal is restricted due to solidification of the solder. Hence the shrinkage stress arises and the jointing strength is reduced during the brazing of high-voltage vacuum interrupters ( HVVIs ) . The solder bound contour was gained by solved energy bound equation. The finite element model of weld beads was established with Surface Evolver software. Then the stress in two different cooling techniques ( natural cooling and force cooling) was calculated with ANSYS. Comparing the stress, a better cooling technique was selected for HVVIs. Its cooling time is shortened by 3 hours while the jointing stress doesn' t increase and the tensile strength of ceramic to metal seal is not decreased. The stress-rupture tests have validated the calculated results. More important, a method is found, by which the brazing technique could be improved in advance instead of blind experiments.

  17. Oceanic corrosion test of bare and zinc-protected aluminum alloys for seawater heat exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Sasscer, D.S.; Ernst, R.; Morgan, T.O.; Rivera, C.; Scott, A.C.; Summerson, T.J.

    1984-01-01

    In a cooperative research effort between The Puerto Rico Center of Energy and Environment Research, Kaiser Aluminum and Chemical Corporation and The Trane Company, a six month study was made of the seawater corrosion performance of various aluminum materials to test their suitability for use in seawater heat exchangers. The materials tested included bare 3004 tubes, 7072 Alclad 3004 tubes and bare and zinc diffusion treated 3003 extrusions from a brazed aluminum, plate-fin heat exchanger extrusions from a brazed aluminium, plate-fin heat exchanger developed by The Trane Company. The test materials were exposed to 1.8 m/sec flowing seawater aboard an open ocean test facility moored 3.4 km off the southeast coast of Puerto Rico. After six months exposure, the average corrosion rates for most varieties of aluminum materials converged to a low value of 0.015 mm/yr (0.6 mils/yr).

  18. Joining SI3N4 for Advanced Turbomachinery Applications

    Energy Technology Data Exchange (ETDEWEB)

    GLASS, S. JILL; LOEHMAN, RONALD E.; HOSKING, F. MICHAEL; STEPHENS JR., JOHN J.; VIANCO, PAUL T.; NEILSEN, MICHAEL K.; WALKER, CHARLES A.; POLLINGER, J.P.; MAHONEY, F.M.; QUILLEN, B.G.

    2000-07-01

    The main objective of this project was to develop reliable, low-cost techniques for joining silicon nitride (Si{sub 3}N{sub 4}) to itself and to metals. For Si{sub 3}N{sub 4} to be widely used in advanced turbomachinery applications, joining techniques must be developed that are reliable, cost-effective, and manufacturable. This project addressed those needs by developing and testing two Si{sub 3}N{sub 4} joining systems; oxynitride glass joining materials and high temperature braze alloys. Extensive measurements were also made of the mechanical properties and oxidation resistance of the braze materials. Finite element models were used to predict the magnitudes and positions of the stresses in the ceramic regions of ceramic-to-metal joints sleeve and butt joints, similar to the geometries used for stator assemblies.

  19. Development and fabrication of 12 Tesla Nb3Sn superconductors

    International Nuclear Information System (INIS)

    Fabrication techniques for large pool boiling conductors for the High Field Test Facility (HFTF), the General Dynamics-Airco 12 T model coil, or a Fusion Engineering Device (FED) are presented. These conductors are manufactured as follows: long continuous segments of a high-current core are fabricated by compacting a cable of small stands in a continuously seam welded copper tube. The operating current of the HFTF conductor is 5000 amp at 12 T. To provide additional wetted surface areas for cooling, the reacted compacted monolith is continuously soldered to embossed copper strips. Bond quality is continuously monitored with ultrasonic testing techniques. The operating current of the General Dynamics-Airco 12 T model coils 12.5 ka at 12 T and the compacted monolithic core is joined to a large aspect ratio copper stabilizer by brazing or diffusion bonding. Properties of brazed joints are reported. 5 refs

  20. Neutron diffraction stress determination in W-laminates for structural divertor applications

    Directory of Open Access Journals (Sweden)

    R. Coppola

    2015-07-01

    Full Text Available Neutron diffraction measurements have been carried out to develop a non-destructive experimental tool for characterizing the crystallographic structure and the internal stress field in W foil laminates for structural divertor applications in future fusion reactors. The model sample selected for this study had been prepared by brazing, at 1085 °C, 13 W foils with 12 Cu foils. A complete strain distribution measurement through the brazed multilayered specimen and determination of the corresponding stresses has been obtained, assuming zero stress in the through-thickness direction. The average stress determined from the technique across the specimen (over both ‘phases’ of W and Cu is close to zero at −17 ± 32 MPa, in accordance with the expectations.

  1. Use of Silicon Carbide as Beam Intercepting Device Material: Tests, Issues and Numerical Simulations

    CERN Document Server

    Delonca, M; Gil Costa, M; Vacca, A

    2014-01-01

    Silicon Carbide (SiC) stands as one of the most promising ceramic material with respect to its thermal shock resistance and mechanical strengths. It has hence been considered as candidate material for the development of higher performance beam intercepting devices at CERN. Its brazing with a metal counterpart has been tested and characterized by means of microstructural and ultrasound techniques. Despite the positive results, its use has to be evaluated with care, due to the strong evidence in literature of large and permanent volumetric expansion, called swelling, under the effect of neutron and ion irradiation. This may cause premature and sudden failure, and can be mitigated to some extent by operating at high temperature. For this reason limited information is available for irradiation below 100°C, which is the typical temperature of interest for beam intercepting devices like dumps or collimators. This paper describes the brazing campaign carried out at CERN, the results, and the theoretical and numeric...

  2. Welding and Joining of Titanium Aluminides

    Directory of Open Access Journals (Sweden)

    Jian Cao

    2014-06-01

    Full Text Available Welding and joining of titanium aluminides is the key to making them more attractive in industrial fields. The purpose of this review is to provide a comprehensive overview of recent progress in welding and joining of titanium aluminides, as well as to introduce current research and application. The possible methods available for titanium aluminides involve brazing, diffusion bonding, fusion welding, friction welding and reactive joining. Of the numerous methods, solid-state diffusion bonding and vacuum brazing have been most heavily investigated for producing reliable joints. The current state of understanding and development of every welding and joining method for titanium aluminides is addressed respectively. The focus is on the fundamental understanding of microstructure characteristics and processing–microstructure–property relationships in the welding and joining of titanium aluminides to themselves and to other materials.

  3. Design of Accelerated Fatigue Tests for Flame Free Refrigeration Fittings

    OpenAIRE

    Wilson, Michael; Bowers, Chad D.

    2014-01-01

    Refrigerant leakage from failed braze joints is a multi-billion dollar problem for the global HVAC&R industry. Leaks are typically caused due to mechanical fatigue from extreme pressure cycling, temperature cycling including exposure to freeze/thaw cycles, or vibrational wear induced from rotating electrical machinery. Three tests to accelerate mechanical fatigue were devised to simulate real world extreme conditions to determine possible failure modes of refrigerant components. The first tes...

  4. Neutron irradiation test of copper alloy/stainless steel joint materials

    OpenAIRE

    山田 弘一; 河村 弘

    2006-01-01

    As a study about the joint technology of copper alloy and stainless steel for utilization as cooling piping in International Thermonuclear Experimental Reactor (ITER), Al2O3-dispersed strengthened copper or CuCrZr was joined to stainless steel by three kinds of joint methods (casting joint, brazing joint and friction welding method) for the evaluation of the neutron irradiation effect on joints. A neutron irradiation test was performed to three types of joints and each copper alloy. The avera...

  5. Experimental evaluation of a R134a/CO2 cascade refrigeration plant

    OpenAIRE

    Sanz Kock, Carlos; Llopis Doménech, Rodrigo; Sánchez García-Vacas, Daniel; Cabello López, Ramón; Torrella Alcaraz, Enrique

    2014-01-01

    We present the experimental evaluation of a R134a/CO2 cascade refrigeration plant designed for low evaporation temperature in commercial refrigeration applications. The test bench incorporates two single- stage vapour compression cycles driven by semi hermetic compressors coupled thermally through two brazed plate cascade heat exchangers working in parallel and controlled by electronic expansion valves. The experimental evaluation (45 steady-states) covers evaporating temperatures from -40 to...

  6. Evaluation of corrosion resistance of multi-layered Ti/gass-ceramic interfaces by electrochemical impedance spectroscopy

    OpenAIRE

    Ariza, E.; Rocha, L. A.

    2005-01-01

    Practical applications of metal/ceramic joints can be found in the biomedical field regarding the encapsulation of implantable telemetric devices, the fabrication of crowns and bridges for dental restoration, or in the production of drug delivery systems, biomedical sensors and electrodes. Most of metal/ceramic joints are produced by the active metal brazing technique, which originates a multi-layered interface which should be able of accommodating the abrupt electronic, crystallographic, ...

  7. Final report: Joining of dissimilar materials for fusion reactor applications

    International Nuclear Information System (INIS)

    The research activities in this project include the following: investigation into the microstructure evolution and structure-property relationship of vanadium alloys under simulated joining conditions, development and characterization of vanadium/stainless steel brazed joints, and studies of fracture and failure behaviors of vanadium/stainless steel dissimilar joints. In addition, both short term training and education towards advanced degrees for six students have been accomplished in this project

  8. Considerations of metal joining processes for space fabrication, construction and repair

    Science.gov (United States)

    Russell, C.; Poorman, R.; Jones, C.; Nunes, A.; Hoffman, D.

    A comprehensive evaluation is conducted of candidate processes for metalworking in orbital (vacuum-microgravity) conditions. Attention is given to electron-beam welding, brazing, gas-tungsten arc welding, laser welding, plasma arc welding, and gas-metal arc welding. It is established that several of these processes will be required to cover all foreseeable requirements. Microgravity effects are considered minor, and efforts are being concentrated on problems associated with vacuum conditions and with process-operator safety.

  9. A review of advanced manufacturing technology

    Science.gov (United States)

    Broughton, T.

    1981-03-01

    Joining techniques, hot forming technology, forging technology, investment casting, small cooling hole manufacturing, combustor technology, quality assurance, and chip forming machining of gas turbine engine components are discussed. Electron and laser beam welding; laser hard facing techniques; automatic TIG and plasma welding; diffusion brazing of titanium and nickel alloys; heated die forming: blow forming; superplastic forming; fan and compressor blade forging; and wheel and disk forging from powder superalloys are described.

  10. Multiphysical Simulation of Laser Material Processing

    Science.gov (United States)

    Otto, Andreas; Koch, Holger; Vazquez, Rodrigo Gomez

    Within this paper a multiphysical simulation model is presented that is capable for simulating a wide range of laser processes like e.g. laser beam welding, brazing, cutting, drilling or ablation. Some important aspects of the model are explained more in detail and results from test cases are compared with analytical solutions revealing the high accuracy of the model. Finally exemplary results from process simulations on laser beam remote cutting of steel and laser beam scribing of silicon wafers are given.

  11. Photocathode electron linac for AFEL

    Science.gov (United States)

    Wood, R. L.; Young, L. M.; Aikin, D. J.; Clark, W. L.; DePaula, R. F.; Gladwell, C.; Ledford, J. E.; Martinez, F. A.; Stovall, J. E.

    1993-06-01

    A compact, high brightness accelerator was designed and fabricated by Los Alamos National Laboratory for use in the Advanced Free Electron Laser (AFEL) Facility. A brazed copper, 1300-MHz, 20-MeV structure is suspended within a thermally insulating vacuum vessel. Integral cooling passages allow introduction of cooling water for normal operation, or liquid nitrogen for cryogenic operation. Its exceptional beam quality is expected to enhance the performance of the FEL experiments planned for the AFEL Facility.

  12. Fuzzy Logic Controller based on geothermal recirculating aquaculture system

    OpenAIRE

    Hanaa M. Farghally; Doaa M. Atia; Hanaa T. El-madany; Faten H. Fahmy

    2014-01-01

    One of the most common uses of geothermal heat is in recirculation aquaculture systems (RAS) where the water temperature is accurately controlled for optimum growing conditions for sustainable and intensive rearing of marine and freshwater fish. This paper presents a design for RAS rearing tank and brazed heat exchanger to be used with geothermal energy as a source of heating water. The heat losses from the RAS tank are calculated using Geo Heat Center Software. Then a plate type heat exchang...

  13. Thermal effect on the thermomechanical behavior of contacts in a Traveling Wave Tube (TWT)

    OpenAIRE

    Chbiki, M; Da Silva Botelho, T; Bauzin, J. G.; Laraqi, N.; Jarno, J.-F

    2015-01-01

    International audience A new thermo-elasto-plastic study of the contact between the helix and the rods of the delay line of Traveling Waves Tubes (TWT) was realized. Our study is focused on the analysis of the hot lines shrinking phenomenon. In the studied case, unlike brazed configuration, the contact areas are not perfect, resulting in a diminution of the heat transfer process. In order to maximize the contact area and to homogenize the contact pressure, a soft thermal conductive materia...

  14. Fracture strength of different soldered and welded orthodontic joining configurations with and without filling material

    Directory of Open Access Journals (Sweden)

    Jens Johannes Bock

    2008-10-01

    Full Text Available The aim of this study was to compare the mechanical strength of different joints made by conventional brazing, TIG and laser welding with and without filling material. Five standardized joining configurations of orthodontic wire in spring hard quality were used: round, cross, 3 mm length, 9 mm length and 7 mm to orthodontic band. The joints were made by five different methods: brazing, tungsten inert gas (TIG and laser welding with and without filling material. For the original orthodontic wire and for each kind of joint configuration or connecting method 10 specimens were carefully produced, totalizing 240. The fracture strengths were measured with a universal testing machine (Zwick 005. Data were analyzed by ANOVA (p=0.05 and Bonferroni post hoc test (p=0.05. In all cases, brazing joints were ruptured on a low level of fracture strength (186-407 N. Significant differences between brazing and TIG or laser welding (p<0.05, Bonferroni post hoc test were found in each joint configuration. The highest fracture strength means were observed for laser welding with filling material and 3 mm joint length (998 N. Using filling materials, there was a clear tendency to higher mean values of fracture strength in TIG and laser welding. However, statistically significant differences were found only in the 9-mm long joints (p<0.05, Bonferroni post hoc test. In conclusion, the fracture strength of welded joints was positively influenced by the additional use of filling material. TIG welding was comparable to laser welding except for the impossibility of joining orthodontic wire with orthodontic band.

  15. Boiling of Binary Zeotropic Blends in the Plate Heat Exchanger of the Heat Pump

    Directory of Open Access Journals (Sweden)

    Mezentseva Nadezhda N.

    2016-01-01

    Full Text Available In this paper, we consider the process of boiling in the evaporator of the heat pump. Zeotropic binary refrigerants R32/R152a (30/70% and R32/R134a (30/70% are used as working medium. Calculations are made for brazed plate heat exchanger during boiling of zeotropic blend refrigerants with account of peculiarities of this process. Results of calculation of the heat transfer coefficient for zeotropic blends are given.

  16. A Study of the Surface Quality of High Purity Copper after Heat Treatment

    CERN Document Server

    Aicheler, M; Atieh, S; Calatroni, S; Riddone, G; Lebet, S; Samoshkin, A

    2011-01-01

    Themanufacturing flow of accelerating structures for the compact linear collider, based on diamond-machined high purity copper components, include several thermal cycles (diffusion bonding, brazing of cooling circuits, baking in vacuum, etc.). The high temperature cycles may be carried out following different schedules and environments (vacuum, reducing hydrogen atmosphere, argon, etc.) and develop peculiar surface topographies which have been the object of extended observations. This study presents and discusses the results of scanning electron microscopy (SEM) and optical microscopy investigations.

  17. Development by surface treatment of a high-operating temperature flue gas recuperator. Final report, July 1981-June 1983

    Energy Technology Data Exchange (ETDEWEB)

    Kindlimann, L.E.

    1983-08-25

    A user survey indicated that a significant number of furnaces having the potential for recuperation operate in the 1500/sup 0/ to 1800/sup 0/F temperature range, for which suitable low-cost heat exchanger materials are not available. A literature survey on use of coatings to extend the service temperature capability of low-cost materials such as steels and lower grade stainless steels showed that diffusion aluminide coating from the gaseous phase (i.e., chemical vapor deposition) was the most promising approach. The program plan featured comparison of vendor capabilities using coupons, followed by coating small plate-fin and tubular heat exchanger segments. Most testing was conducted in air at 1600/sup 0/ to 1800/sup 0/F; a few tests were conducted in sea salt-contminated air at 1600/sup 0/F and in SO/sub 2/-contaminated air at 1800/sup 0/F. Three coating vendors were selected to aluminize small coupons for oxidation testing. The samples of 409 stainless steel were coated over one-half the area on each side with Ni-Cr-Si-B filler metal per AMS 4777 (or AWS BNi-2). The same filler metal was used to join together pieces of 0.009-in. Fe-Ti(IF) to achieve a thickness comparable to the other three materials (0.015 to 0.020 in.). With the exception of 409/4777 tested in air at 1800/sup 0/F, at least one coupon specimen of each material lasted through the 5000-h test period in plain air at either 1600/sup 0/ or 1800/sup 0/F. The brazed 409 developed extensive oxidation at the braze-to-parent metal runout line (halfway up the specimen), which then progressed into the 409. Conversely, in the 0.5 percent SO/sub 2/ test, the nickel-based 4777 braze was attacked preferentially. Modified coatings and materials for application to brazed construction were also tested.

  18. Anodic Activation of Aluminum by Trace Element Tin

    OpenAIRE

    Tan, Juan

    2011-01-01

    Anodic activation of commercial and model aluminum alloys in chloride solution became of practical importance in connection with filiform corrosion of painted aluminum sheet in architectural application and aluminum components of brazed heat exchangers. Activation in chloride solution manifests itself in the form of a significant negative shift in the pitting potential relative to pure aluminum and a significant increase in the anodic current output at potentials where aluminum is normally ex...

  19. Bibliography of the technical literature of the Materials Joining Group, Metals and Ceramics Division, 1951--June 1989

    Energy Technology Data Exchange (ETDEWEB)

    David, S.A.; Goodwin, G.M.; Gardner, K. (comps.)

    1989-10-01

    This document contains a listing of the written scientific information originating in the Materials Joining (formerly the Welding and Brazing Group), Metals and Ceramics Division, Oak Ridge National Laboratory during 1951 through June 1989. This registry of documents is as much as possible, in the order of issue date. A complete cross-referenced listing of the technical literature of the Metals and Ceramics Division is also available.

  20. Thermal and mechanical analysis of the Faraday shield for the Compact Ignition Tokamak

    International Nuclear Information System (INIS)

    The antenna for the ion cyclotron resonance heating (ICRH) system of the Compact Ignition Tokamak (CIT) is protected from the plasma environment by a Faraday shield, an array of gas-cooled metallic tubes. The plasma side of the tubes is armored with graphite tiles, which can be either brazed or mechanically attached to the tube. The Faraday shield has been analyzed using finite element codes to model thermal and mechanical responses to typical CIT heating and disruption loads. Four representative materials (Inconel 718, tantalum-10 tungsten, copper alloy C17510, and molybdenum alloy TZM) and several combinations of tube and armor thicknesses were used in the thermal analysis, which revealed that maximum allowable temperatures were not exceeded for any of the four materials considered. The two-dimensional thermal stress analysis indicated Von Mises stresses greater than twice the yield stress for a tube constructed of Inconel 718 (the original design material) for the brazed-graphite design. Analysis of stresses caused by plasma disruption (/rvec J/ /times/ /rvec B/) loads eliminated the copper and molybdenum alloys as candidate tube materials. Of the four materials considered, tantalum-10 tungsten performed the best for a brazed graphite design, showing acceptable thermal stresses (69% of yield) and disruption stresses (42% of yield). A preliminary thermal analysis of the mechanically attached graphite scheme predicts minimal thermal stresses in the tube. The survivability of the graphite tubes in this scheme is yet to be analyzed. 8 refs., 19 figs., 2 tabs

  1. Investigations on Forging Dies with Ceramic Inserts by means of Finite-Element-Analysis

    Science.gov (United States)

    Behrens, B.-A.; Schäfer, F.; Bistron, M.

    2007-05-01

    The tools in hot forging processes are exposed to high thermal and mechanical loadings. Tempering of the tool edge layer occurs as a result of thermal loadings. This leads to a gradual hardness loss of the tool material and increase of wear over forging cycles. Hence, the tool life in hot forging is mainly limited by wear. An extension of the die service life can be achieved by the use of ceramic inserts. The integration of ceramics into the die base plate made of hot-work steel is realised by active brazing, whereby it possible to apply ceramic in region with high wear. It has to be ensured in the design process of ceramic inserts for forging dies that no critical tensile stresses occur in the ceramics. A reliable design of the ceramic inserts is possible only through consideration of brazing and forming process. The development of a Finite-Element-model for the design of forging dies with ceramic inserts is the intention of the work presented in this paper. At first the forging process with a conventional die is analyzed concerning abrasive die wear to identify regions with high wear risk applying a modified Archard model. Based on the results of wear calculation, a forging die with ceramic inserts is investigated in terms of joint stresses at the end of the active brazing process. Subsequently, the forging process considering the residual stresses caused by joining is simulated in order to obtain the die stress in use.

  2. Design modification of the in-pile test section for increase of sealing capability

    International Nuclear Information System (INIS)

    Since KAERI established the fuel test loop (FTL) at HANARO in 2009, KAERI has carried out several experiments to verify the performances of the equipment. Based on the experiments, the design modification of the In-Pile test Section (IPS) has been processed to improve some difficulties such as difficulty in ejecting the inner assembly of the IPS from the pressure vessel, difficulty of the sealing process of the cooling water, etc. At first, because the cooling water of HANARO in KAERI consists of an open-pool type, if a certain shock is generated during the disassembly process, the cooling water can be spattered out of the pool. Therefore, two jacking bolts will be added on the top flange part of the inner assembly to decrease the shock. Second, at the pressure boundary of the IPS where MI-cables go through, the brazing process has been used to seal out the cooling water. However, because the length of the IPS is up to 5.5 meters, it is too difficult and time consuming to carry out the brazing process at the end part of the IPS. Therefore, the brazing process will be replaced with the mechanical sealing structure to simplify the assembly process. (author)

  3. A comparison between finite element modeling and various thermographic non-destructive testing techniques for the quantification of the thermal integrity of macro-brush plasma facing components used in a tokamak

    Science.gov (United States)

    Pandya, Santosh P.; Pandya, Shwetang N.; Patil, Yashashri V.; Krishnan, Deepu S.; Murugesan, Menaka; Sharath, D.; Singh, K. Premjit; Khan, Md. Shoaib; Arafat, M.; Biju, N.; Khirwadkar, Samir S.; Govidarajan, Jagannathan; Venkatraman, B.; Balasubramaniam, Krishnan

    2016-02-01

    The plasma facing components (PFCs) inside a tokamak are typically exposed to extremely high heat flux of the order of MW/m2. The brazing quality between the plasma facing materials (PFMs) and the heat sink will determine the structural integrity and hence the effective service life of these PFCs. Suitable non-destructive testing (NDT) techniques for the pre-qualification of these components are thus essential to evaluate their structural integrity at various stages of their service life. Macro-brush type mockups of prototype PFCs with graphite as PFM have been inspected for their brazing quality using different active Infrared (IR)-thermographic NDT techniques. The results obtained from these techniques are compared and discussed. The brazing quality was quantified by establishing a comparison between the experimental results and the results from Finite Element Analysis (FEA). The percentage of contact between the PFM and the substrate was varied in FEA. FEA results when compared with experiments shows that tiles have different amounts of contact with the substrate ranging between 10% and 80%.

  4. Progress on the Los Alamos heavy-ion injector

    Science.gov (United States)

    Wilson, D. C.; Riepe, K. B.; Ballard, E. O.; Meyer, E. A.; Shurter, R. P.; Van Haaften, F. W.; Humphries, S.

    1986-01-01

    Heavy-ion fusion using an induction linac requires injection of multiple high-current beams from a pulsed electrostatic accelerator at as high a voltage as practical. Los Alamos National Laboratory is developing a 16-beam, 2-MeV, pulsed electrostatic accelerator for Al+ ions. The ion source will use a pulsed metal vapor arc plasma. A biased grid wil control plasma flux into the ion extraction region. This source has achieved a normalized emittance of ɛnlaser fired diverter is being assembled. The ceramic accelerating column sections have been brazed and leak tested. Voltage hold off on a brazed sample was more than doubled by selective removal of the Ticusil braze fillet extending along the ceramic. A scaled test module held 250 kV for 50 μs, giving confidence that the full module can hold 175 kV per section. The pressure vessel should be received in June 1986. High-voltage testing of a 1 MV column will begin by early 1987.

  5. Integration Science and Technology of Silicon-Based Ceramics and Composites:Technical Challenges and Opportunities

    Science.gov (United States)

    Singh, M.

    2013-01-01

    Ceramic integration technologies enable hierarchical design and manufacturing of intricate ceramic and composite parts starting with geometrically simpler units that are subsequently joined to themselves and/or to metals to create components with progressively higher levels of complexity and functionality. However, for the development of robust and reliable integrated systems with optimum performance for high temperature applications, detailed understanding of various thermochemical and thermomechanical factors is critical. Different technical approaches are required for the integration of ceramic to ceramic and ceramic to metal systems. Active metal brazing, in particular, is a simple and cost-effective method to integrate ceramic to metallic components. Active braze alloys usually contain a reactive filler metal (e.g., Ti, Cr, V, Hf etc) that promotes wettability and spreading by inducing chemical reactions with the ceramics and composites. In this presentation, various examples of brazing of silicon nitride to themselves and to metallic systems are presented. Other examples of joining of ceramic composites (C/SiC and SiC/SiC) using ceramic interlayers and the resulting microstructures are also presented. Thermomechanical characterization of joints is presented for both types of systems. In addition, various challenges and opportunities in design, fabrication, and testing of integrated similar (ceramic-ceramic) and dissimilar (ceramic-metal) material systems will be discussed. Potential opportunities and need for the development of innovative design philosophies, approaches, and integrated system testing under simulated application conditions will also be presented.

  6. Sixteen silver wires to assemble 350 kg of copper

    CERN Multimedia

    Alizée Dauvergne

    2010-01-01

    Assembly of the first radiofrequency quadrupole (RFQ) module for the future LINAC4 linear accelerator has just been completed by CERN's Assembly and Forming section (EN) using a technique called vacuum brazing which involves furnace-baking at 800°C and micron precision, leaving absolutely nothing to chance. Serge Mathot (EN/MME) and his team used the vacuum brazing technique to assemble the first RFQ module for the future LINAC4. The future LINAC4 will use four types of accelerating structures, each playing a different role in increasing the energy of the beam. The first of these are the radiofrequency quadrupole modules (RFQ, see box) which accelerate and focus the beam from the start. "The modules are complex items. Each had to be produced in 4 parts, corresponding to the 4 electrodes," explains physicist Serge Mathot, a vacuum brazing specialist in the Engineering (EN) Department. "To work properly, these modules must be aligned to a precision of a few microns. It...

  7. Development of laser welded appendages to Zircaloy-4 fuel tubing (sheath/cladding)

    Energy Technology Data Exchange (ETDEWEB)

    Livingstone, S., E-mail: steve.livingstone@cnl.ca [Canadian Nuclear Laboratories Limited, Chalk River, ON, Canada K0J 1J0 (Canada); Xiao, L. [Canadian Nuclear Laboratories Limited, Chalk River, ON, Canada K0J 1J0 (Canada); Corcoran, E.C.; Ferrier, G.A.; Potter, K.N. [Department of Chemistry and Chemical Engineering, Royal Military College of Canada, Kingston, ON, Canada K7K 7B4 (Canada)

    2015-04-01

    Highlights: • Examines feasibility of laser welding appendages to Zr-4 tubing. • Laser welding minimizes the HAZ and removes toxic Be. • Mechanical properties of laser welds appear competitive with induction brazed joints. • Work appears promising and lays the foundation for further investigations. - Abstract: Laser welding is a potential alternative to the induction brazing process commonly used for appendage attachment in CANDU{sup ®} fuel fabrication that uses toxic Be as a filler metal, and creates multiple large heat affected zones in the sheath. For this work, several appendages were laser welded to tubing using different laser heat input settings and then examined with a variety of techniques: visual examination, metallography, shear strength testing, impact testing, and fracture surface analysis. Where possible, the examination results are contrasted against production induction brazed joints. The work to date looks promising for laser welded appendages. Further work on joint optimization, corrosion testing, irradiation testing, and post-irradiation examination will be performed in the future.

  8. Technical Consultation of the International Space Station (ISS) Internal Active Thermal Control System (IATCS) Cooling Water Chemistry

    Science.gov (United States)

    Gentz, Steven J.; Rotter, Hank A.; Easton, Myriam; Lince, Jeffrey; Park, Woonsup; Stewart, Thomas; Speckman, Donna; Dexter, Stephen; Kelly, Robert

    2005-01-01

    The Internal Active Thermal Control System (IATCS) coolant exhibited unexpected chemical changes during the first year of on-orbit operation following the launch and activation in February 2001. The coolant pH dropped from 9.3 to below the minimum specification limit of 9.0, and re-equilibrated between 8.3 and 8.5. This drop in coolant pH was shown to be the result of permeation of CO2 from the cabin into the coolant via Teflon flexible hoses which created carbonic acid in the fluid. This unexpected diffusion was the result of having a cabin CO2 partial pressure higher than the ground partial pressure (average 4.0 mmHg vs. less than 0.2 mmHg). This drop in pH was followed by a concurrent increasing coolant nickel concentration. No other metal ions were observed in the coolant and based on previous tests, the source of nickel ion was thought to be the boron nickel (BNi) braze intermetallics used in the construction of HXs and cold plates. Specifically, BNi2 braze alloy was used for the IATCS IFHX and BNi3 braze alloy was used for the IATCS Airlock Servicing and Performance Checkout Unit (SPCU) HX and cold plates. Given the failure criticality of the HXs, a Corrosion Team was established by the IATCS CWG to determine the impact of the nickel corrosion on hardware performance life.

  9. Avaliação das propriedades mecânicas de juntas cerâmicas usando fitas amorfas como metal de adição Evaluation of the mechanical properties of ceramic joint using amorphous ribbons as filler metals

    Directory of Open Access Journals (Sweden)

    Danielton Gomes dos Santos

    2009-09-01

    Full Text Available Este trabalho teve como objetivo determinar os melhores parâmetros para brasagem de juntas cerâmicas de Al2O3 pré-metalizadas com Ti por processo a plasma utilizando fitas amorfas de ligas Cu49Ag45Cx e como metal de adição. As ligas foram preparadas em forno a arco, e, posteriormente processadas por melt-spinning, variando conteúdo Ce de 4-6. %. A brasagem foi realizada em forno à vácuo e as seguintes variáveis analisadas: tempo de deposição do filme de Ti e temperatura e tempo de brasagem , que foram relacionados com a resistência à flexão em 3 pontos da junta brazada. A equação de regressão linear foi obtida, e verificou-se a interação entre estes fatores. As superfícies cerâmicas metalizadas apresentaram excelente uniformidade e as juntas brasadas muito boa adesão atingindo valores de resistência à flexão de até 176,8 MPa.This work had as objective to establish de best brazing parameter to joint Al2O3 pre-metalized with Ti by plasma process using amorphous ribbons of Cu49g45Ce x alloys as filler metals. The alloys were prepared in arc furnace and processed by melt-spinning process varying the Ce percentiles from 4 to 6. % . The brazing was accomplished in vacuum furnace and the following variables analyzed: deposition time of Ti film, brazing temperature and brazing times which were related to the brazed joint 3-point bending resistance. The interaction between those factors was obtained by linear regression equation. The metalized ceramic surfaces presented an good uniformity and the joint a very good adhesion reaching bending resistance up to 176,8 MPa.

  10. NaK pool-boiler solar receiver durability bench test. Volume 2: Metallurgical analysis

    Science.gov (United States)

    Goods, S. H.; Bradshaw, R. W.

    1995-01-01

    The principal materials used in the construction of a NaK based pool-boiler were analyzed. The device, operated for 7500 hours, accumulated 1000 thermal cycles to a peak temperature of 750 C. Haynes 230, used to fabricate the pool-boiler vessel, was found to perform satisfactorily. Air-side corrosion of the pool-boiler vessel was insignificant. Internal surface of the alloy exhibited some NaK-induced elemental dissolution; this dissolution was somewhat more extensive where the alloy was exposed to the liquid metal compared to regions exposed only to NaK vapor; however, the corresponding metal loss in all regions was inconsequential, never exceeding more than a few microns. Autogenous seam welds of the alloy responded in a similar fashion, exhibiting only minimal metal loss over the course of the experiment. While there was 50% loss in ductility of the alloy there remained adequate ductility for the anticipated operating environment. An enhanced boiling nucleation surface comprised of stainless steel powder brazed to the vessel ID showed no change in its structure. It remained intact, showing no cracking after repeated thermal cycling. Other materials used in the experiment showed more extensive degradation after exposure to the NaK. IN 600, used to fabricate thermowells, exhibited extensive surface and intergranular dissolution. Grain boundary dissolution was sufficiently severe in one of the thermowells to cause an air leak, resulting in experiment termination. BNi-3, a brazing alloy used to join the pool-boiler vessel, endcaps and thermowells, showed some dissolution where it was exposed to the NaK as well as thermal aging effects. However, all brazes remained structurally sound. A nickel metal ribbon showed catastrophic dissolution, resulting in the formation of deep (greater than 30 (mu)m) pits and cavities. A zirconium metal foil used to getter oxygen from the NaK became extremely brittle.

  11. Progress report

    International Nuclear Information System (INIS)

    This 2000 issue of the activity report of the CEREM (CEA) gives a general overview of the CEREM organization, activities and human resources with some budgetary information. The main activities described concern the materials fabrication for the nuclear industry and for the medical field, the powder metallurgy, the surface treatments, the joining (by electron beam welding, laser welding, brazing), the electrochemical storage of the energy (SOFC, PEMFC, lithium batteries), the robots for nuclear, automotive and aeronautic industries, the mechanical properties and the cracks, the corrosion and physico-chemistry of fluids, the non-destructive testing and the applications and metrology of ionizing radiations. (O.M.)

  12. Laser-welded Dissimilar Steel-aluminum Seams for Automotive Lightweight Construction

    Science.gov (United States)

    Schimek, M.; Springer, A.; Kaierle, S.; Kracht, D.; Wesling, V.

    By reducing vehicle weight, a significant increase in fuel efficiency and consequently a reduction in CO 2 emissions can be achieved. Currently a high interest in the production of hybrid weld seams between steel and aluminum exists. Previous methods as laser brazing are possible only by using fluxes and additional materials. Laser welding can be used to join steel and aluminum without the use of additives. With a low penetration depth increases in tensile strength can be achieved. Recent results from laser welded overlap seams show that there is no compromise in strength by decreasing penetration depth in the aluminum.

  13. Fabrication of a tantalum neutral source heat exchanger

    International Nuclear Information System (INIS)

    The fabrication and testing of the Neutral Source Heat Exchanger (NSHE), a device required for a plutonium isotope separation pilot plant are described. The unit is a circular water-cooled tantalum plate which will have plutonium cast onto it. After the plutonium is cast and machined to final shape, the assembly will serve as a sputtering substrate for the separation process. The cooling water flow path is unique (adjacent logarithmic spirals terminating 180 degress apart) and created several fabrication and testing challenges. A photograph of the lower plate, showing the water channel geometry and brazing filler material, is shown

  14. Stainless steel component with compressed fiber Bragg grating for high temperature sensing applications

    Science.gov (United States)

    Jinesh, Mathew; MacPherson, William N.; Hand, Duncan P.; Maier, Robert R. J.

    2016-05-01

    A smart metal component having the potential for high temperature strain sensing capability is reported. The stainless steel (SS316) structure is made by selective laser melting (SLM). A fiber Bragg grating (FBG) is embedded in to a 3D printed U-groove by high temperature brazing using a silver based alloy, achieving an axial FBG compression of 13 millistrain at room temperature. Initial results shows that the test component can be used for up to 700°C for sensing applications.

  15. A review of the US joining technologies for plasma facing components in the ITER fusion reactor

    International Nuclear Information System (INIS)

    This paper is a review of the current joining technologies for plasma facing components in the US for the International Thermonuclear Experimental Reactor (ITER) project. Many facilities are involved in this project. Many unique and innovative joining techniques are being considered in the quest to join two candidate armor plate materials (beryllium and tungsten) to a copper base alloy heat sink (CuNiBe, OD copper, CuCrZr). These techniques include brazing and diffusion bonding, compliant layers at the bond interface, and the use of diffusion barrier coatings and diffusion enhancing coatings at the bond interfaces. The development and status of these joining techniques will be detailed in this report

  16. Transient-Liquid-Phase and Liquid-Film-Assisted Joining ofCeramics

    Energy Technology Data Exchange (ETDEWEB)

    Sugar, Joshua D.; McKeown, Joseph T.; Akashi, Takaya; Hong, SungM.; Nakashima, Kunihiko; Glaeser, Andreas M.

    2005-02-09

    Two joining methods, transient-liquid-phase (TLP) joining and liquid-film-assisted joining (LFAJ), have been used to bond alumina ceramics. Both methods rely on multilayer metallic interlayers designed to form thin liquid films at reduced temperatures. The liquid films either disappear by interdiffusion (TLP) or promote ceramic/metal interface formation and concurrent dewetting of the liquid film (LFAJ). Progress on extending the TLP method to lower temperatures by combining low-melting-point (<450 C) liquids and commercial reactive-metal brazes is described. Recent LFAJ work on joining alumina to niobium using copper films is presented.

  17. New plates for different types of plate heat exchangers

    OpenAIRE

    Fernandes, Carla S.; Dias, Ricardo P.; João M. Maia

    2008-01-01

    The first patent for a plate heat exchanger was granted in 1878 to Albretch Dracke, a German inventor. The commercial embodiment of these equipments has become available in 1923. However, the plate heat exchanger development race began in the 1930’s and these gasketed plate and frame heat exchangers were mainly used as pasteurizers (e.g. for milk and beer). Industrial plate heat exchangers were introduced in the 1950’s and initially they were converted dairy models. Brazed plate heat exchange...

  18. Development of high-temperature ultrasonic transducers for under-sodium viewing applications

    International Nuclear Information System (INIS)

    PZT type immersion transducers, bonded using pure lead, can be manufactured and operated satisfactorily in sodium at temperatures up to 2800C. A satisfactory technique of braze bonding lithium niobate Z-cut crystal to stainless steel diaphragms has been developed. The bonded diaphragms can be assembled into transducers which are then capable of operation at temperatures up to 6000C. Sealed transducers which had been pre-oxidised, maintained sensitivity for about 70 days when operated at temperatures between 3000C and 5000C. There was subsequently a slow fall in sensitivity with time at temperature. (Author)

  19. High Temperature Ultrasonic Transducer for Real-time Inspection

    Science.gov (United States)

    Amini, Mohammad Hossein; Sinclair, Anthony N.; Coyle, Thomas W.

    A broadband ultrasonic transducer with a novel porous ceramic backing layer is introduced to operate at 700 °C. 36° Y-cut lithium niobate (LiNbO3) single crystal was selected for the piezoelectric element. By appropriate choice of constituent materials, porosity and pore size, the acoustic impedance and attenuation of a zirconia-based backing layer were optimized. An active brazing alloy with high temperature and chemical stability was selected to bond the transducer layers together. Prototype transducers have been tested at temperatures up to 700 °C. The experiments confirmed that transducer integrity was maintained.

  20. FIRE PERMIT NOW ON EDH!

    CERN Multimedia

    TIS General Safety Group or

    2001-01-01

    The electronic version of the Fire Permit form is now active. The aim of the Fire Permit procedure is to reduce the risk of fire or explosion. It is mandatory when performing 'hot work' (mainly activities which involve the use of naked flames or other heat sources - e.g. welding, brazing, cutting, grinding, etc.). Its use is explained in the CERN Fire Protection Code E. (Fire Protection) The new electronic form, which is substantially unchanged from the previous authorizing procedure, will be available on the Electronic Document Handling system (https://edh.cern.ch/) as of 1st September 2001. From this date use of the paper version should be discontinued.

  1. Wetting by Liquid Metals—Application in Materials Processing: The Contribution of the Grenoble Group

    Directory of Open Access Journals (Sweden)

    Nicolas Eustathopoulos

    2015-03-01

    Full Text Available The wettability of ceramics by liquid metals is discussed from both the fundamental point of view and the point of view of applications. The role of interfacial reactions (simple dissolution of the solid in the liquid or formation of a layer of a new compound is illustrated and analysed. Several results are presented in order to illustrate the role of wettability in materials processing, namely infiltration processing, joining dissimilar materials by brazing and selecting crucibles for crystallising liquid metals and semiconductors. The review includes results obtained during the last 15 years mainly, but not only, by the Grenoble group.

  2. Characteristics of deformation joining of aluminum-stainless steel composite sheet

    Institute of Scientific and Technical Information of China (English)

    李培武; 孙康宁; 李爱民; 李中友; 刘秀忠; 栾新民; 徐秀丽

    2003-01-01

    In order to study the characteristics of deformation joining of aluminum-stainless steel composite sheet,an applied example of this composite sheet was given.The conditions of the composite sheet were discussed,the optical micrographs and scanning electron micrographs were examined by contrast ways of deformation joining and braze joining.Simultaneously the analysis of energy spectrum was also conducted.The results indicate that the deformation joining composite sheet possesses high bonding strength,good corrosion resistance,less inclusions and less microcracks.

  3. Vacuum Chamber for the Measurement System of the Beam Energy

    Science.gov (United States)

    Abakumova, E.; Achasov, M.; Dong, HaiYi; Qu, HuaMin; Krasnov, A.; Kosarev, A.; Muchnoi, N.; Pyata, E.; Xiao, Qiong; Mo, XiaoHu; Wang, YiFang; Zhukov, A.

    Vacuum chamber for the beam energy measurement system based on the Compton backscattering method is presented. The main elements of the chamber are GaAs entrance viewport and a copper mirror. The viewport design provides baking out of the vacuum chamber up to 250 °C. To produce the viewport, an original technology based on brazing GaAs plate by lead has been developed. The vacuum chambers were installed at the BEPC-II and VEPP-4 M colliders. After installation the residual gas pressure is about 10-10 Torr.

  4. The advances and characteristics of high-power diode laser materials processing

    Science.gov (United States)

    Li, Lin

    2000-10-01

    This paper presents a review of the direct applications of high-power diode lasers for materials processing including soldering, surface modification (hardening, cladding, glazing and wetting modifications), welding, scribing, sheet metal bending, marking, engraving, paint stripping, powder sintering, synthesis, brazing and machining. The specific advantages and disadvantages of diode laser materials processing are compared with CO 2, Nd:YAG and excimer lasers. An effort is made to identify the fundamental differences in their beam/material interaction characteristics and materials behaviour. Also an appraisal of the future prospects of the high-power diode lasers for materials processing is given.

  5. Development of Application Technology of a Kagome Truss for a Fuel rod Support Structure

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Ki Ju; Lee, Byung Chul; Kim, Pan Su [Chonnam National University, Gwangju (Korea, Republic of)

    2010-05-15

    The purpose of this work is to design a Wire-woven Bulk Kagome (WBK) cellular metal for a fuel rod support structure of a dual cooled fuel and to fabricate test samples. Design of WBK-based support - To analyze dynamic characteristics of a support structure with WBK core under side impact. - To specify strength of WBK to be used for the support. - To design strut length and diameter of WBK. Fabrication of the test samples - To assemble WBK samples from helically formed wires. - To braze WBK samples with side straps

  6. Environmentally friendly joining of tubes by their ends

    DEFF Research Database (Denmark)

    Silva, Carlos M.A.; Nielsen, Chris Valentin; Alves, Luis M.;

    2015-01-01

    This paper proposes an environmentally friendly joining process for connecting tubes by their ends that has the potential to replace current solutions based on fastened, crimped, welded, brazed or adhesive bonded joints. The process is based on a new type of tubular lap joint produced by local...... plastic instability and compression beading that has a substantial overlap with the counterfacing surfaces of the mating tubes to be joined. The presentation combines independent characterization of the materials, experimentation and numerical simulation of the process in order to identify the modes...

  7. RF-driven Proton Source with a Back-streaming Electron Dump

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Q.; Sy, A.; Kwan, J.W.

    2009-09-20

    This article describes an RF ion source with a back-streaming electron dump. A quartz tube, brazed to a metal plug at one end, is fused in the center of a flat quartz plate. RF power (at 13.6 MHz) is coupled to generate hydrogen plasma using a planar external antenna bonded to the window. Bonding the water-cooled rf antenna to the quartz window significantly lowers its temperature. The water-cooled metal plug serves as the backstreaming electron dump. At 1800W, the current density of extracted hydrogen ions reaches approximately 125 mA/cm{sup 2}.

  8. Structural Characteristics and Properties of Precious Metal Powders and Copper Powder Prepared by High-speed Centrifugal Atomization Technique

    Institute of Scientific and Technical Information of China (English)

    XIE Ming; YANG You-cai; LI Yu-shen; ZHANG Jian-kan; FU Shi-ji; SHI Qing-nan

    2007-01-01

    The principle and characteristics of the rapidly solidified centrifugal atomization technique are studied in present paper. It has been widely used to make fine, rapidly solidified precious metal powders for application as the electrical engineering materials, conductive coatings for electromagnetic shielding and brazing alloys. The silver powder, copper powder and some precious metal alloys powders are prepared by the new method. A comparative analysis is carried out with the conventional electrolytic silver powder and chemical deposition silver powder. The results show that rapidly solidified powders are fine and have higher solid solubility of the alloying elements, and their alloys have excellent properties in various aspects.

  9. Technology handbook of vacuum physics

    CERN Document Server

    Beck, A H

    2013-01-01

    Handbook of Vacuum Physics, Volume 3: Technology is part of a series of publications that presents articles featuring the whole spectrum of vacuum physics. This particular volume presents materials that deal with technology concerns in vacuum mechanics. The first material talks about the utilization of ceramic materials in the construction of vacuum devices. The next paper details the application of vacuum physics in soldering and brazing process. The last article deals with the utilization of vacuum technology in high frequency heating. The book will be of great use to professionals involved

  10. Metals and Ceramics Division. Annual progress report, ending June 30, 1980

    International Nuclear Information System (INIS)

    Research is reported concerning: (1) engineering materials, including materials compatibility, mechanical properties, nondestructive testing, pressure vessel technology, and welding and brazing; (2) fuels and processes consisting of ceramic technology, fuel cycle technology, fuels evaluation, fuel fabrication and metals processing; and (3) materials science which includes, ceramic studies, physical metallurgy properties, radiation effects and microstructural analysis, metastable and superconducting materials, structure and properties of surfaces, theroretical research and x-ray research and applications. Highlights of the work of the metallographic group and the current state of the High-Temperature Materials Laboratory (HTML) and the Materials and Structures Technology Management Center (MSTMC) are presented

  11. Preprototype nitrogen supply subsystem development

    Science.gov (United States)

    Heppner, D. B.; Fort, J. H.; Schubert, F. H.

    1982-01-01

    The design and development of a test stand for the Nitrogen Generation Module (NGM) and a series of tests which verified its operation and performance capability are described. Over 900 hours of parametric testing were achieved. The results from this testing were then used to design an advanced NGM and a self contained, preprototype Nitrogen Supply Subsystem. The NGM consists of three major components: nitrogen generation module, pressure controller and hydrazine storage tank and ancillary components. The most important improvement is the elimination of all sealing surfaces, achieved with a total welded or brazed construction. Additionally, performance was improved by increasing hydrogen separating capability by 20% with no increase in overall packaging size.

  12. Electromagnetic forming - a potentially viable technique for accelerator technology

    International Nuclear Information System (INIS)

    Modern day accelerator development encompasses a myriad technologies required for their diverse needs. Whereas RF, high voltage, vacuum, cryogenics etc., technologies meet their functional requirements, high finish lapping processes, ceramic-metal joining, oven brazing, spark erosion or wire cutting etc., are a must to meet their fabrication requirements. Electromagnetic (EM) forming technique falls in the latter category and is developed as a special technology. It is currently catering to the development as a nuclear reactor technology, but has the potential to meet accelerator requirements too. This paper highlights the general principle of its working, simple design guidelines, advantages, and suggests some specific areas where this could benefit accelerator technologies

  13. Metals and Ceramics Division annual progress report, October 1, 1978-June 30, 1979

    International Nuclear Information System (INIS)

    Research is reported concerning: (1) engineering materials including materials compatibility, mechanical properties, nondestructive testing, pressure vessel technology, and welding and brazing; (2) fuels and processes consisting of ceramic technology, fuel cycle technology, fuels evaluation, fuels fabrication and metals processing; and (3) materials science which includes, ceramic studies, physical metallurgy and properties, radiation effects and microstructural analysis, metastable and superconducting materials, structure and properties of surfaces, theoretical research, and x-ray research and applications. Highlights of the work of the metallographic group and the current status of the High-Temperature Materials Laboratory (HTML) and the Materials and Structures Technology Management Center (MSTMC) are presented

  14. Copper-to-silicon-carbide joints development for Future CLIC Hom Dampers

    CERN Document Server

    Gil Costa, Miguel

    2015-01-01

    Ceramic-to-metal joints have been of paramount importance for the nuclear and aeronautic industry since the last century. In this document, two different approaches to the Cu-to-SiC joining are briefly described and discussed. The first approach consists of an intermediate piece of lower Coefficient of Thermal Expansion than copper aiming to reduce the expansion mismatch with the ceramic during the brazing cycle. Soldering is selected as a second attempt, whose lower joining temperature reduces the absolute expansion difference between Cu and SiC. In addition, four SiC metallization processes are proposed and some of them have been also tested and discussed.

  15. Quality approach and professional regulations; Demarche qualite et regles professionnelles

    Energy Technology Data Exchange (ETDEWEB)

    Bernier, J. [Association Francaise de Froid (AFF), 75 - Paris (France)

    1997-12-31

    After a review of the main performance and environmental issues related to the utilization of alternative refrigerant fluids in refrigerating systems, the thermo-pump concept is proposed for space heating and air conditioning. Performances of reverse heat pumps have been greatly enhanced through the use of scroll and screw compressors, electronic reducing valves and brazed plate exchangers. Installation regulations have been developed in order to ensure optimal operating conditions for residential systems with a power range inferior to 30 kW: information is given on radiating floors with hot and cooled water, the hydraulic network in individual houses, the implementation of underground collectors, and the operation of thermo-pumps

  16. Metals and Ceramics Division annual progress report, October 1, 1978-June 30, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, S. (ed.)

    1979-09-01

    Research is reported concerning: (1) engineering materials including materials compatibility, mechanical properties, nondestructive testing, pressure vessel technology, and welding and brazing; (2) fuels and processes consisting of ceramic technology, fuel cycle technology, fuels evaluation, fuels fabrication and metals processing; and (3) materials science which includes, ceramic studies, physical metallurgy and properties, radiation effects and microstructural analysis, metastable and superconducting materials, structure and properties of surfaces, theoretical research, and x-ray research and applications. Highlights of the work of the metallographic group and the current status of the High-Temperature Materials Laboratory (HTML) and the Materials and Structures Technology Management Center (MSTMC) are presented. (FS)

  17. Control on Electron Beam Scanning Track

    Institute of Scientific and Technical Information of China (English)

    王学东; 姚舜

    2004-01-01

    In order to use electron beam as a movable welding heat source and whose energy distribution along its moving trace can be controlled, a method of electron beam scanning track and scanning mode control was put forward. Based on it, the electron beam scanning track and scanning mode can be edited at will according to actual requirements, and the energy input of each point of the scanning track can be controlled. In addition, the scanning frequency and points control, real time adjusting of the scanning track etc. were explained. This method can be used in electron beam brazing, surface modification, surface heat treatment etc.

  18. Power electronics cooling apparatus

    Science.gov (United States)

    Sanger, Philip Albert; Lindberg, Frank A.; Garcen, Walter

    2000-01-01

    A semiconductor cooling arrangement wherein a semiconductor is affixed to a thermally and electrically conducting carrier such as by brazing. The coefficient of thermal expansion of the semiconductor and carrier are closely matched to one another so that during operation they will not be overstressed mechanically due to thermal cycling. Electrical connection is made to the semiconductor and carrier, and a porous metal heat exchanger is thermally connected to the carrier. The heat exchanger is positioned within an electrically insulating cooling assembly having cooling oil flowing therethrough. The arrangement is particularly well adapted for the cooling of high power switching elements in a power bridge.

  19. Electrochemical characterisation speeds up prediction of corrosion behaviour

    Energy Technology Data Exchange (ETDEWEB)

    Schuring, E.W.; Hooijmans, J.W. [ECN Environment and Energy Engineering, Petten (Netherlands)

    2013-04-15

    The contents of this presentation show the following elements: Introduction; Corrosion in real life; Why Electrochemical characterisation of corrosion; Applications (corrosion resistance coatings, corrosion behaviour (brazed) joints); Available electrochemical corrosion techniques; Standards; Conclusions. In the Conclusions the corrosion screening method is summarized: ECN method fast; within 1h -1 week results depending on test method; Fast pre-selection of promising materials/combinations (cost savings); Determining of corrosion initiation; Determination of corrosion mechanisms and propagation; Life time predictions possible; Strong combination with metallographic post-investigation; Ranking materials / constructions for corrosion performance.

  20. Electrical stator

    Science.gov (United States)

    Fanning, Alan W.; Olich, Eugene E.

    1994-01-01

    An electrical stator of an electromagnetic pump includes first and second spaced apart coils each having input and output terminals for carrying electrical current. An elongate electrical connector extends between the first and second coils and has first and second opposite ends. The connector ends include respective slots receiving therein respective ones of the coil terminals to define respective first and second joints. Each of the joints includes a braze filler fixedly joining the connector ends to the respective coil terminals for carrying electrical current therethrough.

  1. Safety handbook

    International Nuclear Information System (INIS)

    The purpose of the Australian Nuclear Science and Technology Organization's Safety Handbook is to outline simply the fundamental procedures and safety precautions which provide an appropriate framework for safe working with any potential hazards, such as fire and explosion, welding, cutting, brazing and soldering, compressed gases, cryogenic liquids, chemicals, ionizing radiations, non-ionising radiations, sound and vibration, as well as safety in the office. It also specifies the organisation for safety at the Lucas Heights Research Laboratories and the responsibilities of individuals and committees. It also defines the procedures for the scrutiny and review of all operations and the resultant setting of safety rules for them. ills

  2. Aircraft gas turbine materials and processes.

    Science.gov (United States)

    Kear, B H; Thompson, E R

    1980-05-23

    Materials and processing innovations that have been incorporated into the manufacture of critical components for high-performance aircraft gas turbine engines are described. The materials of interest are the nickel- and cobalt-base superalloys for turbine and burner sections of the engine, and titanium alloys and composites for compressor and fan sections of the engine. Advanced processing methods considered include directional solidification, hot isostatic pressing, superplastic foring, directional recrystallization, and diffusion brazing. Future trends in gas turbine technology are discussed in terms of materials availability, substitution, and further advances in air-cooled hardware.

  3. Metals and Ceramics Division. Annual progress report, ending June 30, 1980

    Energy Technology Data Exchange (ETDEWEB)

    1980-09-01

    Research is reported concerning: (1) engineering materials, including materials compatibility, mechanical properties, nondestructive testing, pressure vessel technology, and welding and brazing; (2) fuels and processes consisting of ceramic technology, fuel cycle technology, fuels evaluation, fuel fabrication and metals processing; and (3) materials science which includes, ceramic studies, physical metallurgy properties, radiation effects and microstructural analysis, metastable and superconducting materials, structure and properties of surfaces, theroretical research and x-ray research and applications. Highlights of the work of the metallographic group and the current state of the High-Temperature Materials Laboratory (HTML) and the Materials and Structures Technology Management Center (MSTMC) are presented. (FS)

  4. Experimental evaluation of an Internal Heat Exchanger in a CO2 subcritical refrigeration cycle with gas-cooler

    OpenAIRE

    Llopis Doménech, Rodrigo; Sanz Kock, Carlos; Cabello López, Ramón; Sánchez García-Vacas, Daniel; Torrella Alcaraz, Enrique

    2015-01-01

    We present the experimental evaluation of an internal heat exchanger or suction-line/liquid-line heat exchanger in a CO2 subcritical refrigeration plant with gas-cooler. The plant, driven by a 1.5kW CO2 semi hermetic compressor, uses brazed plate heat exchangers as condenser, evaporator and internal heat exchanger, an air finned tube gas-cooler and an electronic expansion valves. The evaluation (77 steady- states) covers evaporating temperatures from -40 to -25 oC and condensing temperatures ...

  5. Materials design considerations involved in the fabrication of implantable bionics by metallization of ceramic substrates.

    Science.gov (United States)

    Patel, Sunil; Guenther, Thomas; Dodds, Christopher W D; Kolke, Sergej; Privat, Karen L; Matteucci, Paul B; Suaning, Gregg J

    2013-01-01

    The Pt metallization of co-fired Al2O3/SiO2 substrates containing Pt feedthroughs was shown to be a suitable means to construct implantable bionics. The use of forge welding to join an electrode to such a metallized feedthrough was demonstrated and subsequently evaluated through the use of metallography and electron microscopy. Metallurgical phenomena involved in forge welding relevant to the fabrication of all types of biomedical implants are discussed within this paper. The affect of thermal profiles used in brazing or welding to build implantable devices from metal components is analysed and the case for considered selection of alloys in implant design is put forward.

  6. Progress report; Rapport d'activite

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    This 2000 issue of the activity report of the CEREM (CEA) gives a general overview of the CEREM organization, activities and human resources with some budgetary information. The main activities described concern the materials fabrication for the nuclear industry and for the medical field, the powder metallurgy, the surface treatments, the joining (by electron beam welding, laser welding, brazing), the electrochemical storage of the energy (SOFC, PEMFC, lithium batteries), the robots for nuclear, automotive and aeronautic industries, the mechanical properties and the cracks, the corrosion and physico-chemistry of fluids, the non-destructive testing and the applications and metrology of ionizing radiations. (O.M.)

  7. Development of X-band accelerating structures for high gradients

    Institute of Scientific and Technical Information of China (English)

    S. Bini; M. G. Grimaldi; L. Romano; F. Ruffino; R. Parodi; V. Chimenti; A. Marcelli; L. Palumbo; B. Spataro; V. A. Dolgashev; S. Tantawi; A.D. Yeremian; Y. Higashi

    2012-01-01

    Short copper standing wave (SW) structures operating at an X-band frequency have been recently designed and manufactured at the Laboratori Nazionali di Frascati of the Istituto Nazionale di Fisica Nucleare (INFN) using the vacuum brazing technique.High power tests of the structures have been performed at the SLAC National Accelerator Laboratory.In this manuscript we report the results of these tests and the activity in progress to enhance the high gradient performance of the next generation of structures,particularly the technological characterization of high performance coatings obtained via molybdenum sputtering.

  8. Science & Technology Review October 2005

    Energy Technology Data Exchange (ETDEWEB)

    Aufderheide III, M B

    2005-08-22

    This month's issue has the following articles: (1) Important Missions, Great Science, and Innovative Technology--Commentary by Cherry A. Murray; (2) NanoFoil{reg_sign} Solders with Less Heat--Soldering and brazing to join an array of materials are now Soldering and brazing to join an array of materials are now possible without furnaces, torches, or lead; (3) Detecting Radiation on the Move--An award-winning technology can detect even small amounts An award-winning technology can detect even small amounts of radioactive material in transit; (4) Identifying Airborne Pathogens in Time to Respond--A mass spectrometer identifies airborne spores in less than A mass spectrometer identifies airborne spores in less than a minute with no false positives; (5) Picture Perfect with VisIt--The Livermore-developed software tool VisIt helps scientists The Livermore-developed software tool VisIt helps scientists visualize and analyze large data sets; (6) Revealing the Mysteries of Water--Scientists are using Livermore's Thunder supercomputer and new algorithms to understand the phases of water; and (7) Lightweight Target Generates Bright, Energetic X Rays--Livermore scientists are producing aerogel targets for use in inertial Livermore scientists are producing aerogel targets for use in inertial confinement fusion experiments and radiation-effects testing.

  9. Manufacturing and testing of a copper/CFC divertor mock-up for JET

    International Nuclear Information System (INIS)

    An actively cooled divertor is a possible option for future developments at The Joint European Torus (JET). A proof of principle actively cooled tile has been produced in order to qualify the relevant manufacturing technologies and the non destructive control processes. In this frame Ansaldo Ricerche (ARI) has been involved in the construction of a mock-up comprising 6 OFHC copper tubes for water cooling that are brazed to a plate made out of carbon fibre composite (CFC). The final objective was the high heat flux testing of the mock-up at JET in order to evaluate the general behaviour of the component under relevant operating conditions. The key point of the work was the realisation of a sound joint by adapting the expertise gained in ARI in previous R and D activities on brazing heterogeneous materials. Reliable methods for ultrasonic examinations of the pieces were also set up. For successful application to the JET pumped divertor a water-cooled CFC target plate must show surface temperatures of 2. Furthermore, global hydraulic considerations specific to JET limit the system pressure to 0.7 MPa. In such a design, critical heat flux is not the key limit, rather the reliability of the CFC-copper joint in terms of extent of wetting. First tests in the neutral beam test bed at JET show an adequate response for fluxes up to 15 MW/m2. (orig.)

  10. Measurement of bulk residual stresses in molybdenum disilicide/stainless steel joints using neutron scattering

    Energy Technology Data Exchange (ETDEWEB)

    Vaidya, R.U.; Rangaswamy, P.; Bourke, M.A.M.; Butt, D.P. [Los Alamos National Lab., NM (United States). Materials Science and Technology Div.

    1998-03-23

    Neutron diffraction was used to measure the bulk residual strains in molybdenum disilicide (MoSi{sub 2})-316L stainless steel joints. The joints were produced by brazing disks of MoSi{sub 2} and 316L stainless steel along with an interlayer, using Cusil{trademark} as the braze. This study explored the physical parameters of the interlayer on the average phase strains in the MoSi{sub 2} and 316L stainless steel. The effect of the coefficient of thermal expansion was explored by using three different interlayer materials: niobium, nickel, and nickel-iron. The residual strains in MoSi{sub 2} decreased significantly in both radial and axial directions with increasing niobium interlayer thickness. Residual strains were relatively insensitive to changes in 500 {micro}m thick interlayer material. Finite element modeling results were corroborated by the neutron measurements on the joints allowing inferences to be drawn concerning the preference of the interlayer material. The results illustrate the importance of the ductile interlayer in the successful fabrication of MoSi{sub 2}-316L stainless steel joints.

  11. Caractérisation expérimentale du comportement mécanique d'assemblage haute température pour l'électronique de puissance Experimental characterization of the mechanical behavior of high-temperature assembly for power electronics

    Directory of Open Access Journals (Sweden)

    Baazaoui Ahlem

    2013-11-01

    Full Text Available Le comportement mécanique de deux types de connexion haute température mises en œuvre pour l'assemblage de composants d'électronique de puissance a été étudié : une jonction réalisée par brasage en phase liquide transitoire (TLPB d'Ag-In et une autre par brasage d'un eutectique Au88Ge12. Les connexions réalisées à partir d'inserts de cuivre sont caractérisées mécaniquement au moyen d'essais de cisaillement. Une analyse de la microstructure des jonctions en coupe et des faciès de rupture des deux connexions a également été menée. The mechanical behavior of two types of high-temperature connection implemented in the assembly of electronic power components was studied: a joint made by brazing transient liquid phase (TLPB Ag-In and in another by brazing Au88Ge12. Connections made are mechanically characterized using shear tests. The microstructure of the junction section and the fracture surfaces of both connections was also observed.

  12. Material and design considerations for the carbon armored ITER divertor

    International Nuclear Information System (INIS)

    The properties of materials for the carbon armored ITER divertor were evaluated from literature and manufacturers' documentation. Most of these data, however, have been not known or not published yet. We have evaluated an optimum data set of the candidate materials of the ITER divertor, which were needed for finite element analyses (FEM). The materials evaluated are as follows; MFC-1, CX2002U, SEP-N112, P-130, IG-430U for the carbon based materials, and Oxygen Free Copper (OFCu), Dispersion Strengthened Copper (DSCu), TZM, W5Re and W-Cu as a heat sink material. It should be noted that W-Cu is first proposed for a heat sink application of the ITER divertor plate. The finite element analyses were performed for the residual stress induced by brazing, thermal response and thermal stresses under a uniform heat flux of 15 MW/m2 to the plasma facing surface. The stress free temperature of 750degC is assumed for the residual stress by brazing. Ten different geometries of the divertor were considered in the analyses including possible material combinations. The FEM results show that the material combinations of MFC-1 and W-30Cu or DSUc in the flat-plate geometry satisfy the presently accepted ITER requirements. The combinations of CX2002U and TZM or W5Re is considered a good choice in terms of residual and thermal stresses, whereas the surface temperature exceeds the ITER requirements. (author) 106 refs

  13. Repair technology for steam generator tubes

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seung Ho; Jung, Hyun Kyu; Jung, Seung Ho; Kim, Chang Hoi; Jung, Young Moo; Seo, Yong Chil; Kim, Jung Su; Seo, Moo Hong

    2001-02-01

    The most commonly used sleeving materials are thermally treated Alloy 600 and thermally treated Alloy 690 Alloy. Currently, thermally treated Alloy 690 and Alloy 800 are being offered although Alloy 800 has not been licensed in the US. To install sleeve, joint strength, leak tightness, PWSCC resistance, evaluation on process parameter range and the effect of equipments and procedures on repair plan and radiation damage have to be investigated before sleeving. ABB CE provides three type of leak tight Alloy 690 TIG welded and PLUSS sleeve. Currently, Direct Tube Repair technique using Nd:YAG laser has been developed by ABB CE and Westinghouse. FTI has brazed and kinetic sleeve designs for recirculating steam generator and hydraulic and rolled sleeve designs for one-through steam generators. Westinghouse provides HEJ, brazed and laser welded sleeve design. When sleeve is installed in order to repair the damaged S/G tubes, it is certain that defects can be occurred due to the plastic induced stress and thermal stress. Therefore it is important to minimize the residual stress. FTI provides the electrosleeve technique as a future repair candidate using electroplating.

  14. Flexible metallic ultrasonic transducers for structural health monitoring of pipes at high temperatures.

    Science.gov (United States)

    Shih, Jeanne-Louise; Kobayashi, Makiko; Jen, Cheng-Kuei

    2010-09-01

    Piezoelectric films have been deposited by a sol-gel spray technique onto 75-μm-thick titanium and stainless steel (SS) membranes and have been fabricated into flexible ultrasonic transducers (FUTs). FUTs using titanium membranes were glued and those using SS membranes brazed onto steel pipes, procedures that serve as on-site installation techniques for the purpose of offering continuous thickness monitoring capabilities at up to 490 °C. At 150 °C, the thickness measurement accuracy of a pipe with an outer diameter of 26.6 mm and a wall thickness of 2.5 mm was estimated to be 26 μm and the center frequency of the FUT was 10.8 MHz. It is demonstrated that the frequency bandwidth of the FUTs and SNR of signals using glue or brazing materials as high-temperature couplant for FUTs are sufficient to inspect the steel pipes even with a 2.5 mm wall thickness. PMID:20876000

  15. Probe for an ultrasonic flaw detector welded to a support

    International Nuclear Information System (INIS)

    A probe for ultrasonic flaw detectors is described that includes a transducer sandwiched between electrodes and either a protective plate to protect the transducer or a metal body by which the transducer is directly attached to the object to be tested, these two parts being bonded to each other with a heat-resisting brazing or soldering material, which also serves as one of the electrodes of the transducer. Owing to its high bonding strength, the probe thus constituted is not only capable of serving both in the high temperature range and in the low temperature range, but also may be used in a mobile role or in a stationary mode in testing the object. Where a metal body is used for the mounting, this may be cylindrical or wedge-shaped. The transducer may be a single lithium niobate crystal and the brazing material and electrodes may be a Al-Si-Mg alloy or a silver alloy. A coupling medium may be of silicone oil, molten lead or liquid sodium and the object may be a space station or a nuclear reactor pressure vessel. (author)

  16. Crossed-Wire Laser Microwelding of Pt-10 Pct Ir to 316 Low-Carbon Vacuum Melted Stainless Steel: Part I. Mechanism of Joint Formation

    Science.gov (United States)

    Zou, G. S.; Huang, Y. D.; Pequegnat, A.; Li, X. G.; Khan, M. I.; Zhou, Y.

    2012-04-01

    The excellent biocompatibility and corrosion properties of Pt alloys and 316 low-carbon vacuum melted (LVM) stainless steel (SS) make them attractive for biomedical applications. With the increasing complexity of medical devices and in order to lower costs, the challenge of joining dissimilar materials arises. In this study, laser microwelding (LMW) of crossed Pt-10 pct Ir to 316 LVM SS wires was performed and the weldability of these materials was determined. The joint geometry, joining mechanism, joint breaking force (JBF), and fracture modes were investigated using optical microscopy, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and microtensile testing. It was shown that the mechanisms of joint formation transitioned from (1) brazing, (2) a combination of brazing and fusion welding, and (3) fusion welding with increasing pulsed laser energy. The joints demonstrated various tensile failure modes including (1) interfacial failure below a peak power of 0.24 kW, (2) partial interfacial failure that propagated into the Pt-Ir wire, (3) failure in the Pt-Ir wire, and (4) failure in the SS wire due to porosity and severe undercutting caused by overwelding. During this study, the optimal laser peak power range was identified to produce joints with good joint geometry and 90 pct of the tensile strength of the Pt-10 pct Ir wire.

  17. Repair technology for steam generator tubes

    International Nuclear Information System (INIS)

    The most commonly used sleeving materials are thermally treated Alloy 600 and thermally treated Alloy 690 Alloy. Currently, thermally treated Alloy 690 and Alloy 800 are being offered although Alloy 800 has not been licensed in the US. To install sleeve, joint strength, leak tightness, PWSCC resistance, evaluation on process parameter range and the effect of equipments and procedures on repair plan and radiation damage have to be investigated before sleeving. ABB CE provides three type of leak tight Alloy 690 TIG welded and PLUSS sleeve. Currently, Direct Tube Repair technique using Nd:YAG laser has been developed by ABB CE and Westinghouse. FTI has brazed and kinetic sleeve designs for recirculating steam generator and hydraulic and rolled sleeve designs for one-through steam generators. Westinghouse provides HEJ, brazed and laser welded sleeve design. When sleeve is installed in order to repair the damaged S/G tubes, it is certain that defects can be occurred due to the plastic induced stress and thermal stress. Therefore it is important to minimize the residual stress. FTI provides the electrosleeve technique as a future repair candidate using electroplating

  18. Status of VibroIR at Lawrence Livermore National Laboratory

    Science.gov (United States)

    Burke, Michael W.; Miller, Wayne O.

    2004-04-01

    Current efforts at Lawrence Livermore National Laboratory in the area of vibrothermography (VibroIR or SonicIR) are presented. The primary goals of the efforts of the NDE group at LLNL have been to demonstrate the applicability of vibrothermography to new areas, to examine the degree to which VibroIR may replace existing NDE inspection procedures, and to conduct research on the underlying processes and optimal parameters in its implementation. We report three new applications of VibroIR, in the areas of brazed tube joint inspection, evaluationtion of thick multilayer carbon/carbon composites as used in the NASA Shuttle, and the inspection of soft composite materials. The goal of the brazed joint inspection process is ultimately the replacement of a current dye penetrant inspection procedure. Therefore a direct comparison between VibroIR and dye penetrant inspection is made. Preliminary results of the analysis of a leading edge panel from a NASA Shuttle is also reported as an example of the application of VibroIR to thick composites. Finally, a comparison betweeen the effectiveness of VibroIR versus a spectrum of other NDE techniques (ultrasonic imaging, radiographic tomography) for the imaging of known ceramic defects is briefly discussed.

  19. Development and Characterization of the Bonding and Integration Technologies Needed for Fabricating Silicon Carbide Based Injector Components

    Science.gov (United States)

    Halbig,Michael C.; Singh, Mrityunjay

    2008-01-01

    Advanced ceramic bonding and integration technologies play a critical role in the fabrication and application of silicon carbide based components for a number of aerospace and ground based applications. One such application is a lean direct injector for a turbine engine to achieve low NOx emissions. Ceramic to ceramic diffusion bonding and ceramic to metal brazing technologies are being developed for this injector application. For the diffusion bonding technology, titanium interlayers (coatings and foils) were used to aid in the joining of silicon carbide (SiC) substrates. The influence of such variables as surface finish, interlayer thickness, and processing time were investigated. Electron microprobe analysis was used to identify the reaction formed phases. In the diffusion bonds, an intermediate phase, Ti5Si3Cx, formed that is thermally incompatible in its thermal expansion and caused thermal stresses and cracking during the processing cool-down. Thinner interlayers of pure titanium and/or longer processing times resulted in an optimized microstructure. Tensile tests on the joined materials resulted in strengths of 13-28 MPa depending on the SiC substrate material. Nondestructive evaluation using ultrasonic immersion showed well formed bonds. For the joining technology of brazing Kovar fuel tubes to silicon carbide, preliminary development of the joining approach has begun. Various technical issues and requirements for the injector application are addressed.

  20. Bonding and Integration Technologies for Silicon Carbide Based Injector Components

    Science.gov (United States)

    Halbig, Michael C.; Singh, Mrityunjay

    2008-01-01

    Advanced ceramic bonding and integration technologies play a critical role in the fabrication and application of silicon carbide based components for a number of aerospace and ground based applications. One such application is a lean direct injector for a turbine engine to achieve low NOx emissions. Ceramic to ceramic diffusion bonding and ceramic to metal brazing technologies are being developed for this injector application. For the diffusion bonding, titanium interlayers (PVD and foils) were used to aid in the joining of silicon carbide (SiC) substrates. The influence of such variables as surface finish, interlayer thickness (10, 20, and 50 microns), processing time and temperature, and cooling rates were investigated. Microprobe analysis was used to identify the phases in the bonded region. For bonds that were not fully reacted an intermediate phase, Ti5Si3Cx, formed that is thermally incompatible in its thermal expansion and caused thermal stresses and cracking during the processing cool-down. Thinner titanium interlayers and/or longer processing times resulted in stable and compatible phases that did not contribute to microcracking and resulted in an optimized microstructure. Tensile tests on the joined materials resulted in strengths of 13-28 MPa depending on the SiC substrate material. Non-destructive evaluation using ultrasonic immersion showed well formed bonds. For the joining technology of brazing Kovar fuel tubes to silicon carbide, preliminary development of the joining approach has begun. Various technical issues and requirements for the injector application are addressed.

  1. New technology based on clamping for high gradient radio frequency photogun

    Science.gov (United States)

    Alesini, David; Battisti, Antonio; Ferrario, Massimo; Foggetta, Luca; Lollo, Valerio; Ficcadenti, Luca; Pettinacci, Valerio; Custodio, Sean; Pirez, Eylene; Musumeci, Pietro; Palumbo, Luigi

    2015-09-01

    High gradient rf photoguns have been a key development to enable several applications of high quality electron beams. They allow the generation of beams with very high peak current and low transverse emittance, satisfying the tight demands for free-electron lasers, energy recovery linacs, Compton/Thomson sources and high-energy linear colliders. In the present paper we present the design of a new rf photogun recently developed in the framework of the SPARC_LAB photoinjector activities at the laboratories of the National Institute of Nuclear Physics in Frascati (LNF-INFN, Italy). This design implements several new features from the electromagnetic point of view and, more important, a novel technology for its realization that does not involve any brazing process. From the electromagnetic point of view the gun presents high mode separation, low peak surface electric field at the iris and minimized pulsed heating on the coupler. For the realization, we have implemented a novel fabrication design that, avoiding brazing, strongly reduces the cost, the realization time and the risk of failure. Details on the electromagnetic design, low power rf measurements and high power radiofrequency and beam tests performed at the University of California in Los Angeles (UCLA) are discussed in the paper.

  2. Laser -Based Joining of Metallic and Non-metallic Materials

    Science.gov (United States)

    Padmanabham, G.; Shanmugarajan, B.

    Laser as a high intensity heat source can be effectively used for joining of materials by fusion welding and brazing in autogenous or in hybrid modes. In autogenous mode, welding is done in conduction , deep penetration , and keyhole mode. However, due to inherently high energy density available from a laser source, autogenous keyhole welding is the most popular laser welding mode. But, it has certain limitations like need for extremely good joint fit-up, formation of very hard welds in steel , keyhole instability, loss of alloying elements, etc. To overcome these limitations, innovative variants such as laser-arc hybrid welding , induction-assisted welding , dual beam welding , etc., have been developed. Using laser heat, brazing can be performed by melting a filler to fill the joints, without melting the base materials. Accomplishing laser-based joining as mentioned above requires appropriate choice of laser source, beam delivery system, processing head with appropriate optics and accessories. Basic principles of various laser-based joining processes, laser system technology, process parameters, metallurgical effects on different base materials, joint performance, and applications are explained in this chapter.

  3. Ultrasonic inspection of tube to tube plate welds

    International Nuclear Information System (INIS)

    To monitor the deterioration of a weld between a tube and tube plate which has been repaired by a repair sleeve inside the tube and brazed at one end to the tube, ultrasound from a crystal at the end of a rod is launched, in the form of Lamb-type waves, into the tube through the braze and allowed to travel along the tube to the weld and be reflected back along the tube. The technique may also be used for the type of heat exchanger in which, during construction, the tubes are welded to the tube plate via external sleeves in which case the ultrasound is used in a similar manner to inspect the sleeve/tube plate weld. an electromagnetic transducer may be used to generate the ultrasound. The ultrasonic head comprising the crystal and an acoustic baffle is mounted on a Perspex (RTM) rod which may be rotated by a stepping motor. Echo signals from the region of deterioration may be isolated by use of a time gate in the receiver. The device primarily detects circumferentially orientated cracks, and may be used in heat exchangers in nuclear power plants. (author)

  4. A Study of Deposition Coatings Formed by Electroformed Metallic Materials.

    Science.gov (United States)

    Hayashi, Shoji; Sugiyama, Shuta; Shimura, Kojiro; Tobayama, Go; Togashi, Toshio

    2016-01-01

    Major joining methods of dental casting metal include brazing and laser welding. However, brazing cannot be applied for electroformed metals since heat treatment could affect the fit, and, therefore, laser welding is used for such metals. New methods of joining metals that do not impair the characteristics of electroformed metals should be developed. When new coating is performed on the surface of the base metal, surface treatment is usually performed before re-coating. The effect of surface treatment is clinically evaluated by peeling and flex tests. However, these testing methods are not ideal for deposition coating strength measurement of electroformed metals. There have been no studies on the deposition coating strength and methods to test electroformed metals. We developed a new deposition coating strength test for electroformed metals. The influence of the negative electrolytic method, which is one of the electrochemical surface treatments, on the strength of the deposition coating of electroformed metals was investigated, and the following conclusions were drawn: 1. This process makes it possible to remove residual deposits on the electrodeposited metal surface layer. 2. Cathode electrolysis is a simple and safe method that is capable of improving the surface treatment by adjustments to the current supply method and current intensity. 3. Electrochemical treatment can improve the deposition coating strength compared to the physical or chemical treatment methods. 4. Electro-deposition coating is an innovative technique for the deposition coating of electroformed metal. PMID:27326757

  5. SFD-261 crossed-field amplifier manufacturing technology program

    Science.gov (United States)

    Laplante, R. A.; Trojan, F. E.

    1980-09-01

    The objective of the MT program is to demonstrate improved production techniques by a pilot production run of ten (10) tubes to meet performance specification and system compatibility criteria under production line conditions. The SFD-261 is a microwave amplifier used to increase the power level of pulses of energy by a factor of 20. It is used in the Aegis AN/SPY-1 radar transmitter. A single ship's complement without spares is seventy-six. Its internal parts are made from high purity copper and many are complex and involve high precision. Most of the fabrication is by precious metal brazing in hydrogen or in vacuum. Modest production rates (10 to 30 units per month) presently restrict the amount of automation which can be effectively applied. Nearly 30 design changes were made without altering performance significantly. Self-jigging techniques permitted assembly by lower skill levels. A 'one-shot' vacuum braze for the cathode produced significant cost and equipment reduction. If the selling price of the standard design is normalized at 100, the price of the MT design is now 57.

  6. A quick and efficient measurement technique for performance evaluation of thermoelectric materials

    Science.gov (United States)

    Rao, Ashwin; Banjade, Pawan; Bosak, Gregg; Joshi, Binay; Keane, Jennifer; Nally, Luke; Peng, Adam; Perera, Susanthri; Waring, Alfred; Joshi, Giri; Poudel, Bed

    2016-10-01

    Evaluating the performance of thermoelectric (TE) materials is critical for developing an efficient long lasting thermoelectric generator. Various parameters like resistance, TE power, TE efficiency as a function of temperature and time play an important role in developing and optimizing TE materials and legs. If one needs to evaluate the TE legs for performance or contact metallization optimization, study of a brazed or packaged device everytime could prove to be an expensive, time consuming process especially as a quick intermediate qualification. In this work, a simple approach that uses eutectic Gallium Indium (Ga-In) paste as a metallizing substitute with good electrical/thermal contact is employed which also avoids the need for brazing/welding (or any permanent joining) and provides a reliable platform for a quick leg qualification. Using open circuit voltage (V oc) and device voltage (V d), one can evaluate important TE quantities like peak power, material resistance changes, peak current and power versus current characteristics to understand the leg performance. The proposed approach is successfully demonstrated with three different TE material systems namely Bismuth Telluride, Skutterudite and Half Heusler systems.

  7. Microstructure and Mechanical Properties of Joints of Titanium with Stainless Steel Performed using Nickel Filler

    Directory of Open Access Journals (Sweden)

    Szwed B.

    2016-06-01

    Full Text Available Diffusion brazing was performed between titanium (Grade 2 and stainless steel (X5CrNi18-10 using as a filler a nickel foil at the temperatures of 850, 900, 950 and 1000°C. The microstructure was investigated using light microscopy and scanning electron microscopy equipped with an energy dispersive X-ray system (EDS. The structure of the joints on the titanium side was composed of the eutectoid mixture αTi+Ti2Ni and layers of intermetallic phases Ti2Ni, TiNi and TiNi3. The stainless steel-nickel interface is free from any reaction layer at 850°C, above this temperature thin layer of reaction appears. The microhardness measured across the joints reaches higher values than for titanium and stainless steel, and it achieves value from 260 to 446 HV. The highest shear strength (214 MPa was achieved for joints brazed at 900°C.

  8. Quality control of CANDU6 fuel element in fabrication process

    International Nuclear Information System (INIS)

    To enhance the fine control over all aspects of the production process, improve product quality, fuel element fabrication process for CANDU6 quality process control activities carried out by professional technical and management technology combined mode, the quality of the fuel elements formed around CANDU6 weak links - - end plug , and brazing processes and procedures associated with this aspect of strict control, in improving staff quality consciousness, strengthening equipment maintenance, improved tooling, fixtures, optimization process test, strengthen supervision, fine inspection operations, timely delivery carry out aspects of the quality of information and concerns the production environment, etc., to find the problem from the improvement of product quality and factors affecting the source, and resolved to form the active control, comprehensive and systematic analysis of the problem of the quality management concepts, effectively reducing the end plug weld microstructure after the failure times and number of defects zirconium alloys brazed, improved product quality, and created economic benefits expressly provided, while staff quality consciousness and attention to detail, collaboration department, communication has been greatly improved and achieved very good management effectiveness. (authors)

  9. A Study of Deposition Coatings Formed by Electroformed Metallic Materials.

    Directory of Open Access Journals (Sweden)

    Shoji Hayashi

    Full Text Available Major joining methods of dental casting metal include brazing and laser welding. However, brazing cannot be applied for electroformed metals since heat treatment could affect the fit, and, therefore, laser welding is used for such metals. New methods of joining metals that do not impair the characteristics of electroformed metals should be developed. When new coating is performed on the surface of the base metal, surface treatment is usually performed before re-coating. The effect of surface treatment is clinically evaluated by peeling and flex tests. However, these testing methods are not ideal for deposition coating strength measurement of electroformed metals. There have been no studies on the deposition coating strength and methods to test electroformed metals. We developed a new deposition coating strength test for electroformed metals. The influence of the negative electrolytic method, which is one of the electrochemical surface treatments, on the strength of the deposition coating of electroformed metals was investigated, and the following conclusions were drawn: 1. This process makes it possible to remove residual deposits on the electrodeposited metal surface layer. 2. Cathode electrolysis is a simple and safe method that is capable of improving the surface treatment by adjustments to the current supply method and current intensity. 3. Electrochemical treatment can improve the deposition coating strength compared to the physical or chemical treatment methods. 4. Electro-deposition coating is an innovative technique for the deposition coating of electroformed metal.

  10. Cooling the APS storage ring radio-frequency accelerating cavities: Thermal/stress/fatigue analysis and cavity cooling configuration

    International Nuclear Information System (INIS)

    The 7-GeV Advanced Photon Source positron storage ring requires sixteen separate 352-MHz radio-frequency (rf) accelerating cavities. Cavities are installed as groups of four, in straight sections used elsewhere for insertion devices. They occupy the first such straight section after injection, along with the last three just before injection. Cooling is provided by a subsystem of the sitewide deionized water system. Pumping equipment is located in a building directly adjacent to the accelerator enclosure. A prototype cavity was fabricated and tested where cooling was via twelve 19-mm-diameter [3/4 in] brazed-on tubes in a series-parallel flow configuration. Unfortunately, the thermal contact to some tubes was poor due to inadequate braze filler. Here, heat transfer studies, including finite-element analysis and test results, of the Advanced Photon Source (APS) storage ring 352-MHz rf accelerating cavities are described. Stress and fatigue life of the copper are discussed. Configuration of water cooling is presented

  11. Phase transformation and deformation behavior of NiTi-Nb eutectic joined NiTi wires.

    Science.gov (United States)

    Wang, Liqiang; Wang, Cong; Zhang, Lai-Chang; Chen, Liangyu; Lu, Weijie; Zhang, Di

    2016-04-06

    NiTi wires were brazed together via eutectic reaction between NiTi and Nb powder deposited at the wire contact region. Phase transformation and deformation behavior of the NiTi-Nb eutectic microstructure were investigated using transmission electron microscopy (TEM) and cyclic loading-unloading tests. Results show that R phase and B19' martensite transformation are induced by plastic deformation. R phase transformation, which significantly contributes to superelasticity, preferentially occurs at the interfaces between NiTi and eutectic region. Round-shaped Nb-rich phase with rod-like and lamellar-type eutectics are observed in eutectic regions. These phases appear to affect the deformation behavior of the brazed NiTi-Nb region via five distinct stages in stress-strain curves: (I) R phase reorientation, (II) R phase transformation from parent phase, (III) elastic deformation of reoriented martensite accompanied by the plastic deformation of Nb-rich phase and lamellar NiTi-Nb eutectic, (IV) B19' martensitic transformation, and (V) plastic deformation of the specimen.

  12. Phase transformation and deformation behavior of NiTi-Nb eutectic joined NiTi wires.

    Science.gov (United States)

    Wang, Liqiang; Wang, Cong; Zhang, Lai-Chang; Chen, Liangyu; Lu, Weijie; Zhang, Di

    2016-01-01

    NiTi wires were brazed together via eutectic reaction between NiTi and Nb powder deposited at the wire contact region. Phase transformation and deformation behavior of the NiTi-Nb eutectic microstructure were investigated using transmission electron microscopy (TEM) and cyclic loading-unloading tests. Results show that R phase and B19' martensite transformation are induced by plastic deformation. R phase transformation, which significantly contributes to superelasticity, preferentially occurs at the interfaces between NiTi and eutectic region. Round-shaped Nb-rich phase with rod-like and lamellar-type eutectics are observed in eutectic regions. These phases appear to affect the deformation behavior of the brazed NiTi-Nb region via five distinct stages in stress-strain curves: (I) R phase reorientation, (II) R phase transformation from parent phase, (III) elastic deformation of reoriented martensite accompanied by the plastic deformation of Nb-rich phase and lamellar NiTi-Nb eutectic, (IV) B19' martensitic transformation, and (V) plastic deformation of the specimen. PMID:27049025

  13. Progress in hardware development for the SAFE heatpipe reactor system

    Science.gov (United States)

    Ring, P. J.; Sayre, E. D.; van Dyke, Melissa; Houts, Mike

    2002-01-01

    Advanced Methods & Materials Company (AMM) previously fabricated the stainless steel modules for the SAFE 30 system. These earlier modules consisting of five fuel pins surrounding a heat pipe, were brazed together using a tricusp insert in the gaps between tubes to ensure maximum braze coverage. It was decided that if possible the next generations of modules, both stainless steel and refractory alloy, would be diffusion bonded together using a Hot Issostatic Pressing (HIP) process. This process was very successfully used in producing the bonded rhenium Nb-lZr fuel cladding and the heat exchanger for the SP-100 Nuclear Space System Ref. 1 & 2. In addition AMM have since refined the technology enabling them to produce very high temperature rocket thrust chambers. Despite this background the complex geometry required for the SAFE module was quite challenging. It was necessary to develop a method which could be applied for both stainless steel and refractory alloy systems. In addition the interstices between tubes had to be completely filled with the tricusp insert to avoid causing distortion of the tube shape during HIPing and provide thermal conductivity from the fuel tubes to the heat pipes. Nevertheless it was considered worth the effort since Hot Isostatic Pressing, if successful, will produce an assembly with the heat pipe completely embedded within the module such that the diffusion bonded assembly has the thermal conduction and strength equivalent to a solid structure. .

  14. Strategies to Reduce Tin and Other Metals in Electronic Cigarette Aerosol.

    Directory of Open Access Journals (Sweden)

    Monique Williams

    Full Text Available Metals are present in electronic cigarette (EC fluid and aerosol and may present health risks to users.The objective of this study was to measure the amounts of tin, copper, zinc, silver, nickel and chromium in the aerosol from four brands of EC and to identify the sources of these metals by examining the elemental composition of the atomizer components.Four brands of popular EC were dissected and the cartomizers were examined microscopically. Elemental composition of cartomizer components was determined using integrated energy dispersive X-ray microanalysis, and the concentrations of the tin, copper, zinc silver, nickel, and chromium in the aerosol were determined for each brand using inductively coupled plasma optical emission spectroscopy.All filaments were made of nickel and chromium. Thick wires were copper coated with either tin or silver. Wires were joined to each other by tin solder, brazing, or by brass clamps. High concentrations of tin were detected in the aerosol when tin solder joints were friable. Tin coating on copper wires also contributed to tin in the aerosol.Tin concentrations in EC aerosols varied both within and between brands. Tin in aerosol was reduced by coating the thick wire with silver rather than tin, placing stable tin solder joints outside the atomizing chamber, joining wires with brass clamps or by brazing rather than soldering wires. These data demonstrate the feasibility of removing tin and other unwanted metals from EC aerosol by altering designs and using materials of suitable quality.

  15. Experimental evaluation of different mixing promoter for nuclear fuel element by means of a new thermal tracing technique

    International Nuclear Information System (INIS)

    In this work a new experimental method is used to experimentally evaluate the performance of different appendages promoting the turbulent mixing between the coupled subchannels of nuclear fuel elements.The method used will be introduced in another presentation and consists in the generation and measurement of small thermal traces in the refrigerating water flow between the fuel rods.Because it is suitable for heterogeneous and compact subchannels (as Argentinean fuels) with high water flows in simple and affordable tests at atmospheric pressure, this new method is specially well suited for the design of fuel elements, while it offers advantages over other methods of mixing measurement.The experiments carried out on a small test section proved that the buttons brazed to the fuel rods (similar to the 'turbulence promoters' of the Canflex fuel) had an excellent thermohydraulic performance as compared to different mixing vane designs studied.The thermal traces method developed has shown its potential as a thermohydraulic design tool for the development of advanced nuclear fuels, that eventually incorporate mixing promoter elements. In the case of CARA, and as it includes spacer grids, it could be possible to use them to incorporate these elements without the need of brazing them to the rods (as is the case in Canflex), and therefore without penalizing its integrity

  16. Investigation of Be/Cu joints via HHF tests of small-scale mockups

    Energy Technology Data Exchange (ETDEWEB)

    Giniatulin, R.; Gervash, A.; Komarov, V.L.; Litunovsky, N.; Mazul, I.; Yablokov, N. [Efremov Inst., St. Petersburg (Russian Federation)

    1998-01-01

    Beryllium-copper (Be/Cu) joints in divertor components work under cyclic heat loads. To develop reliable joints small-scale mockups are fabricated by divertor technologies and tested under the divertor conditions. One of the critical damaging factors that exist in the divertor and have to be simulated is thermocyclic heat loads in the range of 1-15 MW/m{sup 2}. This work presents the divertor mockups that have beryllium tiles with different dimensions (5 x 5 - 44 x 44) mm{sup 2} brazed with copper alloy heat sink. The electron beam was used to braze these mockups so as to decrease the formation of brittle intermetallic layers. The description of mockups design, geometry of armour tiles and fabrication techniques are presented in the paper. The results of screening and thermocyclic tests of these mockups in the heat flux range of 2-12 MW/m{sup 2} with a number of cycles {approx}10{sup 3} are presented. The results of metallographic analysis are also presented. The results of fabrication and testing with small-scale mockups for first wall application are also described. (author)

  17. Fast mapping of gold jewellery from ancient Egypt with PIXE: Searching for hard-solders and PGE inclusions.

    Science.gov (United States)

    Lemasson, Quentin; Moignard, Brice; Pacheco, Claire; Pichon, Laurent; Guerra, Maria Filomena

    2015-10-01

    A new PIXE setup at the external beamline of the AGLAE accelerator is assessed for fast mapping the joining regions and the PGE inclusions of nine Egyptian gold items from the Louvre museum collection, dated to the end of the 2nd Intermediate Period and to the New Kingdom. The setup is composed of a cluster of SDD detectors divided in two "super detectors" dedicated to analyse the matrix and the trace elements. It provides the possibility to realise large and/or fast maps on artefacts by scanning the beam over the sample surface. Different softwares have been developed or updated to visualise, process, and quantify the data. By using this setup, we could determine the elemental distribution of major elements Au, Ag and Cu on the different joining regions, estimate the composition of the brazes, and show that they were produced by adding Cu to the base gold alloy. By fast mapping the PGE inclusions we could reveal a large variety of compositions within a single object. In addition to the expected Ir-Os-Ru system inclusions, we could also show for several inclusions the presence of another element, Pt. For a region where PGE inclusions overlap the joining area we could show that fast mapping allows to determine the compositions of the inclusion, the brazing alloy, and the base-alloy. PMID:26078160

  18. Metal Foam Analysis: Improving Sandwich Structure Technology for Engine Fan and Propeller Blades

    Science.gov (United States)

    Fedor, Jessica L.

    2004-01-01

    The Life Prediction Branch of the NASA Glenn Research Center is searching for ways to construct aircraft and rotorcraft engine fan and propeller blades that are lighter and less costly. One possible design is to create a sandwich structure composed of two metal faces sheets and a metal foam core. The face sheets would carry the bending loads and the foam core would have to resist the transverse shear loads. Metal foam is ideal because of its low density and energy absorption capabilities, making the structure lighter, yet still stiff. The material chosen for the face sheets and core was 17-4PH stainless steel, which is easy to make and has appealing mechanical properties. This material can be made inexpensively compared to titanium and polymer matrix composites, the two current fan blade alternatives. Initial tests were performed on design models, including vibration and stress analysis. These tests revealed that the design is competitive with existing designs; however, some problems were apparent that must be addressed before it can be implemented in new technology. The foam did not hold up as well as expected under stress. This could be due to a number of issues, but was most likely a result of a large number of pores within the steel that weakened the structure. The brazing between the face sheets and the foam was also identified as a concern. The braze did not hold up well under shear stress causing the foam to break away from the face sheets. My role in this project was to analyze different options for improving the design. I primarily spent my time examining various foam samples, created with different sintering conditions, to see which exhibited the most favorable characteristics for our purpose. Methods of analysis that I employed included examining strut integrity under a microscope, counting the number of cells per inch, measuring the density, testing the microhardness, and testing the strength under compression. Shear testing will also be done to examine

  19. Joining of zirconia mechanically metallized with titanium União de zircônia mecanicamente metalizada com titânio

    Directory of Open Access Journals (Sweden)

    J. S. Pimenta

    2010-07-01

    Full Text Available Direct brazing is a well-known technique for joining ceramics either themselves or to metals, whereby the required costly active filler alloys are considered a handicap of this process. In this work the indirect brazing of zirconia to zirconia mechanically metallized with Ti was successfully achieved using conventional filler alloys. The mechanical metallization specially applied to oxide ceramics is a successfully technique that was patented by Forschungszentrum Juelich, Germany, and it has been the subject of applied researches in the last 10 years. This particular metallization is made at room temperature with low cost production and is environmentally safe. Partially stabilized zirconia with yttria was mechanically metallized with Ti and wetting conditions were evaluated using Ag-28Cu and Au-18Ni fillers. These conventional fillers dissolve part of the Ti-coating becoming on-site at brazing temperature an active filler alloy which reacts with the zirconium oxide to improve wetting on the ceramic surface. Better results were selected for brazing tests in a high-vacuum furnace (A brasagem direta é uma técnica bem conhecida para união de cerâmicas entre si bem como aos metais, segundo a qual as ligas de adição requeridas são consideradas uma relativa desvantagem devido ao aumento nos custos do processo. Neste trabalho, a brasagem indireta da zircônia à zircônia mecanicamente metalizada com Ti foi alcançada com sucesso, usando-se ligas de adição convencionais. A metalização mecânica especialmente aplicada aos óxidos cerâmicos é uma técnica bem sucedida que foi patenteada pelo Forschungszentrum Juelich, Alemanha, e tem sido tema de pesquisas nos últimos 10 anos. Esta metalização particular é feita à temperatura ambiente com baixo custo de produção, sendo ambientalmente segura. Zircônia parcialmente estabilizada com ítria (Y-PSZ foi mecanicamente metalizada com Ti e as condições de molhamento foram avaliadas usando

  20. CEREM activity report

    International Nuclear Information System (INIS)

    This 1997 issue of the activity report of the CEREM (CEA) gives a general overview of the CEREM organization, activities and human resources with some budgetary information. The main activities described concern the materials fabrication for the nuclear and automotive industries, the powders metallurgy (molding by injection, cold pressing modelling), the simulation of the hot and cold working processes, the surface treatments, the joining (brazed joints, sintering, welding), the electrochemical storage of the energy (fuel cells, lithium accumulators), the corrosion and the physico-chemistry of fluids, the mechanical properties and the cracks, the robots for nuclear units dismantlement, the alteration mechanisms of properties under different solicitations (thermal, mechanical, chemical, irradiation) and the solidification-crystallogenesis. (O.M.)