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Sample records for glass weld braze

  1. Brazing, high temperature brazing and diffusion welding

    1989-01-01

    Brazing and high temperature brazing is a major joining technology within the economically important fields of energy technology, aerospace and automotive engineering, that play a leading role for technical development everywhere in the world. Moreover diffusion welding has gained a strong position especially in advanced technologies due to its specific advantages. Topics of the conference are: 1. high-temperature brazing in application; 2. basis of brazing technology; 3. brazing of light metals; 4. nondestructive testing; 5. diffusion welding; 6. brazing of hard metals and other hard materials; and 7. ceramic-metal brazing. 28 of 20 lectures and 20 posters were recorded separately for the database ENERGY. (orig./MM) [de

  2. Weld-brazing - a new joining process. [combination resistance spot welding and brazing of titanium alloys

    Bales, T. T.; Royster, D. M.; Arnold, W. E., Jr.

    1972-01-01

    A joining process designated weld brazing which combines resistance spot welding and brazing has been developed. Resistance spot welding is used to position and align the parts as well as to establish a suitable faying surface gap for brazing. Fabrication is then completed by capillary flow of the braze alloy into the joint. The process has been used successfully to fabricate Ti-6Al-4V titanium alloy joints using 3003 aluminum braze alloy. Test results obtained on single overlap and hat-stiffened structural specimens show that weld brazed joints are superior in tensile shear, stress rupture, fatigue, and buckling than joint fabricated by spotwelding or brazing. Another attractive feature of the process is that the brazed joints is hermetically sealed by the braze material.

  3. Metallographic quality control of welding and brazing

    Slaughter, G.M.

    1979-01-01

    The value of metallography in assuring integrity in the fabrication of metal and components in energy systems is summarized. Metallography also plays an integral role in quality control of welded and brazed joints

  4. Improved Assembly for Gas Shielding During Welding or Brazing

    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.

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

    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.

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

    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)

  7. Gas Shielding Technology for Welding and Brazing

    Nunes, Arthur J.; Gradl, Paul R.

    2012-01-01

    Welding is a common method that allows two metallic materials to be joined together with high structural integrity. When joints need to be leak-tight, light-weight, or free of contaminant-trapping seams or surface asperities, welding tends to be specified. There are many welding techniques, each with its own advantages and disadvantages. Some of these techniques include Forge Welding, Gas Tungsten Arc Welding, Friction Stir Welding, and Laser Beam Welding to name a few. Whichever technique is used, the objective is a structural joint that meets the requirements of a particular component or assembly. A key practice in producing quality welds is the use of shielding gas. This article discusses various weld techniques, quality of the welds, and importance of shielding gas in each of those techniques. Metallic bonds, or joints, are produced when metals are put into intimate contact. In the solid-state "blacksmith welding" process, now called Forge Welding (FOW), the site to be joined is pounded into intimate contact. The surfaces to be joined usually need to be heated to make it easier to deform the metal. The surfaces are sprinkled with a flux to melt surface oxides and given a concave shape so that surface contamination can be squeezed out of the joint as the surfaces are pounded together; otherwise the surface contamination would be trapped in the joint and would weaken the weld. In solid-state welding processes surface oxides or other contamination are typically squeezed out of the joint in "flash."

  8. Welding and brazing of the JET machine components

    Walravens, M.J.

    1985-10-01

    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)

  9. 75 FR 52037 - Welding, Cutting and Brazing Standard; Extension of the Office of Management and Budget's (OMB...

    2010-08-24

    ...] Welding, Cutting and Brazing Standard; Extension of the Office of Management and Budget's (OMB) Approval... requirements contained in the Welding, Cutting and Brazing Standard (29 CFR part 1910, subpart Q). The information collected is used by employers and workers whenever welding, cutting and brazing are performed...

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

    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.

  11. Brazing

    Schwartz, Mel M

    2003-01-01

    Text provides information needed to braze materials that will be used in the 21st century. Revised to include lessons learned on tooling, design, materials, atmospheres, processing, and equipment. For brazing technologists and engineers.

  12. Brazing of Cu with Pd-based metallic glass filler

    Terajima, Takeshi [Joining and Welding Research Institute, Osaka University, 11-1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan)], E-mail: terajima@jwri.osaka-u.ac.jp; Nakata, Kazuhiro [Joining and Welding Research Institute, Osaka University, 11-1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan); Matsumoto, Yuji [Materials and Structures Laboratory, Tokyo Institute of Technology (Japan); Zhang, Wei; Kimura, Hisamichi; Inoue, Akihisa [Institute for Materials Research, Tohoku University (Japan)

    2008-02-25

    Metallic glass has several unique properties, including high mechanical strength, small solidification shrinkage, small elastic modulus and supercooling state, all of which are well suited as a residual stress buffer for metal and ceramic joining. In the present preliminary study, we demonstrated brazing of Cu rods with Pd{sub 40}Cu{sub 30}Ni{sub 10}P{sub 20} metallic glass filler. The brazing was carried out at 873 K for 1 min in a vacuum atmosphere (1 x 10{sup -3} Pa), and then the specimens were quenched at the rate of 30 K/s by blowing He. The metallic glass brazing of Cu using Pd{sub 40}Cu{sub 30}Ni{sub 10}P{sub 20} filler was successful, with the exception that several voids remained in the filler. According to micro-focused X-ray diffraction, no diffraction patterns were observed at both the center of the Pd{sub 40}Cu{sub 30}Ni{sub 10}P{sub 20} filler and the Cu/Pd{sub 40}Cu{sub 30}Ni{sub 10}P{sub 20} interface. The result showed that the Cu specimens were joined with Pd{sub 40}Cu{sub 30}Ni{sub 10}P{sub 20} filler in the glassy state. The tensile fracture strength of the brazed specimens ranged from 20 to 250 MPa. The crack extension from the voids in the Pd{sub 40}Cu{sub 30}Ni{sub 10}P{sub 20} filler may have caused the results to be uneven and very low compared to the strength of Pd-based bulk metallic glass.

  13. 78 FR 53159 - Standard for Welding, Cutting, and Brazing; Extension of the Office of Management and Budget's...

    2013-08-28

    ...] Standard for Welding, Cutting, and Brazing; Extension of the Office of Management and Budget's (OMB... collection requirements contained in the Standard for Welding, Cutting, and Brazing (29 CFR Part 1910, Subpart Q). The information collected is used by employers and workers whenever welding, cutting, and...

  14. Brazing handbook

    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.

  15. Brazing

    Roemer, J.C.

    1979-10-01

    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

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

    Chen Shuhai; Li Liqun; Chen Yanbin; Huang Jihua

    2011-01-01

    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 Ti 7 Al 5 Si 12 and serration-shaped TiAl 3 . For the first time, obvious stacking fault structure in intermetallic phase TiAl 3 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 Mg 2 Si. Interfacial reaction layers of brazing joint were composed of α-Ti, nanosize granular Ti 7 Al 5 Si 12 and serration-shaped TiAl 3 . For the first time, apparent stacking fault structure in intermetallic phase TiAl 3 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.

  17. A Review of Research Progress on Dissimilar Laser Weld-Brazing of Automotive Applications

    Krishnaja, Devireddy; Cheepu, Muralimohan; Venkateswarlu, D.

    2018-03-01

    In recent years, a rapidly growing demand for laser brazing in the transportation industry for automotive parts joining to improve the productivity, quality of the joints and cost efficiency reasons. Due to this, laser brazing technology is extensively used in the major manufacturing companies such as Volkswagen group, General Motors Europe, BMW and Ford manufacturing groups as their openingbulk production solicitation on various parts of vehicles. Laser brazing is different from the welding processes and it will block upanopeningamongst two substrates by mixture of a filler wire on condition that by a concentrated laser beam or any other heat source. Among the all joining processes, laser brazing technique is an alternative and in effect method for welding of dissimilar metals which have large difference in their melting points. It is important to understand therelationsof these phenomena of the fillers of brazing with the substrate surfaces to obtain a high quality joints. The aim of this study is to address the contemporaryenquiriesand its progress on laser-brazing, its importance to the industrial applications and to bring more awareness to the manufacturers about the research results of this technique from various research groups to enhance the research progress and developing new things from this review report.

  18. Reversible brazing process

    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.

  19. Effects of different brazing and welding methods on the fracture load of various orthodontic joining configurations.

    Bock, Jens J; Bailly, Jacqueline; Fuhrmann, Robert A

    2009-06-01

    The aim of this study was to compare the fracture load of different joints made by conventional brazing, tungston inert gas (TIG) and laser welding. Six standardized joining configurations of spring hard quality orthodontic wire were investigated: end-to-end, round, cross, 3 mm length, 9 mm length and 6.5 mm to orthodontic band. The joints were made by five different methods: brazing with universal silver solder, two TIG and two laser welding devices. The fracture loads were measured with a universal testing machine (Zwick 005). Data were analysed with the Mann-Whitney-Wilcoxon and Kruskal-Wallis tests. The significance level was set at Pwelding (Pwelding (826 N). No differences between the various TIG or laser welding devices were demonstrated, although it was not possible to join an orthodontic wire to an orthodontic band using TIG welding. For orthodontic purposes laser and TIG welding are solder free alternatives. TIG welding and laser welding showed similar results. The laser technique is an expensive, but sophisticated and simple method.

  20. Joining technologies for the 1990s: Welding, brazing, soldering, mechanical, explosive, solid-state, adhesive

    Buckley, John D. (Editor); Stein, Bland A. (Editor)

    1986-01-01

    A compilation of papers presented in a joint NASA, American Society for Metals, The George Washington University, American Welding Society, and Society of Manufacturing Engineers Conference on Welding, Bonding, and Fastening at Langley Research Center, Hampton, VA, on October 23 to 25, 1984 is given. Papers were presented on technology developed in current research programs relevant to welding, bonding, and fastening of structural materials required in fabricating structures and mechanical systems used in the aerospace, hydrospace, and automotive industries. Topics covered in the conference included equipment, hardware and materials used when welding, brazing, and soldering, mechanical fastening, explosive welding, use of unique selected joining techniques, adhesives bonding, and nondestructive evaluation. A concept of the factory of the future was presented, followed by advanced welding techniques, automated equipment for welding, welding in a cryogenic atmosphere, blind fastening, stress corrosion resistant fasteners, fastening equipment, explosive welding of different configurations and materials, solid-state bonding, electron beam welding, new adhesives, effects of cryogenics on adhesives, and new techniques and equipment for adhesive bonding.

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

    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.

  2. Effect of dual laser beam on dissimilar welding-brazing of aluminum to galvanized steel

    Mohammadpour, Masoud; Yazdian, Nima; Yang, Guang; Wang, Hui-Ping; Carlson, Blair; Kovacevic, Radovan

    2018-01-01

    In this investigation, the joining of two types of galvanized steel and Al6022 aluminum alloy in a coach peel configuration was carried out using a laser welding-brazing process in dual-beam mode. The feasibility of this method to obtain a sound and uniform brazed bead with high surface quality at a high welding speed was investigated by employing AlSi12 as a consumable material. The effects of alloying elements on the thickness of intermetallic compound (IMC) produced at the interface of steel and aluminum, surface roughness, edge straightness and the tensile strength of the resultant joint were studied. The comprehensive study was conducted on the microstructure of joints by means of a scanning electron microscopy and EDS. Results showed that a dual-beam laser shape and high scanning speed could control the thickness of IMC as thin as 3 μm and alter the failure location from the steel-brazed interface toward the Al-brazed interface. The numerical simulation of thermal regime was conducted by the Finite Element Method (FEM), and simulation results were validated through comparative experimental data. FEM thermal modeling evidenced that the peak temperatures at the Al-steel interface were around the critical temperature range of 700-900 °C that is required for the highest growth rate of IMC. However, the time duration that the molten pool was placed inside this temperature range was less than 1 s, and this duration was too short for diffusion-control based IMC growth.

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

    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.

  4. Dissimilar Joining of Stainless Steel and 5083 Aluminum Alloy Sheets by Gas Tungsten Arc Welding-Brazing Process

    Cheepu, Muralimohan; Srinivas, B.; Abhishek, Nalluri; Ramachandraiah, T.; Karna, Sivaji; Venkateswarlu, D.; Alapati, Suresh; Che, Woo Seong

    2018-03-01

    The dissimilar joining using gas tungsten arc welding - brazing of 304 stainless steel to 5083 Al alloy had been conducted with the addition of Al-Cu eutectic filler metal. The interface microstructure formation between filler metal and substrates, and spreading of the filler metal were studied. The interface microstructure between filler metal and aluminum alloy characterized that the formation of pores and elongated grains with the initiation of micro cracks. The spreading of the liquid braze filler on stainless steel side packed the edges and appeared as convex shape, whereas a concave shape has been formed on aluminum side. The major compounds formed at the fusion zone interface were determined by using X-ray diffraction techniques and energy-dispersive X-ray spectroscopy analysis. The micro hardness at the weld interfaces found to be higher than the substrates owing to the presence of Fe2Al5 and CuAl2 intermetallic compounds. The maximum tensile strength of the weld joints was about 95 MPa, and the tensile fracture occurred at heat affected zone on weak material of the aluminum side and/or at stainless steel/weld seam interface along intermetallic layer. The interface formation and its effect on mechanical properties of the welds during gas tungsten arc welding-brazing has been discussed.

  5. Corrosion in artificial saliva of a Ni-Cr-based dental alloy joined by TIG welding and conventional brazing.

    Matos, Irma C; Bastos, Ivan N; Diniz, Marília G; de Miranda, Mauro S

    2015-08-01

    Fixed prosthesis and partial dental prosthesis frameworks are usually made from welded Ni-Cr-based alloys. These structures can corrode in saliva and have to be investigated to establish their safety. The purpose of this study was to evaluate the corrosion behavior of joints joined by tungsten inert gas (TIG) welding and conventional brazing in specimens made of commercial Ni-Cr alloy in Fusayama artificial saliva at 37°C (pH 2.5 and 5.5). Eighteen Ni-Cr base metal specimens were cast and welded by brazing or tungsten inert gas methods. The specimens were divided into 3 groups (base metal, 2 welded specimens), and the composition and microstructure were qualitatively evaluated. The results of potential corrosion and corrosion current density were analyzed with a 1-way analysis of variance and the Tukey test for pairwise comparisons (α=.05). Base metal and tungsten inert gas welded material showed equivalent results in electrochemical corrosion tests, while the air-torched specimens exhibited low corrosion resistance. The performance was worst at pH 2.5. These results suggest that tungsten inert gas is a suitable welding process for use in dentistry, because the final microstructure does not reduce the corrosion resistance in artificial saliva at 37°C, even in a corrosion-testing medium that facilitates galvanic corrosion processes. Moreover, the corrosion current density of brazed Ni-Cr alloy joints was significantly higher (P<.001) than the base metal and tungsten inert gas welded joints. Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  6. Interfacial Reaction Characteristics and Mechanical Properties of Welding-brazing Bonding Between AZ31B Magnesium Alloy and PRO500 Ultra-high Strength Steel

    CHEN Jian-hua

    2017-11-01

    Full Text Available Experiments were carried out with TIG welding-brazing of AZ31B magnesium alloy to PRO500 steel using TIG arc as heat source. The interfacial reaction characteristics and mechanical properties of the welding-brazing bonding were investigated. The results show that an effective bonding is achieved between AZ31B magnesium alloy and PRO500 steel by using TIG welding-brazing method. Some spontaneous oxidation reactions result in the formation of a transition zone containing AlFe3 phase with rich oxide. The micro-hardness value of the interfacial transition zone is between that of the AZ31B and the PRO500. Temper softening zone appears due to the welding thermal cycle nearby the bonding position in the interface. A higher heat input makes an increase of the brittle phases and leads to an obvious decrease of the bonding strength.

  7. In Situ SEM Observations of Fracture Behavior of Laser Welded-Brazed Al/Steel Dissimilar Joint

    Xia, Hongbo; Tan, Caiwang; Li, Liqun; Ma, Ninshu

    2018-03-01

    Laser welding-brazing of 6061-T6 aluminum alloy to DP590 dual-phase steel with Al-Si12 flux-cored filler wire was performed. The microstructure at the brazing interface was characterized. Fracture behavior was observed and analyzed by in situ scanning electron microscope. The microstructure of the brazing interface showed that inhomogeneous intermetallic compounds formed along the thickness direction, which had a great influence on the crack initiation and propagation. In the top region, the reaction layer at the interface consisted of scattered needle-like Fe(Al,Si)3 and serration-shaped Fe1.8Al7.2Si. In the middle region, the compound at the interface was only serration-shaped Fe1.8Al7.2Si. In the bottom region, the interface was composed of lamellar-shaped Fe1.8Al7.2Si. The cracks were first detected in the bottom region and propagated from bottom to top along the interface. At the bottom region, the crack initiated and propagated along the Fe1.8Al7.2Si/weld seam interface during the in situ tensile test. When the crack propagated into the middle region, a deflection of crack propagation appeared. The crack first propagated along the steel/Fe1.8Al7.2Si interface and then moved along the weld seam until the failure of the joint. The tensile strength of the joint was 146.5 MPa. Some micro-cracks were detected at Fe(Al,Si)3 and the interface between the steel substrate and Fe(Al,Si)3 in the top region while the interface was still connected.

  8. Non-destructive testing of assemblies by welding, brazing or bonding, and material to use for this process

    Benoit, J.

    1983-01-01

    The process consists in doing a neutron photography of the pieces assembled with the aid of a joining material containing a neutrophage element, such as gadolinium, samarium, europium, boron, cadmium. The neutrophage element, e.g. gadolinium, is dispersed in the joining material with contents between 0,5 and 7,5% of weight. Its granulometry must be less than 1000 MESH. The incorporation of a neutrophage element in the joining material of metallic pieces by welding or brazing, allows to visualize, among others, the following defects: blistering, cracks, slag inclusions, undercuts, bad distribution of the successive passes [fr

  9. Crack repair welding by CMT brazing using low melting point filler wire for long-term used steam turbine cases of Cr-Mo-V cast steels

    Kadoi, Kota, E-mail: kadoi@hiroshima-u.ac.jp [Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi-Hiroshima 739-8527 (Japan); Murakami, Aoi; Shinozaki, Kenji; Yamamoto, Motomichi [Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi-Hiroshima 739-8527 (Japan); Matsumura, Hideo [Chugoku Electric Power Co., 3-9-1 Kagamiyama, Higashi-Hiroshima 739-0046 (Japan)

    2016-06-01

    Surface melting by gas tungsten arc (GTA) welding and overlaying by cold metal transfer (CMT) brazing using low melting point filler wire were investigated to develop a repair process for cracks in worn cast steel of steam turbine cases. Cr-Mo-V cast steel, operated for 188,500 h at 566 °C, was used as the base material. Silver and gold brazing filler wires were used as overlaying materials to decrease the heat input into the base metal and the peak temperature during the welding thermal cycle. Microstructural analysis revealed that the worn cast steel test samples contained ferrite phases with intragranular precipitates of Cr{sub 7}C{sub 3}, Mo{sub 2}C, and CrSi{sub 2} and grain boundary precipitates of Cr{sub 23}C{sub 6} and Mo{sub 2}C. CMT brazing using low melting point filler wire was found to decrease the heat input and peak temperature during the thermal cycle of the process compared with those during GTA surface melting. Thus, the process helped to inhibit the formation of hardened phases such as intermetallics and martensite in the heat affected zone (HAZ). Additionally, in the case of CMT brazing using BAg-8, the change in the hardness of the HAZ was negligible even though other processes such as GTA surface melting cause significant changes. The creep-fatigue properties of weldments produced by CMT brazing with BAg-8 were the highest, and nearly the same as those of the base metal owing to the prevention of hardened phase formation. The number of fracture cycles using GTA surface melting and CMT brazing with BAu-4 was also quite small. Therefore, CMT brazing using low melting point filler wire such as BAg-8 is a promising candidate method for repairing steam turbine cases. However, it is necessary to take alloy segregation during turbine operation into account to design a suitable filler wire for practical use.

  10. Influence of thickness of zinc coating on CMT welding-brazing with AlSi5 alloy wire

    Jin, Pengli; Wang, Zhiping; Yang, Sinan; Jia, Peng

    2018-03-01

    Effect of thickness of zinc coating on Cold Mattel Transfer (CMT) brazing of aluminum and galvanized steel is investigated. The thickness of zinc coating is 10 μm, 30 μm, and 60 μm, respectively. A high-speed camera was used to capture images of welding process of different specimens; the microstructure and composition analyses of the welding seam were examined by scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS); the mechanical properties were measured in the form of Nano-indentation experiments. The results showed that arc characteristics and metal transfer behavior were unsteady at the beginning of welding process and that became stable after two cycles of CMT. With the thickness of zinc coating thickening, arc characteristics and metal transfer behaviors were more deteriorated. Compared with 10 μm and 30 μm, clad appearance of 60 μm was straight seam edges and a smooth surface which wetting angle was 60°. Zinc-rich zone at the seam edges was formed by zinc dissolution and motel pool oscillating, and zinc content of 10 μm and 30 μm were 5.8% and 7.75%. Zinc content of 60 μm was 14.61%, and it was a belt between galvanized steel and welding seam. The thickness of intermetallic compounds layer was in the range of 1-8 μm, and it changed with the thickness of zinc coating. The average hardness of the reaction layer of 60 μm is 9.197 GPa.

  11. Comparison of microstructural and mechanical properties of joints developed by high temperature brazing, GTAW and laser welding methods on AISI 316 L stainless steel for specific applications in nuclear components

    Venkatesu, Sadu; Saxena, Rajesh; Ravi Kumar, R.; Chaurasia, P.K; Murugan, S.; Venugopal, S.

    2016-01-01

    Fabrication of instrumented irradiation capsule for evaluating the irradiation performance of fuel and structural materials in a nuclear reactor requires development of thin wall joints capable of withstanding high temperature and/or internal pressure. Thin wall joints for high temperature (∼550℃) applications can be made by laser beam welding (LBW), gas tungsten Arc welding (GTAW) and High Temperature Brazing (HLT) method

  12. Friction welding of bulk metallic glasses to different ones

    Shoji, Takuo; Kawamura, Yoshihito; Ohno, Yasuhide

    2004-01-01

    For application of bulk metallic glasses (BMGs) as industrial materials, it is necessary to establish the metallurgical bonding technology. The BMGs exhibit high-strain-rate superplasticity in the supercooled liquid state. It has been reported that bulk metallic glasses were successfully welded together by friction, pulse-current, explosion and electron-beam methods. In this study, friction welding of the BMGs to different ones were tried for Pd 40 Ni 40 P 20 , Pd 40 Cu 30 P 20 Ni 10 , Zr 55 Cu 30 Al 10 Ni 5 and Zr 41 Be 23 Ti 14 Cu 12 Ni 10 BMGs. Successful welding was obtained in the combinations of the Pd 40 Ni 40 P 20 and Pd 40 Cu 30 P 20 Ni 10 BMGs, and the Zr 55 Cu 30 Al 10 Ni 5 and Zr 41 Be 23 Ti 14 Cu 12 Ni 10 ones. No crystallization was observed and no visible defect was recognized in the interface. The joining strength of the welded BMGs was the same as that of the parent BMG or more. BMGs seem to be successfully welded to the different ones with a difference below about 50 K in glass transition temperature

  13. Welding of Zr-based bulk metallic glasses

    Elahi, M.

    2010-01-01

    Recently, many bulk metallic glass (BMG) materials with high specific strength, hardness and superior corrosion resistance have been developed and the maximum thickness of some Zr-based BMGs have reached several tenths of millimeters. Nevertheless, homogeneous glassy BMGs are not thick enough to be used for structural applications. In order to extend the engineering applications of BMG materials, BMG welding technologies needed to be developed. Specifically, the welding technologies of dissimilar materials such as BMG materials to crystalline alloys are to be developed. The functional use of the specific properties of each material in dissimilar material combination provides flexible design possibilities for products. In this project electron beam welding is employed to join BMG with BMG of different composition as well as with different crystalline materials (i.e. Hastealoy C-276, Inconel-625 and pure Ti metal). Defects free weld joint was achieved in BMG-BMG welding. Some cracks were produced in melt zone of BMG-Ti and BMG-Hastealoy C-276 welding while at joint they fuse properly with BMG. Inconel-625 could not properly weld with BMG. In all cases, hardness of melt zone was found to be higher than the base metals and the heat affected zone (HAZ). (author)

  14. Titanium Brazing for Structures and Survivability

    Doherty, Kevin J; Tice, Jason R; Szewczyk, Steven T; Glide, Gary A

    2007-01-01

    .... While welding is the typical joining method for titanium, vacuum brazing is an option in areas that are difficult to access for welding as well as areas near other nonmetallic materials, such as ceramics...

  15. Characterisation of weld zone reactions in dissimilar glass-to-aluminium pulsed picosecond laser welds

    Ciuca, Octav P., E-mail: octav.ciuca@manchester.ac.uk [School of Materials, University of Manchester, Manchester, M13 9PL (United Kingdom); Carter, Richard M. [Institute of Photonics and Quantum Sciences, Heriot-Watt University, Edinburgh, EH14 4AS (United Kingdom); Prangnell, Philip B. [School of Materials, University of Manchester, Manchester, M13 9PL (United Kingdom); Hand, Duncan P. [Institute of Photonics and Quantum Sciences, Heriot-Watt University, Edinburgh, EH14 4AS (United Kingdom)

    2016-10-15

    Precision welded joints, produced between fused silica glass and aluminium by a newly-developed picosecond-pulse laser technique, have been analysed for the first time using a full range of electron microscopy methods. The welds were produced as lap joints by focusing a 1.2 μm diameter laser beam through the transparent glass top sheet, slightly below the surface of the metal bottom sheet. Despite the extremely short interaction time, extensive reaction was observed in the weld zone, which involved the formation of nanocrystalline silicon and at least two transitional alumina phases, γ- and δ-Al{sub 2}O{sub 3}. The weld formation process was found to be complex and involved: the formation of a constrained plasma cavity at the joint interface, non-linear absorption in the glass, and the creation of multiple secondary keyholes in the metal substrate by beam scattering. The joint area was found to expand outside of the main interaction volume, as the energy absorbed into the low conductivity and higher melting point silica glass sheet melted the aluminium surface across a wider contact area. The reasons for the appearance of nanocrystalline Si and transitional alumina reaction products within the welds are discussed. - Highlights: •Pulsed laser welding of dissimilar materials causes extensive chemical reactivity. •Metastable Al{sub 2}O{sub 3} phases form due to laser-induced highly-transient thermal regime. •Fused silica is reduced by Al to form nanocrystalline Si. •Mechanism of joint formation is discussed.

  16. Welding of CuZr-based metallic glasses on air

    Batalha, W.; Gargarella, P.; Kiminami, C.S.

    2016-01-01

    Metallic glass alloys have been studied aiming at its exceptional mechanical properties. This alloys processing's requires high cooling rates, which diminishes the sample's size. There by welding these samples without the loss of amorphous structure is a good alternative. The DEMa group has developed a technique based on Joule effect heating. By applying pressure and electric current, reaching temperatures of super cold liquids (the temperature between crystallizing and vitric transition), the vitric metal has it’s viscosity reduced and sample binding occur. The objective of this paper was to weld samples of cylindrical geometry of 2 and 3 mm in diameter and 4 mm in length of the compositions Cu46Zr42Al7Y5 and (Cu47Zr45Al8)98Y2. The process was done using 2 copper electrodes under(over) argon flux. The samples were later analysed by microscopy, differential scanning calorimetry and X ray diffraction. The results showed that this kind of welding process is possible since crystal formation on the welding region did not occur and there were no faults like cracks or porosity. (author)

  17. Liquid phase and supercooled liquid phase welding of bulk metallic glasses

    Kawamura, Y.

    2004-01-01

    Recent progress on welding in bulk metallic glasses (BMGs) has been reviewed. BMGs have been successfully welded to BMGs or crystalline metals by liquid phase welding using explosion, pulse-current and electron-beam methods, and by supercooled liquid phase welding using friction method. Successful welding of the liquid phase methods was due to the high glass-forming ability of the BMGs and the high concentration of welding energy in these methods. In contrast, the supercooled liquid phase welding was successful due to the thermally stable supercooled liquid state of the BMGs and the superplasticity and viscous flow of the supercooled liquid. The successful welding of BMGs to BMGs and crystalline materials is promising for the future development of BMGs as engineering materials

  18. Brazing process in nuclear fuel element fabrication

    Katam, K.; Sudarsono

    1982-01-01

    The purpose of the brazing process is to join the spacers and pads of fuel pins, so that the process is meant as a soldering technique and not only as a hardening or reinforcing process such as in common brazing purposes. There are some preliminary processes before executing the brazing process such as: materials preparation, sand blasting, brazing metal coating tack welding the spacers and pads on the fuel cladding. The metal brazing used is beryllium in strip form which will be evaporated in vacuum condition to coat the spacers and pads. The beryllium vapor and dust is very hazardous to the workers, so all the line process of brazing needs specials safety protection and equipment to protect the workers and the processing area. Coating process temperature is 2470 deg C with a vacuum pressure of 10 -5 mmHg. Brazing process temperature process is 1060 deg C with a vacuum pressure of 10 -6 mmHg. The brazing process with beryllium coating probably will give metallurgical structural change in the fuel cladding metal at the locations of spacers and pads. The quality of brazing is highly influenced by and is depending on the chemical composition of the metal and the brazing metal, materials preparations, temperature, vacuum pressure, time of coating and brazing process. The quality control of brazing could be performed with methods of visuality geometry, radiography and metallography. (author)

  19. Soldadura (Welding). Spanish Translations for Welding.

    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…

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

    Moorhead, A.J.; Morgan, C.S.; Woodhouse, J.J.; Reed, R.W.

    1981-01-01

    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

  1. High-temperature brazing, state and development trends

    Lugscheider, E.

    1980-01-01

    The advantages of higher-temperature brazing as compared to welding methods are to be increasingly found in the field of applications, not merely in highly specialized fabriaction branches but also in common fields. Problems on basic materials, brazing construction, brazing method and testing of the joints as well as examples of application are treated. (orig./IHOE) [de

  2. Method for brazing together planar and nonplanar metal members

    Hammersand, F.G.; Witkowski, A.J.

    1985-01-01

    The invention relates to a method and apparatus for brazing two metal members together, at least one of which is nonplanar, in a brazing furnace using a substantially pure brazing material. The method comprises the steps of utilizing a brazing fixture to hold the two metal members in tangential relation to one another along a portion of each member so that a cavity is formed adjacent to the contacting portions. A braze material is then positioned within the cavity. The braze fixture, the metal members, and the braze material are then placed in a brazing furnace. A heat shield is then placed over the braze fixture, the metal members, and the braze material to shield the braze material from direct furnace radiation. The furnace temperature is linearly increased at a rate of about 180 0 C. per hour until a temperature of 350 0 C. is achieved. Heat is transferred by conduction from the metal members to the braze material to cause the braze material to melt. Some material from the metal members slowly diffuses into the braze material forming a braze joint. The furnace is rapidly cooled to room temperature using nitrogen gas. The brazed assemblies made according to this method are superior to assemblies formed by heliarc welding

  3. Electroplating eliminates gas leakage in brazed areas

    Leigh, J. D.

    1966-01-01

    Electroplating method seals brazed or welded joints against gas leakage under high pressure. Any conventional electroplating process with many different metal anodes can be used, as well as the build up of layers of different metals to any required thickness.

  4. Analysis of Welding Joint on Handling High Level Waste-Glass Canister

    Herlan Martono; Aisyah; Wati

    2007-01-01

    The analysis of welding joint of stainless steel austenitic AISI 304 for canister material has been studied. At the handling of waste-glass canister from melter below to interim storage, there is a step of welding of canister lid. Welding quality must be kept in a good condition, in order there is no gas out pass welding pores and canister be able to lift by crane. Two part of stainless steel plate in dimension (200 x 125 x 3) mm was jointed by welding. Welding was conducted by TIG machine with protection gas is argon. Electric current were conducted for welding were 70, 80, 90, 100, 110, 120, 130, and 140 A. Welded plates were cut with dimension according to JIS 3121 standard for tensile strength test. Hardness test in welding zone, HAZ, and plate were conducted by Vickers. Analysis of microstructure by optic microscope. The increasing of electric current at the welding, increasing of tensile strength of welding yields. The best quality welding yields using electric current was 110 A. At the welding with electric current more than 110 A, the electric current influence towards plate quality, so that decreasing of stainless steel plate quality and breaking at the plate. Tensile strength of stainless steel plate welding yields in requirement conditions according to application in canister transportation is 0.24 kg/mm 2 . (author)

  5. Electron beam welding of the dissimilar Zr-based bulk metallic glass and Ti metal

    Kim, Jonghyun [Department of Material Science, Kumamoto University, Kumamoto 860-8555 (Japan)], E-mail: joindoc@kumamoto-u.ac.jp; Kawamura, Y. [Department of Material Science, Kumamoto University, Kumamoto 860-8555 (Japan)

    2007-04-15

    We successfully welded 3 mm thick Zr{sub 41}Be{sub 23}Ti{sub 14}Cu{sub 12}Ni{sub 10} bulk metallic glass plate to Ti metal by electron beam welding with a beam irradiated 0.4 mm on the BMG side of the interface. There was no crystallization or defects in the weld because changes in the chemical composition of the weld metal were prevented. Bending showed that the welded sample had a higher strength than the Ti base metal. The interface had a 10 {mu}m thick interdiffusion layer of Zr and Ti.

  6. Induction Brazing

    Henningsen, Poul

    , or if the hottest area is located outside the joint interface, a number of defects may appear: the braze metal may flow away from the joint, the flux may burn off, poor binding of the braze metal may appear or the braze metal may be overheated. Joint geometry as well as electro-magnetic properties of the work piece...... 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....... The method has proven to give successful results in brazing tube-plate joints of copper-brass, copper-stainless steel, stainless steel-brass, and stainless steel-stainless steel. A new design of an adjustable flux concentrator for induction heating tube-to-plate joints is proposed and tested on a variety...

  7. Fabrication of Metallic Glass Powder for Brazing Paste for High-Temperature Thermoelectric Modules

    Seo, Seung-Ho; Kim, Suk Jun; Lee, Soonil; Seo, Won-Seon; Kim, Il-Ho; Choi, Soon-Mok

    2018-06-01

    Metallic glass (MG) offers the advantage of outstanding oxidation resistance, since it has disordered atomic-scale structure without grain boundaries. We fabricated Al-based MG ribbons (Al84.5Y10Ni5.5) by a melt spinning process. We evaluated the adhesion strength of interfaces between the Al-based MG and a Ni-coated Cu electrode formed under various conditions at high temperature. In addition, we attempted to optimize the process conditions for pulverizing MG ribbons to high-energy ball milling and planetary milling. We confirmed that the electrical resistivity of the Al-based MG ribbon was substantially reduced after annealing at high temperature (over 300°C) due to crystallization.

  8. Laser Welding-Brazing of Immiscible AZ31B Mg and Ti-6Al-4V Alloys Using an Electrodeposited Cu Interlayer

    Zhang, Zequn; Tan, Caiwang; Wang, Gang; Chen, Bo; Song, Xiaoguo; Zhao, Hongyun; Li, Liqun; Feng, Jicai

    2018-03-01

    Metallurgical bonding between immiscible system AZ31B magnesium (Mg) and Ti-6Al-4V titanium (Ti) was achieved by adding Cu interlayer using laser welding-brazing process. Effect of the laser power on microstructure evolution and mechanical properties of Mg/Cu-coated Ti joints was studied. Visually acceptable joints were obtained at the range of 1300 to 1500 W. The brazed interface was divided into three parts due to temperature gradient: direct irradiation zone, intermediate zone and seam head zone. Ti3Al phase was produced along the interface at the direct irradiation zone. Ti-Al reaction layer grew slightly with the increase in laser power. A small amount of Ti2(Cu,Al) interfacial compounds formed at the intermediate zone and the ( α-Mg + Mg2Cu) eutectic structure dispersed in the fusion zone instead of gathering when increasing the laser power at this zone. At the seam head zone, Mg-Cu eutectic structure was produced in large quantities under all cases. Joint strength first increased and then decreased with the variation of the laser power. The maximum fracture load of Mg/Cu-coated Ti joint reached 2314 N at the laser power of 1300 W, representing 85.7% joint efficiency when compared with Mg base metal. All specimens fractured at the interface. The feature of fracture surface at the laser power of 1100 W was characterized by overall smooth surface. Obvious tear ridge and Ti3Al particles were observed at the fracture surface with increase in laser power. It suggested atomic diffusion was accelerated with more heat input giving rise to the enhanced interfacial reaction and metallurgical bonding in direct irradiation zone, which determined the mechanical properties of the joint.

  9. Metallic glass coating on metals plate by adjusted explosive welding technique

    Liu, W.D.; Liu, K.X.; Chen, Q.Y.; Wang, J.T.; Yan, H.H.; Li, X.J.

    2009-01-01

    Using an adjusted explosive welding technique, an aluminum plate has been coated by a Fe-based metallic glass foil in this work. Scanning electronic micrographs reveal a defect-free metallurgical bonding between the Fe-based metallic glass foil and the aluminum plate. Experimental evidence indicates that the Fe-based metallic glass foil almost retains its amorphous state and mechanical properties after the explosive welding process. Additionally, the detailed explosive welding process has been simulated by a self-developed hydro-code and the bonding mechanism has been investigated by numerical analysis. The successful welding between the Fe-based metallic glass foil and the aluminum plate provides a new way to obtain amorphous coating on general metal substrates.

  10. Development of vacuum brazing furnace

    Singh, Rajvir; Yedle, Kamlesh; Jain, A.K.

    2005-01-01

    In joining of components where welding process is not possible brazing processes are employed. Value added components, high quality RF systems, UHV components of high energy accelerators, carbide tools etc. are produced using different types of brazing methods. Furnace brazing under vacuum atmosphere is the most popular and well accepted method for production of the above mentioned components and systems. For carrying out vacuum brazing successfully it is essential to have a vacuum brazing furnace with latest features of modern vacuum brazing technology. A vacuum brazing furnace has been developed and installed for carrying out brazing of components of copper, stainless steel and components made of dissimilar metals/materials. The above furnace has been designed to accommodate jobs of 700mm diameter x 2000mm long sizes with job weight of 500kgs up to a maximum temperature of 1250 degC at a vacuum of 5 x 10 -5 Torr. Oil diffusion pumping system with a combination of rotary and mechanical booster pump have been employed for obtaining vacuum. Molybdenum heating elements, radiation shield of molybdenum and Stainless Steel Grade 304 have been used. The above furnace is computer controlled with manual over ride facility. PLC and Pentium PC are integrated together to maneuver steps of operation and safety interlocks of the system. Closed loop water supply provides cooling to the system. The installation of the above system is in final stage of completion and it will be ready for use in next few months time. This paper presents insights of design and fabrication of a modern vacuum brazing furnace and its sub-system. (author)

  11. Pulsed Nd:YAG laser welding of Cu54Ni6Zr22Ti18 bulk metallic glass

    Kim, Jong Hyun; Lee, Changhee; Lee, D.M.; Sun, J.H.; Shin, S.Y.; Bae, J.C.

    2007-01-01

    Pulsed Nd:YAG laser was used to weld Cu 54 Ni 6 Zr 22 Ti 18 (numbers indicate at.%) metallic glass with glass forming ability of 6 mm. Through a single pulse irradiation on the glassy plate, the pulse condition for welding without crystallization was investigated. Under the selected pulse condition, the Cu 54 Ni 6 Zr 22 Ti 18 plate was periodically welded with different welding speeds. For the welding speed of 60 mm/min, no crystallization was observed in both weldment and heat-affected zone. For the 20 mm/min, the crystallized areas with a band shape were observed along the welding direction

  12. Microstructure of bonding interface for resistance welding of Zr-based metallic glass sheets

    Kuroda, Toshio; Ikeuchi, Kenji; Shimada, Masahiro; Kobayashi, Akira; Kimura, Hisamichi; Inoue, Akihisa

    2009-01-01

    Resistance welding of Zr 55 Cu 30 Al 10 Ni 5 metallic glass sheets was investigated at 723 K in a supercooled liquid region. The welding time was changed from 5 s to 20 s at 723 K. The joint interface of the metallic glass was no defect and no crack. X-ray diffraction technique of the bonding interface of specimens was performed. The specimens showed halo patterns showing existence of only glassy phase, when the welding time was 5 s and 10 s. X-ray diffraction patterns of specimen bonded for 20 s showed crystalline peaks with halo patterns for the welding for 20 s. The crystalline phase at the bonding interface was small. Transmission electron micrograph at the bonding interface showed nanostructures of NiZr 2 and Al 5 Ni 3 Zr 2 . (author)

  13. Development of friction welding process of Zr-based bulk metallic glasses

    Shin, Hyung Seop; Jeong, Young Jin; Kim, Ki Hyun

    2004-01-01

    Bulk Metallic Glasses(BMG) with good mechanical properties have problems that engineering application fields have been limited because of limitation of the alloy size. In order to solving this problem, the friction welding of BMG has been tried using the superplastic-like deformation behavior under the supercooled liquid region. The apparatus for friction welding test was designed and constructed using pneumatic cylinder and gripper based on a conventional lathe. Friction welding have been tried to combination of same BMG alloy and crystalline alloys. The results of welding test were evaluated by X-ray diffraction, measurement of hardness and mechanical properties test. In order to obtain the optimized welding test conditions the temperature of friction interface was measured using Infrared thermal imager

  14. One-step femtosecond laser welding and internal machining of three glass substrates

    Tan, Hua; Duan, Ji'an

    2017-05-01

    In this paper, it demonstrated one-step femtosecond laser welding and internal machining of three fused silica substrates in the optical- and non-optical-contact regimes by focusing 1030-nm laser pulses at the middle of the second substrate. Focusing laser pulses within the second glass in optical-contact and non-optical-contact samples induces permanent internal structural modification, leading to the three glass substrates bonding together simultaneously. The bonding mechanism is based on the internal modification of glass, and this mechanism is different from that of ordinary glass welding at the interface. Welding-spot size is affected by not only the gap distance (ablation effect) and heat transmission, but also by gravity through examining the sizes of the welding spots on the four contact welding surfaces. The maximum bonding strength of the lower interface (56.2 MPa) in the optical-contact regime is more than double that (27.6 MPa) in the non-optical-contact regime.

  15. Nanostructure analysis of friction welded Pd-Ni-P/Pd-Cu-Ni-P metallic glass interface

    Ohkubo, T.; Shoji, S.; Kawamura, Y.; Hono, K.

    2005-01-01

    Friction welded Pd 40 Ni 40 P 20 /Pd 40 Cu 30 Ni 10 P 20 metallic glass interface has been characterized by energy filtering transmission electron microscopy. The interface is fully amorphous with a gradual compositional change of Cu and Ni in the range of 30 nm. By annealing above T g , the interdiffusion of Cu and Ni progressed in the supercooled liquid region, and the crystallization occurred from the Pd 40 Ni 40 P 20 glass

  16. Direct welding of glass and metal by 1  kHz femtosecond laser pulses.

    Zhang, Guodong; Cheng, Guanghua

    2015-10-20

    In the welding process between similar or dissimilar materials, inserting an intermediate layer and pressure assistance are usually thought to be necessary. In this paper, the direct welding between alumina-silicate glass and metal (aluminum, copper, and steel), under exposure from 1 kHz femtosecond laser pulses without any auxiliary processes, is demonstrated. The micron/nanometer-sized metal particles induced by laser ablation were considered to act as the adhesive in the welding process. The welding parameters were optimized by varying the pulse energy and the translation velocity of the sample. The shear joining strength characterized by a shear force testing equipment was as high as 2.34 MPa. This direct bonding technology has potential for applications in medical devices, sensors, and photovoltaic devices.

  17. Development and application of high-precision laser welding technology for manufacturing Ti alloy frames of glasses

    Kim, S. S.; Yang, M. S.; Kim, W. K.; Lee, D. Y.; Kim, J. M.; Leem, B. C.; Shin, J. S.; Lee, D. H.

    1999-12-01

    The research and development efforts of the high precision laser welding technology for manufacturing titanium alloy frames of glasses. For this purpose, laser welding device with the high beam quality is designed and fabricated, which consists of a optical fiber transmission part, a welding monitoring part and a welding controller. The welding nozzle and holding fixtures for manufacturing titanium and shape memory alloy frames of glasses. Titanium and shape memory alloy frames of glasses to be developed were experimentally manufactured by utilizing the laser welding using the optical fiber of GI 400 μm. As a result, the seam welding with the bead width of 0.3 mm or less and the weld penetration of 0.3-0.4mm could be accomplished. The fundamental technology was established through design of welding jigs with a variety of configurations and adequate welding conditions. Also, for the purpose to enable the companies participating in this project to commercialize the developed technology acceleratedly, a training program for the engineers belonging to such companies was conducted along with the technology transfer through joint experiments with the engineers. (author)

  18. 78 FR 75947 - Agency Information Collection Activities; Submission for OMB Review; Comment Request; Welding...

    2013-12-13

    ... for OMB Review; Comment Request; Welding, Cutting, and Brazing Standard ACTION: Notice. SUMMARY: The... information collection request (ICR) titled, ``Welding, Cutting, and Brazing Standard,'' to the Office of... the Welding, Cutting, and Brazing Standard, regulations 29 CFR part 1910, subpart Q. More specifically...

  19. Fluxless aluminum brazing

    Werner, W.J.

    1974-01-01

    This invention relates to a fluxless brazing alloy for use in forming brazed composites made from members of aluminum and its alloys. The brazing alloy consists of 35-55% Al, 10--20% Si, 25-60% Ge; 65-88% Al, 2-20% Si, 2--18% In; 65--80% Al, 15-- 25% Si, 5- 15% Y. (0fficial Gazette)

  20. Comparative Evaluation of Spectral Transmittance of Some Welding Glasses with ANSI Z87.1

    saeed Rahmani

    2016-04-01

    Full Text Available Background: Welding emits harmful rays to the eyes. We evaluate and compare the UV, blue light and IR transmittance characteristics of some currently available welding safety protectors with ANSI Z87.1 criteria.Materials and Methods: Three type of welding safety protectors (three of each type have been evaluated for spectral transmittance. One-sample T-test was performed to establish is there a statistically significant difference between the standard criteria and UV, blue and IR regions for the welding protectors (α=0.05.Results: In ultraviolet (UV (far and near region, two types of the tested protectors (P1, P2 transmitted lower than the maximum allowable value specified in the standard (P<0.001. In infrared (IR spectrum only one type (P3 transmitted lower than the maximum allowable value specified in the standard (P<0.001. In blue light region, all of the tested protectors transmitted lower than the maximum allowable value specified in the standard (P<0.001.Conclusion: Although all of the tested glasses could meet some parts of the criteria, but none of them could meet the complete spectral transmittance requirements of ANSI Z87.1.

  1. Quality assurance of brazed copper plates through advanced ultrasonic NDE

    Segreto, T.; Caggiano, A.; Teti, R.

    2016-01-01

    Ultrasonic non-destructive methods have demonstrated great potential for the detection of flaws in a material under examination. In particular, discontinuities produced by welding, brazing, and soldering are regularly inspected through ultrasonic techniques. In this paper, an advanced ultrasonic non-destructive evaluation technique is applied for the quality control of brazed copper cells in order to realize an accelerometer prototype for cancer proton therapy. The cells are composed of two h...

  2. Effect of focusing condition on molten area characteristics in micro-welding of borosilicate glass by picosecond pulsed laser

    Nordin, I.H.W.; Okamoto, Y.; Okada, A.; Takekuni, T. [Okayama University, Graduate School of Natural Science and Technology, Okayama (Japan); Sakagawa, T. [Kataoka Corporation, Yokohama (Japan)

    2016-05-15

    The characteristics of the molten area are attributed not only by laser energy condition but also the focusing condition. In this study, a picosecond pulsed laser of 1064 nm in wavelength and 12.5 ps in pulse duration was used as a laser source for joining glass material. Influence of focusing condition on micro-welding of glasses was experimentally investigated by using an objective lens with and without spherical aberration correction, and its molten area was characterized. The usage of objective lens with spherical aberration correction led to a larger molten area inside the bulk material of glass even under the same pulse energy, which related to the efficient micro-welding of glass materials. In addition, an optical system with the spherical aberration correction led to a stable absorption of laser energy inside the bulk glass material, stabilizing the shape of molten area, which resulted in the reliable weld joint. On the other hand, breaking strength of the specimens with spherical aberration correction was higher than that without spherical aberration correction. Therefore, it is concluded that the focusing condition with spherical aberration correction led to the larger and stable molten area, which resulted in higher joining strength in micro-welding of glass materials. (orig.)

  3. Soldering and brazing safety guide: A handbook on space practice for those involved in soldering and brazing

    This manual provides those involved in welding and brazing with effective safety procedures for use in performance of their jobs. Hazards exist in four types of general soldering and brazing processes: (1) cleaning; (2) application of flux; (3) application of heat and filler metal; and (4) residue cleaning. Most hazards during those operations can be avoided by using care, proper ventilation, protective clothing and equipment. Specific process hazards for various methods of brazing and soldering are treated. Methods to check ventilation are presented as well as a check of personal hygiene and good maintenance practices are stressed. Several emergency first aid treatments are described.

  4. Corrosion Behavior of Brazed Zinc-Coated Structured Sheet Metal

    A. Nikitin

    2017-01-01

    Full Text Available Arc brazing has, in comparison to arc welding, the advantage of less heat input while joining galvanized sheet metals. The evaporation of zinc is reduced in the areas adjacent to the joint and improved corrosion protection is achieved. In the automotive industry, lightweight design is a key technology against the background of the weight and environment protection. Structured sheet metals have higher stiffness compared to typical automobile sheet metals and therefore they can play an important role in lightweight structures. In the present paper, three arc brazing variants of galvanized structured sheet metals were validated in terms of the corrosion behavior. The standard gas metal arc brazing, the pulsed arc brazing, and the cold metal transfer (CMT® in combination with a pulsed cycle were investigated. In experimental climate change tests, the influence of the brazing processes on the corrosion behavior of galvanized structured sheet metals was investigated. After that, the corrosion behavior of brazed structured and flat sheet metals was compared. Because of the selected lap joint, the valuation of damage between sheet metals was conducted. The pulsed CMT brazing has been derived from the results as the best brazing method for the joining process of galvanized structured sheet metals.

  5. 29 CFR 1910.255 - Resistance welding.

    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. (3...

  6. Amorphous filler metal foils for brazing zirconium grid plates

    Plyushchev, A.N.; Kalin, B.A.; Fedotov, V.T.; Sevryukov, O.N.; Mamedova, T.T.; Shestakov, E.F.; Timoshin, S.N.

    2001-01-01

    A new amorphous ribbon filler metal of Zr-5.5 Fe-2.5 Be-1.0 Nb-8.0 Cu-2.0 Sn-0.4 Cr (mass %) with the temperature of melting onset of 745-750 deg C is designed to braze spacer grids of zirconium base alloys. The brazing conditions (780-790 deg C, 40-45 s) are determined which provide minimal standing at temperatures above 700 deg C (∼ 1.5 min) for spacer grids. Mechanical tests show that tensile strength of brazed joints is 55-59 kgf what is twice that of analogous welded joints. In addition, the brazed joints exhibit high corrosion resistance when testing in a distilled steam-water mixture at a temperature of 350 deg C and 16.5 MPa pressure for 10000 h [ru

  7. Adiabatic surface thermometer for improved production braze quality

    Dittbenner, G.R.

    1975-01-01

    An adiabatic surface thermometer was developed to control automatically the critical temperature-time cycle of a production vacuum-brazing process. Investigations revealed that optimum braze-joint strength required precise control of the brazing temperature. Spot-welded thermocouples could not be used because the spot welds cause surface damage. This thermometer touches the surface and uses a differential thermocouple and heater to measure surface temperature without heat flow, thereby eliminating large errors caused by conduction losses common to conventional spring-loaded thermocouples. Temperatures in air or vacuum are measured to 800 0 C with errors less than 5 0 C. This thermometer has minimized the rejection of production parts, resulting in a cost saving to the U. S. Energy Research and Development Administration

  8. Investigation on Explosive Welding of Zr53Cu35Al12 Bulk Metallic Glass with Crystalline Copper

    Feng, Jianrui; Chen, Pengwan; Zhou, Qiang

    2018-05-01

    A Zr53Cu35Al12 bulk metallic glass (BMG) was welded to a crystalline Cu using explosive welding technique. The morphology and the composition of the composite were characterized using optical microscopy, scanning electron microscopy, energy-dispersive x-ray spectroscopy and transmission electron microscopy. The investigation indicated that the BMG and Cu were tightly joined together without visible defects, and a thin diffusion layer appeared at the interface. The captured jet at the end of the welding region mostly comes from the Cu side. Amorphous and partially crystallized structures have been observed within the diffusion layer, but the BMG in close proximity to the interface still retains its amorphous state. Nanoindentation tests reveal that the interface exhibits an increment in hardness compared with the matrix on both sides.

  9. 75 FR 74083 - Agency Information Collection Activities; Submission for OMB Review; Comment Request; Welding...

    2010-11-30

    ... for OMB Review; Comment Request; Welding, Cutting and Brazing ACTION: Notice. SUMMARY: The Department... (OSHA) sponsored information collection request (ICR) titled, ``Welding, Cutting and Brazing,'' to the... that a periodic inspection of resistance welding equipment be made by qualified maintenance personnel...

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

    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.

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

    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

  12. Study of physicochemical processes and parameters of regime of diffusion brazing of niobium with titanium, zirconium and vanadium

    Grishin, V.L.; Lashko, S.V.

    1986-01-01

    Physicochemical processes at diffusion brazing of niobium with titanium, zirconium and vanadium, producing continious series of solid solutions with niobium are studied. Diffusion coefficients, time of isothermal crystallization of soldered welds, as well as the duration of homogenized thermal treatment of soldered welds necessary to provide the given temperature of weld unsoldering

  13. Investigations of glass sealing and reactive air brazing materials for joining high temperature solid oxide fuel cells by dilatometric examinations; Anwendung dilatometrischer Messungen bei der Entwicklung von Glasloten und reaktiven Metallloten zum Fuegen von Hochtemperaturbrennstoffzellen

    Reichle, M.S. [Parker Hannifin GmbH, Bietigheim-Bissingen (Germany); Federmann, D. [Forschungszentrum Juelich GmbH, ZAT, Juelich (Germany); Reisgen, U. [RWTH Aachen University, ISF, Aachen (Germany); Koppitz, T.

    2011-03-15

    The principle of operation of solid oxide fuel cells (SOFCs) is very simple. However, the fact that very different materials are used for the individual components requires advanced thermal joining techniques to join them in a functional manner. Two very distinct designs have established themselves for the two different intended applications: decentralised power generation (stationary SOFCs) on the one hand, and power converters for vehicles (mobile SOFCs) on the other hand. As a consequence, alternative techniques for joining the individual components are also required. The principal joining process for the stationary SOFC design consists of joining individual steel plates with a glass sealant in an electrically insulating way so that they form an SOFC stack. For the mobile fuel cell design, the SOFC stack consists of individual thin steel cassettes. The window frame of the cassettes, which is made of ferritic chromium steel, is brazed to the ceramic layer of the zirconium oxide solid electrolyte using a filler metal. The material used is a silver-based brazing filler metal which contains only small amounts of copper oxide (CuO) and titanium hydride (TiH{sub 2}) as wetting agents. Both joining processes must be applicable in normal atmospheric air, i. e. under oxidative conditions. R and D activities continue for improving the efficiency and long-term operational stability of the technology to such an extent that SOFCs will become ready for the energy sector market. The two joining techniques described cannot yet be considered standard processes. They, too, will require continuous improvement with respect to reproducibility, endurance and strength of the joints. The Special Joining Techniques working group at Forschungszentrum Juelich uses specially modified dilatometric techniques as suitable quick replacement methods for studying and measuring the joining characteristics of the materials without having to manufacture complex and expensive SOFC stacks. The

  14. Welding.

    Cowan, Earl; And Others

    The curriculum guide for welding instruction contains 16 units presented in six sections. Each unit is divided into the following areas, each of which is color coded: terminal objectives, specific objectives, suggested activities, and instructional materials; information sheet; transparency masters; assignment sheet; test; and test answers. The…

  15. Through-transmission laser welding of glass fibre composite: Experimental light scattering identification

    Cosson, Benoit; Asséko, André Chateau Akué; Dauphin, Myriam

    2018-05-01

    The purpose of this paper is to develop a cost-effective, efficient and quick to implement experimental optical method in order to predict the optical properties (extinction coefficient) of semi-transparent polymer composites. The extinction coefficient takes into account the effects due to the absorption and the scattering phenomena in a semi-transparent component during the laser processes, i.e. TTLW (through-transmission laser welding). The present method used a laser as light source and a reflex camera equipped with a macro lens as a measurement device and is based on the light transmission measurement through different thickness samples. The interaction between the incident laser beam and the semi-transparent composite is exanimated. The results are presented for the case of a semi-transparent composite reinforced with the unidirectional glass fiber (UD). A numerical method, ray tracing, is used to validate the experimental results. The ray tracing method is appropriate to characterize the light-scattering phenomenon in semi-transparent materials.

  16. Dictionary: Welding, cutting and allied processes. Pt. 2

    Kleiber, A.W.

    1987-01-01

    The dictionary contains approximately 40 000 entries covering all aspects of welding technology. It is based on the evaluation of numerous English, American and German sources. This comprehensive and up to date dictionary will be a reliable and helpful aid in evaluation and translating. The dictionary covers the following areas: Welding: gas welding, arc welding, gas shielded welding, resistance welding, welding of plastics, special welding processes; Cutting: flame cutting, arc cutting and special thermal cutting processes; Soldering: brazing and soldering; Other topics: thermal spraying, metal to metal adhesion, welding filler materials and other consumables, test methods, plant and equipment, accessories, automation, welding trade, general welding terminology. (orig./HP) [de

  17. Research Activities at IPT, DTU on Resistance Projection Welding

    Bay, Niels

    2000-01-01

    Resistance welding processes and among these especially the resistance projection welding is considered an industrially strategic process with increasing applications as alternative to other welding processes, soldering, brazing and mechanical assembling. This is due to increasing requirements...... as regards quality assurance and the special possibilities of joining complex metal combinations and geometries using resistance projection welding....

  18. 29 CFR 1910.254 - Arc welding and cutting.

    2010-07-01

    ... 29 Labor 5 2010-07-01 2010-07-01 false Arc welding and cutting. 1910.254 Section 1910.254 Labor... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Welding, Cutting and Brazing § 1910.254 Arc welding and cutting. (a... following limits shall not be exceeded: (i) Alternating-current machines (A) Manual arc welding and cutting...

  19. High temperature brazing of primary-system components in the nuclear field

    Belicic, M.; Fricker, H.W.; Iversen, K.; Leukert, W.

    1981-01-01

    Apart from the well-known welding procedures, high-temperature brazing is successfully applied in the manufacture of primary components in the field of nuclear reactor construction. This technique is applied in all cases where apart from sufficient resistance and high production safety importance is laid on dimensional stability without subsequent mechanical processing of the components. High-temperature brazing is therefore very important in the manufacture of fuel rod spacers or control rod guide tubes. In this context, during one brazing process many brazing seams have to be produced in extremely narrow areas and within small tolerances. As basic materials precipitation hardening alloys with a high nickel percentage, austenitic Cr-Ni-steels or the zirconium alloy Zry 4 are used. Generally applied are: boron free nickel or zirconium brazing filler metals. (orig.)

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

    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.

  1. METHOD OF BRAZING BERYLLIUM

    Hanks, G.S.; Keil, R.W.

    1963-05-21

    A process is described for brazing beryllium metal parts by coating the beryllium with silver (65- 75 wt%)-aluminum alloy using a lithium fluoride (50 wt%)-lithium chloride flux, and heating the coated joint to a temperature of about 700 un. Concent 85% C for about 10 minutes. (AEC)

  2. Analysis on High Temperature Aging Property of Self-brazing Aluminum Honeycomb Core at Middle Temperature

    ZHAO Huan

    2016-11-01

    Full Text Available Tension-shear test was carried out on middle temperature self-brazing aluminum honeycomb cores after high temperature aging by micro mechanical test system, and the microstructure and component of the joints were observed and analyzed using scanning electron microscopy and energy dispersive spectroscopy to study the relationship between brazing seam microstructure, component and high temperature aging properties. Results show that the tensile-shear strength of aluminum honeycomb core joints brazed by 1060 aluminum foil and aluminum composite brazing plate after high temperature aging(200℃/12h, 200℃/24h, 200℃/36h is similar to that of as-welded joints, and the weak part of the joint is the base metal which is near the brazing joint. The observation and analysis of the aluminum honeycomb core microstructure and component show that the component of Zn, Sn at brazing seam is not much affected and no compound phase formed after high temperature aging; therefore, the main reason for good high temperature aging performance of self-brazing aluminum honeycomb core is that no obvious change of brazing seam microstructure and component occurs.

  3. Advances in brazing science, technology and applications

    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...

  4. Microstructure characteristics of vacuum glazing brazing joints using laser sealing technique

    Liu, Sixing; Yang, Zheng; Zhang, Jianfeng; Zhang, Shanwen; Miao, Hong; Zhang, Yanjun; Zhang, Qi

    2018-05-01

    Two pieces of plate glass were brazed into a composite of glazing with a vacuum chamber using PbO-TiO2-SiO2-RxOy powder filler alloys to develop a new type of vacuum glazing. The brazing process was carried out by laser technology. The interface characteristics of laser brazed joints formed between plate glass and solder were investigated using optical microscope, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) techniques. The results show that the inter-diffusion of Pb/Ti/Si/O elements from the sealing solder toward the glass and O/Al/Si elements from the glass toward the solder, resulting in a reaction layer in the brazed joints. The microstructure phases of PbTiO3, AlSiO, SiO2 and PbO in the glass/solder interface were confirmed by XRD analysis. The joining of the sealing solder to the glass was realized by the reaction products like fibrous structures on interface, where the wetting layer can help improve the bonding performance and strength between the sealing solder and the plate glass during the laser brazing process.

  5. Finding Brazing Voids by Holography

    Galluccio, R.

    1986-01-01

    Vibration-induced interference fringes reveal locations of defects. Holographic apparatus used to view object while vibrated ultrasonically. Interference fringes in hologram reveal brazing defects. Holographic technique locates small voids in large brazed joints. Identifies unbrazed regions 1 in. to second power (6 cm to the second power) or less in area.

  6. Induction brazing of complex joints

    Henningsen, Poul; Zhang, Wenqi; Bay, Niels

    2003-01-01

    , or if the hottest area is located outside the joint interface, a number of defects may appear: the braze metal may flow away from the joint, the flux may burn off, poor binding of the braze metal may appear or the braze metal may be overheated. Joint geometry as well as electro-magnetic properties of the work piece...... 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...... proven to give successful results in brazing tube-plate joints of copper-brass, copper-stainless steel, stainless steel-brass, and stainless steel-stainless steel....

  7. High temperature brazing of reactor materials

    Orlov, A.V.; Nechaev, V.A.; Rybkin, B.V.; Ponimash, I.D.

    1990-01-01

    Application of high-temperature brazing for joining products of such materials as molybdenum, tungsten, zirconium, beryllium, magnesium, nickel and aluminium alloys, graphite ceramics etc. is described. Brazing materials composition and brazed joints properties are presented. A satisfactory strength of brazed joints is detected under reactor operation temperatures and coolant and irradiation effect

  8. Brazing graphite to graphite

    Peterson, G.R.

    1976-01-01

    Graphite is joined to graphite by employing both fine molybdenum powder as the brazing material and an annealing step that together produce a virtually metal-free joint exhibiting properties similar to those found in the parent graphite. Molybdenum powder is placed between the faying surfaces of two graphite parts and melted to form molybdenum carbide. The joint area is thereafter subjected to an annealing operation which diffuses the carbide away from the joint and into the graphite parts. Graphite dissolved by the dispersed molybdenum carbide precipitates into the joint area, replacing the molybdenum carbide to provide a joint of graphite

  9. Brazing copper to dispersion-strengthened copper

    Ryding, David G.; Allen, Douglas; Lee, Richard H.

    1996-11-01

    The advanced photon source is a state-of-the-art synchrotron light source that will produce intense x-ray beams, which will allow the study of smaller samples and faster reactions and processes at a greater level of detail than has ben possible to date. The beam is produced by using third- generation insertion devices in a 7-GeV electron/positron storage ring that is 1,104 meters in circumference. The heat load from these intense high-power devices is very high, and certain components must sustain total heat loads of 3 to 15 kW and heat fluxes of 30 W/mm$_2). Because the beams will cycle on and off many times, thermal shock and fatigue will be a problem. High heat flux impinging on a small area causes a large thermal gradient that results in high stress. GlidCop, a dispersion-strengthened copper, is the desired design material because of its high thermal conductivity and superior mechanical properties as compared to copper and its alloys. GlidCop is not amenable to joining by fusion welding, and brazing requires diligence because of high diffusivity. Brazing procedures were developed using optical and scanning electron microscopy.

  10. Microstructural development of diffusion-brazed austenitic stainless steel to magnesium alloy using a nickel interlayer

    Elthalabawy, Waled M.; Khan, Tahir I.

    2010-01-01

    The differences in physical and metallurgical properties of stainless steels and magnesium alloys make them difficult to join using conventional fusion welding processes. Therefore, the diffusion brazing of 316L steel to magnesium alloy (AZ31) was performed using a double stage bonding process. To join these dissimilar alloys, the solid-state diffusion bonding of 316L steel to a Ni interlayer was carried out at 900 deg. C followed by diffusion brazing to AZ31 at 510 deg. C. Metallographic and compositional analyses show that a metallurgical bond was achieved with a shear strength of 54 MPa. However, during the diffusion brazing stage B 2 intermetallic compounds form within the joint and these intermetallics are pushed ahead of the solid/liquid interface during isothermal solidification of the joint. These intermetallics had a detrimental effect on joint strengths when the joint was held at the diffusion brazing temperature for longer than 20 min.

  11. Brazing and diffusion bonding processes as available repair techniques for gas turbine blades and nozzles

    Mazur, Z.

    1997-01-01

    The conventionally welding methods are not useful for repair of heavily damaged gas turbine blades and nozzles. It includes thermal fatigue and craze cracks, corrosion, erosion and foreign object damage, which extend to the large areas. Because of required extensive heat input and couponing, it can cause severe distortion of the parts and cracks in the heat affected zone, and can made the repair costs high. For these cases, the available repair methods of gas turbine blades and nozzles, include brazing and diffusion bonding techniques are presented. Detailed analysis of the brazing and diffusion bonding processes applied for gas turbine blades repair with all elements which presented. Detailed analysis of the brazing and diffusion bonding processes applied for gas turbine blades repair with all elements which have influence to get sound joint is carried out. Depend of kind of blades and nozzle damage or deterioration registered a different methods of brazing and diffusion bonding applicability is presented. (Author) 65 refs

  12. A Brazing Defect Detection Using an Ultrasonic Infrared Imaging Inspection

    Cho, Jai Wan; Choi, Young Soo; Jung, Seung Ho; Jung, Hyun Kyu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2007-10-15

    When a high-energy ultrasound propagates through a solid body that contains a crack or a delamination, the two faces of the defect do not ordinarily vibrate in unison, and dissipative phenomena such as friction, rubbing and clapping between the faces will convert some of the vibrational energy to heat. By combining this heating effect with infrared imaging, one can detect a subsurface defect in material in real time. In this paper a realtime detection of the brazing defect of thin Inconel plates using the UIR (ultrasonic infrared imaging) technology is described. A low frequency (23 kHz) ultrasonic transducer was used to infuse the welded Inconel plates with a short pulse of sound for 280 ms. The ultrasonic source has a maximum power of 2 kW. The surface temperature of the area under inspection is imaged by an infrared camera that is coupled to a fast frame grabber in a computer. The hot spots, which are a small area around the bound between the two faces of the Inconel plates near the defective brazing point and heated up highly, are observed. And the weak thermal signal is observed at the defect position of brazed plate also. Using the image processing technology such as background subtraction average and image enhancement using histogram equalization, the position of defective brazing regions in the thin Inconel plates can be located certainly

  13. Structural Performance of Inconel 625 Superalloy Brazed Joints

    Chen, Jianqiang; Demers, Vincent; Cadotte, Eve-Line; Turner, Daniel; Bocher, Philippe

    2017-02-01

    The purpose of this work was to investigate tensile and fatigue behaviors of Inconel 625 superalloy brazed joints after transient liquid-phase bonding process. Brazing was performed in a vacuum furnace using a nickel-based filler metal in a form of paste to join wrought Inconel 625 plates. Mechanical tests were carried out on single-lap joints under various lap distance-to-thickness ratios. The fatigue crack initiation and crack growth modes were examined via metallographic analysis, and the effect of local stress on fatigue life was assessed by finite element simulations. The fatigue results show that fatigue strength and endurance limit increase with overlap distance, leading to a relatively large scatter of results. Fatigue cracks nucleated in the high-stressed region of the weld fillets from brittle eutectic phases or from internal brazing cavities. The present work proposes to rationalize the results by using the local stress at the brazing fillet. When using this local stress, all fatigue-obtained results find themselves on a single S- N curve, providing a design curve for any joint configuration in fatigue solicitation.

  14. Structure/property relationships in multipass GMA welding of beryllium.

    Hochanadel, P. W. (Patrick W.); Hults, W. L. (William L.); Thoma, D. J. (Dan J.); Dave, V. R. (Vivek R.); Kelly, A. M. (Anna Marie); Pappin, P. A. (Pallas A.); Cola, M. J. (Mark J.); Burgardt, P. (Paul)

    2001-01-01

    Beryllium is an interesting metal that has a strength to weight ratio six times that of steel. Because of its unique mechanical properties, beryllium is used in aerospace applications such as satellites. In addition, beryllium is also used in x-ray windows because it is nearly transparent to x-rays. Joining of beryllium has been studied for decades (Ref.l). Typically joining processes include braze-welding (either with gas tungsten arc or gas metal arc), soldering, brazing, and electron beam welding. Cracking which resulted from electron beam welding was recently studied to provide structure/property relationships in autogenous welds (Ref. 2). Braze-welding utilizes a welding arc to melt filler, and only a small amount of base metal is melted and incorporated into the weld pool. Very little has been done to characterize the braze-weld in terms of the structure/property relationships, especially with reference to multipass welding. Thus, this investigation was undertaken to evaluate the effects of multiple passes on microstructure, weld metal composition, and resulting material properties for beryllium welded with aluminum-silicon filler metal.

  15. Welding and Joining of Titanium Aluminides

    Cao, Jian; Qi, Junlei; Song, Xiaoguo; Feng, Jicai

    2014-01-01

    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. PMID:28788113

  16. Welding and Joining of Titanium Aluminides

    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.

  17. Thermally stable diamond brazing

    Radtke, Robert P [Kingwood, TX

    2009-02-10

    A cutting element and a method for forming a cutting element is described and shown. The cutting element includes a substrate, a TSP diamond layer, a metal interlayer between the substrate and the diamond layer, and a braze joint securing the diamond layer to the substrate. The thickness of the metal interlayer is determined according to a formula. The formula takes into account the thickness and modulus of elasticity of the metal interlayer and the thickness of the TSP diamond. This prevents the use of a too thin or too thick metal interlayer. A metal interlayer that is too thin is not capable of absorbing enough energy to prevent the TSP diamond from fracturing. A metal interlayer that is too thick may allow the TSP diamond to fracture by reason of bending stress. A coating may be provided between the TSP diamond layer and the metal interlayer. This coating serves as a thermal barrier and to control residual thermal stress.

  18. Welding and joining of single crystals of BCC refractory metals

    Hiraoka, Yutaka; Fujii, Tadayuki

    1989-01-01

    Welding and joining is one of key technologies for the wider utilizations of a material. In the present work, the applicability of welding and joining for a single crystal of BCC refractory metal was investigated. Electron-beam welding and tungsten-inert-gas welding by a melt-run technique, and high-temperature brazing by using brazing metals such as Mo-40%Ru alloy, vanadium or platinum were conducted for molybdenum single crystal which had been prepared by means of secondary recrystallization. 12 refs.,12 figs., 2 tabs. (Author)

  19. High-temperature brazing, present situation and development trends - brazing alloys

    Lugscheider, E.

    1980-01-01

    The range of application of high-temperature brazing is described. The process is defined. High-temperature nickel-base brazing alloys (alloying constituents, types of products. properties of the brazing alloys) and high-temperature brazing alloys for special metals and ceramics are dealt with. (orig.) [de

  20. Gas-Flame Brazing of Metals

    Asinovskaya, G

    1964-01-01

    ...), with subsequent crystallization of the latter, is called brazing or soldering; according to the Webster definition, brazing properly applies only to high- temperature soldering, soldering both to high and low-temperature work...

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

    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.

  2. Dictionary: Welding, cutting and allied processes. Pt. 2. German/English. Fachwoerterbuch: Schweissen, Schneiden und verwandte Verfahren. Bd. 2. Deutsch/Englisch

    Kleiber, A W

    1987-01-01

    The dictionary contains approximately 40 000 entries covering all aspects of welding technology. It is based on the evaluation of numerous English, American and German sources. This comprehensive and up to date dictionary will be a reliable and helpful aid in evaluation and translating. The dictionary covers the following areas: Welding: gas welding, arc welding, gas shielded welding, resistance welding, welding of plastics, special welding processes; Cutting: flame cutting, arc cutting and special thermal cutting processes; Soldering: brazing and soldering; Other topics: thermal spraying, metal to metal adhesion, welding filler materials and other consumables, test methods, plant and equipment, accessories, automation, welding trade, general welding terminology.

  3. Welding of CuZr-based metallic glasses on air; Soldagem ao ar de ligas vitreas baseadas em Cu e Zr

    Batalha, W.; Gargarella, P.; Kiminami, C.S., E-mail: wbatalha@dema.ufscar.br [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil). Departamento de Engenharia de Materiais

    2016-07-01

    Metallic glass alloys have been studied aiming at its exceptional mechanical properties. This alloys processing's requires high cooling rates, which diminishes the sample's size. There by welding these samples without the loss of amorphous structure is a good alternative. The DEMa group has developed a technique based on Joule effect heating. By applying pressure and electric current, reaching temperatures of super cold liquids (the temperature between crystallizing and vitric transition), the vitric metal has it’s viscosity reduced and sample binding occur. The objective of this paper was to weld samples of cylindrical geometry of 2 and 3 mm in diameter and 4 mm in length of the compositions Cu46Zr42Al7Y5 and (Cu47Zr45Al8)98Y2. The process was done using 2 copper electrodes under(over) argon flux. The samples were later analysed by microscopy, differential scanning calorimetry and X ray diffraction. The results showed that this kind of welding process is possible since crystal formation on the welding region did not occur and there were no faults like cracks or porosity. (author)

  4. Interfacial microstructure and mechanical properties of brazed aluminum / stainless steel - joints

    Fedorov, V.; Elßner, M.; Uhlig, T.; Wagner, G.

    2017-03-01

    Due to the demand of mass and cost reduction, joints based on dissimilar metals become more and more interesting. Especially there is a high interest for joints between stainless steel and aluminum, often necessary for example for automotive heat exchangers. Brazing offers the possibilities to manufacture several joints in one step at, in comparison to fusion welding, lower temperatures. In the recent work, aluminum / stainless steel - joints are produced by induction brazing using an AlSi10 filler and a non-corrosive flux. The mechanical properties are determined by tensile shear tests as well as fatigue tests at ambient and elevated temperatures. The microstructure of the brazed joints and the fracture surfaces of the tested samples are investigated by SEM.

  5. 29 CFR 1910.253 - Oxygen-fuel gas welding and cutting.

    2010-07-01

    ... 29 Labor 5 2010-07-01 2010-07-01 false Oxygen-fuel gas welding and cutting. 1910.253 Section 1910..., DEPARTMENT OF LABOR OCCUPATIONAL SAFETY AND HEALTH STANDARDS Welding, Cutting and Brazing § 1910.253 Oxygen-fuel gas welding and cutting. (a) General requirements—(1) Flammable mixture. Mixtures of fuel gases...

  6. Nondestructive testing of welds on thin-walled tubing

    Hagemaier, D. J.; Posakony, G. J.

    1969-01-01

    Special ultrasonic search unit, or transducer assembly, reliably inspects the quality of melt-through welds of fusion welded tubing couplers for hydraulic lines. This instrumentation can also be used to detect faulty braze bonds in thin-walled, small diameter joints and wall thickness of thin-walled metal tubing.

  7. Joining of molybdenum disilicide to stainless steel using amorphous metal brazes - residual stress analysis

    Vaidya, R.U.; Gallegos, D.E.; Kautz, D.D. [Los Alamos National Lab. (United States)

    2007-07-01

    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}/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. 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). (orig.)

  8. Simulation based analysis of laser beam brazing

    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.

  9. Combination of a Nd:YAG laser and a liquid cooling device to (Zr53Cu30Ni9Al8)Si0.5 bulk metallic glass welding

    Wang, H.S.; Chen, H.G.; Jang, J.S.C.; Chiou, M.S.

    2010-01-01

    Research highlights: → A liquid cooling device (LCD) helps to produce a lower initial welding temperature. → A lower initial welding temperature leads to a faster welding thermal cycle (WTC). → A faster WTC produces a crystallization free weld for a laser welded Zr-based BMG. - Abstract: Using pre-selected welding parameters, a crystallization-free weld for (Zr 53 Cu 30 Ni 9 Al 8 )Si 0.5 bulk metallic glass (BMG) was successfully produced by adopting a Nd:YAG pulse laser in combination with a liquid cooling device (LCD). When a LCD was employed, a faster cooling rate and shorter retention time for the crystallization temperature interval were produced, thus, no crystallization was observed in the weld fusion zone (WFZ) or heat affected zone (HAZ). The hardness in those areas did not differ significantly in comparison to the parent material (PM). For the room temperature laser weld (LCD was not employed), HAZ crystallization seemed unavoidable, although no crystallization occurred within the WFZ. The major crystalline phase in the HAZ was identified as Zr 2 Cu. When the precipitates were greater in the crystallized area (i.e., HAZ), cracks were more likely to form, thus, hardness in the area was decreased.

  10. Weld Repair of Thin Aluminum Sheet

    Beuyukian, C. S.; Mitchell, M. J.

    1986-01-01

    Weld repairing of thin aluminum sheets now possible, using niobium shield and copper heat sinks. Refractory niobium shield protects aluminum adjacent to hole, while copper heat sinks help conduct heat away from repair site. Technique limits tungsten/inert-gas (TIG) welding bombardment zone to melt area, leaving surrounding areas around weld unaffected. Used successfully to repair aluminum cold plates on Space Shuttle, Commercial applications, especially in sealing fractures, dents, and holes in thin aluminum face sheets or clad brazing sheet in cold plates, heat exchangers, coolers, and Solar panels. While particularly suited to thin aluminum sheet, this process also used in thicker aluminum material to prevent surface damage near weld area.

  11. 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

    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)

  12. Fabrication of high-quality brazed joints

    Orlov, A.V.

    1980-01-01

    Problem of ensuring of joint high-quality when brazing different parts in power engineering is considered. To obtain high-quality joints it is necessary to correctly design brazed joint and to choose a gap width, overlap length and fillet radius; to clean up carefully the surfaces to be brazed and fix them properly one relative to another; to apply a solder so as to provide its flowing into the gap and sticking in it; to exactly regulate thermal conditions of brazing. High quality and reliability of brazed joints are ensured by the application of solders based on noble metals, and cheap solders based on nickel, manganese and copper. Joints brazed with nickel base solders may operate at temperatures as high as 888 deg C

  13. Glasses

    Dyre, Jeppe

    2004-01-01

    The temperature dependence of the viscosity of most glassforming liquids is known to depart significantly from the classical Arrhenius behaviour of simple fluids. The discovery of an unexpected correlation between the extent of this departure and the Poisson ratio of the resulting glass could lead...... to new understanding of glass ageing and viscous liquid dynamics....

  14. Metallizing of machinable glass ceramic

    Seigal, P.K.

    1976-02-01

    A satisfactory technique has been developed for metallizing Corning (Code 9658) machinable glass ceramic for brazing. Analyses of several bonding materials suitable for metallizing were made using microprobe analysis, optical metallography, and tensile strength tests. The effect of different cleaning techniques on the microstructure and the effect of various firing temperatures on the bonding interface were also investigated. A nickel paste, used for thick-film application, has been applied to obtain braze joints with strength in excess of 2000 psi

  15. Brazing Inconel 625 Using the Copper Foil

    Chen, Wen-Shiang; Wang, Cheng-Yen; Shiue, Ren-Kae

    2013-12-01

    Brazing Inconel 625 (IN-625) using the copper foil has been investigated in this research. The brazed joint is composed of nanosized CrNi3 precipitates and Cr/Mo/Nb/Ni quaternary compound in the Cu/Ni-rich matrix. The copper filler 50 μm in thickness is enough for the joint filling. However, the application of Cu foil 100 μm in thickness has little effect on the shear strength of the brazed joint. The specimen brazed at 1433 K (1160 °C) for 1800 seconds demonstrates the best shear strength of 470 MPa, and its fractograph is dominated by ductile dimple fracture with sliding marks. Decreasing the brazing temperature slightly decreases the shear strength of the brazed joint due to the presence of a few isolated solidification shrinkage voids smaller than 15 μm. Increasing the brazing temperature, especially for the specimen brazed at 1473 K (1200 °C), significantly deteriorates the shear strength of the joint below 260 MPa because of coalescence of isothermal solidification shrinkage voids in the joint. The Cu foil demonstrates potential in brazing IN-625 for industrial application.

  16. Welding, Bonding and Fastening, 1984

    Buckley, J. D. (Editor); Stein, B. A. (Editor)

    1985-01-01

    A compilation of papers presented in a joint NASA, American Society for Metals, The George Washington University, American Welding Soceity, and Society of Manufacturing Engineers conference on Welding, Bonding, and Fastening at Langley Research Center, Hampton, VA, on October 23 to 25, 1984 is given. Papers were presented on technology developed in current research programs relevant to welding, bonding, and fastening of structural materials required in fabricating structures and mechanical systems used in the aerospace, hydrospace, and automotive industries. Topics covered in the conference included equipment, hardware and materials used when welding, brazing, and soldering, mechanical fastening, explosive welding, use of unique selected joining techniques, adhesives bonding, and nondestructive evaluation. A concept of the factory of the future was presented, followed by advanced welding techniques, automated equipment for welding, welding in a cryogenic atmosphere, blind fastening, stress corrosion resistant fasteners, fastening equipment, explosive welding of different configurations and materials, solid-state bonding, electron beam welding, new adhesives, effects of cryogenics on adhesives, and new techniques and equipment for adhesive bonding.

  17. High-temperature brazing of graphite using aluminium as brazing alloy

    Anikin, L.T.; Kravetskij, G.A.; Dergunova, V.S.

    1977-01-01

    The possibility of enhancing the strength of brazed joints, as well as the effect of the parameters of resistance heating of graphite VPP with PA-4 aluminium on the structure, composition and strength of the joint have been studied. It has been established that brazing of graphite materials, using an aluminium solder will produce a heat-resistant joint of a graphitic composition if the brazing temperature exceeds 2200 deg C. Thermocycling in the course of brazing results in a substantial (1.5-fold) increase in the strength of brazed joints

  18. Effect of welding processes on corrosion resistance of UNS S31803 duplex stainless steel

    Chiu, Liu Ho; Hsieh, Wen Chin

    2003-01-01

    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, γ 2 and Cr 2 N 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% FeCl 3 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

  19. Narrow groove gas metal-arc welding of aluminum

    Armstrong, R.E.

    1975-01-01

    The Gas Metal-Arc (GMA) welding process is explained and the equipment used described with an analysis of power supply function and the action of the arc, followed by discussion of general applications and problems. GMA braze welding of beryllium is then described, as is the development of a special high purity filler wire and a narrow deep groove joint design for improved weld strength in beryllium. This joint design and the special wire are applied in making high strength welds in high strength aluminum for special applications. High speed motion pictures of the welding operation are shown to illustrate the talk. (auth)

  20. Fluxless furnace brazing and its theoretical fundamentals

    Lison, R.

    1979-01-01

    In this paper the theoretical fundamental of fluxless furnace brazing are described. The necessary conditions for a wetting in the vacuum, under a inert-gas and with a reducing gas are discussed. Also other methods to reduce the oxygen partial pressure are described. Some applications of fluxless furnace brazing are outlined. (orig.) [de

  1. METHODS FOR BRAZING UNUSUAL METAL COMBINATIONS

    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.)

  2. Automatic-Control System for Safer Brazing

    Stein, J. A.; Vanasse, M. A.

    1986-01-01

    Automatic-control system for radio-frequency (RF) induction brazing of metal tubing reduces probability of operator errors, increases safety, and ensures high-quality brazed joints. Unit combines functions of gas control and electric-power control. Minimizes unnecessary flow of argon gas into work area and prevents electrical shocks from RF terminals. Controller will not allow power to flow from RF generator to brazing head unless work has been firmly attached to head and has actuated micro-switch. Potential shock hazard eliminated. Flow of argon for purging and cooling must be turned on and adjusted before brazing power applied. Provision ensures power not applied prematurely, causing damaged work or poor-quality joints. Controller automatically turns off argon flow at conclusion of brazing so potentially suffocating gas does not accumulate in confined areas.

  3. Combined scale effects for effective brazing at low temperatures

    Bartout D.

    2012-12-01

    Full Text Available In modern joining technology, the focus is on effective brazing and soldering of temperature sensitive materials. Here, as well as in diffusion welding processes the needed thermal energy is externally realized in the joint zone. This produces a heating of the whole joining parts, since in laminar joining the thermal energy is transported in interior by thermal conduction. An excess of critical temperatures or tolerable impact periods in wide parts of materials and respectively components is often not avoidable. This leads to thermal damages. In this point of view nanotechnology shows promising possibilities as scale effects and their resulting thermophysical effects such as melting temperature reduction and high diffusion rates can be used for providing a self-propagating high-temperature synthesis at room temperature. After ignition by an external energy source a self-propagating exothermic reaction is started. By producing a multilayer system with alternately arranged nanoscaled layers of e.g. Al and Ni the resulting thin foil can be used as heat source for melting the braze or solder material within the joining zone without any external preheating. Due to the high process velocities up to 30 m/s and the local heat input significant thermal influences on the joined parts are not detectable.

  4. Strength evaluation of jointed parts between ODS cladding and end plug by means of alternative welding method. Research report

    Hatakeyama, Koichi; Mizuta, Syunji; Fujiwara, Masayuki; Ukai, Shigeharu

    2001-12-01

    For the purpose of urgently discerning the applicability of ODS cladding tube to the long life core of the fast reactors, the irradiation test using Russian fast reactor BOR-60 is planned. In this irradiation test, TIG welding or laser welding will be applied as welding method of ODS cladding with end plug. In this report, applicability of alternative welding method, i.e., TIG welding, laser welding, and also electron beam welding and 3 kinds of brazing diffusion bonding technique was evaluated. In addition, bending test and internal creep rupture test of the samples which were welded by laser and TIG welding were carried out. Following results were obtained in this study. (1) Tensile strength of laser welding test specimens with the highest energy density is most excellent in the welding process (over 90% of the base metal strength). (2) In the brazing filler metal, the tensile strength of the nickel brazing was most excellent (over 84% of the base metal strength). (3) In the bending test of laser and TIG welded test specimens, the crack was generated in circumferential direction of weld zone, which relatively corresponds to small bending angle. (4) As result of internal creep rupture test at 700degC, cladding itself was ruptured in the high stress region, whereas, weld zone was ruptured in the low stress level. (author)

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

    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.

  6. Theory and modeling of active brazing.

    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.

  7. Corrosion Mechanisms in Brazed Al-Base Alloy Sandwich Structures as a Function of Braze Alloy and Process Variables

    2013-02-01

    concerns. These braze alloys use a high Si content to produce a low melting Al-Si near eutectic alloy. The recommended 11 brazing temperature for A A...each successive dip enhancing the 21 high temperature Si enrichment outside of the braze gap and decreasing the Si content within the braze gap.6...Nevertheless equilibrium phases should be considered as a reference point for grain boundaries after high temperature brazing . Recent literature [22

  8. Direct metal brazing to cermet feedthroughs

    Hopper, A.C. Jr.

    1984-01-01

    An improved method for brazing metallic components to a cermet surface in an alumina substrate eliminates the prior art metallized layer over the cermet via and adjoining alumina surfaces. Instead, a nickel layer is applied over the cermet surface only and metallic components are brazed directly to this nickel coated cermet surface. As a result, heretofore unachievable tensile strength joints are produced. In addition, cermet vias with their brazed metal components can be spaced more closely in the alumina substrate because of the elimination of the prior art metallized alumina surfaces

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

    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.

  10. The interaction of reaction-bonded silicon carbide and inconel 600 with a nickel-based brazing alloy

    McDermid, J. R.; Pugh, M. D.; Drew, R. A. L.

    1989-09-01

    The objective of the present research was to join reaction-bonded silicon carbide (RBSC) to INCONEL 600 (a nickel-based superalloy) for use in advanced heat engine applications using either direct brazing or composite interlayer joining. Direct brazing experiments employed American Welding Society (AWS) BNi-5, a commercial nickel-based brazing alloy, as a filler material; composite interlayers consisted of intimate mixtures of α-SiC and BNi-5 powders. Both methods resulted in the liquid filler metal forming a Ni-Si liquid with the free Si in the RBSC, which, in turn, reacted vigorously with the SiC component of the RBSC to form low melting point constituents in both starting materials and Cr carbides at the metal-ceramic interface. Using solution thermodynamics, it was shown that a Ni-Si liquid of greater than 60 at. pct Ni will decompose a-SiC at the experimental brazing temperature of 1200 ‡C; these calculations are consistent with the experimentally observed composition profiles and reaction morphology within the ceramic. It was concluded that the joining of RBSC to INCONEL 600 using a nickel-based brazing alloy is not feasible due to the inevitability of the filler metal reacting with the ceramic, degrading the high-temperature properties of the base materials.

  11. Gas-Flame Brazing of Metals

    Asinovskaya, G

    1964-01-01

    .... Since a gas flame implies the presence of considerable heat, the term brazing will be used in this translation save where low heats are specifically indicated, or where both high and low heats...

  12. On the Metallurgy of Active Brazing

    Paulasto, M.; Loo, van F.J.J.; Kivilahti, J.

    1996-01-01

    Advanced ceramics like silicon nitride are increasingly used as structural components in demanding high temperature applications as well as in electronics industry. Complex, multicomponent structures for engineering applications generally. The interfacial microstructures formed when Si3N4 is brazed

  13. Improved corrosion resistance of aluminum brazing sheet by a post-brazing heat treatment

    Norouzi Afshar, F.; Tichelaar, F.D.; Glenn, A. M.; Taheri, P.; Sababi, M.; Terryn, H.A.; Mol, J.M.C.

    2017-01-01

    This work studies the influence of the microstructure on the corrosion mechanism and susceptibility of as-brazed aluminum sheet. Various microstructures are obtained using postbrazing heat treatments developed to enhance the corrosion resistance of an AA4xxx/AA3xxx brazing sheet. The heat

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

    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.

  15. Design of a braze alloy for fast epitaxial brazing of superalloys

    Piegert, S.; Laux, B.; Rösier, J.

    2012-07-01

    For the repair of directionally solidified turbine components made of nickel-based superalloys, a new high-temperature brazing method has been developed. Utilising heterogeneous nucleation on the crack surface, the microstructure of the base material can be reproduced, i.e. single crystallinity can be maintained. In contrast to commonly used eutectic braze alloys, such as nickel-boron or nickel-silicon systems, the process is not diffusion controlled but works with a consolute binary base system. The currently applied epitaxial brazing methods rely on isothermal solidification diffusing the melting point depressants into the base material until their concentration is reduced so that the liquid braze solidifies. Contrary, the identified Ni-Mn consolute system enables a temperature driven epitaxial solidification resulting in substantially reduced process duration. The development of the braze alloys was assisted using the CALPHAD software Thermo-Calc. The solidification behaviour was estimated by kinetic calculations with realistic boundary conditions. Finally, the complete system, including braze alloy as well as substrate material, was modelled by means of DICTRA. Subsequently, the thermodynamic properties of the braze alloys were experimentally analysed by DSC measurements. For brazing experiments 300 μm wide parallel gaps were used. Complete epitaxial solidification, i.e. the absence of high-angle grain boundaries, could be achieved within brazing times being up to two orders of magnitude shorter compared to diffusion brazing processes. Theoretically and experimentally evaluated process windows reveal similar shapes. However, a distinct shift has to be stated which can be ascribed to the limited accuracy of the underlying thermodynamic databases.

  16. Interfacial microstructure and joining properties of Titanium–Zirconium–Molybdenum alloy joints brazed using Ti–28Ni eutectic brazing alloy

    Song, X.G., E-mail: songxg@hitwh.edu.cn [State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Shandong Provincial Key Lab of Special Welding Technology, Harbin Institute of Technology at Weihai, Weihai 264209 (China); Tian, X. [State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Shandong Provincial Key Lab of Special Welding Technology, Harbin Institute of Technology at Weihai, Weihai 264209 (China); Zhao, H.Y. [Shandong Provincial Key Lab of Special Welding Technology, Harbin Institute of Technology at Weihai, Weihai 264209 (China); Si, X.Q.; Han, G.H.; Feng, J.C. [State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Shandong Provincial Key Lab of Special Welding Technology, Harbin Institute of Technology at Weihai, Weihai 264209 (China)

    2016-01-20

    Vacuum brazing of Titanium–Zirconium–Molybdenum (Abbreviated as TZM) alloy using Ti–28Ni (wt%) eutectic brazing alloy was successfully achieved in this study. Reliable TZM brazed joints were obtained at the temperatures ranging from 1000 °C to 1160 °C for 600 s. The interfacial microstructure of TZM joints was characterized by employing SEM, EDS and XRD. The effects of brazing temperature on interfacial microstructure and joining properties were investigated in details. TZM brazed joints mainly consisted of δ-Ti{sub 2}Ni phase and Ti-based solid solution (Ti(s,s)). The interfacial microstructure of TZM joints was influenced obviously by brazing temperature. Both the thickness of brazing seam and the amount of δ-Ti{sub 2}Ni phase was reduced with the increasing brazing temperature, while the Ti(s,s) layer did not change significantly. The maximum average shear strength of TZM joints reached 107 MPa when brazed at 1080 °C. The presence of δ-Ti{sub 2}Ni intermetallic phase and crack-like structure in joints deteriorated the joining properties, which resulted in the formation of brittle fracture after shear test. In addition, fracture locations were related to the brazing temperature. When the brazing temperature was relatively low, cracks initiated and propagated in the continuous δ-Ti{sub 2}Ni layer. However, the fracture locations preferred to locating at the interface between TZM substrate and brazing seam when brazing temperature exceeded 1080 °C.

  17. Improving Casing Integrity by Induction Brazing of Casing Connections

    Ernens, Dennis; Hariharan, Hari; van Haaften, Willem Maarten; Pasaribu, Rihard; Jabs, Matthew; McKim, Richard

    2017-01-01

    Brazing technology allows metallurgical joining of dissimilar materials using a filler material. In this paper brazing technology applied to casing connections is presented. The initial application was triggered by challenges with mechanical and pressure integrity after expansion of casing

  18. The development of brazing filler for ITER thermal anchor attachment

    Lee, P.Y.; Sun, Z.C.; Pan, C.J.; Hou, B.L.; Han, S.L.; Pei, Y.Y.; Long, W.M.

    2011-01-01

    Magnet supports is one of the key components to sustain the ITER superconductor magnet coils, which operate at several K low temperature. Cooling of the supports is needed for maintaining temperature balance. It is suggested to use brazing connection to attach the thermal anchor to the support which made from SS 316LN plates. In this study, several kinds of brazing filler were developed as candidates, including Sn-Pb brazing filler, Ag-based and Cu-based brazing filler. The test result shows that Ag-based brazing filler has the best weldability with 316LN, but Cu-based alloy shows the best mechanical properties at both room temperature and 77 K. Even though the Sn-Pb alloy shows the lowest strength, it can be easily brazed due to the low brazing temperature. Detail of the brazing filler selection is suggested and discussed in this article.

  19. Tungsten wire and tubing joined by nickel brazing

    1965-01-01

    Thin tungsten wire and tungsten tubing are brazed together using a contacting coil of nickel wire heated to its melting point in an inert-gas atmosphere. This method is also effective for brazing tungsten to tungsten-rhenium parts.

  20. Investigação sobre a eficiência da fibra de vidro e da fibra cerâmica como suporte de solda na soldagem unilateral Investigation over the eficiency of fiber glass and ceramic fiber as weld support in one-sided welding

    Luiz Cláudio Tatagiba

    2011-12-01

    Full Text Available O objetivo deste trabalho foi avaliar uma nova categoria de suporte de solda para a soldagem unilateral do aço carbono, usando tecidos de fibra de vidro e fibra cerâmica. Trata-se de uma proposta de inovação tecnológica, uma evolução do suporte cerâmico convencional. A soldagem unilateral com este tipo de suporte de solda foi executada em chapas de aço carbono com arame tubular (FCAW e MIG-MAG (GMAW. A eficiência da fibra de vidro e da fibra cerâmica em suportar o metal de solda líquido foi verificada durante a soldagem do passe de raiz. Várias espessuras e combinações de tecidos de fibra de vidro e fibra cerâmica foram testadas, bem como foram identificados pontos de trabalho. As seguintes variáveis do processo foram estudadas: a abertura de raiz, a corrente e a velocidade de soldagem. Os resultados mostram que os materiais à base de fibra de vidro e fibra cerâmica são eficientes para suportar a poça de solda líquida. O modo de fixação do suporte de solda na junta soldada também mostrou ser efetivo. Foi possível estimar uma faixa de operação do processo, com abertura de raiz de 2,0 a 4,0 mm, a energia de soldagem menor que 1,8 kJ/mm, a técnica de soldagem ligeiramente puxando e com pequena oscilação da tocha, espessura do suporte de solda de tecido de fibra de vidro maior que 1,6 mm. Macrogafias da juntas soldadas mostraram que houve penetração nas laterais do chanfro, reforço de solda adequado na raiz e não foram notados defeitos.The objective of this work was to evaluate a new chategory of weld support for the one-sided welding of carbon steel, using fiber glass and ceramic fiber tissues. This is a proposal of techonological innovation proposed, an evolution of the conventional ceramic support. The one-sided welding with this type of weld support was made in carbon steel with FCAW and GMAW. The efficiency of fiber glass and ceramic fiber was verified during the root weld bead. Several thicknesses and

  1. process controller for induction vacuum brazing

    Aldea, A.

    2016-01-01

    A brazing operation involves joining two parts made of different materials, using a filler material that has a melting temperature lower than the base materials used. The temperature of the process must be carefully controlled, sometimes with an accuracy of about 1°C, because overshooting the prescribed temperature results in detrimental metallurgic phenomena and joints of poor quality. The brazing system is composed of an operating cabinet, a mid-frequency generator, a vacuum chamber with an induction coil inside and the parts that have to be brazed. Until now, to operate this system two operators were required: one to continuously read the temperature with an optical pyrometer and another to manually adjust the current in the induction coil according to his intuition and prediction gained only by experience. The improvement that we made to the system involved creating an automatic temperature control unit, using a PID closed loop controller that reads the temperature of the parts and adjusts automatically the current in the coil. Using the PID controller, the brazing engineer can implement a certain temperature slope for the current brazing process. (authors)

  2. Inert Welding/Brazing Gas Filters and Dryers

    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.

  3. Improved performance of brazed plate heat exchangers made of stainless steel type EN 1.4401 (UNS S31600) when using a iron-based braze filler

    Sjoedin, P. [Alfa Laval Materials, Lund (Sweden)

    2004-07-01

    The mechanical properties of brazed plate heat exchangers, made of stainless steel plates type EN 1.4401, brazed with a new iron-based braze filler ''AlfaNova'', have been evaluated. The results were compared with heat exchangers brazed with a copper (pure copper) and a nickel-based (MBF 51) braze filler. Their resistance against pressure- and temperature fatigue, which are important for the lifetime of a heat exchanger, and the burst pressure, which is important for pressure vessel approvals, were tested and evaluated. It was found that the pressure fatigue resistance was extraordinary good for the heat exchangers brazed the iron-based filler and its temperature fatigue resistance was better than those brazed with nickel-based braze filler and slightly lower than those brazed with copper. The highest burst pressures were achieved for the copper brazed units followed by the iron-brazed units and rearmost the nickel-brazed units. (orig.)

  4. ZIRCONIUM-TITANIUM-BERYLLIUM BRAZING ALLOY

    Gilliland, R.G.; Patriarca, P.; Slaughter, G.M.; Williams, L.C.

    1962-06-12

    A new and improved ternary alloy is described which is of particular utility in braze-bonding parts made of a refractory metal selected from Group IV, V, and VI of the periodic table and alloys containing said metal as a predominating alloying ingredient. The brazing alloy contains, by weight, 40 to 50 per cent zirconium, 40 to 50 per cent titanium, and the balance beryllium in amounts ranging from 1 to 20 per cent, said alloy having a melting point in the range 950 to 1400 deg C. (AEC)

  5. Capillary Flow of Liquid Metals in Brazing

    Dehsara, Mohammad

    Capillary flow is driven or controlled by capillary forces, exerted at the triple line where the fluid phases meet the solid boundary. Phase field (PF) models naturally accommodate diffusive triple line motion with variable contact angle, thus allowing for the no-slip boundary condition without the stress singularities. Moreover, they are uniquely suited for modeling of topological discontinuities which often arise during capillary flows. In this study, we consider diffusive triple line motion within two PF models: the compositionally compressible (CC) and the incompressible (IC) models. We derive the IC model as a systematic approximation to the CC model, based on a suitable choice of continuum velocity field. The CC model, applied to the fluids of dissimilar mass densities, exhibits a computational instability at the triple line. The IC model perfectly represents the analytic equilibria. We develop the parameter identification procedure and show that the triple line kinetics can be well represented by the IC model's diffusive boundary condition. The IC model is first tested by benchmarking the phase-field and experimental kinetics of water, and silicone oil spreading over the glass plates in which two systems do not interact with the substrate. Then, two high-temperature physical settings involving spreading of the molten Al-Si alloy: one over a rough wetting substrate, the other over a non-wetting substrate are modeled in a T-joint structure which is a typical geometric configuration for many brazing and soldering applications. Surface roughness directly influences the spreading of the molten metal by causing break-ups of the liquid film and trapping the liquid away from the joint. In the early stages of capillary flow over non-wetting surface, the melting and flow are concurrent, so that the kinetics of wetting is strongly affected by the variations in effective viscosity of the partially molten metal. We define adequate time-dependent functions for the

  6. Analysis for the brazing deformation of AFA3G spider

    Lin Feng

    2015-01-01

    Spider, the key component of the AFA3G cluster control assemblies (RCCA), is brazed with body, vanes and fingers. Vacuum brazing is crucial in the spider process and it is directly relevant to the final product quality. This paper analyze the deformation of the AFA3G spider in vacuum brazing procedure based on a large amount of data. The results indicate that the parallelism of the finger is most affected by the brazing and its deformation has obvious regularity. Deformation is mainly caused by the different contraction directions of components along with the interactions among them during cooling process. An optimized design of the brazing fixture based on the regularity and the value of the deformation greatly improves the parallelism of the fingers. Besides, the vacuum brazing procedure also affects the hole diameter of the finger, however, we could reduce the deformation by using columnar pin on the brazing fixture. (author)

  7. The effect of brazing parameters on corrosion behavior of brazed aluminum joints

    Ghasimakbari, Farzam; Hadian, Ali Mohammad; Ershadrad, Soheil; Omidazad, Amir Mansour

    2018-01-01

    Fluid transmission pipes made of aluminum are widely used in petrochemical industries. For many applications, they have to be brazed to each other. The brazed joints, in many cases, are encountered with corrosive medias. This paper reports a part of a work to investigate the corrosion behavior of brazed AA6061 using AA4047 as filler metal with and without the use of flux under different brazing atmospheres. The samples brazed under air, vacuum, argon, and hydrogen atmospheres. The interfacial area of the joints was examined to ensure being free of any defects. The sides of each test piece were covered with an insulator and the surface of the joint was encountered to polarization test. The results revealed a significant difference of corrosion resistance. The samples that brazed under argon and hydrogen atmospheres had better corrosion resistance than other samples. The microstructure of the corroded joints revealed that the presence of defects, impurities due to use of flux and depth of filter metal penetration in base metal are crucial variables on the corrosion resistance of the joints.

  8. WRC bulletin. High-temperature brazing

    Pattee, H.E.

    1974-01-01

    Significant research is discussed and representative procedures for producing sound, reliable joints are reviewed from the standpoint of base metal, filler metal, brazing atmosphere and cycle, etc. Domestic and foreign developments since 1950 are emphasized. Materials include stainless steels, Ni-base alloys, superalloys, reactive metals (Ti, Be, Zr), and refractory metals (Nb, Mo, Ta, W). 30 tables, 9 figures, 165 references

  9. Nickel-chromium-silicon brazing filler metal

    Martini, Angelo J.; Gourley, Bruce R.

    1976-01-01

    A brazing filler metal containing, by weight percent, 23-35% chromium, 9-12% silicon, a maximum of 0.15% carbon, and the remainder nickel. The maximum amount of elements other than those noted above is 1.00%.

  10. Titanium Brazing for Structures and Survivability

    2007-05-01

    first method ( Weld +HIP) was a tungsten inert gas ( TIG ) weld around the exterior of the Ti- 6Al-4V blocks followed by hot isostatic pressing (HIP) at...beam welding plus hot isostatic pressing (E-beam+HIP) process in the encapsulation of a ceramic within a titanium structure. The testing of the...different joining methods highlighted some definite candidates for the replacement of the E-beam+HIP process , such as the Weld +HIP, and demonstrated

  11. Hydrogen and deuterium plasma interactions with brazed first wall elements

    Smid, I. and others.

    1991-09-01

    Four different high temperature brazes (Zr, 90wt%Ni.10%Ti, 90Cu.10Ti and 70Ag.27Cu.3Ti, nominal composition prior to brazing) were used to join isotropic fine grain graphite and TZM, a high temperature alloy of molybdenum. The general response of the brazes to a high flux deuterium plasma bombardement was examined using samples whose exposed surface intersected the braze line. Only in the case of Zr, which is known for its hydride forming properties, near-surface layers chipped off in the braze region directly exposed to the plasma. However, in graphite-shielded Zr-braze regions no disintegration of the interface was observed. The other brazes showed no visible attack at all. The interaction of a hydrogen plasma and a braze surface was studied in more detail by bombarding specimens in the PISCES-B facility. In this case the graphite was removed completely to enable an exaggerated plasma attack onto the bare braze. Even under these testing conditions the brazes CuTi and NiTi showed no particular sensitivity towards hydrogen. To prove the thermal stability of the brazed joints each quality was heat treated for 1 hr and 10 hrs, respectively, 50 o below the softening temperature of the braze in 1 bar of Ar or 96vol%Ar/4%H 2 . After the heat treatment no changes or damages were observed in the brazes AgCuTi and CuTi, whereas interstices are found in the widened NiTi-interlayer after 10 hrs in both, Ar and Ar/H 2 . Zr suffers different microstructural changes in particular after treatment in Ar/H 2 atmosphere. (Authors) (also appeared in Fusion Technology 1990, p. 411-415)

  12. Hydrogen and deuterium plasma interactions with brazed first wall elements

    Smid, I.; Wallura, E.; Winter, J.; Nickel, H.; Doerner, R.; Hirooka, Y.; Chevalier, G.; Conn, R. W.; Jaeger, W.; Grasserbauer, M.; Kny, E.; Reheis, N.

    1995-01-01

    Four different high temperature brazes (Zr, 90wt%Ni.10%Ti, 90Cu.10Ti and 70Ag.27Cu.3Ti, nominal composition prior to brazing) were used to join isotropic fine grain graphite and TZM, a high temperature alloy of molybdenum. The general response of the brazes to a high flux deuterium plasma bombardement was examined using samples whose exposed surface intersected the braze line. Only in the case of Zr, which is known for its hydride forming properties, near-surface layers chipped off in the braze region directly exposed to the plasma. However, in graphite-shielded Zr-braze regions no disintegration of the interface was observed. The other brazes showed no visible attack at all. The interaction of a hydrogen plasma and a braze surface was studied in more detail by bombarding specimens in the PISCES-B facility. In this case the graphite was removed completely to enable an exaggerated plasma attack onto the bare braze. Even under these testing conditions the brazes CuTi and NiTi showed no particular sensitivity towards hydrogen. To prove the thermal stability of the brazed joints each quality was heat treated for 1 hr and 10 hrs, respectively, 50 degree below the softening temperature of the braze in 1 bar of Ar or 96 vol % Ar / 4 % H 2 . After the heat treatment no changes or damages were observed in the brazes AgCuTi and CuTi, whereas interstices are found in the widened NiTi-interlayer after 10 hrs in both, Ar and Ar/H 2 . Zr suffers different microstructural changes in particular after treatment in Ar/H 2 atmosphere. (author)

  13. Welding hazards

    Khan, M.A.

    1992-01-01

    Welding technology is advancing rapidly in the developed countries and has converted into a science. Welding involving the use of electricity include resistance welding. Welding shops are opened in residential area, which was causing safety hazards, particularly the teenagers and children who eagerly see the welding arc with their naked eyes. There are radiation hazards from ultra violet rays which irritate the skin, eye irritation. Welding arc light of such intensity could damage the eyes. (Orig./A.B.)

  14. Welding processes and ocular hazards and protection.

    Pabley, A S; Keeney, A H

    1981-07-01

    There are approximately 60 different forms of welding, but only six of these are commonly used. Shielded metal-arc or stick welding, gas metal-arc welding, and oxyacetylene welding are the most frequently used. All produce ultraviolet, visible, and infrared radiation at damaging levels. Conventional glass welding shields contain ultraviolet, visible, and infrared absorbers. Infrared absorbers, however, cause heating and secondary re-radiation. New polycarbonate lenses offer greater impact resistance, and have less tendency to welding spatter. Early abrasion-resistant and reflective coatings on plastics were ineffective. Thin layers of gold with proprietary coatings provide cool reflection and surface resistance. Thermal monitoring of welding indicated that these new shields reduce temperature rises above the ambient by 150% to 175% compared to green glass filter plates without interfering with the welder's vision.

  15. High temperature sealing method : induction brazing for SOFCs

    Heo, Y.H.; Lee, S.B.; Song, R.H.; Shin, D.R. [Korea Inst. of Energy Research, Daejeon (Korea, Republic of); Lim, T.H. [Korea Inst. of Energy Research, Daejeon (Korea, Republic of). Advanced Fuel Cell Research Center

    2009-07-01

    This study examined the use of induction brazing as a high temperature sealing method for solid oxide fuel cells (SOFCs). Nickel-based brazing alloys were modified using reactive titanium-hydride (TiH2). The gas sealing properties of the induction brazing process on anode-supported tubular SOFCs and ferritic stainless steel were evaluated. Brazing alloys BNi-2 and BNi-4 were not wetted in a yttria-silica-zircon (YSZ) electrolyte. The brazing alloy with added TiH2 showed good wettability with the YSZ electrolyte as a result of the formation of a TiOX layer. Only the BNi-4 alloy joined with the YSZ electrolyte. An open circuit voltage (OCV) value was used to estimate the gas tightness of the brazed cell. It was concluded that the BNi-4 TiH2 modified alloy is a suitable sealing material for SOFCs operating in temperatures up to 750 degrees C.

  16. The story of laser brazing technology

    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.

  17. Ductility of brazing assemblies with high-temperature materials

    Colbus, J.; De Paoli, A.

    1977-01-01

    Brazing assemblies with the high temperature materials X8CrNiNb1613, X12CrNiMo12 and X8NiCrAlTiMo7020 have been produced using different solder metals. These brazing assemblies have been studied with the emphasis on the interrelation between microstructure and ductility. Besides the ordinary impact bend tests of notched and unnotched brazed joints, the impact bend tests of unnotched brazed joints with drawing of a Strength-Way-Diagram have been added for better results. (GSC) [de

  18. PROSES BRAZING Cu-Ag BERBAHAN BAKAR BIOGAS TERMURNIKAN

    Ali Kusrijadi

    2015-01-01

    Full Text Available Pemanfaatan biogas sebagai salah satu alternatif bahan bakar  pada proses brazing merupakan langkah diversifikasi biogas, yang diharapkan dapat meningkatkan tingkat efisiensi dan keramahan teknologi. Permasalahan yang bersifat teknis dan menjadi kendala dalam pemanfaatan biogas ini adalah rendahnya konsentrasi CH4 dikarenakan adanya pengotor utama berupa air, karbondioksida dan asam disulfida. Penelitian dilakukan melalui dua tahap yaitu  tahap  pressureized storage process meliputi pemisahan komponen pengotor yang terdapat dalam biogas melalui teknik absorbsi sehingga dihasilkan biogas yang berkualitas gas alam terbarukan dan proses injeksi ke dalam suatu tangki penyimpanan, dan tahap selanjutnya adalah menggunakan biogas tersebut pada proses brazing logam Cu (tembaga dengan bahan tambah Ag (silver. Analisis hasil brazing dilakukan melalui analisis struktur mikro (metalografi untuk melihat kualitas tampak dari hasil brazing, serta analisis kekerasan mikro dan analisis parameter fisik standar terhadap hasil proses brazing. Penelitian ini telah menghasilkan perangkat alat pemurnian biogas yang dapat memurnikan biogas menjadi metana mendekati 100% dan sistem pengemasan (storage system  biogas bertekanan hingga 2 bar. Dari hasil analisis struktur mikro dan uji kekerasan mikro diketahui bahwa hasil proses brazing dengan biogas menghasilkan kualitas yang sama dengan hasil proses brazing dengan gas acetylene sehingga disimpulkan bahwa biogas dapat menjadi bahan bakar alternatif untuk proses brazing, khususnya untuk logam Cu dengan bahan tambah Ag.  Kata kunci : Biogas, Pressureized Storage, Brazing

  19. Welding Curriculum.

    Alaska State Dept. of Education, Juneau. Div. of Adult and Vocational Education.

    This competency-based curriculum guide is a handbook for the development of welding trade programs. Based on a survey of Alaskan welding employers, it includes all competencies a student should acquire in such a welding program. The handbook stresses the importance of understanding the principles associated with the various elements of welding.…

  20. Influence of brazing conditions on the strength of brazed joints of alumina dispersion-strengthened copper to 316 stainless steel

    Nishi, H.; Kikuchi, K.

    1998-01-01

    Brazing of alumina dispersion-strengthened copper (DS Cu) to 316 stainless steel were conducted in order to investigate the influence of filler metals and brazing conditions on the joint strength. The brazing were performed with a silver-base (BAg-8) and three kinds of gold-base (BAu-2.4.11) filler metals with varying brazing joint clearance and brazing time. The filler metal had a greater effect on the joint strength than the brazing joint clearance and brazing time. The joint with BAu-2 was superior to the joint with other filler metals. The tensile strength of the joint with BAu-2 was as large as that of DS Cu, however, the Charpy and low cycle fatigue strength were lower than those of DS Cu. The DS Cu melted near the brazed zone, consequently recrystallization and agglomeration of alumina occurred in the diffusion layer for all filler metals. The grain size after the recrystallization was small in order of BAu-2. BAu-4 and BAu-11, that was in accordance with the order of the brazing temperature. The excellent fracture strength for the joint with BAu-2 was attributed to the smallest grain size. (orig.)

  1. In Situ Synthesis of Al-Si-Cu Alloy During Brazing Process and Mechanical Property of Brazing Joint

    LONG Wei-min

    2016-06-01

    Full Text Available The Al-Si-Cu alloy system is considered to be a promising choice of filler metal for aluminium alloys brazing due to its high strength and low melting point. The greatest obstacle is its lack of plastic forming ability and being difficult to be processed by conventional methods. This disadvantage is ascribed to the considerable amount of brittle CuAl2 intermetallic compound which forms when alloy composition is around the ternary eutectic point. In order to overcome this deficiency, authors of this article proposed to synthesize Al-Si-Cu filler metal by using in situ synthesis method, and the structure and properties of brazing joints were studied. The results show that AlSi alloy is used as the wrap layer, and CuAl alloy is used as the powder core in the composite brazing wire, the two alloys have similar melting points. The machinability of the composite brazing wire is much superior to the traditional Al-Si-Cu filler metal. During the induction brazing of 3A21 alloy, when using AlSi-CuAl composite filler wire, AlSi and CuAl alloys melt almost simultaneously, then after short time holding, Al-Si-Cu braze filler is obtained, the brazing seam has uniform composition and good bonding interface, also, the shearing strength of the brazing joints is higher than the joint brazed by conventional Al-Si-Cu filler metal.

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

    Yadav, D.P.; Kaul, R.; Ganesh, P.; Shiroman, Ram; Tiwari, Pragya; Sridhar, R.; Kukreja, L.M.

    2013-01-01

    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)

  3. Assessment of the Biological Effects of Welding Fumes Emitted From Metal Active Gas and Manual Metal Arc Welding in Humans.

    Dewald, Eva; Gube, Monika; Baumann, Ralf; Bertram, Jens; Kossack, Veronika; Lenz, Klaus; Reisgen, Uwe; Kraus, Thomas; Brand, Peter

    2015-08-01

    Emissions from a particular welding process, metal inert gas brazing of zinc-coated steel, induce an increase in C-reactive protein. In this study, it was investigated whether inflammatory effects could also be observed for other welding procedures. Twelve male subjects were separately exposed to (1) manual metal arc welding fumes, (2) filtered air, and (3) metal active gas welding fumes for 6 hours. Inflammatory markers were measured in serum before, and directly, 1 and 7 days after exposure. Although C-reactive protein concentrations remained unchanged, neutrophil concentrations increased directly after exposure to manual metal arc welding fumes, and endothelin-1 concentrations increased directly and 24 hours after exposure. After exposure to metal active gas and filtered air, endothelin-1 concentrations decreased. The increase in the concentrations of neutrophils and endothelin-1 may characterize a subclinical inflammatory reaction, whereas the decrease of endothelin-1 may indicate stress reduction.

  4. Brazing molybdenum and tungsten for high temperature service

    Lundberg, L.B.; Turner, W.C.; Hoffman, C.G.

    1978-01-01

    Investigations were conducted to develop vacuum brazes for molybdenum and tungsten which can be used in seal joint applications up to 1870 K (1597 C, 2907 F). Joints were attempted in molybdenum, tungsten and tungsten--molybdenum. The braze materials included: Ti--10Cr powder, Ti--30V wire, Ti--65V wire, V wire, Ni electroplate, MoB--50MoC powder mixture, V--50Mo powder mixture, Mo--15MoB 2 powder mixture and Mo--49V--15MoB 2 powder mixture. Braze temperature ranged from 1900 K (1627 C, 2961 F) to 2530 K, (2257 C, 4095 F), and leak-tight joints were made with all braze materials except Ti--10Cr. After heat treatments up to 1870 K (1597 C, 2907 F) Kirkendall voiding was found to cause leakage of some of the joints made with only substitutional alloying elements. However, adding base metal powders to the braze or narrowing the root opening eliminated this problem. Kirkendall voiding was not a problem when interstitial elements were a major ingredient in the braze material. Shear testing of Ti--65V, V, MoB--50MoC and V--50Mo brazed molybdenum at 1670 K (1397 C, 2547 F) indicated strengths equal to or better than the base metal. Ti--65V, V--50Mo and MoB--50MoC brazed joints were exposed to basalt at 1670 K (1397 C, 2547 F) for 3 h without developing leaks

  5. Microwave-assisted brazing of alumina ceramics for electron tube ...

    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 ...

  6. Liquid Film Migration in Warm Formed Aluminum Brazing Sheet

    Benoit, M. J.; Whitney, M. A.; Wells, M. A.; Jin, H.; Winkler, S.

    2017-10-01

    Warm forming has previously proven to be a promising manufacturing route to improve formability of Al brazing sheets used in automotive heat exchanger production; however, the impact of warm forming on subsequent brazing has not previously been studied. In particular, the interaction between liquid clad and solid core alloys during brazing through the process of liquid film migration (LFM) requires further understanding. Al brazing sheet comprised of an AA3003 core and AA4045 clad alloy, supplied in O and H24 tempers, was stretched between 0 and 12 pct strain, at room temperature and 523K (250 °C), to simulate warm forming. Brazeability was predicted through thermal and microstructure analysis. The rate of solid-liquid interactions was quantified using thermal analysis, while microstructure analysis was used to investigate the opposing processes of LFM and core alloy recrystallization during brazing. In general, liquid clad was consumed relatively rapidly and LFM occurred in forming conditions where the core alloy did not recrystallize during brazing. The results showed that warm forming could potentially impair brazeability of O temper sheet by extending the regime over which LFM occurs during brazing. No change in microstructure or thermal data was found for H24 sheet when the forming temperature was increased, and thus warm forming was not predicted to adversely affect the brazing performance of H24 sheet.

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

    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. Advanced Welding Concepts

    Ding, Robert J.

    2010-01-01

    Four advanced welding techniques and their use in NASA are briefly reviewed in this poster presentation. The welding techniques reviewed are: Solid State Welding, Friction Stir Welding (FSW), Thermal Stir Welding (TSW) and Ultrasonic Stir Welding.

  9. Resistance seam welding

    Schueler, A.W.

    1977-01-01

    The advantages and disadvantages of the resistance seam welding process are presented. Types of seam welds, types of seam welding machines, seam welding power supplies, resistance seam welding parameters and seam welding characteristics of various metals

  10. Thermochemistry of brazing ceramics and metals in air

    Bobzin, Kirsten; Schlaefer, Thomas; Kopp, Nils [RWTH Aachen (DE). Surface Engineering Inst. (IOT)

    2011-08-15

    Reactive air brazing offers economically and technologically advantageous joining of ceramics to metals. Solid oxide fuel cells and membranes for oxyfuel combustion are recent fields of application. However, it remains a problem that strong metallurgical reactions between brazes and base materials occur. These reactions were analysed by differential scanning calorimetry tests to get a better understanding. Therefore, three braze alloys (Ag8Cu, Ag8Cu0.5Ti and Ag4Cu4Ni) and five base materials (alumina, 3YSZ partially stabilised zirconia, BSCF perovskite ceramic, X1CrTi-La22 and X15CrNiSi25-20) were investigated. The reaction peaks correlate with the formation of reaction layers, which were observed in metallographic analysis of brazed specimens. The results help to explain the reaction mechanisms and allow optimised selection of filler metals and brazing temperature. (orig.)

  11. Brazing of the Tore Supra actively cooled Phase III Limiter

    Nygren, R.E.; Walker, C.A.; Lutz, T.J.; Hosking, F.M.; McGrath, R.T.

    1993-01-01

    The head of the water-cooled Tore Supra Phase 3 Limiter is a bank of 14 round OFHC copper tubes, curved to fit the plasma radius, onto which several hundred pyrolytic graphite (PG) tiles and a lesser number of carbon fiber composite tiles are brazed. The small allowable tolerances for fitting the tiles to the tubes and mating of compound curvatures made the brazing and fabrication extremely challenging. The paper describes the fabrication process with emphasis on the procedure for brazing. In the fixturing for vacuum furnace brazing, the tiles were each independently clamped to the tube with an elaborate set of window frame clamps. Braze quality was evaluated with transient heating tests. Some rebrazing was necessary

  12. Welding Technician

    Smith, Ken

    2009-01-01

    About 95% of all manufactured goods in this country are welded or joined in some way. These welded products range in nature from bicycle handlebars and skyscrapers to bridges and race cars. The author discusses what students need to know about careers for welding technicians--wages, responsibilities, skills needed, career advancement…

  13. Coating system to permit direct brazing of ceramics

    Cadden, Charles H.; Hosking, F. Michael

    2003-01-01

    This invention relates to a method for preparing the surface of a ceramic component that enables direct brazing using a non-active braze alloy. The present invention also relates to a method for directly brazing a ceramic component to a ceramic or metal member using this method of surface preparation, and to articles produced by using this brazing method. The ceramic can be high purity alumina. The method comprises applying a first coating of a silicon-bearing oxide material (e.g. silicon dioxide or mullite (3Al.sub.2 O.sub.3.2SiO.sub.2) to the ceramic. Next, a thin coating of active metal (e.g. Ti or V) is applied. Finally, a thicker coating of a non-active metal (e.g. Au or Cu) is applied. The coatings can be applied by physical vapor deposition (PVD). Alternatively, the active and non-active metals can be co-deposited (e.g. by sputtering a target made of mullite). After all of the coatings have been applied, the ceramic can be fired at a high temperature in a non-oxidizing environment to promote diffusion, and to enhance bonding of the coatings to the substrate. After firing, the metallized ceramic component can be brazed to other components using a conventional non-active braze alloy. Alternatively, the firing and brazing steps can be combined into a single step. This process can replace the need to perform a "moly-manganese" metallization step.

  14. Evaluation of brazing joint of graphites and molybdenum

    Ishiyama, Shintarou; Kodaira, Tsuneo; Oku, Tatsuo

    1991-01-01

    Bonding test of six kinds of graphites to molybdenum was performed in the following conditions: Brazing elements was obtained by mixing of titanium nickel and copper in the range of 90∼51w%, 40∼10w%, 31∼0w%, respectively. Nonpressed brazing was performed at maximum temperature 1,000degC in a vacuum. Strength tests of these brazed joints were done in the conditions of at high temperature up to, 1,100degC in a vacuum, after 200 heat cycles from room temperature to about 900degC. Optical observation were performed before and after electron beam tests at 3.0 kW/cm 2 ·0.1 s·5 shots. The following results were derived: (1) The good mixing condition was found for titanium, nickel and copper brazing material at 64, 23 and 13w%, respectively. (2) Bending strengths of the brazed joints at room temperature were found to be proportional to the bending strengths of the graphite. (3) Bending strengths of the brazed joints shows no change until tested temperature reached 900degC in a vacuum. (4) Bending strength of the brazed joints showed no change after 200 heat cycles in the temperature range of room ∼ about 900degC and the electron beam tests. (author)

  15. Electron beam welding of dissimilar metals

    Metzger, G.; Lison, R.

    1976-01-01

    Thirty-three two-memeber combinations of dissimilar metals were electron beam welded as square-groove butt joints in 0.08 and 0.12 in. sheet material. Many joints were ''braze welded'' by offsetting the electron beam about 0.02 in. from the butt joint to achieve fusion of the lower melting point metal, but no significant fusion of the other member of the pair. The welds were evaluated by visual and metallographic examination, transverse tensile tests, and bend tests. The welds Ag/Al, Ag/Ni15Cr7Fe, Cu/Ni15Cr7Fe, Cu/V, Cu20Ni/Ni15Cr7Fe, Fe18Cr8Ni/Ni, Fe18Cr8Ni/Ni15Cr7Fe, Nb/Ti, Nb/V, Ni/Ni15Cr7Fe, and Cb/V10Ti were readily welded and weld properties were excellent. Others which had only minor defects included the Ag/Cu20Ni, Ag/Ti, Ag/V, Cu/Fe18Cr8Ni, Cu/V10Ti, Cu20Ni/Fe18Cr8Ni, and Ti/Zr2Sn welds. The Cu/Ni weld had deep undercut, but was in other respects excellent. The mechanical properties of the Ag/Fe18Cr8Ni weld were poor, but the defect could probably be corrected. Difficulty with cracking was experienced with the Al/Ni and Fe18Cr8Ni/V welds, but sound welds had excellent mechanical properties. The remaining welds Al-Cu, Al/Cu20Ni, Al/Fe18Cr8Ni, Al/Ni15Cr7Fe, Cu20Ni/V, Cu20Ni/V10Ti, Cb/Zr2Sn, Ni/Ti, Ni15Cr7Fe/V, Ni15Cr7Fe/V10Ti, and Ti/V were unsuccessful, due to brittle phases, primarily at the weld metal-base metal interface. In addition to the two-member specimens, several joints were made by buttering. Longitudinal weld specimens of the three-member combination Al/Ni/Fe18Cr8Ni and the five member combination Fe18Cr8Ni/V/Cb/Ti/Zr2Sn showed good tensile strength and satisfactory elongation. 6 tables, 16 figures

  16. The dissimilar brazing of Kovar alloy to SiCp/Al composites using silver-based filler metal foil

    Wang, Peng; Xu, Dongxia; Zhai, Yahong; Niu, Jitai

    2017-09-01

    Aluminum metal matrix composites with high SiC content (60 vol.% SiCp/Al MMCs) were surface metallized with a Ni-P alloy coating, and vacuum brazing between the composites and Kovar alloy were performed using rapidly cooled Ag-22.0Cu-15.9In-10.86Sn-1.84Ti (wt%) foil. The effects of Ni-P alloy coating and brazing parameters on the joint microstructures and properties were researched by SEM, EDS, and single lap shear test, respectively. Results show that Ag-Al intermetallic strips were formed in the 6063Al matrix and filler metal layer because of diffusion, and they were arranged regularly and accumulated gradually as the brazing temperature was increased ( T/°C = 550-600) or the soaking time was prolonged ( t/min = 10-50). However, excessive strips would destroy the uniformity of seams and lead to a reduced bonding strength (at most 70 MPa). Using a Ni-P alloy coating, void free joints without those strips were obtained at 560 °C after 20 min soaking time, and a higher shear strength of 90 MPa was achieved. The appropriate interface reaction ( 2 μm transition layer) that occurred along the Ni-P alloy coating/filler metal/Kovar alloy interfaces resulted in better metallurgical bonding. In this research, the developed Ag-based filler metal was suitable for brazing the dissimilar materials of Ni-P alloy-coated SiCp/Al MMCs and Kovar alloy, and capable welding parameters were also broadened.

  17. Brazing of Sealing for Instrumentation Feed through of high Pressure Vessel

    Jeong, H. Y.; Ahn, S. H.; Joung, C. Y.; Lee, J. M.; Lee, C. Y. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2011-05-15

    Fuel Test Loop(FTL) is a facility which could conduct a fuel irradiation test at HANARO(High-flux Advanced Neutron Application Reactor). FTL simulates commercial NPP's operating conditions such as the pressure, temperature and neutron flux levels to conduct the irradiation and thermo-hydraulic tests. It is composed of an In-Pile test Section(IPS) and an Out- Pile System(OPS). The OPS contains a pressurizer, cooler, pump, heater and purification system which are necessary to maintain the proper fluid conditions. In addition, the OPS contains engineered safety systems that could safely shutdown both HANARO and FTL if an accident occurs. The IPS accommodating fuel pins has loaded IP-1 hole in HANARO has a double pressure vessel for the design conditions of 350 .deg. C, 17.5MPa and is composed of outer assembly and inner assembly. It has instruments such as a thermocouple, LVDT and SPND to measure the fuel performances during the test. FTL coolant is supplied to the IPS at the core of commercial nuclear power plants and the same temperature, pressure and flow conditions. Sensors installed on the inside of IPS to send a signal transmission MI-Cables to the outside for instrumentation is through the pressure boundary. Therefore, pressure boundary should be maintained in the sealing performance. Brazing is typically lower than the melting point of material without melting the material almost would be like welding when it is necessary to use. It is commonly used to use BAg(ASME II SFA-5.8 UNS-P07563) filler metal, but corrosion occurs containing a large quantity of copper in Bag, and when contact with the coolant, the coolant water quality is influenced. Therefore, using BNi-2(ASME II SFA-5.8 UNS-N99620) filler metal is considered. Brazing at the Sealing Plug in the top of IPS was considered for Mi-cable's integrity and to maintain the pressure boundary. After brazing is performed, brazing the Mi-cable integrity and pressure boundary sealing performance was

  18. Brazing of Sealing for Instrumentation Feed through of high Pressure Vessel

    Jeong, H. Y.; Ahn, S. H.; Joung, C. Y.; Lee, J. M.; Lee, C. Y.

    2011-01-01

    Fuel Test Loop(FTL) is a facility which could conduct a fuel irradiation test at HANARO(High-flux Advanced Neutron Application Reactor). FTL simulates commercial NPP's operating conditions such as the pressure, temperature and neutron flux levels to conduct the irradiation and thermo-hydraulic tests. It is composed of an In-Pile test Section(IPS) and an Out- Pile System(OPS). The OPS contains a pressurizer, cooler, pump, heater and purification system which are necessary to maintain the proper fluid conditions. In addition, the OPS contains engineered safety systems that could safely shutdown both HANARO and FTL if an accident occurs. The IPS accommodating fuel pins has loaded IP-1 hole in HANARO has a double pressure vessel for the design conditions of 350 .deg. C, 17.5MPa and is composed of outer assembly and inner assembly. It has instruments such as a thermocouple, LVDT and SPND to measure the fuel performances during the test. FTL coolant is supplied to the IPS at the core of commercial nuclear power plants and the same temperature, pressure and flow conditions. Sensors installed on the inside of IPS to send a signal transmission MI-Cables to the outside for instrumentation is through the pressure boundary. Therefore, pressure boundary should be maintained in the sealing performance. Brazing is typically lower than the melting point of material without melting the material almost would be like welding when it is necessary to use. It is commonly used to use BAg(ASME II SFA-5.8 UNS-P07563) filler metal, but corrosion occurs containing a large quantity of copper in Bag, and when contact with the coolant, the coolant water quality is influenced. Therefore, using BNi-2(ASME II SFA-5.8 UNS-N99620) filler metal is considered. Brazing at the Sealing Plug in the top of IPS was considered for Mi-cable's integrity and to maintain the pressure boundary. After brazing is performed, brazing the Mi-cable integrity and pressure boundary sealing performance was tested

  19. Pressure brazing of ceramics to metals with copper solder

    Pavlova, M.A.; Metelkin, I.I.

    1986-01-01

    The effect on the quality of joints brazed with copper of different non metallized aluminooxide dielectrics with metals and alloys of a series of technological parameters (temperature, pressure, holding, and medium) in the course of pressure brazing is investigated. It is shown that in case of brazing with kovar and nickel the character of dependences is identical, however in all cases the joints with nickel are more durable. For the ceramics - molybdenum system characterized by weak interaction with copper solder kinetic dependences have no maximum and only under holding of more than 20 min the constant strength of 150-190 MPa is attained

  20. Resistance welding

    Bay, Niels; Zhang, Wenqi; Rasmussen, Mogens H.

    2003-01-01

    Resistance welding comprises not only the well known spot welding process but also more complex projection welding operations, where excessive plastic deformation of the weld point may occur. This enables the production of complex geometries and material combinations, which are often not possible...... to weld by traditional spot welding operations. Such joining processes are, however, not simple to develop due to the large number of parameters involved. Development has traditionally been carried out by large experimental investigations, but the development of a numerical programme system has changed...... this enabling prediction of the welding performance in details. The paper describes the programme in short and gives examples on industrial applications. Finally investigations of causes for failure in a complex industrial joint of two dissimilar metals are carried out combining numerical modelling...

  1. Microstructure and Mechanical Properties of Stainless Steel/Brass Joints Brazed by Sn-Electroplated Ag Brazing Filler Metals

    Wang, Xingxing; Peng, Jin; Cui, Datian

    2018-05-01

    To develop a high-Sn-content AgCuZnSn brazing filler metal, the BAg50CuZn was used as the base filler metal and a Sn layer was electroplated upon it. Then, the 304 stainless steel and the H62 brass were induction-brazed with the Sn-plated brazing filler metals. The microstructures of the joints were examined with an optical microscope, a scanning electron microscope and an x-ray diffractometer. The corresponding mechanical properties were obtained with a universal tensile testing machine. The results indicated that the induction brazed joints consisted of the Ag phase, the Cu phase and the CuZn phase. When the content of Sn in the Sn-plated Ag brazing filler metal was 6.0 or 7.2 wt.%, the Cu5Zn8, the Cu41Sn11 and the Ag3Sn phases appeared in the brazed joint. The tensile strength of the joints brazed with the Sn-plated filler metal was higher compared to the joints with the base filler metal. When the content of Sn was 6.0 wt.%, the highest tensile strength of the joint reached to 395 MPa. The joint fractures presented a brittle mode, mixed with a low amount of ductile fracture, when the content of Sn exceeded 6.0 wt.%.

  2. Glass-Metal Joining in Nuclear Environment: the State of the Art

    Jacobs, M.

    2007-01-01

    Full text of publication follows: In the ITER fusion machine and in material testing fission reactors, it is not possible to avoid the use of non-metallic materials like glass for example. There is therefore a need to apply metal to glass joints. This problem arose already at the beginning of the 19. century when the electric light bulb was invented. Nowadays this type of glass-metal joint is very successful and widely used in the electronic industry. In the case of ITER and material testing reactors, glass-metal joints are necessary for the fixation of the optical windows and optical fibres to a metal structure to perform diagnostics. These types of joints are still difficult to make and their behaviour is not fully understood. A joint between glass and metal for a nuclear or fusion application has indeed to resist high temperatures and high neutron fluences, while keeping a good mechanical strength and remaining leak tight. These characteristics are difficult to obtain under these severe conditions. This paper presents an overview of the different joining technologies that can be used to join glass to metal in a severe nuclear environment. The working mechanism of the technologies are explained, together with their respective advantages and drawbacks. Three different types of joining are discussed: fastening, liquid phase joining and solid phase joining. Fastening is a mechanical attachment technique, not achieving easily hermetic seals. Liquid and solid phase joining on the other hand form a real bond, what makes the joint much stronger. The most important technologies using liquid phase joining are adhesive bonding, fusion welding and brazing. In the case of the solid phase joining the choices are ultrasonic torsion welding, diffusion bonding and electrostatic bonding. If it is usually not possible to join the glass directly to the metal, an interlayer must be used. One speaks then of indirect joining. The paper will conclude with a discussion on the best

  3. Investigation on laser welding characteristics for appendage of bearing pads of nuclear fuel element

    Kim, S. S.; Kim, W. K.; Park, C. H.; Ko, J. H.; Lee, J. W.; Yang, M. S.

    2001-01-01

    In CANDU nuclear fuel manufacturing the brazing technology has been adopted conventionally to attach the bearing pads of nuclear fuel elements. However, in order to meet good performance of nuclear fuel and improved working efficiency, we started developing the laser welding technology for attachments of the bearing pads. Since the YAG laser can be suitable for small parts and transmit the beam through the optical fiber, the process is corresponding to mass-production with working shops. Making the most of this feature, we have developed the laser welding for appendage of the bearing pads of nuclear fuel elements, and has studied on the laser welding characterisitcs of appendages for nuclear fuel element

  4. Comparison of Metallurgical and Ultrasonic Inspections of Galvanized Steel Resistance Spot Welds

    Potter, Timothy J.; Ghaffari, Bita; Mozurkewich, George; Reverdy, Frederic; Hopkins, Deborah

    2006-01-01

    Metallurgical examination of galvanized steel resistance spot welds was used to gauge the capabilities of two ultrasonic, non-destructive, scanning techniques. One method utilized the amplitude of the echo from the weld faying surface, while the other used the spectral content of the echo train to map the fused area. The specimens were subsequently sectioned and etched, to distinguish the fused, zinc-brazed, and non-fused areas. The spectral maps better matched the metallurgical maps, while the interface-amplitude method consistently overestimated the weld size

  5. The development of argon arc brazing with Cu-based filler for ITER thermal anchor attachment

    Sun Zhenchao; Li Pengyuan; Pan Chuanjie; Hou Binglin; Han Shilei; Pei Yinyin; Long Weimin

    2012-01-01

    Thermal anchor is the key component of ITER magnet supports to maintain the low temperature for the nor mal operation of superconducting coils. During the advanced research of ITER thermal anchor attachment, dozens of brazing filler and several kinds of brazing technique have been developed and investigated. The test result shows that Cu-based alloy have the preferable mechanical properties at both room temperature and liquid nitrogen temperatures (77 K) for high brazing temperature. And it has a good weldability to 316LN. The brazing temperature of Cu-based filler is over 1000℃, but heat input is relatively low for shallower heating depth of argon arc brazing. Lower heat input is good for the control of brazing deformation. It is no need to clean after brazing because for argon arc brazing there is no bra- zing flux used. Arc brazing with Cu-based filler was chosen as the principal method for the attachment of thermal anchor. (authors)

  6. Vacuum brazing techniques for irradiation devices at TRIGA research reactor

    Savu, M.; Valeca, S. C.; Amzoi, A.

    2016-01-01

    Metallic thin-walled thermocouples are required for monitoring the temperature value for experiments that are conducted in a nuclear research reactor. The different location wall crossing is made by instrumented passage. Such a passage produced by vacuum brazing using a BNi-7 alloy, represents the proper way to obtain a sealed joint, which can withstand corrosion and high temperatures, having in the same time a small neutron cross section. This paper presents the brazing experiments of K-type thermocouples with stainless steel and Inconel 600 sheath. The sheaths brittleness, hardness changing in joint.s vicinity and structural modification emphasized by metallographic analysis are aspects treated by comparing different samples obtained in brazing laboratory. For finding the correct answer regarding the attenuation of negative effects which are occurring during brazing procedure using Inconel 600 - BNi-7 combination, one can assess both the adopted solution used in designing instrumented passage and thermal regime parameters and its precisely control. (authors)

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

    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.

  8. Solidification phenomena in nickel base brazes containing boron and silicon

    Tung, S.K.; Lim, L.C.; Lai, M.O.

    1996-01-01

    Nickel base brazes containing boron and/or silicon as melting point depressants are used extensively in the repair and joining of aero-engine hot-section components. These melting point depressants form hard and brittle intermetallic compounds with nickel which are detrimental to the mechanical properties of brazed joints. The present investigation studied the microstructural evolution in nickel base brazes containing boron and/or silicon as melting point depressant(s) in simple systems using nickel as the base metal. The basic metallurgical reactions and formation of intermetallic compounds uncovered in these systems will be useful as a guide in predicting the evolution of microstructures in similar brazes in more complex systems involving base metals of nickel base superalloys. The four filler metal systems investigated in this study are: Ni-Cr-Si; Ni-Cr-B; Ni-Si-B and Ni-Cr-Fe-Si-B

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

    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.

  10. Self-brazing Mechanism of Aluminum Alloy at Medium Temperature

    CHENG Fang-jie

    2018-01-01

    Full Text Available ZnCl2 and SnCl2 were added to the AlF3-CsF eutectic flux, which can be used for connecting aluminum alloy sheet by self-brazing at medium temperature. The influence of the amount of ZnCl2 and SnCl2 and the size of the T-joint area on the interface microstructure and the self-brazing joint mechanical properties was investigated. The interface microstructure, chemical compositions, defects and tensile fractography of the self-brazing joints were analyzed by metallographic microscope, scanning electron microscope and energy dispersive spectroscopy. The results show that the joints are soundly bonded when both the mass fractions of ZnCl2 and SnCl2 are about 4%; the replacement reactions between Zn2+, Sn2+ of flux and Al atoms of base metal occur during brazing, then the liquid metals of Sn and Zn appear, a great degree of Zn which has high solid solution with Al spreads rapidly to the base metal; Sn is distributed along the interface forming a low melting point metal layer with Zn and Al; the brazing of joints with small area can be realized easily; there are a lot of dimples on the fracture surface and the tensile strength of the brazing joint reaches (58±5MPa.

  11. Brazing refractory metals used in high-temperature nuclear instrumentation

    Palmer, A. J.; Woolstenhulme, C. J.

    2009-01-01

    As part of the U. S. Department of Energy (DOE)-sponsored Next Generation Nuclear Project (NGNP) currently ongoing at Idaho National Laboratory (INL), the irradiation performance of candidate high-temperature gas reactor fuels and materials is being evaluated at INL's Advanced Test Reactor (ATR). The design of the first Advanced Gas Reactor (AGR-1) TRISO fuel experiment, currently being irradiated in the ATR, required development of special techniques for brazing niobium and molybdenum. Brazing is one technique used to join refractory metals to each other and to stainless steel alloys. Although brazing processes are well established, it is difficult to braze niobium, molybdenum, and most other refractory metals because they quickly develop adherent oxides when exposed to room-temperature air. Specialized techniques and methods were developed by INL to overcome these obstacles. This paper describes the techniques developed for removing these oxides, as well as the ASME Section IX-qualified braze procedures that were developed as part of the AGR-1 project. All brazes were made using an induction coil with an inert or reducing atmosphere at low pressure. Other parameters, such as filler metals, fluxes used, and general setup procedures, are also discussed. (authors)

  12. Brazing Refractory Metals Used In High-Temperature Nuclear Instrumentation

    Palmer, A.J.; Woolstenhulme, C.J.

    2009-01-01

    As part of the U. S. Department of Energy (DOE) sponsored Next Generation Nuclear Project (NGNP) currently ongoing at Idaho National Laboratory (INL), the irradiation performance of candidate high-temperature gas reactor fuels and materials is being evaluated at INL's Advanced Test Reactor (ATR). The design of the first Advanced Gas Reactor (AGR 1) experiment, currently being irradiated in the ATR, required development of special techniques for brazing niobium and molybdenum. Brazing is one technique used to join refractory metals to each other and to stainless steel alloys. Although brazing processes are well established, it is difficult to braze niobium, molybdenum, and most other refractory metals because they quickly develop adherent oxides when exposed to room-temperature air. Specialized techniques and methods were developed by INL to overcome these obstacles. This paper describes the techniques developed for removing these oxides, as well as the ASME Section IX-qualified braze procedures that were developed as part of the AGR-1 project. All brazes were made using an induction coil with an inert or reducing atmosphere at low pressure. Other parameters, such as filler metals, fluxes used, and general setup procedures, are also discussed

  13. Brazing refractory metals used in high-temperature nuclear instrumentation

    Palmer, A. J. [Idaho National Laboratory, MS 3840, P.O. Box 1625, Idaho Falls, ID 83415-3840 (United States); Woolstenhulme, C. J. [EG and G Services, Inc., (United States)

    2009-07-01

    As part of the U. S. Department of Energy (DOE)-sponsored Next Generation Nuclear Project (NGNP) currently ongoing at Idaho National Laboratory (INL), the irradiation performance of candidate high-temperature gas reactor fuels and materials is being evaluated at INL's Advanced Test Reactor (ATR). The design of the first Advanced Gas Reactor (AGR-1) TRISO fuel experiment, currently being irradiated in the ATR, required development of special techniques for brazing niobium and molybdenum. Brazing is one technique used to join refractory metals to each other and to stainless steel alloys. Although brazing processes are well established, it is difficult to braze niobium, molybdenum, and most other refractory metals because they quickly develop adherent oxides when exposed to room-temperature air. Specialized techniques and methods were developed by INL to overcome these obstacles. This paper describes the techniques developed for removing these oxides, as well as the ASME Section IX-qualified braze procedures that were developed as part of the AGR-1 project. All brazes were made using an induction coil with an inert or reducing atmosphere at low pressure. Other parameters, such as filler metals, fluxes used, and general setup procedures, are also discussed. (authors)

  14. Manufacture and Characterization of Silver-free Braze Material

    Baffie, T.; Calapez, J.; Chabrol, C. [DRT/LITEN/DTH, CEA/GRENOBLE, 17 Rue des Martyrs, 38054 Grenoble Cedex 9 (France); De Vito, E. [UTEN/DTH/LCPEM, CEA/GRENOBLE, 17 Rue des Martyrs, 38054 Grenoble (France); Portra, T. [DRT/LITEN/DTH, CEA/GRENOBLE, 17 Rue des Martyrs, 38054 Grenoble CEDEX 9 (France); Peacock, A. [EFDA-Close Support Unit, Max-Planck-Institut fuer Plasmaphysik, Boltzmannstrasse, 2, D-85748 Garching (Germany); Rigal, E. [CEA Grenoble, DRT/LITEN, F-38054 Grenoble (France)

    2007-07-01

    Full text of publication follows: Induction brazing is one of the most successful techniques for joining Beryllium (Be) armour tiles to CuCrZr heat sink material, used as High Heat Flux Components for ITER. In the early days of the development for Fusion, silver based brazes were used because of their appropriate liquidus and solidus temperatures and their wide application in different industrial fields. However, it is known that the use of silver containing brazes could have a negative impact on the vacuum systems in ITER because of the transmutation of silver into cadmium. Copper (Cu) based brazes were produced in ribbons form using melt spinning technique. Several compositions in the Cu-Sn-In-Ni-Mn system were elaborated and characterized using Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD) and Differential Scanning Calorimetry (DSC). All the ribbons obtained are micro crystallized. Foils are 8 mm wide and their thickness is between 60 and 90 {mu}m. Among the compositions studied, two were selected for Be/CuCrZr mock-ups brazing tests; their ribbons can be easily manipulated and their last transformations are close to 740 deg. C. The results of the braze trials on the mock-ups are also reported here. (authors)

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

    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.

  16. WELDING TORCH

    Correy, T.B.

    1961-10-01

    A welding torch into which water and inert gas are piped separately for cooling and for providing a suitable gaseous atmosphere is described. A welding electrode is clamped in the torch by a removable collet sleeve and a removable collet head. Replacement of the sleeve and head with larger or smaller sleeve and head permits a larger or smaller welding electrode to be substituted on the torch. (AEC)

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

    Howard, Stanley R [Windsor, SC; Korinko, Paul S [Aiken, SC

    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.

  18. Welding stresses

    Poirier, J.; Barbe, B.; Jolly, N.

    1976-01-01

    The aim is to show how internal stresses are generated and to fix the orders of magnitude. A realistic case, the vertical welding of thick plates free to move one against the other, is described and the deformations and stresses are analyzed. The mathematical model UEDA, which accounts for the elastic modulus, the yield strength and the expansion coefficient of the metal with temperature, is presented. The hypotheses and results given apply only to the instantaneous welding of a welded plate and to a plate welded by a moving electrode [fr

  19. Microstructure and fatigue properties of Mg-to-steel dissimilar resistance spot welds

    Liu, L.; Xiao, L.; Chen, D.L.; Feng, J.C.; Kim, S.; Zhou, Y.

    2013-01-01

    Highlights: ► Mg/steel dissimilar spot weld had the same fatigue strength as Mg/Mg similar weld. ► Crack propagation path of Mg/Mg and Mg/steel welds was the same. ► Penetration of Zn into the Mg base metal led to crack initiation of Mg/steel weld. ► HAZ weakening and stress concentration led to crack initiation of Mg/Mg weld. -- Abstract: The structural application of lightweight magnesium alloys in the automotive industry inevitably involves dissimilar welding with steels and the related durability issues. This study was aimed at evaluating the microstructural change and fatigue resistance of Mg/steel resistance spot welds, in comparison with Mg/Mg welds. The microstructure of Mg/Mg spot welds can be divided into: base metal, heat affected zone and fusion zone (nugget). However, the microstructure of Mg/steel dissimilar spot welds had three different regions along the joined interface: weld brazing, solid-state joining and soldering. The horizontal and vertical Mg hardness profiles of Mg/steel and Mg/Mg welds were similar. Both Mg/steel and Mg/Mg welds were observed to have an equivalent fatigue resistance due to similar crack propagation characteristics and failure mode. Both Mg/steel and Mg/Mg welds failed through thickness in the magnesium sheet under stress-controlled cyclic loading, but fatigue crack initiation of the two types of welds was different. The crack initiation of Mg/Mg welds was occurred due to a combined effect of stress concentration, grain growth in the heat affected zone (HAZ), and the presence of Al-rich phases at HAZ grain boundaries, while the penetration of small amounts of Zn coating into the Mg base metal stemming from the liquid metal induced embrittlement led to crack initiation in the Mg/steel welds.

  20. Ultrasonic inspection of tube to tube plate welds

    Telford, D.W.; Peat, T.S.

    1985-01-01

    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)

  1. Laser Brazing Characteristics of Al to Brass with Zn-Based Filler

    Tan, Caiwang; Liu, Fuyun; Sun, Yiming; Chen, Bo; Song, Xiaoguo; Li, Liqun; Zhao, Hongyun; Feng, Jicai

    2018-05-01

    Laser brazing of Al to brass in lap configuration with Zn-based filler was performed in this work. The process parameters including laser power, defocused distance were found to have a significant influence on appearance, microstructure and mechanical properties. The process parameters were optimized to be laser power of 2700 W and defocusing distance of + 40 mm from brass surface. In addition, preheating exerted great influence on wetting and spreading ability of Zn filler on brass surface. The microstructure observation showed the thickness of reaction layer (CuZn phase) at the interface of the brass side would grow with the increase in laser power and the decrease in the laser defocusing distance. Moreover, preheating could increase the spreading area of the filler metal and induced the growth of the reaction layer. The highest tensile-shear load of the joint could reach 2100 N, which was 80% of that of Al alloy base metal. All the joints fractured along the CuZn reaction layer and brass interface. The fracture morphology displayed the characteristics of the cleavage fracture when without preheating before welding, while it displayed the characteristics of the quasi-cleavage fracture with preheating before welding.

  2. WELDING METHOD

    Cornell, A.A.; Dunbar, J.V.; Ruffner, J.H.

    1959-09-29

    A semi-automatic method is described for the weld joining of pipes and fittings which utilizes the inert gasshielded consumable electrode electric arc welding technique, comprising laying down the root pass at a first peripheral velocity and thereafter laying down the filler passes over the root pass necessary to complete the weld by revolving the pipes and fittings at a second peripheral velocity different from the first peripheral velocity, maintaining the welding head in a fixed position as to the specific direction of revolution, while the longitudinal axis of the welding head is disposed angularly in the direction of revolution at amounts between twenty minutas and about four degrees from the first position.

  3. Characterisation of metallic glass incorporated Zircaloy-2 weldments

    Mishra, S.; Savalia, R.T.; Bhanumurthy, K.; Dey, G.K.; Banerjee, S.

    1995-01-01

    In this study the effect of incorporation of Zr based Fe and Ni bearing metallic glass in spot welds in Zircaloy components has been examined. A comparison of strength and microstructure of the welded joint with and without glass has been carried out. The welded joint with metallic glass has been found to be stronger than the one without metallic glass. The microstructure of the welded region with metallic glass has been found to comprise a large region having martensite. This large martensitic region has also been found to have considerable amount of excess solute (Fe, Ni). The higher strength of the weld with metallic glass seems to originate due to solid solution strengthening, small grain size and the presence of martensitic structure over a large region. (orig.)

  4. THE INFLUENCE OF HIGH-TEMPERATURE BRAZING UPON INDICATORS OF MATERIAL BRAZEABILITY

    Roman Koleňák

    2010-03-01

    Full Text Available The effect of both common and extreme parameters of AISI 321stainless steel high-temperature brazing using the NI 102 brazing alloy upon material brazeability indicators. The ascertainment of the wetting angle, the area over which Ni brazing alloy spreads, the width of AISI 321 steel's dissolubility band, and the width of Ni brazing alloy’s diffusion band into the basic material.

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

    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

  6. Arc brazing of austenitic stainless steel to similar and dissimilar metals

    Moschini, Jamie Ian

    There is a desire within both the stainless steel and automotive industries to introduce stainless steel into safety critical areas such as the crumple zone of modem cars as a replacement for low carbon mild steel. The two main reasons for this are stainless steel's corrosion resistance and its higher strength compared with mild steel. It has been anticipated that the easiest way to introduce stainless steel into the automotive industry would be to incorporate it into the existing design. The main obstacle to be overcome before this can take place is therefore how to join the stainless steel to the rest of the car body. In recent times arc brazil g has been suggested as a joining technique which will eliminate many of the problems associated with fusion welding of zinc coated mild steel to stainless steel.Similar and dissimilar parent material arc brazed joints were manufactured using three copper based filler materials and three shielding gases. The joints were tested in terms of tensile strength, impact toughness and fatigue properties. It was found that similar parent material stainless steel joints could be produced with a 0.2% proof stress in excess of the parent material and associated problems such as Liquid Metal Embrittlement were not experienced. Dissimilar parent material joints were manufactured with an ultimate tensile strength in excess of that of mild steel although during fatigue testing evidence of Liquid Metal Embrittlement was seen lowering the mean fatigue load.At the interface of the braze and stainless steel in the similar material butt joints manufactured using short circuit transfer, copper appeared to penetrate the grain boundaries of the stainless steel without embrittling the parent material. Further microscopic investigation of the interface showed that the penetration could be described by the model proposed by Mullins. However, when dissimilar metal butt joints were manufactured using spray arc transfer, penetration of copper into the

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

    Koppitz, Th; Pintsuk, G; Reisgen, U; Remmel, J; Hirai, T; Sievering, R; Rojas, Y; Casalegno, V

    2007-01-01

    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

  8. Direct brazing of ceramics, graphite, and refractory metals

    Canonico, D.A.; Cole, N.C.; Slaughter, G.M.

    1976-03-01

    ORNL has been instrumental in the development of brazing filler metals for joining ceramics, graphite, and refractory metals for application at temperatures above 1000 0 C. The philosophy and techniques employed in the development of these alloys are presented. A number of compositions are discussed that have been satisfactorily used to braze ceramics, graphite, and refractory metals without a prior surface treatment. One alloy, Ti--25 percent Cr--21 percent V, has wet and flowed on aluminum oxide and graphite. Further, it has been utilized in making brazes between different combinations of the three subject materials. The excellent flowability of this alloy and alloys from the Ti--Zr--Ge system is evidenced by the presence of filler metal in the minute pores of the graphite and ceramics

  9. A review of oxide, silicon nitride, and silicon carbide brazing

    Santella, M.L.; Moorhead, A.J.

    1987-01-01

    There is growing interest in using ceramics for structural applications, many of which require the fabrication of components with complicated shapes. Normal ceramic processing methods restrict the shapes into which these materials can be produced, but ceramic joining technology can be used to overcome many of these limitations, and also offers the possibility for improving the reliability of ceramic components. One method of joining ceramics is by brazing. The metallic alloys used for bonding must wet and adhere to the ceramic surfaces without excessive reaction. Alumina, partially stabilized zirconia, and silicon nitride have high ionic character to their chemical bonds and are difficult to wet. Alloys for brazing these materials must be formulated to overcome this problem. Silicon carbide, which has some metallic characteristics, reacts excessively with many alloys, and forms joints of low mechanical strength. The brazing characteristics of these three types of ceramics, and residual stresses in ceramic-to-metal joints are briefly discussed

  10. Welding process

    Abdul Nassir Ibrahim; Azali Muhammad; Ab. Razak Hamzah; Abd. Aziz Mohamed; Mohamad Pauzi Ismail

    2008-01-01

    For the final chapter of this book, there is basic introduction on welding process. The good radiography must know somehow on welding process so that they can know what kind of welding that must rejected or not. All of the exposure technique that mention in earlier chapter almost applicable in this field because welding process is critical problem if there is no inspection will be done. So, for this chapter, all the discontinuity that usually appeared will be discussed and there is another discontinuity maybe not to important and do not give big impact if found it, do not described here. On top of that, the decision to accept or reject based on code, standard and specification that agreed by both to make sure that decision that agreed is corrected and more meaningful.

  11. Vacuum brazing of electroless Ni-P alloy-coated SiCp/Al composites using aluminum-based filler metal foil

    Wang, Peng; Xu, Dongxia; Niu, Jitai

    2016-12-01

    Using rapidly cooled (Al-10Si-20Cu-0.05Ce)-1Ti (wt%) foil as filler metal, the research obtained high-performance joints of electroless Ni-P alloy-coated aluminum matrix composites with high SiC particle content (60 vol%, SiCp/Al-MMCs). The effect of brazing process on joint properties and the formation of Al-Ni and Al-Cu-Ni intermetallic compounds were investigated, respectively. Due to the presence of Ni-P alloy coating, the wettability of liquid filler metal on the composites was improved obviously and its contact angle was only 21°. The formation of Al3Ni2 and Al3(CuNi)2 intermetallic compounds indicated that well metallurgical bonding occurred along the 6063Al matrix alloy/Ni-P alloy layer/filler metal foil interfaces by mutual diffusion and dissolution. And the joint shear strength increased with increasing the brazing temperature from 838 to 843 K or prolonging the soaking time from 15 to 35 min, while it decreased a lot because of corrosion occurring in the 6063Al matrix at high brazing temperature of 848 K. Sound joints with maximum shear strength of 112.5 MPa were obtained at 843 K for soaking time of 35 min. In this research, the beneficial effect of surface metallization by Ni-P alloy deposits on improving wettability on SiCp/Al-MMCs was demonstrated, and capable welding parameters were broadened as well.

  12. Some problems of brazing technology for the divertor plate manufacturing

    Prokofiev, Yu. G.; Barabash, V. R.; Khorunov, V. F.; Maksimova, S. V.; Gervash, A. A.; Fabritsiev, S. A.; Vinokurov, V. F.

    1992-09-01

    Among the different design options of the ITER reactor divertor, the joints of the carbon-based materials and molybdenum alloys and joints of tungsten and copper alloys are considered. High-temperature brazing is one of the most promising joining methods for the plasma facing and heat sink materials. The use of brazing for creation of W-Cu and graphite-Mo joints are given here. In addition, the investigation results of microstructure, microhardness and mechanical properties of the joints are presented. For W-Cu samples an influence of the neutron irradiation on the joining strength was studied.

  13. Some problems of brazing technology for the divertor plate manufacturing

    Prokofiev, Yu.G.; Barabash, V.R.; Gervash, A.A.; Khorunov, V.F.; Maksimova, S.V.; Vinokurov, V.F.; Fabritsiev, S.A.

    1992-01-01

    Among the different design options of the ITER reactor divertor, the joints of the carbon-based materials and molybdenum alloys and joints of tungsten and copper alloys are considered. High-temperature brazing is one of the most promising joining methods for the plasma facing and heat sink materials. The use of brazing for creation of W-Cu and graphite-Mo joints are given here. In addition, the investigation results of microstructure, microhardness and mechanical properties of the joints are presented. For W-Cu samples an influence of the neutron irradiation on the joining strength was studied. (orig.)

  14. Some problems of brazing technology for the divertor plate manufacturing

    Prokofiev, Yu.G.; Barabash, V.R.; Gervash, A.A. (D.V. Efremov Scientific Research Inst. of Electrophysical Apparatus, St. Petersburg (Russia)); Khorunov, V.F.; Maksimova, S.V. (E.O. Paton Inst. of Electronwelding, Kiev (Ukraine)); Vinokurov, V.F. (Central Scientific Research Inst. of Structural Materials ' Prometey' , St. Petersburg (Russia)); Fabritsiev, S.A.

    1992-09-01

    Among the different design options of the ITER reactor divertor, the joints of the carbon-based materials and molybdenum alloys and joints of tungsten and copper alloys are considered. High-temperature brazing is one of the most promising joining methods for the plasma facing and heat sink materials. The use of brazing for creation of W-Cu and graphite-Mo joints are given here. In addition, the investigation results of microstructure, microhardness and mechanical properties of the joints are presented. For W-Cu samples an influence of the neutron irradiation on the joining strength was studied. (orig.).

  15. Orifice jet brazing process development, qualification, and initial application

    1971-05-01

    Experiments were carried out to develop acceptable procedures for brazing molybdenum alloy orifices to fuel element channel inlets of the NERVA R-1 reactor core. Results achieved with various procedures are described, and qualification tests of the selected process are documented. The recommended procedure includes preplacing of Au-Ni-Cr alloy washers and induction heating to 1600 0 F, holding two minutes, heating further to 2400 0 F, holding one minute, and allowing to cool. Inert atmosphere is used, and fixturing maintains proper positioning of the orifices. Leak testing of the joints has demonstrated reproducibly satisfactory sealing. Repair brazing is feasible if needed. (auth)

  16. Analysis of nature of brazed joints fracture under operating conditions

    Orlov, A.V.; Gura, P.M.

    1985-01-01

    Technique establishing causes leading to brazed joint fracture in pressure boundary components, operating under heavy conditions of high temperature and corrosive medium is described. Some cases of tube brazed joint fractures in a superheater of 12Kh1MF and 08Kh18N10T steels are considered. The attention is paid on using metallography for determination of mechanical or corrosion fracture properties. The diagram is developed permitting to take into account the interrelation between the fracture area in the given zone and its strength

  17. Influence of cyclic thermal loading on brazed composites for fusion applications

    Šmid, I.; Kny, E.; Kneringer, G.; Reheis, N.

    1990-04-01

    Reactor grade graphite and molybdenum (TZM) were brazed with different high temperature brazes. The resulting tiles had a size of 50 × 50 mm2 with a graphite thickness of 10 mm and a TZM thickness of 5 mm. The brazed composites have been tested in electron beam simulation for their thermal fatigue properties. The parameters of these tests were chosen to match NET design specifications for normal operation and "slow" peak energy deposition. The resulting damage and microstructural changes on the graphites and the brazes are discussed. Additional information is supplied on X-ray diffraction data proving the presence of different phases in the brazes.

  18. Brazing Inconel 625 Using Two Ni/(Fe)-Based Amorphous Filler Foils

    Chen, Wen-Shiang; Shiue, Ren-Kae

    2012-07-01

    For MBF-51 filler, the brazed joint consists of interfacial grain boundary borides, coarse Nb6Ni16Si7, and Ni/Cr-rich matrix. In contrast, the VZ-2106 brazed joint is composed of interfacial Nb6Ni16Si7 precipitates as well as grain boundary borides, coarse Nb6Ni16Si7, and Ni/Cr/Fe-rich matrix. The maximum tensile strength of 443 MPa is obtained from the MBF-51 brazed specimen. The tensile strengths of VZ-2106 brazed joints are approximately 300 MPa. Both amorphous filler foils demonstrate potential in brazing IN-625 substrate.

  19. Laser brazing of hard metal on steel; Laserstrahlloeten von Hartmetall an Stahl

    Haferkamp, H.; Frohmann, A.; Block, B.; Goede, M. [Laser Zentrum Hannover e.V., Hannover (Germany); Muenz, U. [Forschungsgemeinschaft Werkzeuge und Werkstoffe e.V., Remscheid (Germany)

    2001-07-01

    Topic of the investigations presented here is the laser beam brazing of hardmetal plates onto tool steel. Three different kinds of laser beam sources are comparatively used, a diode laser, a Nd:YAG laser and a CO{sub 2} laser. The investigations concentrate on the variation of two process parameters: brazing time and laser performance. Following the brazing process both visual observation as well as hardness measurements and shear tests are made. The investigations show that by brazing, high seam qualities can be achieved, which withstand the comparison with inductively brazed joints. (orig.)

  20. Influence of cycling thermal loading on brazed composites for fusion applications

    Smid, I.; Kny, E.; Kneringer, G.; Reheis, N.

    1995-01-01

    Reactor grade graphite and molybdenum (TZM) were brazed with different high temperature brazes. The resulting tiles had a size of 50 x 50 mm 2 with a graphite thickness of 10 mm and a TZM thickness of 5 mm. The brazed composites have been tested in electron beam simulation for their thermal fatigue properties. The parameters of these tests were chosen to match NET design specifications for normal operation and 'slow' peak energy deposition. The resulting damage and microstructural changes on the graphites and the brazes are discussed. Additional information is supplied on X-ray diffraction data proving the presence of different phases in the brazes. (author)

  1. Syllabus in Trade Welding.

    New York State Education Dept., Albany. Bureau of Secondary Curriculum Development.

    The syllabus outlines material for a course two academic years in length (minimum two and one-half hours daily experience) leading to entry-level occupational ability in several welding trade areas. Fourteen units covering are welding, gas welding, oxyacetylene welding, cutting, nonfusion processes, inert gas shielded-arc welding, welding cast…

  2. Development of a Cu-Sn based brazing system with a low brazing and a high remelting temperature

    Schmieding, M.; Holländer, U.; Möhwald, K.

    2017-03-01

    Objective of the project presented is the development of a joining process for hot working steel components at low brazing temperatures leading to a bond with a much higher remelting temperature. This basically is achieved by the use of a Cu-Sn melt spinning foil combined with a pure Cu foil. During brazing, the Sn content of the foil is decreased by diffusion of Sn into the additional Cu resulting in a homogenious joint with a increased remelting temperature of the filler metal. Within this project specimens were brazed and diffusion annealed in a vacuum furnace at 850 °C varying the processing times (0 - 10 h). The samples prepared were studied metallographically and diffusion profiles of Sn were recorded using EDX line scans. The results are discussed in view of further investigations and envisaged applications.

  3. Evaluation of high temperature brazes for graphite first wall protection elements

    Smid, I.; Koizlik, K.; Linke, J.; Nickel, H.; Wallura, E.; Kny, E.

    1989-01-01

    Four different high temperature brazed with melting points from 800 to 1865degC have been used to braze a commercial reactor grade graphite to TZM substrates. Those brazes were Zr, 90Ni 10Ti, 99Cu 10Ti and 70Ag 27Cu 3Ti (wt %). The resulting composite tiles of 80 x 80 mm 2 with a graphite thickness of 10 mm brazed on a 8 mm TZM substrate have been tested in electron beam experiments for their thermal fatigue properties. The parameters of the electron beam testing were chosen to match NET design specificatios for normal operation and 'slow' peak energy deposition. The resulting damages and microstructural changes on the graphite and the brazes are discussed. Additional information is supplied on tensile test and thermal conductivity data of brazed composites. These measurements confirm that thermal contact between TZM-substrate and graphite is improved by brazing. (author). 6 refs.; 5 figs.; 2 tabs

  4. Evaluation of high temperature brazes for graphite first wall protection elements

    Smid, I.; Koizlik, K.; Linke, J.; Nickel, H.; Wallura, E.; Kny, E.

    1995-01-01

    Four different high temperature brazes with melting points from 800 to 1865 degree C have been used to braze a commercial reactor grade graphite to TZM substrates. Those brazes were Zr, 90Ni 10Ti, 90Cu 10Ti and 70Ag 27Cu 3Ti (wt %). The resulting composite tiles of 80 x 80 mm 2 with a graphite thickness of 10 mm brazed on a 3 mm TZM substrate have been tested in electron beam experiments for their thermal fatigue properties. The parameters of the electron beam testing were chosen to match NET design specifications for normal operation and 'slow' peak energy deposition. The resulting damages and microstructural changes on the graphite and the brazes are discussed. Additional information is supplied on tensile test and thermal conductivity data of brazed composites. These measurements confirm that thermal contact between TZM-substrate and graphite is improved by brazing. (author)

  5. Effect of alumina strengthening particles on brazed joints of GlidCop Al-15 copper alloy

    Chen, S.; Liu, J.Y.; Chin, B.A.

    1994-01-01

    Brazed joints of the alumina dispersion-strengthened copper alloy were developed using resistance heating brazing with BCuP-3 braze alloy. Experimental results show that tensile strength and fatigue properties are a function of the brazing process temperature cycle. Maximum tensile and fatigue properties can be obtained by choice of an optimal braze time and temperature. However, in both tensile and fatigue tests the brazed joints exhibited low ductility. Metallography of the fractured tensile and fatigue samples showed that cracks always initiated in and propagated along the interface between the transition layer and the braze metal. EDS analysis across the joint showed that P diffused very quickly into base metal along grain boundaries. A strong Al peak (associated with the detection of Al 2 O 3 ) was found that corresponded with the transition layer. Fractography showed an intergranular fracture pattern across this transition zone indicating that the observed segregation of alumina particles reduces the ductility of this region. ((orig.))

  6. Influence of surface pretreatment in resistance spot welding of aluminum AA1050

    Al Naimi, Ihsan K.; Al Saadi, Moneer H.; Daws, Kasim M.

    2015-01-01

    quality. An experimental study of the influence of pretreatment on weld quality in RSW of AA1050 sheets with three thicknesses, comparing welding of as-received sheet with pretreated sheet by either pickling in NaOH or glass-blasting were investigated. Different weld settings were applied with low...

  7. High heat flux performance of W-Eurofer brazed joints

    de Prado, J.; Sánchez, M.; Wirtz, M.; Pintsuk, G.; Du, J.; Linke, J.; Ureña, A.

    2018-02-01

    The qualification process of the materials and components for the next generation of fusion reactors makes it necessary to expose them to similar service conditions as expected during the service life of the reactor. In the present work, W-Eurofer brazed joints (tungsten block: 8 × 8 × 4 mm; steel block: 8 × 8 × 4 mm; joined to an actively cooled copper heat sink) were exposed to steady state heat loads to study the effect of the thermal fatigue on their microstructure and mechanical integrity. Three different W surface temperatures were tested (400, 500 and 600 °C) varying the number of applied cycles (100 and 1000). The results allowed identifying a braze temperature of 359 °C as threshold condition under which the brazed joints could be used without deterioration. The increase of the surface temperature deteriorated the mechanical integrity of the joints in comparison to those analyzed after the brazing process and accordingly reduced the refrigeration capabilities.

  8. Field installed brazed thermocouple feedthroughs for high vacuum experiments

    Anderson, P.; Messick, C.

    1983-01-01

    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 have been 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 0 C (482 0 F) bakeout temperature. 2) No high vapor pressure elements. 3) Good wetting properties when used in air with acceptable flux. 4) Good wettability to 300 series stainless steel and inconel

  9. Microwave-assisted brazing of alumina ceramics for electron tube ...

    Vickers microhardness measurement indicated reliable joint performance for the microwave-assisted brazed joints during ... Alumina ceramics are used in wide range of applications due to their .... temperature were recorded by DAQSOFT software in a sep- .... Tubes: Design and Development Capabilities (MTDDC)',.

  10. Evaluation of the Low Heat Input Process for Weld Repair of Nickel-Base Superalloys

    Durocher, J.; Richards, N. L.

    2011-10-01

    The repair of turbine blades and vanes commonly involves gas tungsten arc welding or an equivalent process, but unfortunately these components are often susceptible to heat-affected zone (HAZ) cracking during the weld repair process. This is a major problem especially in cast alloys due to their coarse-grain size and where the (Al + Ti) contents is in excess of 3-4%; vacuum brazing is also used but mainly on low stress non-rotating components such as vanes. Micro-welding has the potential to deposit small amounts of filler at low heat input levels with minimum HAZ and thus is an attractive process for depositing a quality weld. As with conventional fusion processes, the filler alloy is deposited by the generation of a low power arc between a consumable electrode and the substrate. The low heat input of this process offers unique advantages over more common welding processes such as gas tungsten arc, plasma arc, laser, and electron beam welding. In this study, the low heat input characteristic of micro-welding has been used to simulate weld repair using Inconel (IN) (Inconel and IN are trademarks of INCO Alloys International) 625, Rene (Rene is a trademark of General Electric Company) 41, Nimonic (Nimonic is a trademark of INCO Alloys International) 105 and Inconel 738LC filler alloys, to a cast Inconel 738LC substrate. The effect of micro-welding process parameters on the deposition rate, coating quality, and substrate has been investigated.

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

    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.

  12. Microstructure investigation of bronze/steel brazed joints proposed for HHF components of ITER manufacturing

    Kalinin, G.M. [Research and Development Institute of Power Engineering, P.O. Box 788, Moscow 101000 (Russian Federation)], E-mail: gmk@nikiet.ru; Krestnikov, N.S. [Research and Development Institute of Power Engineering, P.O. Box 788, Moscow 101000 (Russian Federation); Jarovinskiy, Yu.L.; Makhin, I.D.; Nikolaev, V.V. [Rocket and Space Corporation ' Energia' , Korolev, Lenina Street 4-a, Moscow 141070 (Russian Federation); Skladnov, K.S.; Strebkov, Yu.S.; Zolotarev, V.B. [Research and Development Institute of Power Engineering, P.O. Box 788, Moscow 101000 (Russian Federation)

    2008-12-15

    Brazing is considered as one of the perspective option of high heat flux components of ITER manufacturing. CuCrZr bronze, austenitic steel AISI 321-type and PM-17-type (Ni-Mn-Fe-Si-Sn-B alloy) brazed material were used for the development of brazing technology. Two type of brazing have been studied within the framework of recent investigation: - Hot isostatic pressing (HIP)-assisted brazing. - Furnace-assisted brazing (with uniaxial compression loading). For the hydrostatic pressing (HIP) the brazed components were pressed out for about 175 MPa during 2.5 h at the temperature 1035-1040 deg. C. For the furnace-assisted brazing all components were inserted into the sealed can, vacuumed and heated up to brazing temperature {approx}950 deg. C. Fast cooling and ageing heat treatment (500 deg. C and 4 h) were applied to provide high strength of CuCrZr bronze. Microsections of specimens cut from the joints were studied by optical microscopy and by scanning electron microscopy (SEM). The microstructure, distribution of alloying elements of base metals and of brazed material components were studied in the joints. Results of these studies are discussed in this paper. The data shows that there is a potential for using more simple and cheap (in comparison with common HIP) technologies of bronze to steel joining with satisfactory quality.

  13. Microgalvanic Corrosion Behavior of Cu-Ag Active Braze Alloys Investigated with SKPFM

    Armen Kvryan

    2016-04-01

    Full Text Available The nature of microgalvanic couple driven corrosion of brazed joints was investigated. 316L stainless steel samples were joined using Cu-Ag-Ti and Cu-Ag-In-Ti braze alloys. Phase and elemental composition across each braze and parent metal interface was characterized and scanning Kelvin probe force microscopy (SKPFM was used to map the Volta potential differences. Co-localization of SKPFM with Energy Dispersive Spectroscopy (EDS measurements enabled spatially resolved correlation of potential differences with composition and subsequent galvanic corrosion behavior. Following exposure to the aggressive solution, corrosion damage morphology was characterized to determine the mode of attack and likely initiation areas. When exposed to 0.6 M NaCl, corrosion occurred at the braze-316L interface preceded by preferential dissolution of the Cu-rich phase within the braze alloy. Braze corrosion was driven by galvanic couples between the braze alloys and stainless steel as well as between different phases within the braze microstructure. Microgalvanic corrosion between phases of the braze alloys was investigated via SKPFM to determine how corrosion of the brazed joints developed.

  14. Welding template

    Ben Venue, R.J. of.

    1976-01-01

    A welding template is described which is used to weld strip material into a cellular grid structure for the accommodation of fuel elements in a nuclear reactor. On a base plate the template carries a multitude of cylindrical pins whose upper half is narrower than the bottom half and only one of which is attached to the base plate. The others are arrested in a hexagonal array by oblong webs clamped together by chuck jaws which can be secured by means of screws. The parts are ground very accurately. The template according to the invention is very easy to make. (UWI) [de

  15. Wetting and spreading behavior of molten brazing filler metallic alloys on metallic substrate

    Kogi, Satoshi; Kajiura, Tetsurou; Hanada, Yukiakira; Miyazawa, Yasuyuki

    2014-08-01

    Wetting and spreading of molten brazing filler material are important factors that influence the brazing ability of a joint to be brazed. Several investigations into the wetting ability of a brazing filler alloy and its surface tension in molten state, in addition to effects of brazing time and temperature on the contact angle, have been carried out. In general, dissimilar-metals brazing technology and high-performance brazed joint are necessities for the manufacturing field in the near future. Therefore, to address this requirement, more such studies on wetting and spreading of filler material are required for a deeper understanding. Generally, surface roughness and surface conditions affect spreading of molten brazing filler material during brazing. Wetting by and interfacial reactions of the molten brazing filler material with the metallic substrate, especially, affect strongly the spreading of the filler material. In this study, the effects of surface roughness and surface conditions on the spreading of molten brazing filler metallic alloys were investigated. Ag-(40-x)Cu-xIn and Ag- (40-x)Cu-xSn (x=5, 10, 15, 20, 25) alloys were used as brazing filler materials. A mild-steel square plate (S45C (JIS); side: 30 mm; thickness: 3mm) was employed as the substrate. A few surfaces with varying roughness were prepared using emery paper. Brazing filler material and metallic base plate were first washed with acetone, and then a flux was applied to them. The filler, 50 mg, was placed on the center of the metallic base with the flux. A spreading test was performed under Ar gas using an electrically heated furnace, after which, the original spreading area, defined as the sessile drop area, and the apparent spreading area, produced by the capillary grooves, were both evaluated. It was observed that the spreading area decreased with increasing In and Sn content.

  16. The experiment progress of bracket brazing to SSMIC for the ITER ELM prototype coil

    Shi, Yi, E-mail: shiyi@ipp.ac.cn; Wu, Yu; Jin, Huan; Ren, Zhibin; Han, Houxiang; Qian, Jing; Qian, Li; Liu, Bo

    2014-11-15

    Highlights: • In this study, the experimental research of brackets brazing to stainless steel jacketed, Mineral Insulated Conductor (SSMIC) of the first Edge Localized Modes (ELMs) prototype coil for ITER has been made. • The technology for controlling the fluidity of silver-based brazing alloy is developed to meet the bracket brazing. • Brazing experiments to find the reason for cracks are carried out and the improved brazing technologies to restrain the cracks in the Inconel 625 jacket with silver-based alloy are developed. - Abstract: The first Edge Localized Modes (ELMs) prototype coil for International Thermonuclear Experimental Reactor (ITER) has been manufactured in the Institute of Plasma Physics, CAS (ASIPP) at 2014. The all 19 brackets need to braze to the stainless steel jacketed, Mineral Insulated Conductor (SSMIC) for transporting the nuclear heating in the brackets to the water-cooled SSMIC. Silver-based alloy is the only candidate brazing filler for the bracket brazing due to the limitation from melting point temperature and strength. In this paper, firstly, the experimental study for controlling the fluidity of silver-based brazing alloy is developed. And then, the brazing experiment of prototype bracket is introduced to develop the brazing process and some cracks in the Inconel 625 jackets surface appeared unexpectedly. The microstructures and tensile performance study of the cracked Inconel 625 jacket were made to explore the reason for cracks and the improved brazing technologies to suppress the cracks are developed. Finally, the bracket brazing experiment for the first ELM prototype coil is carried out, In spite of this, some cracks also appear in the Inconel 625 jackets.

  17. The experiment progress of bracket brazing to SSMIC for the ITER ELM prototype coil

    Shi, Yi; Wu, Yu; Jin, Huan; Ren, Zhibin; Han, Houxiang; Qian, Jing; Qian, Li; Liu, Bo

    2014-01-01

    Highlights: • In this study, the experimental research of brackets brazing to stainless steel jacketed, Mineral Insulated Conductor (SSMIC) of the first Edge Localized Modes (ELMs) prototype coil for ITER has been made. • The technology for controlling the fluidity of silver-based brazing alloy is developed to meet the bracket brazing. • Brazing experiments to find the reason for cracks are carried out and the improved brazing technologies to restrain the cracks in the Inconel 625 jacket with silver-based alloy are developed. - Abstract: The first Edge Localized Modes (ELMs) prototype coil for International Thermonuclear Experimental Reactor (ITER) has been manufactured in the Institute of Plasma Physics, CAS (ASIPP) at 2014. The all 19 brackets need to braze to the stainless steel jacketed, Mineral Insulated Conductor (SSMIC) for transporting the nuclear heating in the brackets to the water-cooled SSMIC. Silver-based alloy is the only candidate brazing filler for the bracket brazing due to the limitation from melting point temperature and strength. In this paper, firstly, the experimental study for controlling the fluidity of silver-based brazing alloy is developed. And then, the brazing experiment of prototype bracket is introduced to develop the brazing process and some cracks in the Inconel 625 jackets surface appeared unexpectedly. The microstructures and tensile performance study of the cracked Inconel 625 jacket were made to explore the reason for cracks and the improved brazing technologies to suppress the cracks are developed. Finally, the bracket brazing experiment for the first ELM prototype coil is carried out, In spite of this, some cracks also appear in the Inconel 625 jackets

  18. Micro-focus x-ray inspection of the bearing pad welded by laser for CANDU fuel element

    Kim, W. K.; Kim, S. S.; Lee, J. W.; Yang, M. S.

    2001-01-01

    To attach the bearing pads on the surface of CANDU fuel element, laser welding technique has been reviewed to replace brazing technology which is complicate process and makes use of the toxic beryllium. In this study, to evaluate the soundness of the weld of the bearing pad of CANDU fuel element, a precise X-ray inspection system was developed using a micro-focus X-ray generator with an image intensifier and a real time camera system. The weld of the bearing pad welded by Nd:YAG laser has been inspected by the developed inspection system. Image processing technique has been applied to reduce random noise and to enhance the contrast of the X-ray image. A few defects on the weld of the bearing pads have been detected by the X-ray inspection process

  19. A Study on the Optimal Conditions of friction Welding for JLF and STS304 Using AE Technique

    Yoon, Han Ki; Lee, Sang Pil; Kong, Yu Sik; Lee, Jin Kyung

    2003-01-01

    Japanese low activation terrific steel(JLF) is a good material for the parts of heat exchanger such as blanket and diverter. At first, JLF was developed as a candidate for structural materials in nuclear fusion applications. However, the development of the jointing technique of JLF steel to other materials is important for wide applications of this material to the industry fields. Recently the jointing technologies including diffusion bonding, brazing, roll bonding, explosive bonding and hot iso-static pressing have been studied for the heterogeneous materials of JLF-1 steel(Fe-9Cr-2W-V-Ta) and stainless steel(STS304). Friction welding is one of the most popular welding methods for two different kinds of materials. In this paper, the JLF-1 steel was jointed to SIS304 by friction welding method and the optimal conditions of the friction welding discussed. Acoustic emission was used as a nondestructive technique to evaluate the weld quality in processing

  20. Enabling new sensor applications for (V)HTRS by laser hybrid brazing of oxide ceramics

    Heilmann, F.; Rixecker, G. [Robert Bosch GmbH, Stuttgart (Germany). Corporate Research and Development; Herrmann, M.; Lippmann, W.; Hurtado, A. [Univ. of Technology, Dresden (Germany). Chair of Hydrogen- and Nuclear Engineering

    2008-07-01

    The use of (very) high temperature reactors ((V)HTRs) requires a sensor technology suitable to withstand thermal loads both in normal operation mode and under incident conditions which may appear during service. Especially ceramic sensors are ideal to suit this purpose. A special sensor type that is based upon oxide ceramics is the high temperature oxygen sensor. Base material for this application is yttria-doped zirconia. At elevated temperatures (above 450 C) the activation energy of oxygen ions is sufficient to migrate in the ZrO{sub 2} lattice following an oxygen partial pressure gradient. This diffusion process is facilitated by the trivalent yttrium ions which give rise to a high concentration of oxygen vacancies. The macroscopical effect of the migration of the oxygen ions can be detected as a Nernst voltage or, alternatively, as an electrical current. Thus it is possible to compare the oxygen content of measured media with that of a known reference gas. To be able to produce such sensors both efficiently and in the desired quality, joining technologies adapted to ceramics are necessary. Laser-based technologies for brazing with glass or glass-ceramic solders are especially suitable, as they combine high precision with high throughput. They thus enable cost efficient production processes both for large and small lot sizes. (orig.)

  1. Active metal brazing of titanium to high-conductivity carbon-based sandwich structures

    Singh, M.; Morscher, Gregory N.; Shpargel, Tarah P.; Asthana, Rajiv

    2008-01-01

    Reactive brazing technology was developed and processing parameters were optimized for the bonding of titanium tubes, graphite foam, and high-conductivity carbon-carbon composite face sheets using the active braze Cusil-ABA paste and foils. The microstructure and composition of the joints, examined using scanning electron microscopy coupled with energy-dispersive spectroscopy, showed good bonding and braze penetration in all systems when braze paste was used. The hardness values of the brazed joints were consistent for the different specimen stacking configurations. Mechanical testing of Ti tube/foam/C-C composite structures both in tension and shear showed that failure always occurred in the foam material demonstrating that the brazed joint was sufficient for these types of sandwich structures

  2. Investigation into mechanical properties of joints of heterogeneous materials brazed with high-temperature solders

    Lomenko, V.I.; Merkushev, V.P.; Borodina, L.M.; Sycheva, T.S.; Tokhtina, O.A.; Frolov, N.N.

    1988-01-01

    Mechanical properties of copper joints with copper, 12Kh18M10T steel and KhD50 composite obtained by vacuum brazing by copper-titanium solder as compared with properties of joints brazed by PSr 72 and PMFOTsr 6-4-0.03 solders in hydrogen are studied. Dependences of joints strength on temperature of contact - reactive vacuum brazing are obtained. Possible applications of joints of dissimilar materials in electrovacuum devices subjected to the effect of dynamic loadings are established

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

    Klotz, U.E.; Elsener, H.R.; Elsener, H.R.

    2005-01-01

    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)

  4. WELDABILITY, WELDING METALLURGY, WELDING CHEMISTRY

    Sarjito Jokosisworo

    2012-01-01

    Sambungan las merupakan bagian penting dari stuktur/bangunan yang dilas, dan kunci dari logam induk yang baik adalah kemampuan las (weld ability). Kemampuan las yang baik dan kemudahan dalam fabrikasi dari suatu logam merupakan pertimbangan dalam memilih suatu logam untuk konstruksi.

  5. Electron beam welding: study of process capabilities and limitations towards development of nuclear components

    Vadolia, Gautam; Singh, Kongkham Premjit

    2015-01-01

    Electron beam (EB) welding technology is an established and widely adopted technique in nuclear research and development area. Electron Beam welding is thought of as a candidate process for ITER Vacuum Vessel Fabrication. Dhruva Reactor @ BARC, Mumbai and Niobium Superconducting accelerator Cavitity @ BARC has adopted the EB welding technique as a fabrication route. The highly concentrated energy input of the electron beam has added the advantages over the conventional welding as being less HAZ and provided smooth and clean surface. EB Welding has also been used for the joining of various reactive and refractory materials. EB system as heat source has also been used for vacuum brazing application. The Welding Institute (TWI) has demonstrated that EBW is potentially suitable to produce high integrity joints in 50 mm pure copper. TWI has also examined 150 kV Reduced Pressure Electron Beam (RPEB) gun in welding 140 mm and 147 mm thickness Nuclear Reactor Pressure Vessel Steel (SA 508 grade). EBW in 10 mm thick SS316 plates were studied at IPR and results were encouraging. In this paper, the pros and cons and role of electron beam process will be studied to analyze the importance of electron beam welding in nuclear components fabrication. Importance of establishing the high precision Wire Electro Discharge Machining (WEDM) facility will also be discussed. (author)

  6. Effects of service environments on aluminum-brazed titanium (ABTi)

    Cotton, W. L.

    1978-01-01

    Aluminum brazed titanium (ABTi) structures were evaluated during prolonged exposure to extreme environments: elevated temperature exposure to airline service fluids, hydraulic fluid, and seawater, followed by laboratory corrosion tests. Solid-face and perforated face honeycomb sandwich panel specimens, stressed panel assemblies, and faying surface brazed joints were tested. The corrosion resistance of ABTi is satisfactory for commercial airline service. Unprotected ABTi proved inherently resistant to attack by all of the extreme service aircraft environments except: seawater at 700 K (800 F) and above, dripping phosphate ester hydraulic fluid at 505 K (450 F), and a marine environment at ambient temperature. The natural oxides and deposits present on titanium surfaces in airline service provide protection against hot salt corrosion pitting. Coatings are required to protect titanium dripping phosphate ester fluid at elevated temperatures and to protect exposed acoustic honeycomb parts against corrosion in a marine environment.

  7. Determination of brazed joint constitutive law by inverse method

    Lovato, G.; Moret, F.; Gallo, P. le; Cailletaud, G.; Pilvin, P.

    1993-01-01

    An important parameter often neglected for the calculation of residual stresses in brazed ceramic/metal assemblies is the joint constitutive law. In situ camber measurements on a model system (axisymmetric TZM/InCuSil ABA/316L samples) performed using a special vertical dilatometer during the whole brazing thermal cycle are compared with results of FEM calculations based on published filler metal constitutive laws. A strong disagreement is observed. Actual constitutive law of the joint is determined from these measurements using a numerical inverse method. Calculated displacements are fully consistent with experimental ones. True solidification temperature of the joint is determined. The identified constitutive law of the joint exhibits a low flow stress from solidification temperature to 320 C. (orig.)

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

    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.

  9. Beryllium brazing considerations in CANDU fuel bundle manufacture

    Harmsen, J.; Pant, A.; Lewis, B.J.; Thompson, W.T.

    2010-01-01

    'Full text:' Appendages of CANDU fuel bundle elements are currently joined to zircaloy sheaths by vacuum beryllium brazing. Ongoing environmental and workplace concerns about beryllium combined with the continuous efforts by Cameco Fuel Manufacturing in its improvement process, initiated this study to find a substitute for pure beryllium. The presentation will review the necessary functionality of brazing alloy components and short list a series of alloys with the potential to duplicate the performance of pure beryllium. Modifications to current manufacturing processes based on in-plant testing will be discussed in relation to the use of these alloys. The presentation will conclude with a summary of the progress to date and further testing expected to be necessary.

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

    Hildebrandt, S; Wiehl, G; Silze, F

    2016-01-01

    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. (paper)

  11. Mechanical properties and dual atmosphere tolerance of Ag-Al based braze

    Kim, Jin Yong; Choi, Jung-Pyung; Scott Weil, K. [Pacific Northwest National Laboratory, Richland, WA 99352 (United States)

    2008-07-15

    In this paper, the effects of aluminum on the microstructure, mechanical properties, and high temperature dual atmosphere tolerance of silver and silver-copper oxide filler metals were investigated. It was found that joints brazed with binary Ag-Al braze foils containing more than 2 at% Al retained a metallic form of aluminum within the metallic braze filler matrix after brazing at 1000 C in air. The bend strengths of these joints decreased with increasing aluminum content due to the formation of interfacial aluminum oxide. However, the existence of metallic aluminum in the braze filler matrix appeared to enhance the high-temperature dual atmosphere tolerance of the silver-based braze filler, which displayed measurably less porosity after 1000h of exposure at 800 C in a dual reducing/oxidizing atmosphere environment than unalloyed silver. A series of binary and ternary braze pastes based on the Ag-Al(-Cu) system were also formulated as potential pSOFC (planar solid oxide fuel cell) sealants. Model alumina joints brazed with these pastes exhibited an increase in bend strength with increasing copper content. However, unlike the binary Ag-Al filler metals, the ternary compositions often retained no protective metallic aluminum after brazing. Thus, while the addition of copper improves filler metal wettability and, therefore, joint strength in the Ag-Al alloys, it appears to reduce the dual atmosphere tolerance of these filler metals. (author)

  12. Research for Brazing Materials of High-Temperature Thermoelectric Modules with CoSb3 Thermoelectric Materials

    Lee, Yu Seong; Kim, Suk Jun; Kim, Byeong Geun; Lee, Soonil; Seo, Won-Seon; Kim, Il-Ho; Choi, Soon-Mok

    2017-05-01

    Metallic glass (MG) can be a candidate for an alternative brazing material of high-temperature thermoelectric modules, since we can expect both a lower brazing temperature and a high operating temperature for the junction from the MG brazers. Another advantage of MG powders is their outstanding oxidation resistance, namely, high-temperature durability in atmosphere. We fabricated three compositions of Al-based MGs—Al-Y-Ni, Al-Y-Ni-Co, and Al-Y-Ni-Co-La—by using the melt spinning process, and their T gs were 273°C, 264°C, and 249°C, respectively. The electrical resistivity of the Al-Y-Ni MG ribbon dropped significantly after annealing at 300°C. The electrical resistivity of crystallized Al-Y-Ni reduced down to 0.03 mΩ cm, which is an order of magnitude lower than that of the amorphous one. After the MG ribbons were pulverized to sub-100 μm, the average particle size was about 400 μm.

  13. Mechanical properties of brazing joints of alumina dispersion strengthened copper to 316 stainless steel for fusion reactor divertor

    Nishi, Hiroshi; Araki, Toshiaki.

    1994-01-01

    Brazing of alumina dispersion strengthened copper to 316 stainless steel was carried out with the brazing parameters such as brazing alloy, clearance and time to investigate the influence of brazing conditions on the joint strength. Tensile and Charpy impact tests of the joint specimens were performed to evaluate their strength. Microstructure and hardness of the brazed zone were examined with an optical microscope and a Vickers hardness tester. The excellent brazing joint strength was achieved with BAu-2 brazing alloy. The tensile strength of the joint with the brazing clearance of 0.2mm and the brazing time of 300s was as large as that of the diffusion bonding joint. However, Charpy absorbed energy of the brazing was lower than that of the diffusion bonding. Alumina dispersion strengthened copper remelted near the brazed zone because of diffusion of the brazing alloy, and the specimens fractured at the remelted zone. The brazed zone included many voids, which caused a scattering of the strength. (author)

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

    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.

  15. Ultrasonic guided wave inspection of Inconel 625 brazed lap joints

    Comot, Pierre; Bocher, Philippe; Belanger, Pierre

    2016-04-01

    The aerospace industry has been investigating the use of brazing for structural joints, as a mean of reducing cost and weight. There therefore is a need for a rapid, robust, and cost-effective non-destructive testing method for evaluating the structural integrity of the joints. The mechanical strength of brazed joints depends mainly on the amount of brittle phases in their microstructure. Ultrasonic guided waves offer the possibility of detecting brittle phases in joints using spatio-temporal measurements. Moreover, they offer the opportunity to inspect complex shape joints. This study focused on the development of a technique based on ultrasonic guided waves for the inspection of Inconel 625 lap joints brazed with BNi-2 filler metal. A finite element model of a lap joint was used to optimize the inspection parameters and assess the feasibility of detecting the amount of brittle phases in the joint. A finite element parametric study simulating the input signal shape, the center frequency, and the excitation direction was performed. The simulations showed that the ultrasonic guided wave energy transmitted through, and reflected from, the joints was proportional to the amount of brittle phases in the joint.

  16. WELDING PROCESS

    Zambrow, J.; Hausner, H.

    1957-09-24

    A method of joining metal parts for the preparation of relatively long, thin fuel element cores of uranium or alloys thereof for nuclear reactors is described. The process includes the steps of cleaning the surfaces to be jointed, placing the sunfaces together, and providing between and in contact with them, a layer of a compound in finely divided form that is decomposable to metal by heat. The fuel element members are then heated at the contact zone and maintained under pressure during the heating to decompose the compound to metal and sinter the members and reduced metal together producing a weld. The preferred class of decomposable compounds are the metal hydrides such as uranium hydride, which release hydrogen thus providing a reducing atmosphere in the vicinity of the welding operation.

  17. Solid state impact welding of BMG and copper by vaporizing foil actuator welding

    Vivek, Anupam, E-mail: vivek.4@osu.edu [Department of Materials Science and Engineering, The Ohio State University, 2041 College Road, Columbus, OH 43210 (United States); Presley, Michael [Department of Materials Science and Engineering, The Ohio State University, 2041 College Road, Columbus, OH 43210 (United States); Flores, Katharine M. [Department of Materials Science and Engineering, The Ohio State University, 2041 College Road, Columbus, OH 43210 (United States); Department of Mechanical Engineering and Materials Science, Institute of Materials Science and Engineering, Washington University, One Brookings Drive, St. Louis, MO 63130 (United States); Hutchinson, Nicholas H.; Daehn, Glenn S. [Department of Materials Science and Engineering, The Ohio State University, 2041 College Road, Columbus, OH 43210 (United States)

    2015-05-14

    The objective of this study was to create impact welds between a Zr-based Bulk Metallic Glass (BMG) and copper at a laboratory scale and subsequently investigate the relationship between interfacial structure and mechanical properties. Vaporizing Foil Actuator (VFA) has recently been demonstrated as a versatile tool for metalworking applications: impact welding of dissimilar materials being one of them. Its implementation for welding is termed as VFA Welding or VFAW. With 8 kJ input energy into an aluminum foil actuator, a 0.5 mm thick Cu110 alloy sheet was launched toward a BMG target resulting in an impact at a velocity of nearly 600 m/s. For this experiment, the welded interface was straight with a few BMG fragments embedded in the copper sheet in some regions. Hardness tests across the interface showed increase in strength on the copper side. Instrumented peel test resulted in failure in the parent copper sheet. A slower impact velocity during a separate experiment resulted in a weld, which had wavy regions along the interface and in peel failure again happened in the parent copper sheet. Some through-thickness cracks were observed in the BMG plate and there was some spall damage in the copper flyers. TEM electron diffraction on a sample, cut out from the wavy weld interface region using a focused ion beam, showed that devitrification of the BMG was completely avoided in this welding process.

  18. Welding processes handbook

    Weman, Klas

    2011-01-01

    Offers an introduction to the range of available welding technologies. This title includes chapters on individual techniques that cover principles, equipment, consumables and key quality issues. It includes material on such topics as the basics of electricity in welding, arc physics, and distortion, and the weldability of particular metals.$bThe first edition of Welding processes handbook established itself as a standard introduction and guide to the main welding technologies and their applications. This new edition has been substantially revised and extended to reflect the latest developments. After an initial introduction, the book first reviews gas welding before discussing the fundamentals of arc welding, including arc physics and power sources. It then discusses the range of arc welding techniques including TIG, plasma, MIG/MAG, MMA and submerged arc welding. Further chapters cover a range of other important welding technologies such as resistance and laser welding, as well as the use of welding techniqu...

  19. HIGH TEMPERATURE BRAZING ALLOY FOR JOINT Fe-Cr-Al MATERIALS AND AUSTENITIC AND FERRITIC STAINLESS STEELS

    Cost, R.C.

    1958-07-15

    A new high temperature brazing alloy is described that is particularly suitable for brazing iron-chromiumaluminum alloys. It consists of approximately 20% Cr, 6% Al, 10% Si, and from 1.5 to 5% phosphorus, the balance being iron.

  20. Friction Stir Welding

    Nunes, Arthur C., Jr.

    2008-01-01

    Friction stir welding (FSW) is a solid state welding process invented in 1991 at The Welding Institute in the United Kingdom. A weld is made in the FSW process by translating a rotating pin along a weld seam so as to stir the sides of the seam together. FSW avoids deleterious effects inherent in melting and promises to be an important welding process for any industries where welds of optimal quality are demanded. This article provides an introduction to the FSW process. The chief concern is the physical effect of the tool on the weld metal: how weld seam bonding takes place, what kind of weld structure is generated, potential problems, possible defects for example, and implications for process parameters and tool design. Weld properties are determined by structure, and the structure of friction stir welds is determined by the weld metal flow field in the vicinity of the weld tool. Metal flow in the vicinity of the weld tool is explained through a simple kinematic flow model that decomposes the flow field into three basic component flows: a uniform translation, a rotating solid cylinder, and a ring vortex encircling the tool. The flow components, superposed to construct the flow model, can be related to particular aspects of weld process parameters and tool design; they provide a bridge to an understanding of a complex-at-first-glance weld structure. Torques and forces are also discussed. Some simple mathematical models of structural aspects, torques, and forces are included.

  1. Brazed thermocouple pass-through for sodium service in a liquid-metal-cooled fast breeder reactor

    Walker, D.E.

    1975-10-01

    Sensors installed in special fuel elements for the EBR-II reactor had 30-ft-long leads that would pass from the sodium environment through a sealed bulkhead. A hydrogen-atmosphere, induction-heated brazing furnace was constructed to simultaneously braze 20-26 separate sensor leads at one time. The brazed seals were leak-tight, and the sheath wall has less than 10 percent interaction with the braze alloy

  2. Introduction to Welding.

    Fortney, Clarence; Gregory, Mike

    This curriculum guide provides six units of instruction on basic welding. Addressed in the individual units of instruction are the following topics: employment opportunities for welders, welding safety and first aid, welding tools and equipment, basic metals and metallurgy, basic math and measuring, and procedures for applying for a welding job.…

  3. Distortion Control during Welding

    Akbari Pazooki, A.M.

    2014-01-01

    The local material expansion and contraction involved in welding result in permanent deformations or instability i.e., welding distortion. Considerable efforts have been made in controlling welding distortion prior to, during or after welding. Thermal Tensioning (TT) describes a group of in-situ

  4. Welding and cutting

    Drews, P.; Schulze Frielinghaus, W.

    1978-01-01

    This is a survey, with 198 literature references, of the papers published in the fields of welding and cutting within the last three years. The subjects dealt with are: weldability of the materials - Welding methods - Thermal cutting - Shaping and calculation of welded joints - Environmental protection in welding and cutting. (orig.) [de

  5. Assessing braze quality in the actively cooled Tore Supra phase III outboard pump limiter

    Hygren, R.; Lutz, T.; Miller, J.

    1994-01-01

    This paper discusses the assessment of quality of brazing of pyrolytic graphite (PG) armor brazed to copper tubes in Tore Supra's Phase III Outboard Pump Limiter (OPL). The limiter head is a bank of 14 water-cooled copper tubes with several hundred brazed PG tiles. Braze quality was first assessed through pre-service qualification testing of individual copper/tiles assemblies. The quality of brazes was evaluated using (non-destructive) transient heating (open-quotes hot waterclose quotes) tests performed in the high temperature, high pressure flow loop at Sandia's Plasma Materials Test Facility. The surface temperatures of tiles were monitored with an infra-red (IR) camera as water at 120 degrees C water at about 2.07 MPa (300 psi) passed through a tube assembly initially at 30 degrees C. For tiles with braze voids or cracks, the surface temperatures lagged behind those of adjacent well bonded tiles. Temperature lags were correlated with flaw sizes observed during repairs using a detailed 2-D heat transfer analyses. open-quotes Badclose quotes tiles, i.e., temperature lags of 10-20 degrees C depending upon tile's size, were easy to detect and, when removed, revealed braze voids of roughly 50% of the joint area. 11 of the 14 tubes were rebrazed after bad tiles were detected and removed. Three tubes were re-brazed twice

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

    Wang, C.Y. [Faculty of Mechanical and Electronic Engineering, Guangdong University of Technology, Guangzhou 510006 (China)], E-mail: cywang@gdut.edu.cn; Zhou, Y.M.; Zhang, F.L.; Xu, Z.C. [Faculty of Mechanical and Electronic Engineering, Guangdong University of Technology, Guangzhou 510006 (China)

    2009-05-12

    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. Cr{sub 7}C{sub 3} and Cr{sub 3}C{sub 2} 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.

  7. Brazing process for beryllium pieces at a temperature lower than 800 deg

    Cerutti, R.; Flegeau, G.; Haas, C.

    1992-01-01

    This patent describes a brazing process of a beryllium plate with monel rod at a temperature lower than 1073 K under high vacuum. The brazing alloy is composed (% in weight) of silver (58 to 65%), copper (26 to 29%), indium (9 to 13%) and titanium (0 to 2%). (A.B.). 4 refs., 1 fig

  8. Influence of cyclic thermal loading on brazed composites for fusion applications

    Smid, I.; Kny, E.; Kneringer, G.; Reheis, N.

    1990-01-01

    Reactor grade graphite and molybdenum (TZM) were brazed with different high temperature brazes (100Zr, 90Cu10Ti, 90Ni10Ti, 70Ag27Cu3Ti) The resulting tiles had a size of 50x50 mm 2 with a graphite thickness of 100 mm and a TZM thickness of 5 mm. The brazed composites have been tested in electron beam simulation for their thermal fatigue properties. The parameters of these tests were chosen to match NET design specifications for normal operation and ''slow'' peak energy deposition. The resulting damage and microstructural changes on the graphites and the brazes are discussed. Additional information is supplied on X-ray diffraction data proving the presence of different phases in the brazes. (orig./MM)

  9. Experimental and thermodynamic assessment of beryllium-replacement materials for CANDU brazed joints

    Potter, K.N.; Ferrier, G.A.; Corcoran, E.C., E-mail: Kieran.Potter@rmc.ca [Royal Military College of Canada, Kingston ON, (Canada); Dimayuga, F.C. [Canadian Nuclear Laboratories, Chalk River, ON (Canada)

    2015-07-01

    Currently, appendages are joined to CANDU fuel elements via a brazing process, with beryllium as the filler material. A potential reduction in the occupational limit on airborne beryllium particulates has motivated research into alternative brazing materials. To this end, the Canadian nuclear industry has funded an initiative to identify and evaluate the suitability of several candidate brazing materials. This work describes contributions toward the assessment of alternative brazing materials from the Royal Military College of Canada (RMCC). An impact testing method was developed to evaluate the mechanical strength of candidate braze joints.Thermodynamic modelling was performed to predict the aqueous behaviour of each candidate material in CANDU coolant conditions characteristic of reactor shutdown, and corrosion experiments are underway to support modelling predictions.The results of these activities will assist in selecting a suitable replacement material for beryllium. (author)

  10. Advanced Welding Applications

    Ding, Robert J.

    2010-01-01

    Some of the applications of advanced welding techniques are shown in this poster presentation. Included are brief explanations of the use on the Ares I and Ares V launch vehicle and on the Space Shuttle Launch vehicle. Also included are microstructural views from four advanced welding techniques: Variable Polarity Plasma Arc (VPPA) weld (fusion), self-reacting friction stir welding (SR-FSW), conventional FSW, and Tube Socket Weld (TSW) on aluminum.

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

    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.

  12. A preliminary study of cladding steel with NiTi by microwave-assisted brazing

    Chiu, K.Y.; Cheng, F.T.; Man, H.C.

    2005-01-01

    Nickel titanium (NiTi) plate of 1.2 mm thickness was successfully clad on AISI 316L stainless steel substrate by a microwave-assisted brazing process. Brazing was conducted in a multimode microwave oven in air using a copper-based brazing material in tape form. The brazing material was melted in a few minutes by microwave-induced plasma initiated by conducting wires surrounding the brazing assembly. Metallographic study by scanning-electron microscopy (SEM) and compositional analysis by energy-dispersive spectroscopy (EDS) of the brazed joint revealed metallurgical bonding formed via inter-diffusion between the brazing filler and the adjacent materials. A shear bonding strength in the range of 100-150 MPa was recorded in shear tests of the brazed joint. SEM and X-ray diffractometry (XRD) analysis for the surface of as-received NiTi plate and NiTi cladding showed similar microstructure and phase composition. Nanoindentation tests also indicated that the superelastic properties of NiTi were essentially retained. The cavitation erosion resistance of the NiTi cladding was essentially the same as that of as-received NiTi plate, and higher than that obtained in laser or TIG (tungsten-inert gas) surfacing. The high resistance could be attributed to avoidance of dilution and defect formation in the NiTi clad since the cladding did not undergo melting and solidification in the brazing process. Electrochemical tests also recorded similar corrosion resistance in both as-received NiTi and NiTi cladding. Thus, the present study indicates that microwave-assisted brazing is a simple, economical, and feasible process for cladding NiTi on 316L stainless steel for enhancing cavitation erosion resistance

  13. Diode Laser Welding/Brazing of Aluminum Alloy to Steel Using a Nickel Coating

    Jin Yang

    2018-06-01

    Full Text Available Joining Al alloy to steel is of great interest for application in the automotive industry. Although a vast number of studies have been conducted to join Al to steel, the joining of Al to steel is still challenging due to the formation of brittle Fe–Al intermetallic compounds. In this work, the microstructure and mechanical properties of the dissimilar Al/steel joints with and without a nickel coating are comparatively investigated. A homogenous reaction layer composed of FeZn10 and Fe2Al5 is formed at the interface in the joints without Ni coating, and the joint facture load is only 743 N. To prevent the formation of brittle Fe2Al5, Ni electroplated coating is applied onto a steel surface. It has been shown that a nonhomogeneous reaction layer is observed at the interfacial region: Ni5Zn21 is formed at the direct irradiation zone, while Al3Ni is formed at the fusion zone root. The microhardness of the interfacial layer is reduced, which leads to the improvement of the joint mechanical properties. The average fracture load of the Al/Ni-coated steel joints reaches 930 N. In all of the cases, failure occurs at the Ni coating/fusion zone interface.

  14. 49 CFR 178.50 - Specification 4B welded or brazed steel cylinders.

    2010-10-01

    ... of the testing machine may not exceed 1/8 inch per minute during yield strength determination. (l... conducted to determine yield strength, tensile strength, elongation, and reduction of area of material as... strength not over 73 percent of tensile strength. In this instance, a flattening test is not required. (2...

  15. 49 CFR 178.55 - Specification 4B240ET welded or brazed cylinders.

    2010-10-01

    ... of the testing machine may not exceed 1/8 inch per minute during yield strength determination. (l... test must be conducted to determine yield strength, tensile strength, elongation, and reduction of area... cases and a yield strength not over 73 percent of tensile strength. In this instance the flattening test...

  16. 49 CFR 178.51 - Specification 4BA welded or brazed steel cylinders.

    2010-10-01

    ... must be set at the calculated corresponding strain. (iv) Cross-head speed of the testing machine may... the minimum tensile strength of the material determined as required in paragraph (j) of this section..., tensile strength, elongation, and reduction of area of material, as follows: (1) The test is required on 2...

  17. Investigations into the high temperature brazing of type NiCr20Ti nickel alloy under vacuum conditions

    Zaremba, P.

    1977-01-01

    Joints made from NiCr20Ti material brazed in a vacuum furnace (brazing gap width 10, 30 and 50 μm, brazing temperature 1,040 0 C and 1,100 0 C) were tensile tested and subjected to metallographic investigation. Furthermore, the angle of wetting and the pattern of hardness across the brazed joint was established. The results obtained showed that, amongst other things, a relationship existed between the micro-hardness at the centre of the joint and the tensile strength of the brazed joint itself. (orig.) [de

  18. Graphite to Inconel brazing using active filler metal

    King, J.F.; Baity, F.W.; Walls, J.C.; Hoffman, D.J.

    1989-01-01

    Ion cyclotron resonant frequency (ICRF) antennas are designed to supply large amounts of auxiliary heating power to fusion-grade plasmas in the Toroidal Fusion Test Reactor (TFTR) and Tore Supra fusion energy experiments. A single Faraday shield structure protects a pair of resonant double loops which are designed to launch up to 2 MW of power per loop. The shield consists of two tiers of actively cooled Inconel alloy tubes with the front tier being covered with semicircular graphite tiles. Successful operation of the antenna requires the making of high integrity bonds between the Inconel tubes and graphite tiles by brazing. This paper discusses this process

  19. In-situ quality monitoring during laser brazing

    Ungers, Michael; Fecker, Daniel; Frank, Sascha; Donst, Dmitri; Märgner, Volker; Abels, Peter; Kaierle, Stefan

    Laser brazing of zinc coated steel is a widely established manufacturing process in the automotive sector, where high quality requirements must be fulfilled. The strength, impermeablitiy and surface appearance of the joint are particularly important for judging its quality. The development of an on-line quality control system is highly desired by the industry. This paper presents recent works on the development of such a system, which consists of two cameras operating in different spectral ranges. For the evaluation of the system, seam imperfections are created artificially during experiments. Finally image processing algorithms for monitoring process parameters based the captured images are presented.

  20. Selected Welding Techniques, Part 2

    1964-01-01

    Partial contents: CONVENTIONAL WELD JOINTS VERSUS BUTT JOINTS IN 1-INCH ALUMINUM PLATE, SPECIAL WELD JOINT PREPARATION, UPSET METAL EDGES FOR INCREASED WELD JOINT STRENGTH, OUT-OF-POSITION WELDING OF HEAVY GAGE...

  1. Joining of cemented carbides to steel by laser beam welding

    Barbatti, C.; Garcia, J.; Pyzalla, A. [Max-Planck-Institut fuer Eisenforschung GmbH, 40237 Duesseldorf (Germany); Liedl, G. [TU Wien, Institut fuer Umform- und Hochleistungslasertechnik (IFLT), 1040 Vienna (Austria)

    2007-11-15

    Welding of dissimilar materials such as steel and cemented carbides (hardmetals, cermets) is particularly challenging e.g. because mismatches in their thermal expansion coefficients and thermal conductivities result in residual stress formation and because of the formation of brittle intermetallic phases. Laser beam welding of cemented carbides to steel appears as an attractive complementary technique to conventional brazing processes due to its high precision, high process speed, low heat input and the option of welding without filler. Here a laser welding process including pre-heat treatment and post-heat treatment was applied successfully to joining as-sintered and nitrided hardmetals and cermets to low alloyed steel. The microstructure and mechanical properties of the welds are investigated by microscopy, X-ray diffraction, microhardness measurements, and bending tests. The results reveal that the three-step laser beam welding process produced crack-free and non-porous joints. Nitridation of the cemented carbides results in a significant reduction of the amount of brittle intermetallic phases. The mechanical properties of the joints are competitive to those of the conventional brazed steel-cemented carbide joints. (Abstract Copyright [2007], Wiley Periodicals, Inc.) [German] Das Schweissen von ungleichartigen Werkstoffen wie z. B. Staehlen mit Hartmetallen und Cermets stellt eine erhebliche Herausforderung dar, u. a. infolge der unterschiedlichen thermischen Ausdehnungskoeffizienten und Waermeleitfaehigkeiten, welche die Bildung von Eigenspannungen zur Folge haben, sowie aufgrund der Bildung sproeder intermetallischer Phasen. Das Laserstrahlschweissen von Hartmetallen/Cermets mit Stahl erscheint als attraktives komplementaeres Verfahren zum ueblicherweise verwendeten Loeten, da es die Herstellung von Verbindungen mit hoeherer Praezision, hoeherer Geschwindigkeit sowie geringerem Waermeeintrag erlaubt und die Verwendung eines Zusatzwerkstoffs nicht notwendig ist

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

    Yan, Fei; Wang, Chun Ming; Wang, Ya Jun; Xu, Dao Rong; Wu, S.C.; Sun, Qin De

    2012-01-01

    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

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

    Song, Zhihua; Nakata, Kazuhiro; Wu, Aiping; Liao, Jinsun

    2013-01-01

    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 3 . The formation of interfacial IMC layer and its effect on mechanical property of the joint are discussed in the present study.

  4. Automatic welding of fuel elements

    Briola, J.

    1958-01-01

    The welding process depends on the type of fuel element, the can material and the number of cartridges to be welded: - inert-gas welding (used for G2 and the 1. set of EL3), - inert atmosphere arc welding (used for welding uranium and zirconium), - electronic welding (used for the 2. set of EL3 and the tank of Proserpine). (author) [fr

  5. Detecting flaws in welds

    Woodacre, A.; Lawton, H.

    1979-01-01

    An apparatus and a method for detecting flaws in welds in a workpiece, the portion of the workpiece containing the weld is maintained at a constant temperature and the weld is scanned by an infra red detector. The weld is then scanned again with the workpiece in contact with a cooling probe to produce a steeper temperature gradient across the weld. Comparison of the signals produced by each scan reveals the existence of defects in the welds. The signals may be displayed on an oscilloscope and the display may be observed by a TV camera and recorded on videotape. (UK)

  6. Fusion welding process

    Thomas, Kenneth C.; Jones, Eric D.; McBride, Marvin A.

    1983-01-01

    A process for the fusion welding of nickel alloy steel members wherein a ferrite containing pellet is inserted into a cavity in one member and melted by a welding torch. The resulting weld nugget, a fusion of the nickel containing alloy from the members to be welded and the pellet, has a composition which is sufficiently low in nickel content such that ferrite phases occur within the weld nugget, resulting in improved weld properties. The steel alloys encompassed also include alloys containing carbon and manganese, considered nickel equivalents.

  7. Problems in laser repair welding of polished surfaces

    A. Skumavc

    2014-10-01

    Full Text Available This paper presents problems in laser repair welding of the tools for injection moulding of plastics and light metals. Tools for injection moulding of the car headlamps are highly polished in order to get a desirable quality of the injected part. Different light metals, glasses, elastomers, thermoplastics and thermosetting polymers are injected into the die cavity under high pressures resulting in the surface damages of the tool. Laser welding is the only suitable repair welding technique due to the very limited sputtering during deposition of the filler metal. Overlapping of the welds results in inhomogeneous hardness of the remanufactured surface. Results have shown strong correlation between hardness and surface waviness after final polishing of the repair welded surface.

  8. Microstructural control of thin-film diffusion-brazed titanium

    Wells, R.R.

    1976-01-01

    This study was designed to determine what parameters should be controlled to achieve quality joints of good toughness and high strength in titanium alloys. Emphasis was placed upon studying those parameters which provided tough joints compatible with the titanium base metal being joined. This paper is concerned with thin-film diffusion brazing based upon the eutectic system formed between copper and titanium. In order to control the joint microstructure, the copper diffusion rates and the beta-phase decomposition kinetics were studied. This information was used to produce various types of microstructures in test specimens. These were then evaluated to select the best microstructures for toughness and strength which were compatible with the titanium alloys. Results show that it is possible to accurately control properties of joints produced by thin-film diffusion brazing. This is done by controlling the initial copper content and the time-temperature parameters used in processing. Alloys studied were Ti--8Al--1Mo--1V and Ti--6Al--4V

  9. Determination of phosphorus in gold or silver brazing alloys

    Antepenko, R.J.

    1976-01-01

    A spectrophotometric method has been devised for measuring microgram levels of phosphorus in brazing alloys of gold or silver alloys is normally measured by solid mass spectrometry, but the high nickel concentration produces a double ionized nickel spectral interference. The described procedures is based upon the formation of molybdovandophosphoric acid when a molybdate solution is added to an acidic solution containing orthophosphate and vanadate ions. The optimum acidity for forming the yellow colored product is 0.5 N hydrochloric acid. The working concentration range is from 0.1 to 1 ppm phosphorus using 100-mm cells and measuring the absorbance at 460 nm. The sample preparation procedure employs aqua regia to dissolve the alloy oxidize the phosphorus to orthophosphate. Cation-exchange chromatography is used to remove nickel ions and anion-exchange and chromatography to remove gold ions as the chloride complex. Excellent recoveries are obtained for standard phosphorus solutions run through the sample procedure. The procedure is applicable to a variety of gold or silver braze alloys requiring phosphorus analysis

  10. Weld controller for automated nuclear service welding

    Barfield, K.L.; Strubhar, P.M.; Green, D.I.

    1995-01-01

    B and W Nuclear Technologies (BWNT) uses many different types of weld heads for automated welding in the commercial nuclear service industry. Some weld heads are purchased as standard items, while others are custom designed and fabricated by BWNT requiring synchronized multiaxis motion control. BWNT recently completed a development program to build a common weld controller that interfaces to all types of weld heads used by BWNT. Their goal was to construct a system that had the flexibility to add different modules to increase the capability of the controller as different application needs become necessary. The benefits from having a common controller are listed. This presentation explains the weld controller system and the types of applications to which it has been applied

  11. The Application of 40Ti-35Ni-25Nb Filler Foil in Brazing Commercially Pure Titanium

    Shan-Bo Wang

    2018-03-01

    Full Text Available The clad ternary 40Ti-35Ni-25Nb (wt % foil has been applied in brazing commercially pure titanium (CP-Ti. The wavelength dispersive spectroscope (WDS was utilized for quantitative chemical analyses of various phases/structures, and electron back scattered diffraction (EBSD was used for crystallographic analyses in the brazed joint. The microstructure of brazed joint relies on the Nb and Ni distributions across the joint. For the β-Ti alloyed with high Nb and low Ni contents, the brazed zone (BZ, consisting of the stabilized β-Ti at room temperature. In contrast, eutectoid decomposition of the β-Ti into Ti2Ni and α-Ti is widely observed in the transition zone (TZ of the joint. Although average shear strengths of joints brazed at different temperatures are approximately the same level, their standard deviations decreased with increasing the brazing temperature. The presence of inherent brittle Ti2Ni intermetallics results in higher standard deviation in shear test. Because the Ni content is lowered in TZ at a higher brazing temperature, the amount of eutectoid is decreased in TZ. The fracture location is changed from TZ into BZ mixed with α and β-Ti.

  12. Mechanical design of ceramic beam tube braze joints for NOvA kicker magnets

    Ader, C.R.; Reilly, R.E.; Wilson, J.H.; /Fermilab

    2010-05-01

    The NO?A Experiment will construct a detector optimized for electron neutrino detection in the existing NuMI neutrino beam. The NuMI beam line is capable of operating at 400 kW of primary beam power and the upgrade will allow up to 700 kW. Ceramic beam tubes are utilized in numerous kicker magnets in different accelerator rings at Fermi National Accelerator Laboratory. Kovar flanges are brazed onto each beam tube end, since kovar and high alumina ceramic have similar expansion curves. The tube, kovar flange, end piece, and braze foil alloy brazing material are stacked in the furnace and then brazed. The most challenging aspect of fabricating kicker magnets in recent years have been making hermetic vacuum seals on the braze joints between the ceramic and flange. Numerous process variables can influence the robustness of conventional metal/ceramic brazing processes. The ceramic-filler metal interface is normally the weak layer when failure does not occur within the ceramic. Differences between active brazing filler metal and the moly-manganese process will be discussed along with the applicable results of these techniques used for Fermilab production kicker tubes.

  13. Microstructure and interfacial behaviour of Alumina/Inconel 600 joints prepared by brazing route

    Laik, A.; Mishra, P.; Bhanumurthy, K.; Kashyap, B.P.

    2010-01-01

    Joining of metals to ceramics remains a technological challenge due to the wide difference in the physical and mechanical properties of the two classes of materials. Attempt was made to produce leak tight joints between Inconel-600 and alumina using the brazing route with Au-Ni brazing alloy. Alumina tubes were metallised following the Mo-Mn route and then coated with Ni. The metallised alumina tubes were brazed to Inconel-600 ferrules using Au-18%Ni brazing alloy under vacuum, at optimised process parameters. In order to study the effect of prolong annealing on the microstructural stability and the micro-chemistry of the brazing zone, brazed joints were subjected to prolong annealing at 400 deg C and 560 deg C for 8000 hrs each. Detailed analysis of the interfacial structure of the brazing zones was done using an electron probe microanalyser (EPMA). X-ray maps of the elements Fe, Ni, Cr, Al, Au, Mo and Mn along with BSE images of the brazing zone are given. These X-ray maps precisely reveal the micro-chemistry of the brazing zones. The various phases formed were identified. The distribution of the various elements across the interfaces was also obtained, which helps to reveal the chemical behaviour of the individual elements during the process of brazing. Two phases appear very distinctly in the brazement, one is rich in Au and the other is rich in Ni. Depending upon their affinity, rest of the elements shows a partitioning in these two phases. While Fe, Cr and Mo get dissolved in the Ni-rich phase, Mn seems to partition in the Au-rich phase. The microstructure and the X-ray maps of the couple annealed at 400 deg C shows that the spatial variation in the composition throughout the brazing zone gets homogenised due to diffusion at high temperatures. This effect is even more pronounced on annealing at 560 deg C. Moreover, the transport of Cr from the Inconel side to the surface of alumina is very evident. On annealing at 560 deg C, a region rich in Cr, was found to

  14. Influence of time presetting procedure for rapid local heat;.ng on brazing temperature conditions

    Lezhnin, G.P.; Tul'skikh, V.E.

    1985-01-01

    Correlation of known and suggested presetting procedures for heating period during induction brazing was conducted. It is shown that brazing time must be established considering heat propagation during heating in order to obtain the assigned joint temperature regardless of heating rate change. Methods for temperature calculation in assigned zones of the joint are suggested. The suggested presetting procedure for heating time was applied for induction vacuum brazing of a tube of 12Kh18N10T steel to a pipe connection of VT20 alloy

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

    J. W. Elmer

    2001-05-01

    Full Text Available 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

  16. Handbook of Plastic Welding

    Islam, Aminul

    The purpose of this document is to summarize the information about the laser welding of plastic. Laser welding is a matured process nevertheless laser welding of micro dimensional plastic parts is still a big challenge. This report collects the latest information about the laser welding of plastic...... materials and provides an extensive knowhow on the industrial plastic welding process. The objectives of the report include: - Provide the general knowhow of laser welding for the beginners - Summarize the state-of-the-art information on the laser welding of plastics - Find the technological limits in terms...... of design, materials and process - Find the best technology, process and machines adaptive to Sonion’s components - Provide the skills to Sonion’s Design Engineers for successful design of the of the plastic components suitable for the laser welding The ultimate goal of this report is to serve...

  17. Nondestructive testing: welding industry

    Raj, Baldev; Subramanian, C.V.

    1992-01-01

    This chapter highlights various conventional and advanced nondestructive testing (NDT) techniques that have been used for weld evaluation. Welding Codes and Standards of International and National organisations that have been followed in India for various weld evaluation purposes are also included. The chapter also emphasises the importance of NDT by way of a few case studies that have been carried out on important critical welded components. (author). 12 refs., 17 figs., 1 appendix

  18. Instructional Guidelines. Welding.

    Fordyce, H. L.; Doshier, Dale

    Using the standards of the American Welding Society and the American Society of Mechanical Engineers, this welding instructional guidelines manual presents a course of study in accordance with the current practices in industry. Intended for use in welding programs now practiced within the Federal Prison System, the phases of the program are…

  19. Welding Course Curriculum.

    Genits, Joseph C.

    This guide is intended for use in helping students gain a fundamental background on the major aspects of the welding trade. The course emphasis is on mastery of the manipulative skills necessary to develop successful welding techniques and on acquisition of an understanding of the specialized tools and equipment used in welding. The first part…

  20. Underwater welding of steel

    Ibarra, S.; Olson, D.L.

    1992-01-01

    A fundamental basis to understand the behavior of wet underwater welding of steel is introduced. Both the pyrometallurgical and physical metallurgy concepts are discussed. Modifications of welding consumables and practice are suggested. This chapter promotes further contributions of meatllurgical research to improve and promote wet underwater welding. (orig.)

  1. Welding Over Paint Primer

    Johnson, Kevin S; Liu, Stephen; Olson, David L

    1998-01-01

    .... According to the hydrogen-oxygen and }hydrogen-fluorine equilibrium considerations, an increase in the partial pressure of oxygen or fluorine could decrease the partial pressure of hydrogen within the welding arc. Consequently, a welding consumable that contains chemical ingredients of high oxygen and fluorine potential would be capable of minimizing hydrogen pick-up in the weld pool.

  2. Nano-Phase Powder Based Exothermic Braze Repair Technology For RCC Materials, Phase I

    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 itself...

  3. Brazing of AlN to SiC by a Pr silicide: Physicochemical aspects

    Koltsov, A. [SIMAP - UMR CNRS 5266, INP Grenoble-UJF, Domaine Universitaire, BP 75, 1130 rue de la Piscine, 38402 Saint Martin d' Heres, Cedex (France)], E-mail: alexey.koltsov@arcelor.com; Hodaj, F.; Eustathopoulos, N. [SIMAP - UMR CNRS 5266, INP Grenoble-UJF, Domaine Universitaire, BP 75, 1130 rue de la Piscine, 38402 Saint Martin d' Heres, Cedex (France)

    2008-11-15

    In view of their very different thermomechanical properties, joining of metals to ceramics by brazing is usually performed by means of one or more interlayers. In a recent investigation AlN was chosen as interlayer material for brazing SiC to a superalloy. The aim of the present study is to determine an alloy with a high melting point (close to 1200 deg. C) enabling brazing of AlN to SiC. Two types of experiments are performed with a Si-17 at.% Pr eutectic alloy (T{sub m} = 1212 deg. C): sessile drop experiments to determine wetting and brazing of AlN and SiC plates to determine gap filling. Experiments are carried out in high vacuum to promote deoxidation. Interfacial reactivity, joint microstructure and type of failure occurring during cooling are examined by optical and scanning electron microscopy.

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

    Santos Sérgio Ivan dos

    2004-01-01

    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.

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

    Hong, Jintae; Kim, Kahye; Heo, Sungho; Ahn, Sungho; Joung, Changyoung; Son, Kwangjae; Jung, Yangil [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-12-15

    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.

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

    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.

  7. Brazing of AlN to SiC by a Pr silicide: Physicochemical aspects

    Koltsov, A.; Hodaj, F.; Eustathopoulos, N.

    2008-01-01

    In view of their very different thermomechanical properties, joining of metals to ceramics by brazing is usually performed by means of one or more interlayers. In a recent investigation AlN was chosen as interlayer material for brazing SiC to a superalloy. The aim of the present study is to determine an alloy with a high melting point (close to 1200 deg. C) enabling brazing of AlN to SiC. Two types of experiments are performed with a Si-17 at.% Pr eutectic alloy (T m = 1212 deg. C): sessile drop experiments to determine wetting and brazing of AlN and SiC plates to determine gap filling. Experiments are carried out in high vacuum to promote deoxidation. Interfacial reactivity, joint microstructure and type of failure occurring during cooling are examined by optical and scanning electron microscopy

  8. Nano-Phase Powder Based Exothermic Braze Repair Technology For RCC Materials, Phase II

    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...

  9. Tensile tests and metallography of brazed AISI 316L specimens after irradiation

    Groot, P.; Franconi, E.

    1994-01-01

    Stainless steel type 316L tensile specimens were vacuum brazed with three kinds of alloys: BNi-5, BNi-6, and BNi-7. The specimens were irradiated up to 0.7 dpa at 353 K in the High Flux Reactor at JRC Petten, the Netherlands. Tensile tests were performed at a constant displacement rate of 10 -3 s -1 at room temperature in the ECN hot cell facility. BNi-5 brazed specimens showed ductile behaviour. Necking and fractures were localized in the plate material. BNi-6 and BNi-7 brazed specimens failed brittle in the brazed zone. This was preceded by uniform deformation of the plate material. Tensile test results of irradiated specimens showed higher stresses due to radiation hardening and a reduction of the elongation of the plate material compared to the reference. SEM examination of the irradiated BNi-6 and BNi-7 fracture surfaces showed nonmetallic phases. These phases were not found in the reference specimens. ((orig.))

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

    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%.

  11. Brazing techniques for side-coupled electron accelerator structures

    Hansborough, L.D.; Clark, W.L.; DePaula, R.A.; Martinez, F.A.; Roybal, P.L.; Wilkerson, L.C.; Young, L.M.

    1986-01-01

    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

  12. Orbital welding technique

    Hoeschen, W.

    2003-01-01

    The TIG (Tungsten-inert gas) orbital welding technique is applied in all areas of pipe welding. The process is mainly used for austenitic and ferritic materials but also for materials like aluminium, nickel, and titanium alloys are commonly welded according to this technique. Thin-walled as well as thick-walled pipes are welded economically. The application of orbital welding is of particular interest in the area of maintenance of thick-walled pipes that is described in this article. (orig.) [de

  13. A carbon-metal brazing for divertor plates in fusion devices

    Matsuda, T.; Matsumoto, T.; Miki, S.; Sogabe, T.; Okada, M.; Kubota, Y.; Sagara, A.; Noda, N.; Motojima, O.; Hino, T.; Yamashina, T.

    1993-01-01

    A divertor unit, which consists of carbon armors brazed to a copper cooling channel, is under development for fusion devices. Isotropic graphite (IG-430U) and CFC (CX-2002U) are used for the armor, and a copper for the cooling tube. A technique named as dissolution and deposit of base metal was employed for brazing. The reliability of the brazed components was evaluated both by 4-point bending test and thermal shock test. According to the results of a 4-point bending test under the temperature ranged from RT to 800 C in a vacuum, it was found that the strength of the brazed surface at RT was maintained up to the higher temperature, 600 C. High heat load test has been also performed on the brazed sample in order to find whether the samples meet the requirement of the divertor plates of LHD (Large Helical Device). Active Cooling Teststand (ACT:NIFS) with electron beam power of 100kW was used. In LHD, it is presumed that the maximum heat flux is 10MW/m 2 . In addition, the surface temperature of divertor has to be kept below 1,200 C to avoid RES, by active cooling. The heat load test showed that the brazing components of CX-2002U (flat plate type CFC-Cu brazed) was stable at 1,300 C under a heat flux of 10MW/m 2 , when the flow velocity of cooling water was 6m/s. No damage nor deterioration was found at the brazed zone after the heat load test

  14. Cold metal transfer spot plug welding of AA6061-T6-to-galvanized steel for automotive applications

    Cao, R.; Huang, Q.; Chen, J.H.; Wang, Pei-Chung

    2014-01-01

    Highlights: • Two Al-to-galvanized steel spot plug welding joints were studied by CMT method. • The optimum process variables for the two joints were gotten by orthogonal test. • Connection mechanism of the two joints were discussed. -- Abstract: In this study, cold metal transfer (CMT) spot plug joining of 1 mm thick Al AA6061-T6 to 1 mm thick galvanized steel (i.e., Q235) was studied. Welding variables were optimized for a plug weld in the center of a 25 mm overlap region with aluminum 4043 wire and 100% argon shielding gas. Microstructures and elemental distributions were characterized by scanning electron microscopy with energy dispersive X-ray spectrometer. Mechanical testing of CMT spot plug welded joints was conducted. It was found that it is feasible to join Al AA6061T6-to-galvanized steel by CMT spot plug welding method. The process variables for two joints with Al AA6061T6-to-galvanized mild steel and galvanized mild steel-to-Al AA6061T6 are optimized. The strength of CMT spot welded Al AA6061T6-to-galvanized mild steel is determined primarily by the strength and area of the brazed interface. While, the strength of the galvanized mild steel-to-Al AA6061T6 joint is mainly dependent upon the area of the weld metal

  15. Glass sealing

    Brow, R.K.; Kovacic, L.; Chambers, R.S. [Sandia National Labs., Albuquerque, NM (United States)

    1996-04-01

    Hernetic glass sealing technologies developed for weapons component applications can be utilized for the design and manufacture of fuel cells. Design and processing of of a seal are optimized through an integrated approach based on glass composition research, finite element analysis, and sealing process definition. Glass sealing procedures are selected to accommodate the limits imposed by glass composition and predicted calculations.

  16. Use of a cobalt-based metallic glass for joining MoSi{sub 2} to stainless steel

    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.)

  17. Electrochromic Glasses.

    1980-07-31

    this glass and that dipole-dipole correlations contribute to the "ferroelectric-like" character of this amorphous system. The TeO2 -W03 glasses can only...shows the dielectric constant and Fig. I(b) glass from pure TeO2 ot pure WO. In addition, glass the tan 8 of the WO glass as a function of temperature... glasses containing WO, in various glass forming nitworks of LifO-B1O0, Na:O-BzO,, and TeO2 were prepared from reagent grade oxides at 800 C - 9SO C in

  18. Homogeneous weldings of copper

    Campurri, C.; Lopez, M.; Fernandez, R.; Osorio, V.

    1995-01-01

    This research explored the metallurgical and mechanical properties of arc welding of copper related with influence of Argon, Helium and mixtures of them. Copper plates of 6 mm thickness were welded with different mixtures of the mentioned gases. The radiography of welded specimens with 100% He and 100% Ar does not show show any porosity. On the other hand, the copper plates welded different gas mixtures presented uniform porosity in the welded zone. The metallographies show recrystallized grain in the heat affected zone, while the welding zone showed a dendritic structure. The results of the tensile strength vary between a maximum of 227 MPa for 100% He and a minimum of 174 MOa for the mixture of 60% He and 40% Ar. For the elongation after fracture the best values, about 36%, were obtained for pure gases. As a main conclusion, we can say that arc welding of copper is possible without loosing the mechanical and metallurgical properties of base metal. 6 refs

  19. Surface preparation for high purity alumina ceramics enabling direct brazing in hydrogen atmospheres

    Cadden, Charles H.; Yang, Nancy Yuan Chi; Hosking, Floyd M.

    2001-01-01

    The present invention relates to a method for preparing the surface of a high purity alumina ceramic or sapphire specimen that enables direct brazing in a hydrogen atmosphere using an active braze alloy. The present invention also relates to a method for directly brazing a high purity alumina ceramic or sapphire specimen to a ceramic or metal member using this method of surface preparation, and to articles produced by this brazing method. The presence of silicon, in the form of a SiO.sub.2 -containing surface layer, can more than double the tensile bond strength in alumina ceramic joints brazed in a hydrogen atmosphere using an active Au-16Ni-0.75 Mo-1.75V filler metal. A thin silicon coating applied by PVD processing can, after air firing, produce a semi-continuous coverage of the alumina surface with a SiO.sub.2 film. Room temperature tensile strength was found to be proportional to the fraction of air fired surface covered by silicon-containing films. Similarly, the ratio of substrate fracture versus interface separation was also related to the amount of surface silicon present prior to brazing. This process can replace the need to perform a "moly-manganese" metallization step.

  20. Brazed graphite/refractory metal composites for first-wall protection elements

    Šmid, I.; Croessmann, C. D.; Salmonson, J. C.; Whitley, J. B.; Kny, E.; Reheis, N.; Kneringer, G.; Nickel, H.

    1991-03-01

    The peak surface heat flux deposition on divertor elements of near term fusion devices is expected to exceed 10 MW/m 2. The needed reliability of brazed plasma interactive components, particularly under abnormal operating conditions with peak surface temperatures well beyond 1000°C, makes refractory metallic substrates and brazes with a high melting point very attractive. TZM, a high temperature alloy of molybdenum, and isotropic graphite, materials very closely matched in their thermal expansion, were brazed with four high-temperature brazes. The brazes used were Zr, 90Ni/10Ti, 90Cu/10Ti and 70Ag/27Cu/3Ti (nominal composition prior to brazing, wt%). The resulting composite tiles of 50 × 50 mm2 with a TZM thickness of 5 mm and a graphite thickness of 10 mm have been tested in high heat flux simulation for their thermal fatigue properties. Up to 600 loading cycles were carried out with an average heat flux of 10 MW/m 2 for 0.5 s pulses. The maximum surface temperature was 1100°C. In support of the experiment, the thermal response and temperature gradients of the samples were investigated using a finite element model.

  1. Experimental Investigation on High-Cycle Fatigue of Inconel 625 Superalloy Brazed Joints

    Chen, Jianqiang; Demers, Vincent; Turner, Daniel P.; Bocher, Philippe

    2018-04-01

    The high-cycle fatigue performance and crack growth pattern of transient liquid phase-brazed joints in a nickel-based superalloy Inconel 625 were studied. Assemblies with different geometries and types of overlaps were vacuum-brazed using the brazing paste Palnicro-36M in conditions such as to generate eutectic-free joints. This optimal microstructure provides the brazed assemblies with static mechanical strength corresponding to that of the base metal. However, eutectic micro-constituents were observed in the fillet region of the brazed assembly due to an incomplete isothermal solidification within this large volume of filler metal. The fatigue performance increased significantly with the overlap distance for single-lap joints, and the best performance was found for double-lap joints. It was demonstrated that these apparent changes in fatigue properties according to the specimen geometry can be rationalized when looking at the fatigue data as a function of the local stress state at the fillet radii. Fatigue cracks were nucleated from brittle eutectic phases located at the surface of the fillet region. Their propagation occurred through the bimodal microstructure of fillet and the diffusion region to reach the base metal. High levels of crack path tortuosity were observed, suggesting that the ductile phases found in the microstructure may act as a potential crack stopper. The fillet region must be considered as the critical region of a brazed assembly for fatigue applications.

  2. Brazed graphite/refractory metal composites for first-wall protection elements

    Smid, I.; Croessmann, C.D.; Salmonson, J.C.; Whitley, J.B.; Nickel, H.

    1991-01-01

    The peak surface heat flux deposition on divertor elements of near term fusion devices is expected to exceed 10 MW/m 2 . The needed reliability of brazed plasma interactive components, particularly under abnormal operating conditions with peak surface temperatures well beyond 1000deg C, makes refractory metallic substrates and brazes with a high melting point very attractive. TZM, a high temperature alloy of molybdenum, and isotropic graphite, materials very closely matched in their thermal expansion, were brazed with four high-temperature brazes. The brazes used were Zr, 90Ni/10Ti, 90Cu/10Ti and 70Ag/27Cu/3Ti (nominal composition prior to brazing, wt%). The resulting composite tiles of 50x50 mm 2 with a TZM thickness of 5 mm and a graphite thickness of 10 mm have been tested in high heat flux simulation for their thermal fatigue properties. Up to 600 loading cycles were carried out with an average heat flux of 10 MW/m 2 for 0.5 s pulses. The maximum surface temperature was 1100deg C. In support of the experiment, the thermal response and temperature gradients of the samples were investigated using a finite element model. (orig.)

  3. Brazed graphite/refractory metal composites for first-wall protection elements

    Smid, I.; Croessmann, C. D.; Salmonson, J. C.; Whitley, J. B.; Kny, E.; Reheis, N.; Kneringer, G.; Nickel, H.

    1995-01-01

    The peak surface heat flux deposition on divertor elements of near term fusion devices is expected to exceed 10 MW/m 2 . The needed reliability of brazed plasma interactive components, particularly under abnormal operating conditions with peak surface temperatures well beyond 1000 degree C, makes refractory metallic substrates and brazes with a high melting point very attractive. TZM, a high temperature alloy of molybdenum, and isotropic graphite, materials very closely matched in their thermal expansion, were brazed with four high-temperature brazes. The brazes used were Zr, 90Ni/10Ti, 90Cu/10Ti and 70Ag/27Cu/3Ti (nominal composition prior to brazing, wt%). The resulting composite tiles of 5O X 50 mm 2 with a TZM thickness of 5 mm and a graphite thickness of 10 mm have been tested in high heat flux simulation for their thermal fatigue properties. Up to 600 loading cycles were carried out with an average heat flux of 10 MW/m 2 for 0.5 s pulses. The maximum surface temperature was 1100 degree C. In support of the experiment, the thermal response and temperature gradients of the samples were investigated using a finite element model. (author)

  4. Brazed graphite/refractory metal composites for first wall protection elements

    Smid, I.; Croessmann, C. D.; Salmonson, J. C.; Whitley, J. B.; Kny, E.; Reheis, N; Kneringer, G.; Nickel, H.

    1995-01-01

    The peak surface heat flux deposition on divertor elements of near term fusion devices is expected to exceed 10 MW/m 2 . The needed reliability of brazed plasma interactive components, particularly under abnormal operating conditions with peak surface temperatures well beyond 1000 degree C, makes refractory metallic substrates and brazes with a high melting point very attractive. TZM, a high temperature alloy of molybdenum, and isotropic graphite, materials very closely matched in their thermal expansion, were brazed with four high-temperature brazes. The brazes used were Zr, 90Ni/10Ti, 90Cu/10Ti and 70Ag/27Cu/10Ti (nominal composition prior to brazing, wt%). The resulting composite tiles of 50 x 50 mm with a TZM thickness of 5 mm and a graphite thickness of 10 mm have been tested in high heat flux simulation for their thermal fatigue properties. Up to 600 loading cycles were carried out with the experimental parameters chosen to cover NET/ITER design specifications. In support of the experiment, the thermal response and temperature gradients of the samples were investigated using a finite element model. (author)

  5. Manufacturing and testing in reactor relevant conditions of brazed plasma facing components of the ITER divertor

    Bisio, M.; Branca, V.; Marco, M. Di; Federici, A.; Grattarola, M.; Gualco, G.; Guarnone, P.; Luconi, U.; Merola, M.; Ozzano, C.; Pasquale, G.; Poggi, P.; Rizzo, S.; Varone, F.

    2005-01-01

    A fabrication route based on brazing technology has been developed for the realization of the high heat flux components for the ITER vertical target and Dome-Liner. The divertor vertical target is armoured with carbon fiber reinforced carbon and tungsten in the lower straight part and in the upper curved part, respectively. The armour material is joined to heat sinks made of precipitation hardened copper-chromium-zirconium alloy. The plasma facing units of the dome component are based on a tungsten flat tile design with hypervapotron cooling. An innovative brazing technique based on the addition of carbon fibers to the active brazing alloy, developed by Ansaldo Ricerche for applications in the field of the energy production, has been used for the carbon fiber composite to copper joint to reduce residual stresses. The tungsten-copper joint has been realized by direct casting. A proper brazing thermal cycle has been studied to guarantee the required mechanical properties of the precipitation hardened alloy after brazing. The fabrication route of plasma facing components for the ITER vertical target and dome based on the brazing technology has been proved by means of thermal fatigue tests performed on mock-ups in reactor relevant conditions

  6. Improving contour accuracy and strength of reactive air brazed (RAB) ceramic/metal joints by controlling interface microstructure

    Li, Chichi; Kuhn, Bernd; Brandenberg, Joerg; Beck, Tilmann; Singheiser, Lorenz [Forschungszentrum Juelich GmbH, Institute for Energy and Climate Research (IEK), Microstructure and Properties of Materials (IEK-2), 52425 Juelich (Germany); Bobzin, Kirsten; Bagcivan, Nazlim; Kopp, Nils [Surface Engineering Institute (IOT), RWTH Aachen University, Kackertstr. 15, 52072 Aachen (Germany)

    2012-06-15

    The development of high-temperature electrochemical devices such as solid oxide fuel cells, oxygen, and hydrogen separators and gas reformers poses a great challenge in brazing technology of metal/ceramic joints. To maintain the integrity of such equipment, the resulting seals have to be stable and hermetic during continuous and cyclic high temperature operation. As a solution for joining metal and ceramic materials, reactive air brazing has gained increasing interest in recent years. This paper compares joints brazed by different filler alloys: pure Ag, AgCu, and AgAl in three different aspects: contour accuracy, room temperature delamination resistance, and corresponding microstructures of the as-brazed and fractured brazed joints. Discussion focuses on fracture mechanism and associated delamination resistance. AgAl brazed joints exhibit the most promising mechanical properties and contour accuracy. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  7. Braze alloy process and strength characterization studies for 18 nickel grade 200 maraging steel with application to wind tunnel models

    Bradshaw, James F.; Sandefur, Paul G., Jr.; Young, Clarence P., Jr.

    1991-01-01

    A comprehensive study of braze alloy selection process and strength characterization with application to wind tunnel models is presented. The applications for this study include the installation of stainless steel pressure tubing in model airfoil sections make of 18 Ni 200 grade maraging steel and the joining of wing structural components by brazing. Acceptable braze alloys for these applications are identified along with process, thermal braze cycle data, and thermal management procedures. Shear specimens are used to evaluate comparative shear strength properties for the various alloys at both room and cryogenic (-300 F) temperatures and include the effects of electroless nickel plating. Nickel plating was found to significantly enhance both the wetability and strength properties for the various braze alloys studied. The data are provided for use in selecting braze alloys for use with 18 Ni grade 200 steel in the design of wind tunnel models to be tested in an ambient or cryogenic environment.

  8. Development of a high power electron beam welding gun with replaceable high voltage feed-through insulators

    Saha, T.K; Mascarenhas, M.; Kandaswamy, E., E-mail: tanmay@barc.gov.in [Power Beam Equipment Design Section, Bhabha Atomic Research Centre, Mumbai (India)

    2014-07-01

    Ceramic to metal sealed feed-through insulators are commonly used in electron beam welding gun. The above feed-through insulators are susceptible to failure, as the brazing joints in them are not always very strong. Failure in one of these feed-through could render the complete gun unusable. This problem has already been faced in BARC, which led to the development of the electron gun with replaceable feed through insulators. A 24 kW Electron Beam Welding (EBW) gun with indigenous designed replaceable insulators is fabricated in BARC. Emphasis during the design of the gun had been to reduce the use of imported components to zero. This paper describes the design and fabrication of this gun and reports various simulations and tests performed. Beam trajectory of the gun is numerically computed and presented. Weld passes were carried out on stainless steel plates show satisfactory penetrations. (author)

  9. Effects of brazing temperature on microstructure and mechanical performance of Al{sub 2}O{sub 3}/AgCuTi/Fe–Ni–Co brazed joints

    Cao, Yongtong; Yan, Jiazhen, E-mail: yanjiazhen@scu.edu.cn; Li, Ning; Zheng, Yi; Xin, Chenglai

    2015-11-25

    Al{sub 2}O{sub 3}/Fe–Ni–Co joints are achieved using Ag–Cu–8Ti filler alloy, and the dependence of the joint microstructure and mechanical performance on the brazing temperature has been studied by means of SEM, EDS, XRD and tensile test. The results show that the brazing seam is composed of TiO, Ti{sub 3}Al, Ag (s, s), Cu (s, s), (Cu, Ni) and Ni{sub 4}Ti{sub 3} phases. A layer of Ti{sub 3}Al and TiO products is observed at the Al{sub 2}O{sub 3}/AgCuTi interface and the fracture testing indicates that the thickness of the reaction layer plays a critical role in the joint strength. The joint strength firstly increases and then declines with the thickness of the (Ti{sub 3}Al + TiO) layer increasing, and the formation of the cracks is ascribed to the existence of Ti{sub 3}Al phase. The thermokinetic analysis for the interfacial reaction between Al{sub 2}O{sub 3} and AgCuTi show that the Gibbs free energy equals −88.939 kJ/mol for forming Ti{sub 3}Al and TiO phases, and the growth rate of the reaction layer mainly depends on the diffusion rate of Ti across the formed reaction layer. Meanwhile, the quantitative relationship among brazing temperature, holding time and reaction layer thickness has been established. - Graphical abstract: The theoretical curve of brazing time and thickness is close proximity to the measured values, which means the extracted mathematical relationship (X = 2.2616 × 10{sup −1} exp (−143.85 × 10{sup 3}/8.314 T) × t{sup 0.5}) relatively closed to the actual situation. The growth rate of reaction layer declines with the increase of brazing time, and this phenomenon indicates that the diffusion rate of Ti atoms across the reaction layer is less than the rate of the chemical reaction during brazing, that is, the growth rate of reaction layer mainly depends on the diffusion rate of Ti atoms across the formed reaction layer. - Highlights: • The dependence of seam microstructure on brazing temperature is discussed. • Thermokinetic

  10. Microstructure and Mechanical Property of 3003 Aluminum Alloy Joint Brazed with Al-Si-Cu-Zn Filler Metal

    LI Xiao-qiang

    2016-09-01

    Full Text Available Al-Si-Cu-Zn filler metal was developed to braze 3003 aluminum alloy. The microstructure and fracture surface of the joint were analyzed by XRD, SEM and EDS, and the effects of brazing temperature on microstructure and property of the joint were investigated. The results show that good joints are obtained at brazing temperature of 540-580℃ for 10min. The brazed joint consists of α(Al solid solution, θ(Al2Cu intermetallic compound, fine silicon phase and AlCuFeMn+Si phase in the central zone of brazed seam, and α(Al solid solution and element diffusion layers at both the sides of brazed seam, and the base metal. The room temperature (RT shear fracture of the joint occurs at the interface between the teeth shape α(Al in the diffusion layer and the center zone of brazed seam, which is mainly characterized as brittle cleavage. As the brazing temperature increases, α(Al solid solution crystals in the diffusion zone grow up, and the interfacial bonding of the joint is in the form of interdigitation. Brazing at 560℃ for 10min, the RT shear strength of the joint reaches the maximum value of 92.3MPa, which is about 62.7% of the base material.

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

    Paiva, O.C.; Barbosa, M.A.

    2008-01-01

    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 μA cm -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 μA cm -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 brazed interface seem to

  12. Experimental and Simulative Investigation of Laser Transmission Welding under Consideration of Scattering

    Devrient, M.; Da, X.; Frick, T.; Schmidt, M.

    Laser transmission welding is a well known joining technology for thermoplastics. Because of the needs of lightweight, cost effective and green production thermoplastics are usually filled with glass fibers. These lead to higher absorption and more scattering within the upper joining partner with a negative influence on the welding process. Here an experimental method for the characterization of the scattering behavior of semi crystalline thermoplastics filled with short glass fibers and a finite element model of the welding process capable to consider scattering as well as an analytical model are introduced. The experimental data is used for the numerical and analytical investigation of laser transmission welding under consideration of scattering. The scattering effects of several thermoplastics onto the calculated temperature fields as well as weld seam geometries are quantified.

  13. Microstructure and Tensile Behavior of Laser Arc Hybrid Welded Dissimilar Al and Ti Alloys

    Ming Gao

    2014-02-01

    Full Text Available Fiber laser-cold metal transfer arc hybrid welding was developed to welding-braze dissimilar Al and Ti alloys in butt configuration. Microstructure, interface properties, tensile behavior, and their relationships were investigated in detail. The results show the cross-weld tensile strength of the joints is up to 213 MPa, 95.5% of same Al weld. The optimal range of heat input for accepted joints was obtained as 83–98 J·mm−1. Within this range, the joint is stronger than 200 MPa and fractures in weld metal, or else, it becomes weaker and fractures at the intermetallic compounds (IMCs layer. The IMCs layer of an accepted joint is usually thin and continuous, which is about 1μm-thick and only consists of TiAl2 due to fast solidification rate. However, the IMCs layer at the top corner of fusion zone/Ti substrate is easily thickened with increasing heat input. This thickened IMCs layer consists of a wide TiAl3 layer close to FZ and a thin TiAl2 layer close to Ti substrate. Furthermore, both bead shape formation and interface growth were discussed by laser-arc interaction and melt flow. Tensile behavior was summarized by interface properties.

  14. Multi-Scale Computational Modeling of Ni-Base Superalloy Brazed Joints for Gas Turbine Applications

    Riggs, Bryan

    Brazed joints are commonly used in the manufacture and repair of aerospace components including high temperature gas turbine components made of Ni-base superalloys. For such critical applications, it is becoming increasingly important to account for the mechanical strength and reliability of the brazed joint. However, material properties of brazed joints are not readily available and methods for evaluating joint strength such as those listed in AWS C3.2 have inherent challenges compared with testing bulk materials. In addition, joint strength can be strongly influenced by the degree of interaction between the filler metal (FM) and the base metal (BM), the joint design, and presence of flaws or defects. As a result, there is interest in the development of a multi-scale computational model to predict the overall mechanical behavior and fitness-for-service of brazed joints. Therefore, the aim of this investigation was to generate data and methodology to support such a model for Ni-base superalloy brazed joints with conventional Ni-Cr-B based FMs. Based on a review of the technical literature a multi-scale modeling approach was proposed to predict the overall performance of brazed joints by relating mechanical properties to the brazed joint microstructure. This approach incorporates metallurgical characterization, thermodynamic/kinetic simulations, mechanical testing, fracture mechanics and finite element analysis (FEA) modeling to estimate joint properties based on the initial BM/FM composition and brazing process parameters. Experimental work was carried out in each of these areas to validate the multi-scale approach and develop improved techniques for quantifying brazed joint properties. Two Ni-base superalloys often used in gas turbine applications, Inconel 718 and CMSX-4, were selected for study and vacuum furnace brazed using two common FMs, BNi-2 and BNi-9. Metallurgical characterization of these brazed joints showed two primary microstructural regions; a soft

  15. Welding skate with computerized controls

    Wall, W. A., Jr.

    1968-01-01

    New welding skate concept for automatic TIG welding of contoured or double-contoured parts combines lightweight welding apparatus with electrical circuitry which computes the desired torch angle and positions a torch and cold-wire guide angle manipulator.

  16. Tensile Creep Properties of the 50Au-50Cu Braze Alloy

    Stephens, J.J.

    1999-01-01

    The 50Au-50CU (wt.%) alloy is a solid-solution strengthened braze alloy used extensively in conventional, hermetic metal/ceramic brazing applications where low vapor pressure is a requirement. Typical metal/ceramic base materials would be Kovar TM alloy and metallized and Ni-plated 94% alumina ceramic. The elevated temperature mechanical properties are important for permitting FEA evaluation of residual stresses in metal/ceramic brazes given specific geometries and braze cooldown profiles. For material with an atomic composition of 76.084 at.% CL 23.916 Au (i.e., on the Cu-rich side of Cu 3 Au) that was annealed for 2 hr. at 750 ampersand deg;C and water quenched a Garofalo sinh equation was found to adequately characterize the minimum strain rate data over the temperature mnge 450-850 ampersand deg;C. At lower temperatures (250 arid 350 ampersand deg;C), a conventional power law equation was found to characterize the data. For samples held long periods of time at 375 ampersand deg;C (96 hrs.) and slowly cooled to room temperature, a slight strengthening reaction was observed: with the stress necessary to reach the same strain rate increasing by about 15% above the baseline annealed and quenched data. X-ray diffiction indicates that the 96 hr at 375 ampersand deg;C + slow cool condition does indeed order. The microhardness of the ordered samples indicates a value of 94.5 VHN, compared to 93.7 VHN for the baseline annealed and quenched (disordered FCC) samples. From a brazing perspective, the relative sluggishness of this ordering reaction does not appear to pose a problem for braze joints cooled at reasonable rates following brazing

  17. Challenges to Resistance Welding

    Song, Quanfeng

    This report originates from the compulsory defense during my Ph.D. study at the Technical University of Denmark. Resistance welding is an old and well-proven technology. Yet the emergence of more and more new materials, new designs, invention off new joining techniques, and more stringent...... requirement in quality have imposed challenges to the resistance welding. More some research and development have to be done to adapt the old technology to the manufacturing industry of the 21st century. In the 1st part of the report, the challenging factors to the resistance welding are reviewed. Numerical...... simulation of resistance welding has been under development for many years. Yet it is no easy to make simulation results reliable and accurate because of the complexity of resistance welding process. In the 2nd part of the report numerical modeling of resistance welding is reviewed, some critical factors...

  18. Ultrasonic Stir Welding

    Nabors, Sammy

    2015-01-01

    NASA Marshall Space Flight Center (MSFC) developed Ultrasonic Stir Welding (USW) to join large pieces of very high-strength metals such as titanium and Inconel. USW, a solid-state weld process, improves current thermal stir welding processes by adding high-power ultrasonic (HPU) energy at 20 kHz frequency. The addition of ultrasonic energy significantly reduces axial, frictional, and shear forces; increases travel rates; and reduces wear on the stir rod, which results in extended stir rod life. The USW process decouples the heating, stirring, and forging elements found in the friction stir welding process allowing for independent control of each process element and, ultimately, greater process control and repeatability. Because of the independent control of USW process elements, closed-loop temperature control can be integrated into the system so that a constant weld nugget temperature can be maintained during welding.

  19. Automatization of welding

    Iwabuchi, Masashi; Tomita, Jinji; Nishihara, Katsunori.

    1978-01-01

    Automatization of welding is one of the effective measures for securing high degree of quality of nuclear power equipment, as well as for correspondence to the environment at the site of plant. As the latest ones of the automatic welders practically used for welding of nuclear power apparatuses in factories of Toshiba and IHI, those for pipes and lining tanks are described here. The pipe welder performs the battering welding on the inside of pipe end as the so-called IGSCC countermeasure and the succeeding butt welding through the same controller. The lining tank welder is able to perform simultaneous welding of two parallel weld lines on a large thin plate lining tank. Both types of the welders are demonstrating excellent performance at the shops as well as at the plant site. (author)

  20. Dual wire welding torch and method

    Diez, Fernando Martinez; Stump, Kevin S.; Ludewig, Howard W.; Kilty, Alan L.; Robinson, Matthew M.; Egland, Keith M.

    2009-04-28

    A welding torch includes a nozzle with a first welding wire guide configured to orient a first welding wire in a first welding wire orientation, and a second welding wire guide configured to orient a second welding wire in a second welding wire orientation that is non-coplanar and divergent with respect to the first welding wire orientation. A method of welding includes moving a welding torch with respect to a workpiece joint to be welded. During moving the welding torch, a first welding wire is fed through a first welding wire guide defining a first welding wire orientation and a second welding wire is fed through a second welding wire guide defining a second welding wire orientation that is divergent and non-coplanar with respect to the first welding wire orientation.

  1. Glass consistency and glass performance

    Plodinec, M.J.; Ramsey, W.G.

    1994-01-01

    Glass produced by the Defense Waste Processing Facility (DWPF) will have to consistently be more durable than a benchmark glass (evaluated using a short-term leach test), with high confidence. The DWPF has developed a Glass Product Control Program to comply with this specification. However, it is not clear what relevance product consistency has on long-term glass performance. In this report, the authors show that DWPF glass, produced in compliance with this specification, can be expected to effectively limit the release of soluble radionuclides to natural environments. However, the release of insoluble radionuclides to the environment will be limited by their solubility, and not glass durability

  2. Electric arc welding gun

    Luttrell, Edward; Turner, Paul W.

    1978-01-01

    This invention relates to improved apparatus for arc welding an interior joint formed by intersecting tubular members. As an example, the invention is well suited for applications where many similar small-diameter vertical lines are to be welded to a long horizontal header. The improved apparatus includes an arc welding gun having a specially designed welding head which is not only very compact but also produces welds that are essentially free from rolled-over solidified metal. The welding head consists of the upper end of the barrel and a reversely extending electrode holder, or tip, which defines an acute angle with the barrel. As used in the above-mentioned example, the gun is positioned to extend upwardly through the vertical member and the joint to be welded, with its welding head disposed within the horizontal header. Depending on the design of the welding head, the barrel then is either rotated or revolved about the axis of the vertical member to cause the electrode to track the joint.

  3. Electron beam welding

    Schwartz, M.M.

    1974-01-01

    Electron-beam equipment is considered along with fixed and mobile electron-beam guns, questions of weld environment, medium and nonvacuum welding, weld-joint designs, tooling, the economics of electron-beam job shops, aspects of safety, quality assurance, and repair. The application of the process in the case of individual materials is discussed, giving attention to aluminum, beryllium, copper, niobium, magnesium, molybdenum, tantalum, titanium, metal alloys, superalloys, and various types of steel. Mechanical-property test results are examined along with the areas of application of electron-beam welding

  4. Robot welding process control

    Romine, Peter L.

    1991-01-01

    This final report documents the development and installation of software and hardware for Robotic Welding Process Control. Primary emphasis is on serial communications between the CYRO 750 robotic welder, Heurikon minicomputer running Hunter & Ready VRTX, and an IBM PC/AT, for offline programming and control and closed-loop welding control. The requirements for completion of the implementation of the Rocketdyne weld tracking control are discussed. The procedure for downloading programs from the Intergraph, over the network, is discussed. Conclusions are made on the results of this task, and recommendations are made for efficient implementation of communications, weld process control development, and advanced process control procedures using the Heurikon.

  5. Use of servo controlled weld head for end closure welding

    Pathak, S.K.; Setty, D.S.; Rameswara Rao, A.; Hemantha Rao, G.V.S.; Jayaraj, R.N. [Nuclear Fuel Complex, Dept. of Atomic Energy, Hyderabad (India)

    2010-07-01

    In the PHWR fuel fabrication line resistance welding processes are used for joining various zirconium based alloy components to fuel tube of similar material. The quality requirement of these welding processes is very stringent and has to meet all the product requirements. At present these welding processes are being carried out by using standard resistance welding machines. In the resistance welding process in addition to current and time, force is one of the critical and important parameter, which influences the weld quality. At present advanced feed back type fast response medium frequency weld controllers are being used. This has upslope/down slope, constant and repetitive weld pattern selection features makes this critical welding process more reliable. Compared to weld controllers, squeeze force application devices are limited and normally standard high response pneumatic cylinders are used in the welding process. With this type of devices the force is constant during welding process and cannot be varied during welding process as per the material deformation characteristics. Similarly due to non-availability of feed back systems in the squeeze force application systems restricts the accuracy and quality of the welding process. In the present paper the influence of squeeze force pattern on the weld quality using advanced feed back type servo based force control system was studied. Different squeeze forces were used during pre and post weld heat periods along with constant force and compared with the weld quality. (author)

  6. Microstructure and properties of nickel base superalloy joints brazed with Ni-Cr-Co-B and BNi-1a filler metals

    Zhuang, H. [Beijing Univ. of Aeronautics and Astronautics (China); Liu, W. [Dalian Railway Inst. (China). Welding Div.

    1995-12-31

    In this study, the kind and compositions of brittle phases formed in joints of a nickel-base superalloy brazed with the Ni-Cr-Co-B and BNi-1a (Ni-Cr-B-Si) filler metals were investigated. Their brittle-phase-free maximum brazing clearances (MBC) were characterized in dependence on the brazing conditions. The improvement on joint structures by post-braze heat treatment was also examined. (orig./MM)

  7. Colloidal glasses

    First page Back Continue Last page Overview Graphics. Colloidal glasses. Glassy state is attained when system fails to reach equilibrium due to crowding of constituent particles. In molecular glasses, glassy state is reached by rapidly lowering the temperature. In colloidal glasses, glassy state is reached by increasing the ...

  8. Characterization of crystallization kinetics of a Ni- (Cr, Fe, Si, B, C, P) based amorphous brazing alloy by non-isothermal differential scanning calorimetry

    Raju, S.; Kumar, N.S. Arun; Jeyaganesh, B.; Mohandas, E.; Mudali, U. Kamachi

    2007-01-01

    The thermal stability and crystallization kinetics of a Ni- (Cr, Si, Fe, B, C, P) based amorphous brazing foil have been investigated by non-isothermal differential scanning calorimetry. The glass transition temperature T g , is found to be 720 ± 2 K. The amorphous alloy showed three distinct, yet considerably overlapping crystallization transformations with peak crystallization temperatures centered around 739, 778 and 853 ± 2 K, respectively. The solidus and liquidus temperatures are estimated to be 1250 and 1300 ± 2 K, respectively. The apparent activation energies for the three crystallization reactions have been determined using model free isoconversional methods. The typical values for the three crystallization reactions are: 334, 433 and 468 kJ mol -1 , respectively. The X-ray diffraction of the crystallized foil revealed the presence of following compounds Ni 3 B (Ni 4 B 3 ), CrB, B 2 Fe 15 Si 3 , CrSi 2 , and Ni 4.5 Si 2 B

  9. Wide gap active brazing of ceramic-to-metal-joints for high temperature applications

    Bobzin, K.; Zhao, L.; Kopp, N.; Samadian Anavar, S.

    2014-03-01

    Applications like solid oxide fuel cells and sensors increasingly demand the possibility to braze ceramics to metals with a good resistance to high temperatures and oxidative atmospheres. Commonly used silver based active filler metals cannot fulfill these requirements, if application temperatures higher than 600°C occur. Au and Pd based active fillers are too expensive for many fields of use. As one possible solution nickel based active fillers were developed. Due to the high brazing temperatures and the low ductility of nickel based filler metals, the modification of standard nickel based filler metals were necessary to meet the requirements of above mentioned applications. To reduce thermally induced stresses wide brazing gaps and the addition of Al2O3 and WC particles to the filler metal were applied. In this study, the microstructure of the brazed joints and the thermo-chemical reactions between filler metal, active elements and WC particles were analyzed to understand the mechanism of the so called wide gap active brazing process. With regard to the behavior in typical application oxidation and thermal cycle tests were conducted as well as tensile tests.

  10. Study of an induction brazing process for the instrumentation feed through part

    Hong, Jintae; Ahn, Sung Ho; Joung, Chang Young; Kim, Ka Hye; Heo, Sung Ho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-10-15

    In general, brazing is used to seal out the feed through part of thin wires, and several studies in nuclear fields used brazing as a sealing method. However, previous techniques using a manual torch or an induction brazing by blowing Ar gas as a shield gas cannot avoid soot, which is difficult to remove. In addition, because their brazing quality is not uniform, instrumentation cables cannot deliver signals due to damage of excessive heat. In this study, an automatically controlled induction brazing system has been developed including a vacuum chamber to prevent generation of soot. A loop is a facility to carry out irradiation test for nuclear fuels and materials in a research reactor by measuring the irradiation behavior of them in a timely manner. Because flow condition of coolant in a loop should be the same with that of NPPs', highly pressurized (15.5 MPa) and highly heated (300 .deg. C) coolant is circulated through the loop. Therefore, sealing of the pressure boundary is one of the most important processes in fabricating the in-pile test section (IPS). In particular, sensors such as thermocouples, LVDTs and SPNDs are attached in a test rig and deliver signals to the measuring device at the outside of the reactor pool through instrumentation cables, which pass through the pressure boundary of the test rig. Therefore, it needs to seal out the instrumentation feed through part to not leak the coolant.

  11. Springback of aluminum alloy brazing sheet in warm forming

    Han, Kyu Bin; George, Ryan; Kurukuri, Srihari; Worswick, Michael J.; Winkler, Sooky

    2017-10-01

    The use of aluminum is increasing in the automotive industry due to its high strength-to-weight ratio, recyclability and corrosion resistance. However, aluminum is prone to significant springback due to its low elastic modulus coupled with its high strength. In this paper, a warm forming process is studied to improve the springback characteristics of 0.2 mm thick brazing sheet with an AA3003 core and AA4045 clad. Warm forming decreases springback by lowering the flow stress. The parts formed have complex features and geometries that are representative of automotive heat exchangers. The key objective is to utilize warm forming to control the springback to improve the part flatness which enables the use of harder temper material with improved strength. The experiments are performed by using heated dies at several different temperatures up to 350 °C and the blanks are pre-heated in the dies. The measured springback showed a reduction in curvature and improved flatness after forming at higher temperatures, particularly for the harder temper material conditions.

  12. Elemental analysis of brazing alloy samples by neutron activation technique

    Eissa, E.A.; Rofail, N.B.; Hassan, A.M.; El-Shershaby, A.; Walley El-Dine, N.

    1996-01-01

    Two brazing alloy samples (C P 2 and C P 3 ) have been investigated by Neutron activation analysis (NAA) technique in order to identify and estimate their constituent elements. The pneumatic irradiation rabbit system (PIRS), installed at the first egyptian research reactor (ETRR-1) was used for short-time irradiation (30 s) with a thermal neutron flux of 1.6 x 10 1 1 n/cm 2 /s in the reactor reflector, where the thermal to epithermal neutron flux ratio is 106. Long-time irradiation (48 hours) was performed at reactor core periphery with thermal neutron flux of 3.34 x 10 1 2 n/cm 2 /s, and thermal to epithermal neutron flux ratio of 79. Activation by epithermal neutrons was taken into account for the (1/v) and resonance neutron absorption in both methods. A hyper pure germanium detection system was used for gamma-ray acquisitions. The concentration values of Al, Cr, Fe, Co, Cu, Zn, Se, Ag and Sb were estimated as percentages of the sample weight and compared with reported values. 1 tab

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

    Anwar, S.M.; Aly, M.M.

    2002-01-01

    Cadmium (CD) is considered a metal of the 20 th 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 beta 2 - 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 /m 3 ). (1) This study demonstrated elevation levels of blood CD, urea, creatinine and urinary CD and beta 2 -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

  14. Elemental analysis of brazing alloy samples by neutron activation technique

    Eissa, E A; Rofail, N B; Hassan, A M [Reactor and Neutron physics Department, Nuclear Research Centre, Atomic Energy Authority, Cairo (Egypt); El-Shershaby, A; Walley El-Dine, N [Physics Department, Faculty of Girls, Ain Shams Universty, Cairo (Egypt)

    1997-12-31

    Two brazing alloy samples (C P{sup 2} and C P{sup 3}) have been investigated by Neutron activation analysis (NAA) technique in order to identify and estimate their constituent elements. The pneumatic irradiation rabbit system (PIRS), installed at the first egyptian research reactor (ETRR-1) was used for short-time irradiation (30 s) with a thermal neutron flux of 1.6 x 10{sup 1}1 n/cm{sup 2}/s in the reactor reflector, where the thermal to epithermal neutron flux ratio is 106. Long-time irradiation (48 hours) was performed at reactor core periphery with thermal neutron flux of 3.34 x 10{sup 1}2 n/cm{sup 2}/s, and thermal to epithermal neutron flux ratio of 79. Activation by epithermal neutrons was taken into account for the (1/v) and resonance neutron absorption in both methods. A hyper pure germanium detection system was used for gamma-ray acquisitions. The concentration values of Al, Cr, Fe, Co, Cu, Zn, Se, Ag and Sb were estimated as percentages of the sample weight and compared with reported values. 1 tab.

  15. Silicate glasses

    Lutze, W.

    1988-01-01

    Vitrification of liquid high-level radioactive wastes has received the greatest attention, world-wide, compared to any other HLW solidification process. The waste form is a borosilicate-based glass. The production of phosphate-based glass has been abandoned in the western world. Only in the Soviet Union are phosphate-based glasses still being developed. Vitrification techniques, equipment and processes and their remote operation have been developed and studied for almost thirty years and have reached a high degree of technical maturity. Industrial demonstration of the vitrification process has been in progress since 1978. This chapter is a survey of world-wide research and development efforts in nuclear waste glasses and its production technology. The principal glasses considered are silicate glasses which contain boron, i.e., borosilicate glasses

  16. Measuring weld heat to evaluate weld integrity

    Schauder, V., E-mail: schauder@hks-prozesstechnik.de [HKS-Prozesstechnik GmbH, Halle (Germany)

    2015-11-15

    Eddy current and ultrasonic testing are suitable for tube and pipe mills and have been used for weld seam flaw detection for decades, but a new process, thermography, is an alternative. By measuring the heat signature of the weld seam as it cools, it provides information about weld integrity at and below the surface. The thermal processes used to join metals, such as plasma, induction, laser, and gas tungsten arc welding (GTAW), have improved since they were developed, and they get better with each passing year. However, no industrial process is perfect, so companies that conduct research in flaw detection likewise continue to develop and improve the technologies used to verify weld integrity: ultrasonic testing (UT), eddy current testing (ET), hydrostatic, X-ray, magnetic particle, and liquid penetrant are among the most common. Two of these are used for verifying the integrity of the continuous welds such as those used on pipe and tube mills: UT and ET. Each uses a transmitter to send waves of ultrasonic energy or electrical current through the material and a receiver (probe) to detect disturbances in the flow. The two processes often are combined to capitalize on the strengths of each. While ET is good at detecting flaws at or near the surface, UT penetrates the material, detecting subsurface flaws. One drawback is that sound waves and electrical current waves have a specific direction of travel, or an alignment. A linear defect that runs parallel to the direction of travel of the ultrasonic sound wave or a flaw that is parallel to the coil winding direction of the ET probe can go undetected. A second drawback is that they don't detect cold welds. An alternative process, thermography, works in a different fashion: It monitors the heat of the material as the weld cools. Although it measures the heat at the surface, the heat signature provides clues about cooling activity deep in the material, resulting in a thorough assessment of the weld's integrity It

  17. TIG welding method and TIG welding device

    Yoneda, Eishi

    1998-01-01

    The present invention provides a method of TIG welding for members having different heat capacities including a cladding tube and an end plug of a fuel rod to be used, for example, in a reactor, and a device therefor. Namely, in the TIG welding method, the flow rate of a sealed gas to the side of a member having smaller heat capacity is made greater than that on the side of the member having greater heat capacity bordered on the top end of a welding electrode. Since the sealed gas is jetted being localized relative to the welding electrode, arc is restricted in a region of the member having smaller heat capacity and is increased at a region having a larger heat capacity. As a result, the arc is localized, so that the heat input amount to the region having a large heat capacity is increased, and then a plurality of members at the abutting portion are melted uniformly thereby capable of obtaining a uniform molten pool. A bead is formed at the abutting portion thereby capable of obtaining a welded portion with less unevenness and having large strength. (I.S.)

  18. Explosion metal welding

    Popoff, A.A.

    1976-01-01

    Process parameters pertaining to welding similar and dissimilar metals using explosives are reviewed. The discussion centers on the interrelationship of physical parameters which play a part in achieving desirable metallurgical results. Present activities in explosion metal welding at LASL are presented and shown how they related to the interests of the ERDA community

  19. Electron beam welding

    Gabbay, M.

    1972-01-01

    The bead characteristics and the possible mechanisms of the electron beam penetration are presented. The different welding techniques are exposed and the main parts of an electron beam welding equipment are described. Some applications to nuclear, spatial and other industries are cited [fr

  20. Influence of liquid copper-silver brazing alloy on properties of high-strength and heat resistant alloys and steels

    Semenov, V.N.

    1999-01-01

    The influence of temperature, heating rate, microstructure, the duration of Cu-Ag melt attack during brazing, the thickness and the material of barrier coating on properties of materials (Ni-Cr alloys, Cr-Ni steals, a Fe-Ni base EhJ-702 alloy) being brazed is studied. The tests of specimens with a brazing alloy are carried out in the temperature range of 780-1000 deg C. It is revealed that heat resistant alloys under brazing conditions experience brittle fracture. Multiphase structure coarse grain, increased hydrogen content mechanical stress concentrators are found to intensity embrittlement of the materials. The use of barrier coating displaying a chemical affinity to the brazing alloy results in a decrease of the tendency to embrittlement

  1. Welding problems in nuclear power engineering

    Zubchenko, A.S.

    1986-01-01

    The problems of welding industry in nuclear power plant engineering, mainly related to the improvement of molten bath protection, are considered. Development of new materials for welding electrodes, for cladding and welding fluxes, is pointed out. Production of the following equipment is brought to a commercial level: welding heads and welding machines for branch pipe welding, anticorrosion cladding, zonal thermal treatment, electron beam welding facilities for the welding and maintenance of turbineblades, equipment for nondestructive testing of welded joints

  2. Vacuum brazing of high volume fraction SiC particles reinforced aluminum matrix composites

    Cheng, Dongfeng; Niu, Jitai; Gao, Zeng; Wang, Peng

    2015-03-01

    This experiment chooses A356 aluminum matrix composites containing 55% SiC particle reinforcing phase as the parent metal and Al-Si-Cu-Zn-Ni alloy metal as the filler metal. The brazing process is carried out in vacuum brazing furnace at the temperature of 550°C and 560°C for 3 min, respectively. The interfacial microstructures and fracture surfaces are investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy spectrum analysis (EDS). The result shows that adequacy of element diffusion are superior when brazing at 560°C, because of higher activity and liquidity. Dislocations and twins are observed at the interface between filler and composite due to the different expansion coefficient of the aluminum alloy matrix and SiC particles. The fracture analysis shows that the brittle fracture mainly located at interface of filler and composites.

  3. Brazing and machining of carbon based materials for plasma facing components

    Brossa, M.; Guerreschi, U.; Rossi, M.

    1994-01-01

    Carbon based materials in the recent years have often been considered and used as armour material in plasma facing components for several fusion devices, because of their low Z and good high temperature characteristics that are compatible with the operation of nuclear reactors. These materials are often connected (mechanically or by brazing) to metals, that allow the support and the cooling functions (heat sink materials). In the following the experience of Ansaldo Ricerche about the study and the manufacturing of plasma facing components and mockups is described with reference to the influence of the carbon materials in performing brazing junction with metals. It is interesting to observe how the different characteristics of the carbon materials influence the brazing process. ((orig.))

  4. Surface development of a brazing alloy during heat treatment-a comparison between UHV and APXPS

    Rullik, L.; Johansson, N.; Bertram, F.; Evertsson, J.; Stenqvist, T.; Lundgren, E.

    2018-01-01

    In an attempt to bridge the pressure gap, APXPS was used to follow the surface development of an aluminum brazing sheet during heating in an ambient oxygen-pressure mimicking the environment of an industrial brazing furnace. The studied aluminum alloy brazing sheet is a composite material consisting of two aluminum alloy standards whose surface is covered with a native aluminum oxide film. To emphasize the necessity of studies of this system in ambient sample environments it is compared to measurements in UHV. Changes in thickness and composition of the surface oxide were followed after heating to 300 °C, 400 °C, and 500 °C. The two sets presented in this paper show that the surface development strongly depends on the environment the sample is heated in.

  5. Experimental and thermodynamic studies of beryllium replacement materials for CANDU brazed joints

    Potter, K.N.; Ferrier, G.A.; Corcoran, E.C., E-mail: Kieran.Potter@rmc.ca [Royal Military College of Canada, Kingston, ON (Canada)

    2015-07-01

    Currently, appendages are joined to CANDU fuel elements via a brazing process, which uses beryllium as the filler material. A potential reduction in the occupational limit on airborne beryllium particulates has motivated research into alternative brazing materials. To this end, the Canadian nuclear industry has funded an initiative to identify and evaluate the suitability of several candidate materials. This work describes contributions toward the assessment of alternative brazing materials from the Royal Military College of Canada. Thermodynamic modelling was performed to predict the aqueous behaviour of each candidate material in CANDU coolant conditions characteristic of reactor shutdown, and experiments are underway to support modelling predictions. These results will assist in selecting a suitable replacement material for beryllium. (author)

  6. Method for welding beryllium

    Dixon, R.D.; Smith, F.M.; O`Leary, R.F.

    1997-04-01

    A method is provided for joining beryllium pieces which comprises: depositing aluminum alloy on at least one beryllium surface; contacting that beryllium surface with at least one other beryllium surface; and welding the aluminum alloy coated beryllium surfaces together. The aluminum alloy may be deposited on the beryllium using gas metal arc welding. The aluminum alloy coated beryllium surfaces may be subjected to elevated temperatures and pressures to reduce porosity before welding the pieces together. The aluminum alloy coated beryllium surfaces may be machined into a desired welding joint configuration before welding. The beryllium may be an alloy of beryllium or a beryllium compound. The aluminum alloy may comprise aluminum and silicon. 9 figs.

  7. Method for welding beryllium

    Dixon, R.D.; Smith, F.M.; O'Leary, R.F.

    1997-01-01

    A method is provided for joining beryllium pieces which comprises: depositing aluminum alloy on at least one beryllium surface; contacting that beryllium surface with at least one other beryllium surface; and welding the aluminum alloy coated beryllium surfaces together. The aluminum alloy may be deposited on the beryllium using gas metal arc welding. The aluminum alloy coated beryllium surfaces may be subjected to elevated temperatures and pressures to reduce porosity before welding the pieces together. The aluminum alloy coated beryllium surfaces may be machined into a desired welding joint configuration before welding. The beryllium may be an alloy of beryllium or a beryllium compound. The aluminum alloy may comprise aluminum and silicon. 9 figs

  8. Transition welds in welding of two-ply steels

    Fartushnyj, V.G.; Evsyukov, Yu.G.

    1977-01-01

    Studied were physico-mechanical properties of welds made by various welding wires of chromium-nickel and nickel-chromium steels in submerged arc welding of double-layer steels with main layer of the VSt.3sp. carbon steel. It is shown that service-reliable structures welded of two-layer steels are obtained by providing the content from 11 to 20 % Ni in the automatically welded transition layer

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

    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.

  10. Grinding Parts For Automatic Welding

    Burley, Richard K.; Hoult, William S.

    1989-01-01

    Rollers guide grinding tool along prospective welding path. Skatelike fixture holds rotary grinder or file for machining large-diameter rings or ring segments in preparation for welding. Operator grasps handles to push rolling fixture along part. Rollers maintain precise dimensional relationship so grinding wheel cuts precise depth. Fixture-mounted grinder machines surface to quality sufficient for automatic welding; manual welding with attendant variations and distortion not necessary. Developed to enable automatic welding of parts, manual welding of which resulted in weld bead permeated with microscopic fissures.

  11. Prediction of Weld Residual Stress of Narrow Gap Welds

    Yang, Jun Seog; Huh, Nam Su

    2010-01-01

    The conventional welding technique such as shield metal arc welding has been mostly applied to the piping system of the nuclear power plants. It is well known that this welding technique causes the overheating and welding defects due to the large groove angle of weld. On the other hand, the narrow gap welding(NGW) technique has many merits, for instance, the reduction of welding time, the shrinkage of weld and the small deformation of the weld due to the small groove angle and welding bead width comparing with the conventional welds. These characteristics of NGW affect the deformation behavior and the distribution of welding residual stress of NGW, thus it is believed that the residual stress results obtained from conventional welding procedure may not be applied to structural integrity evaluation of NGW. In this paper, the welding residual stress of NGW was predicted using the nonlinear finite element analysis to simulate the thermal and mechanical effects of the NGW. The present results can be used as the important information to perform the flaw evaluation and to improve the weld procedure of NGW

  12. Capabilities of infrared weld monitor

    Sanders, P.G.; Keske, J.S.; Leong, K.H.; Kornecki, G.

    1997-11-01

    A non-obtrusive pre-aligned, solid-state device has been developed to monitor the primary infrared emissions during laser welding. The weld monitor output is a 100-1000 mV signal that depends on the beam power and weld characteristics. The DC level of this signal is related to weld penetration, while AC portions of the output can be correlated with surface irregularities and part misalignment or contamination. Changes in DC behavior are also noted for both full and deep penetration welds. Full penetration welds are signified by an abrupt reduction in the weld monitor output. Bead on plate welds were made on steel, aluminum, and magnesium with both a CW CO{sub 2} laser and a pulsed Nd:YAG laser to explore the relationships between the weld characteristics and the weld monitor output.

  13. Development of brazing process for W-EUROFER joints using Cu-based fillers

    de Prado, J.; Sánchez, M.; Ureña, A.

    2016-02-01

    A successful joint between W and EUROFER using high temperature brazing technique has been achieved for structural application in future fusion power plants. Cu-based powder alloy mixed with a polymeric binder has been used as filler. Microstructural analysis of the joints revealed that the joint consisted mainly of primary phases and acicular structures in a Cu matrix. Interaction between EUROFER and filler took place at the interface giving rise to several Cu-Ti-Fe rich layers. A loss of hardness at the EUROFER substrate close to the joint due to a diffusion phenomenon during brazing cycle was measured; however, the joints had an adequate shear strength value.

  14. Pre- and postirradiation properties of brazed joints of AISI 316L stainless steel

    Brossa, M.; Franconi, E.; Guerreschi, U.; Pierazzi, L.; Poggi, P.; Rustia, V.

    1994-01-01

    An extensive test campaign has been performed to verify the reliability and the endurance of brazed joints between AISI 316L parts for structural applications in the nuclear field. The tests, conducted for comparison with three different high melting temperature alloys, included tensile tests (normal and shear), fatigue tests (fatigue crack propagation, low cycle fatigue, 4-point bending fatigue) and impact tests; besides, tensile tests have been performed with both unirradiated and irradiated specimens. Generally, the tests demonstrated satisfactory mechanical properties of the joints and revealed occasionally strong differences in the behaviour of the different brazing alloys, thus providing important design indications. ((orig.))

  15. Brazing of molybdenum- and tungsten based refractory materials with copper and graphite

    Boutes, J.; Falbriard, P.; Rochette, P.; Nicolas, G.

    1989-01-01

    Molybdenum and Tungsten base refractory metals and alloys have been brazed 1. to copper between 800 0 C and 900 0 C with silver base metal; 2. to graphite, with CVD coatings between 800 0 C and 900 0 C with silver base metal and between 1100 0 C and 1200 0 C with copper base metal; 3. to graphite between 800 0 C and 1100 0 C with silver or nickel base metal. The brazed joints have been characterized by micrographic observations before and after bending tests from room temperature to 800 0 C. 2 tabs., 9 figs. (Author)

  16. Features of Pd-Ni-Fe solder system for vacuum brazing of low alloy steels

    Radzievskij, V.N.; Kurochko, R.S.; Lotsmanov, S.N.; Rymar', V.I.

    1975-01-01

    The brazing solder of the Pd-Ni-Fe alloyed with copper and lithium, in order to decrease the melting point and provide for a better spreading, when soldered in vacuum ensures a uniform strength of soldered joints with the base metal of low-alloyed steels of 34KHNIM-type. The properties of low-alloyed steel joints brazed with the Pd-Ni-Fe-system solder little depend on the changes in the soldering parameters. The soldered joint keeps a homogeneous structure after all the stages of heat treatment (annealing, quenching and tempering)

  17. Welding method, and welding device for use therein, and method of analysis for evaluating welds

    Aendenroomer, A.J.; Den Ouden, G.; Xiao, Y.H.; Brabander, W.A.J.

    1995-01-01

    Described is a method of automatically welding pipes, comprising welding with a pulsation welding current and monitoring, by means of a sensor, the variations occurring in the arc voltage caused by weld pool oscillations. The occurrence of voltage variations with only frequency components below 100

  18. Recycle Glass in Foam Glass Production

    Petersen, Rasmus Rosenlund; König, Jakob; Yue, Yuanzheng

    The foam glass industry turn recycle glass into heat insulating building materials. The foaming process is relative insensitive to impurities in the recycle glass. It is therefore considered to play an important role in future glass recycling. We show and discuss trends of use of recycled glasses...... in foam glass industry and the supply sources and capacity of recycle glass....

  19. Weld analysis and control system

    Kennedy, Larry Z. (Inventor); Rodgers, Michael H. (Inventor); Powell, Bradley W. (Inventor); Burroughs, Ivan A. (Inventor); Goode, K. Wayne (Inventor)

    1994-01-01

    The invention is a Weld Analysis and Control System developed for active weld system control through real time weld data acquisition. Closed-loop control is based on analysis of weld system parameters and weld geometry. The system is adapted for use with automated welding apparatus having a weld controller which is capable of active electronic control of all aspects of a welding operation. Enhanced graphics and data displays are provided for post-weld analysis. The system provides parameter acquisition, including seam location which is acquired for active torch cross-seam positioning. Torch stand-off is also monitored for control. Weld bead and parent surface geometrical parameters are acquired as an indication of weld quality. These parameters include mismatch, peaking, undercut, underfill, crown height, weld width, puddle diameter, and other measurable information about the weld puddle regions, such as puddle symmetry, etc. These parameters provide a basis for active control as well as post-weld quality analysis and verification. Weld system parameters, such as voltage, current and wire feed rate, are also monitored and archived for correlation with quality parameters.

  20. Welding processes handbook

    Weman, Klas

    2003-01-01

    Deals with the main commercially significant and commonly used welding processes. This title takes the student or novice welder through the individual steps involved in each process in an easily understood way. It covers many of the requirements referred to in European Standards including EN719, EN 729, EN 729 and EN 287.$bWelding processes handbook is a concise, explanatory guide to the main commercially significant and commonly-used welding processes. It takes the novice welder or student through the individual steps involved in each process in a clear and easily understood way. It is intended to provide an up-to-date reference to the major applications of welding as they are used in industry. The contents have been arranged so that it can be used as a textbook for European welding courses in accordance with guidelines from the European Welding Federation. Welding processes and equipment necessary for each process are described so that they can be applied to all instruction levels required by the EWF and th...

  1. Large scale use of brazing and high temperature brazing for the fabrication of the 6.4 km long vacuum system of the HERA electron storage ring

    Ballion, R.; Boster, J.; Giesske, W.; Hartwig, H.; Jagnow, D.; Kouptsidis, J.; Pape, R.; Prohl, W.; Schumann, G.; Schwartz, M.; Iversen, K.; Mucklenbeck, J.

    1989-01-01

    The 6.4 km long vacuum system for electrons in the large storage ring HERA at Hamburg consists of about 1,400 components having lengths between .14 and 12 m. The vacuum components are mainly made from variously shaped tubes of the copper alloy CuSn2. This alloy combines sufficient mechanical strength with the high thermal conductivity needed to remove the 6 MW dissipated power of the synchrotron-light. The vacuum components consist additionally of parts made from stainless steel such as flanges, chambers for pumps, beam monitors, etc. All of these parts are connected in a vacuum tight manner and on a large scale by using brazing and high temperature brazing both in a vacuum or in a reducing gas atmosphere. (orig.)

  2. Thermal stir welding process

    Ding, R. Jeffrey (Inventor)

    2012-01-01

    A welding method is provided for forming a weld joint between first and second elements of a workpiece. The method includes heating the first and second elements to form an interface of material in a plasticized or melted state interface between the elements. The interface material is then allowed to cool to a plasticized state if previously in a melted state. The interface material, while in the plasticized state, is then mixed, for example, using a grinding/extruding process, to remove any dendritic-type weld microstructures introduced into the interface material during the heating process.

  3. Thermal stir welding apparatus

    Ding, R. Jeffrey (Inventor)

    2011-01-01

    A welding method and apparatus are provided for forming a weld joint between first and second elements of a workpiece. The method includes heating the first and second elements to form an interface of material in a plasticized or melted state interface between the elements. The interface material is then allowed to cool to a plasticized state if previously in a melted state. The interface material, while in the plasticized state, is then mixed, for example, using a grinding/extruding process, to remove any dendritic-type weld microstructures introduced into the interface material during the heating process.

  4. Review of Welding Terminology

    Angelika Petrėtienė

    2011-04-01

    Full Text Available The paper discusses welding terms in accordance with the Lithuanian standard LST EN 1792 „Welding. The multilingual list of welding terms and similar processes”, „The Russian–Lithuanian dictionary of the terms of mechanical engineering technology and welding“ and the examples from postgraduates‘ final works. It analyses the infringement of lexical, word-building and morphological rules. First-year students should already be familiar with the standardized terms of their speciality. More active propagation of the terms should help to avoid terminology mistakes in various scientific spheres.

  5. Half bead welding technique

    Canonico, D.A.; Holz, P.P.

    1978-05-01

    The ORNL has employed the Section XI half-bead procedure for six repair welds. Table 2 identifies the repairs and the components upon which they were accomplished. The weld repairs were performed to permit us to evaluate material properties, residual stresses, weld repair procedures, and structural behavior of repaired pressure vessels. As a consequence of our study we concluded that when the half bead procedure is correctly applied: (1) there is no metallurgical degradation of the base material, (2) residual stresses of yield point magnitude will be present, and (3) the structural integrity of the pressure vessel is not impaired at Charpy V-notch upper shelf temperatures

  6. Diffusion brazing of Ti–6Al–4V and austenitic stainless steel using silver-based interlayer

    Soltani Tashi, R.; Akbari Mousavi, S.A.A.; Mazar Atabaki, M.

    2014-01-01

    Highlights: • Ti–6Al–4V and stainless steel 316L were successfully joined by diffusion brazing. • The wettability of the filler alloy was escalated by increasing the temperature. • By increasing the brazing temperature various intermetallic compounds were formed. • There is a noteworthy effect of the brazing temperature on the fracture footpath. - Abstract: In the present study, vacuum brazing was applied to join Ti–6Al–4V and stainless steel using AgCuZn filler metal. The bonds were characterized by scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction analysis. Mechanical strengths of the joints were evaluated by the shear test and microhardness showed that shear strength decreased with increasing the brazing temperature and time. The results showed that the wettability of the filler alloy was increased by enhancing the wetting test temperature. It was shown that by increasing the brazing temperature various intermetallic compounds were formed in the bond area. These intermetallic compounds were mainly a combination of CuTi and Fe–Cu–Ti. The shear test results verified the influence of the bonding temperature on the strength of the joints based on the formation of different intermetallics in the bond zone. The fracture analysis also revealed different fracture footpath and morphology for the different brazing temperatures

  7. Recent developments in pipeline welding practice

    1979-01-01

    Fourteen chapters are included: overview of pipeline welding systems and quality assurance, CRC automatic welding system, H.C. Price Co. automatic welding system, semi-automatic MIG-welding process, partial penetration welding of steel pipes for gas distribution, construction procedures and quality control in offshore pipeline construction, welding in repair and maintenance of gas transmission pipelines, British Gas studies of welding on pressurized gas transmission pipelines, hot tapping pipelines, underwater welding for offshore pipelines and associated equipment, radial friction welding, material composition vs weld properties, review of NDT of pipeline welds, and safety assurance in pipeline construction. A bibliography of approximately 150 references is included, arranged according to subject and year.

  8. Hybrid laser-arc welding

    Hybrid laser-arc welding (HLAW) is a combination of laser welding with arc welding that overcomes many of the shortfalls of both processes. This important book gives a comprehensive account of hybrid laser-arc welding technology and applications. The first part of the book reviews...... the characteristics of the process, including the properties of joints produced by hybrid laser-arc welding and ways of assessing weld quality. Part II discusses applications of the process to such metals as magnesium alloys, aluminium and steel as well as the use of hybrid laser-arc welding in such sectors as ship...... building and the automotive industry. With its distinguished editor and international team of contributors, Hybrid laser-arc welding, will be a valuable source of reference for all those using this important welding technology. Professor Flemming Ove Olsen works in the Department of Manufacturing...

  9. Residual stress by repair welds

    Mochizuki, Masahito; Toyoda, Masao

    2003-01-01

    Residual stress by repair welds is computed using the thermal elastic-plastic analysis with phase-transformation effect. Coupling phenomena of temperature, microstructure, and stress-strain fields are simulated in the finite-element analysis. Weld bond of a plate butt-welded joint is gouged and then deposited by weld metal in repair process. Heat source is synchronously moved with the deposition of the finite-element as the weld deposition. Microstructure is considered by using CCT diagram and the transformation behavior in the repair weld is also simulated. The effects of initial stress, heat input, and weld length on residual stress distribution are studied from the organic results of numerical analysis. Initial residual stress before repair weld has no influence on the residual stress after repair treatment near weld metal, because the initial stress near weld metal releases due to high temperature of repair weld and then stress by repair weld regenerates. Heat input has an effect for residual stress distribution, for not its magnitude but distribution zone. Weld length should be considered reducing the magnitude of residual stress in the edge of weld bead; short bead induces high tensile residual stress. (author)

  10. Cosmos & Glass

    Beim, Anne

    1996-01-01

    The article unfolds the architectural visions of glass by Bruno Taut. It refers to inspirations by Paul Sheerbart and litterature and the Crystal Chain, also it analyses the tectonic univers that can be found in the glass pavillion for the Werkbund exposition in Cologne....

  11. Glass Glimpsed

    Lock, Charles

    2015-01-01

    Glass in poetry as it reflects the viewer and as its power of reflection are both reduced and enhanced by technology.......Glass in poetry as it reflects the viewer and as its power of reflection are both reduced and enhanced by technology....

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

    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.

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

    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.

  14. Copper-silver-titanium-tin filler metal for direct brazing of structural ceramics

    Moorhead, Arthur J.

    1988-04-05

    A method of joining ceramics and metals to themselves and to one another at about 800.degree. C. is described using a brazing filler metal consisting essentially of 35 to 50 at. % copper, 40 to 50 at. % silver, 1 to 15 at. % titanium, and 2 to 8 at. % tin. This method produces strong joints that can withstand high service temperatures and oxidizing environments.

  15. Copper-silver-titanium filler metal for direct brazing of structural ceramics

    Moorhead, Arthur J.

    1987-01-01

    A method of joining ceramics and metals to themselves and to one another is described using a brazing filler metal consisting essentially of 35 to 50 atomic percent copper, 15 to 50 atomic percent silver and 10 to 45 atomic percent titanium. This method produces strong joints that can withstand high service temperatures and oxidizing environments.

  16. Repairs of Damaged Castings Made of Graphitic Cast Iron by Means of Brazing

    Mičian M.

    2017-09-01

    Full Text Available The article summarizes the theoretical knowledge from the field of brazing of graphitic cast iron, especially by means of conventional flame brazing using a filler metal based on CuZn (CuZn40SnSi – brass alloy. The experimental part of the thesis presents the results of performance assessment of brazed joints on other than CuZn basis using silicone (CuSi3Mn1 or aluminium bronze (CuAl10Fe. TIG electrical arc was used as a source of heat to melt these filler materials. The results show satisfactory brazed joints with a CuAl10Fe filler metal, while pre-heating is not necessary, which favours this method greatly while repairing sizeable castings. The technological procedure recommends the use of AC current with an increased frequency and a modified balance between positive and negative electric arc polarity to focus the heat on a filler metal without melting the base material. The suitability of the joint is evaluated on the basis of visual inspection, mechanic and metallographic testing.

  17. Brazing of special metallic materials and material combinations using a special material

    Lison, R.

    1981-01-01

    The special materials include metals of groups IVa, Va and VIa of the periodic tables and their alloys. Their particular properties have won them applications in many highly specialized industries. For these materials to be used, mastery of thermal joining methods appropriate to their characteristics is necessary. High-temperature brazing is one such method for joining special materials. This paper presents variants of this technique suitable for each individual special material. Compatibility tests between various brazing metals and various special materials have been carried out by simulating the temperature/time cycle involved in brazing procedures. Special materials are relatively expensive, and their special properties are not required at every point in a structure: elsewhere they can be replaced by a different special material or by other metals or alloys. This means that joints must be made between two special materials or between a special material and a conventional material. When certain conditions are fulfilled, such joins can be made by high-temperature brazing. This paper also shows the extent to which the geometry of the join determines the choice of process. Example of applications are also given. (orig.)

  18. Brazing retort manifold design concept may minimize air contamination and enhance uniform gas flow

    Ruppe, E. P.

    1966-01-01

    Brazing retort manifold minimizes air contamination, prevents gas entrapment during purging, and provides uniform gas flow into the retort bell. The manifold is easily cleaned and turbulence within the bell is minimized because all manifold construction lies outside the main enclosure.

  19. Gaseous Shielding Gas Additives as Flux Substitute for TIG Arc Brazing

    Uwe Reisgen

    2015-09-01

    Full Text Available Abstract Brazing is one of the key technologies in the field of joining of metal components. To improve the wetting of brazing material and work-piece surface, it is often required to fall back on the use of flux. The application of these substances requires accuracy and is often connected with considerable expenditure and it is, just as the removal of flux residues, often an additional working step which has to be carried out manually. Within the framework of a DFG research project it has been investigated to which degree gaseous substances as addition to the shielding gas may replace conventional flux in TIG arc brazing. To this end, investigations have been carried out using different combinations of base and filler materials. Mainly monosilane as a gaseous flux substitute has been added in low concentrations to the shielding gas volume flow. The resulting brazed joints have been quantified with regard to their geometry, their fusion conditions and their chemical compositions. These qualities were then correlated and evaluated with the provided quantity of monosilane in order to identify dependencies.

  20. Assessing braze quality in the actively cooled Tore Supra Phase III outboard pump limiter

    Nygren, R.E.; Lutz, T.L.; Miller, J.D.; McGrath, R.; Dale, G.

    1994-01-01

    The quality of brazing of pyrolytic graphite armor brazed to copper tubes in Tore Supra's Phase III Outboard Pump Limiter was assessed through pre-service qualification testing of individual copper/tile assemblies. The evaluation used non-destructive, hot water transient heating tests performed in the high-temperature, high-pressure flow loop at Sandia's Plasma Materials Test Facility. Surface temperatures of tiles were monitored with an infrared camera as water at 120 degrees C at about 2.07 MPa (300 psi) passed through a tube assembly initially at 30 degrees C. For tiles with braze voids or cracks, the surface temperatures tagged behind those of adjacent well-bonded tiles. Temperature tags were correlated with flaw sizes observed during repairs based upon a detailed 2-D heat transfer analyses. open-quotes Badclose quotes tiles, i.e., temperature tags of 10-20 degrees C depending upon tile's size, were easy to detect and, when removed, revealed braze voids of roughly 50% of the joint area. Eleven of the 14 tubes were rebrazed after bad tiles were detected and removed. Three tubes were rebrazed twice

  1. Welding of refractory alloys

    Lessmann, G.G.

    1984-01-01

    This review primarily summarizes welding evaluations supported by NASA-Lewis Research Center in the 1960s. A literature search run in preparation for this review indicates that more recent work is modest by comparison. Hence, this review restates these accomplishments briefly and addresses opportunities which have evolved in welding technology (such as lasers) in the intervening decade. Emphasis in this review is given to tantalum- and niobium-base alloys. Considerable work was also done to assure that a consistent comparison was made with tungsten. A wide variety of candidate alloys derived primarily from developments directed at aircraft propulsion applications were available. Early efforts by NASA were directed at screening studies to select promising structural alloys for the space power application. This objective required fine tuning of welding procedures, e.g., the demonstration of stringent standards for control of welding atmosphere to assure good corrosion resistance in liquid alkali metals. 16 figures, 6 tables

  2. Multispot fiber laser welding

    Schutt Hansen, Klaus

    This dissertation presents work and results achieved in the field of multi beam fiber laser welding. The project has had a practical approach, in which simulations and modelling have been kept at a minimum. Different methods to produce spot patterns with high power single mode fiber lasers have...... been examined and evaluated. It is found that both diamond turned DOE’s in zinc sulphide and multilevel etched DOE’s (Diffractive Optical Elements) in fused silica have a good performance. Welding with multiple beams in a butt joint configuration has been tested. Results are presented, showing it has...... been possible to control the welding width in incremental steps by adding more beams in a row. The laser power was used to independently control the keyhole and consequently the depth of fusion. An example of inline repair of a laser weld in butt joint configuration was examined. Zinc powder was placed...

  3. Friction stir welding tool

    Tolle,; Charles R. , Clark; Denis E. , Barnes; Timothy, A [Ammon, ID

    2008-04-15

    A friction stir welding tool is described and which includes a shank portion; a shoulder portion which is releasably engageable with the shank portion; and a pin which is releasably engageable with the shoulder portion.

  4. Spin glasses

    Bovier, Anton

    2007-01-01

    Spin glass theory is going through a stunning period of progress while finding exciting new applications in areas beyond theoretical physics, in particular in combinatorics and computer science. This collection of state-of-the-art review papers written by leading experts in the field covers the topic from a wide variety of angles. The topics covered are mean field spin glasses, including a pedagogical account of Talagrand's proof of the Parisi solution, short range spin glasses, emphasizing the open problem of the relevance of the mean-field theory for lattice models, and the dynamics of spin glasses, in particular the problem of ageing in mean field models. The book will serve as a concise introduction to the state of the art of spin glass theory, usefull to both graduate students and young researchers, as well as to anyone curious to know what is going on in this exciting area of mathematical physics.

  5. Microstructure evolution and mechanical properties of Ti−22Al−25Nb alloy joints brazed with Ti−Ni−Nb alloy

    Wang, Y.; Cai, X.Q.; Yang, Z.W., E-mail: tjuyangzhenwen@163.com; Qiu, Q.W.; Wang, D.P.; Liu, Y.C.

    2016-10-01

    Ti{sub 45}Ni{sub 45}Nb{sub 10} (at.%) brazing alloy, fabricated by arc melting, was successfully used to braze Ti−22Al−25Nb (at.%) alloy. The microstructures of Ti{sub 45}Ni{sub 45}Nb{sub 10} brazing alloy and Ti−22Al−25Nb alloy brazed joints were analyzed using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), electron backscatter diffraction (EBSD), and micro-area X-ray diffraction (XRD). The effects of the brazing parameters on the interfacial microstructure and mechanical properties of the Ti−22Al−25Nb alloy brazed joints were investigated. The results showed that the joint was primarily comprised of two characteristic zones: diffusion zone I and central zone II, and the reaction phases formed in the brazed joint were the B2, O, τ{sub 3}, and Ti{sub 2}Ni phase. The crystal orientation of B2 phase in diffusion zone I was consistent with that in the Ti−22Al−25Nb substrate. The O phase was precipitated from the B2 phase. As the brazing temperature or holding time increased, τ{sub 3} was gradually replaced by the B2 phase, and the Ti{sub 2}Ni phase decreased and ultimately disappeared. The maximum shear strength achieved at room temperature was 318 MPa when the joint was brazed at 1180 °C for 20 min, whereas it was 278 MPa at 650 °C. Crack primarily propagated in the τ{sub 3} compound, which was extremely hard and brittle, and partially traversed the B2 and O phases. - Highlights: • Ti{sub 45}Ni{sub 45}Nb{sub 10} alloy was successfully developed to braze Ti−22Al−25Nb alloy. • Ti−22Al−25Nb alloy was transformed from B2 phase into the O + B2 duplex phase after brazing. • Crystal orientation of B2 in joint was dependent on metal substrate. • Correlation between joint microstructure and mechanical properties was revealed. • Ti−22Al−25Nb brazed joint had excellent ambient and high temperature strength.

  6. Underwater Welding Techniques

    Esam F. Alajmi; Ahmad A. Alqenaei

    2017-01-01

    Welding demand in offshore and marine applications is increased with the increasing in oil and gas activities as well as increasing in the marine transportation and industrial applications. Applications of underwater welding well be increased in Kuwait in the coming years due to the strategic directive of the country toward starting the offshore oil and gas exploration and production, and the increase in marine transportation projects. Therefore, there is a need to understand the concept of u...

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

    Afshar, F. Norouzi; Ambat, R.; Kwakernaak, C.; Wit, J.H.W. de; Mol, J.M.C.; Terryn, H.

    2012-01-01

    Highlights: ► Localized electrochemical cell and glow discharge optical emission spectrometry were used. ► An electrochemical depth profile of an aluminum brazing sheet was obtained. ► The electrochemical responses were correlated to the microstructural features. - Abstract: 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 potential, cathodic and anodic reactivities, and tracking their changes as a function of depth, the evolution of electrochemical responses through out the material thickness were analyzed and correlated to the corresponding microstructural features. Polarization curves in 1 wt% NaCl solution at pH 2.8 were obtained at different depths from the surface using controlled sputtering in a glow discharge optical emission spectrometer as a sample preparation technique. The anodic and cathodic reactivity of the top surface areas were significantly higher than that of the bulk, thus indicating these areas to be more susceptible to localized attack. Consistent with this, optical microscopy and scanning electron microscope analysis revealed a relatively high density of fine intermetallic and silicon particles at these areas. The corrosion mechanism of the top layers was identified to be intergranular and pitting corrosion, while lower sensitivity to these localized attacks were detected toward the brazing sheet core. The results highlight the successful application of the electrochemical depth profiling approach in prediction of the corrosion behavior of the aluminum brazing sheet and the importance of the electrochemical activity of the outer 10 μm in controlling the corrosion performance of the aluminum brazing sheet.

  8. Hermetic diamond capsules for biomedical implants enabled by gold active braze alloys.

    Lichter, Samantha G; Escudié, Mathilde C; Stacey, Alastair D; Ganesan, Kumaravelu; Fox, Kate; Ahnood, Arman; Apollo, Nicholas V; Kua, Dunstan C; Lee, Aaron Z; McGowan, Ceara; Saunders, Alexia L; Burns, Owen; Nayagam, David A X; Williams, Richard A; Garrett, David J; Meffin, Hamish; Prawer, Steven

    2015-01-01

    As the field of biomedical implants matures the functionality of implants is rapidly increasing. In the field of neural prostheses this is particularly apparent as researchers strive to build devices that interact with highly complex neural systems such as vision, hearing, touch and movement. A retinal implant, for example, is a highly complex device and the surgery, training and rehabilitation requirements involved in deploying such devices are extensive. Ideally, such devices will be implanted only once and will continue to function effectively for the lifetime of the patient. The first and most pivotal factor that determines device longevity is the encapsulation that separates the sensitive electronics of the device from the biological environment. This paper describes the realisation of a free standing device encapsulation made from diamond, the most impervious, long lasting and biochemically inert material known. A process of laser micro-machining and brazing is described detailing the fabrication of hermetic electrical feedthroughs and laser weldable seams using a 96.4% gold active braze alloy, another material renowned for biochemical longevity. Accelerated ageing of the braze alloy, feedthroughs and hermetic capsules yielded no evidence of corrosion and no loss of hermeticity. Samples of the gold braze implanted for 15 weeks, in vivo, caused minimal histopathological reaction and results were comparable to those obtained from medical grade silicone controls. The work described represents a first account of a free standing, fully functional hermetic diamond encapsulation for biomedical implants, enabled by gold active alloy brazing and laser micro-machining. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Automatic welding machine for piping

    Yoshida, Kazuhiro; Koyama, Takaichi; Iizuka, Tomio; Ito, Yoshitoshi; Takami, Katsumi.

    1978-01-01

    A remotely controlled automatic special welding machine for piping was developed. This machine is utilized for long distance pipe lines, chemical plants, thermal power generating plants and nuclear power plants effectively from the viewpoint of good quality control, reduction of labor and good controllability. The function of this welding machine is to inspect the shape and dimensions of edge preparation before welding work by the sense of touch, to detect the temperature of melt pool, inspect the bead form by the sense of touch, and check the welding state by ITV during welding work, and to grind the bead surface and inspect the weld metal by ultrasonic test automatically after welding work. The construction of this welding system, the main specification of the apparatus, the welding procedure in detail, the electrical source of this welding machine, the cooling system, the structure and handling of guide ring, the central control system and the operating characteristics are explained. The working procedure and the effect by using this welding machine, and the application to nuclear power plants and the other industrial field are outlined. The HIDIC 08 is used as the controlling computer. This welding machine is useful for welding SUS piping as well as carbon steel piping. (Nakai, Y.)

  10. Microstructure of the Transitional Area of the Connection of a High-temperature Ni-based Brazing Alloy and Stainless Steel AISI 321 (X6CrNiTi 18–10

    R. Augustin

    2010-01-01

    Full Text Available This paper presents a detailed examination of the structure of the transitional area between a brazing alloy and the parent material, the dimensions of the diffusion zones that are created, and the influence on them of a change in the brazing parameters. Connections between Ni-based brazing alloys (NI 102 with a small content of B and AISI 321 stainless steel (X6CrNiTi 18–10 were created in a vacuum (10−2 Pa at various brazing temperatures and for various holding times at the brazing temperature. Various specimens were tested. First, the brazing alloys were wetted and the dependence of the wetting on the brazing parameters was assessed. Then a chemical microanalysis was made of the interface between the brazing alloy and the parent material. The individual diffusion zones were identified on pictures from a light microscope and REM, and their dimensions, together with their dependence on the brazing parameters, were determined.

  11. Alternate Welding Processes for In-Service Welding

    2009-04-24

    Conducting weld repairs and attaching hot tap tees onto pressurized pipes has the advantage of avoiding loss of service and revenue. However, the risks involved with in-service welding need to be managed by ensuring that welding is performed in a rep...

  12. Certification of a weld produced by friction stir welding

    Obaditch, Chris; Grant, Glenn J

    2013-10-01

    Methods, devices, and systems for providing certification of friction stir welds are disclosed. A sensor is used to collect information related to a friction stir weld. Data from the sensor is compared to threshold values provided by an extrinsic standard setting organizations using a certification engine. The certification engine subsequently produces a report on the certification status of the weld.

  13. Ultrasonic inspection of austenitic welds

    Baikie, B.L.; Wagg, A.R.; Whittle, M.J.; Yapp, D.

    1976-01-01

    The ultrasonic examination of austenitic stainless steel weld metal has always been regarded as a difficult proposition because of the large and variable ultrasonic attenuations and back scattering obtained from apparently similar weld deposits. The work to be described shows how the existence of a fibre texture within each weld deposit (as a result of epitaxial growth through successive weld beads) produces a systematic variation in the ultrasonic attenuation coefficient and the velocity of sound, depending upon the angle between the ultrasonic beam and the fibre axis. Development work has shown that it is possible to adjust the welding parameters to ensure that the crystallographic texture within each weld is compatible with improved ultrasonic transmission. The application of the results to the inspection of a specific weld in type 316 weld metal is described

  14. Arc-weld pool interactions

    Glickstein, S.S.

    1978-08-01

    The mechanisms involved in arc-weld pool interactions are extremely complex and no complete theory is presently available to describe much of the phenomena observed during welding. For the past several years, experimental and analytical studies have been undertaken at the Bettis Atomic Power Laboratory to increase basic understanding of the gas tungsten arc welding process. These studies have included experimental spectral analysis of the arc in order to determine arc temperature and analytical modeling of the arc and weld puddle. The investigations have been directed toward determining the cause and effects of variations in the energy distribution incident upon the weldment. In addition, the effect of weld puddle distortion on weld penetration was investigated, and experimental and analytical studies of weld process variables have been undertaken to determine the effects of the variables upon weld penetration and configuration. A review of the results and analysis of these studies are presented

  15. Diffusion Brazing of Ti-6Al-4V and Stainless Steel 316L Using AgCuZn Filler Metal

    R. Soltani Tashi

    2013-09-01

    Full Text Available In the present study, vacuum brazing was applied to join Ti-6Al-4V and stainless steel using AgCuZn filler metal. The bonds were characterized by scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction analysis. Mechanical strengths of the joints were evaluated by the shear test and microhardness. It has been shown that shear strength decreased with increasing the brazing temperature and time. The wettability of the filler alloy was increased by enhancing the wetting test temperature. By increasing the brazing temperature various intermetallic compounds were formed in the bond area. These intermetallic compounds were mainly a combination of CuTi and Fe-Cu-Ti. The shear test results verified the influence of the bonding temperature on the strength of the joints based on the formation of different intermetallics in the bond zone. The fracture analysis also revealed different fracture footpath and morphology for different brazing temperatures.

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

    Singh, K.P.; Pandya, Santosh P.; Khirwadkar, S.S.; Patel, Alpesh; Patil, Y.; Buch, J.J.U.; Khan, M.S.; Tripathi, Sudhir; Pandya, Shwetang; Govindrajan, J.; Jaman, P.M.; Rathore, Devendra; Rangaraj, L.; Divakar, C.

    2011-01-01

    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 2 uniform heat flux. Details about experimental and computational work are presented here.

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

    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.

  18. The stress-corrosion behaviour in water media containing chlorine of the brazing joint of grids for PWR fuel element

    Zhang Weijie; Li Wenqing.

    1985-01-01

    This paper details the testing results of the stress-corrosion behaviour in the 150 deg C water media containing chlorine for the brazing joints made from three alloy systems, which are Ni-Cr-Si, Ni-Cr-P and Ni-P, including 16 compositions. The test results indicate that, in the Ni-Cr-Si system, Ni-Cr-Si-Ge brazing joint is the best, to resist stress-corrosion, while Ni-Cr-Si-P-Ge-Pd and BNi5 brazing joints are better. In the Ni-Cr-P system, only the Ni-Cr-P-Mo-Zr brazing joint has an excellent resistance to stress-corrosion

  19. Metal/not metal joints: analysis of graphite junction for electric use of titanium by direct brazing with reactive alloy

    Guimaraes, A.S.; Rebello, J.M.A.

    1988-01-01

    The usual techniques of joining graphite (for electrical use) and titanium by brazing with zirconium alloys are described. The morphological and the chemical aspects obtained by X-ray diffraction analysis are also presented. (C.G.C.) [pt

  20. Resistance Spot Welding of dissimilar Steels

    Ladislav Kolařík

    2012-01-01

    Full Text Available This paper presents an analysis of the properties of resistance spot welds between low carbon steel and austenitic CrNi stainless steel. The thickness of the welded dissimilar materials was 2 mm. A DeltaSpot welding gun with a process tape was used for welding the dissimilar steels. Resistance spot welds were produced with various welding parameters (welding currents ranging from 7 to 8 kA. Light microscopy, microhardness measurements across the welded joints, and EDX analysis were used to evaluate the quality of the resistance spot welds. The results confirm the applicability of DeltaSpot welding for this combination of materials.

  1. GLASS BOX

    Curtis, Laura

    2008-01-01

    The goals of this effort were to develop Glass Box capabilities to allow for the capturing of analyst activities and the associated data resources, track and log the results of automated processing...

  2. Nanoparticle-Assisted Diffusion Brazing of Metal Microchannel Arrays: Nanoparticle Synthesis, Deposition, and Characterization

    Eluri, Ravindranadh T.

    Microchannel process technology (MPT) offers several advantages to the field of nanomanufacturing: 1) improved process control over very short time intervals owing to shorter diffusional distances; and 2) reduced reactor size due to high surface area to volume ratios and enhanced heat and mass transfer. The objective of this thesis was to consider how nanomaterials, produced in part using MPT, could be used to solve problems associated with the fabrication of MPT devices. Specifically, many MPT devices are produced using transient liquid-phase brazing involving an electroplated interlayer consisting of a brazing alloy designed for melting temperature suppression. Unfortunately, these alloys can form brittle secondary phases which significantly reduce bond strength. In contrast, prior efforts have shown that it is possible to leverage the size-dependent properties of nanomaterials to suppress brazing temperatures. In this prior work, thin films of off-the-shelf elemental nanoparticles were used as interlayers yielding joints with improved mechanical properties. In the present investigation, efforts have been made to characterize the synthesis and deposition of various elemental nanoparticle suspensions for use in the transient liquid-phase brazing of aluminum and stainless steel. Advances were used to demonstrate the nanoparticle-assisted diffusion brazing of a microchannel array. In the first section, a silver nanoparticle (AgNP) interlayer was produced for the diffusion brazing of heat exchanger aluminum. Efforts are made to examine the effect of braze filler particle size (˜5 nm and ˜50 nm) and processing parameters (heating rate: 5ºC/min and 25ºC/min; brazing temperature: 550ºC and 570ºC) on thin coupons of diffusion-brazed 3003 Al. A tensile strength of 69.7 MPa was achieved for a sample brazed at 570°C for 30 min under 1 MPa with an interlayer thickness of approximately 7 microm. Further suppression of the brazing temperature to 500ºC was achieved by

  3. Multipass autogenous electron beam welding

    Murphy, J.L.; Mustaleski, T.M. Jr.; Watson, L.C.

    1986-01-01

    A multipass, autogenous welding procedure was developed for 7.6 mm (0.3 in.) wall thickness Type 304L stainless steel cylinders. The joint geometry has a 1.5 mm (0.06 in.) root-face width and a rectangular stepped groove that is 0.762 mm (0.03 in.) wide at the top of the root face and extends 1.5 mm in height, terminating into a groove width of 1.27 mm which extends to the outside of the 1.27 mm high weld-boss. One weld pass is made on the root, three passes on the 0.762 mm wide groove and three passes to complete the weld. Multipass, autogenous, electron beam welds maintain the characteristic high depth-to-width ratios and low heat input of single-pass, electron beam welds. The increased part distortion (which is still much less than from arc processes) in multipass weldments is corrected by a preweld machined compensation. Mechanical properties of multipass welds compare well with single-pass welds. The yield strength of welds in aluminum alloy 5083 is approximately the same for single-pass or multipass electron beam and gas, metal-arc welds. The incidence and size of porosity is less in multipass electron beam welding of aluminum as compared to gas, metal-arc welds. The multipass, autogenous, electron beam welding method has proven to be a reliable way to make some difficult welds in multilayer parts or in an instance where inside part temperature or weld underbead must be controlled and weld discontinuities must be minimized

  4. Neutron diffraction study of internal stresses in brazed CFC/Mo divertor structures for NET/ITER

    Ceretti, M [Laboratoire Leon-Brillouin, CEA/CE Saclay, F-91191, Gif-sur-Yvette (France); Coppola, R [ENEA/Casaccia, INN-FIS, C.P. 2400, I-00100 Rome (Italy); Di Pietro, E [ENEA/Frascati, Dip. FUS, C.P. 2400, I-00100 Rome (Italy); Lodini, A [Laboratoire Leon-Brillouin, CEA/CE Saclay, F-91191, Gif-sur-Yvette (France) Universite de Champagne-Ardennes, Reims (France); Perrin, M [Laboratoire Leon-Brillouin, CEA/CE Saclay, F-91191, Gif-sur-Yvette (France); Piant, A [Laboratoire Leon-Brillouin, CEA/CE Saclay, F-91191, Gif-sur-Yvette (France); Rustichelli, F [Istituto di Scienze Fisiche, Universita di Ancona (Italy)

    1994-09-01

    This contribution presents the first results of a study, performed by neutron diffraction, on the internal stresses remaining after brazing at 860 C in graphite/molybdenum samples developed for NET/ITER. Samples of polycrystalline graphite and a carbon-fiber composite are considered. The deformation field is characterized close to the brazing interface, within a linear spatial resolution of approximately 2 mm. The results are discussed with reference to those obtainable by other methods and to theoretical considerations. ((orig.))

  5. Laser welding engineering

    Bhieh, N. M.; El Eesawi, M. E.; Hashkel, A. E.

    2007-01-01

    Laser welding was in its early life used mainly for unusual applications where no other welding process would be suitable that was twenty five years ago. Today, laser welding is a fully developed part of the metal working industry, routinely producing welds for common items such as cigarette lighters, which springs, motor/transformer lamination, hermetic seals, battery and pacemaker cans and hybrid circuit packages. Yet very few manufacturing engineering have seriously considers employing lasers in their own operations. Why? There are many reasons, but a main one must be not acquainted with the operation and capabilities of a laser system. Other reasons, such as a relatively high initial cost and a concern about using lasers in the manufacturing environment, also are frequently cited, and the complexity of the component and flexibility of the light delivery system. Laser welding could be used in place of many different standard processes, such as resistance (spot or seam), submerged arc, RF induction, high-frequency resistance, ultrasonic and electronic and electron-beam. while each of these techniques has established an independent function in the manufacturing world, the flexible laser welding approach will operate efficiently and economically in many different applications. Its flexibility will even permit the welding system to be used for other machining function, such as drilling, scribing, sealing and serializing. In this article, we will look at how laser welding works and what benefits it can offer to manufacturing engineers. Some industry observers state that there are already 2,000 laser machine tools being used for cutting, welding and drilling and that the number could reach 30,000 over the next 15 years as manufacturing engineers become more aware of the capabilities of lasers [1). While most laser applications are dedicated to one product or process that involves high-volume, long-run manufacturing, the flexibility of a laser to supply energy to hard

  6. Welding. Performance Objectives. Intermediate Course.

    Vincent, Kenneth

    Several intermediate performance objectives and corresponding criterion measures are listed for each of nine terminal objectives for an intermediate welding course. The materials were developed for a 36-week (3 hours daily) course designed to prepare the student for employment in the field of welding. Electric welding and specialized (TIG & MIG)…

  7. Welding. Performance Objectives. Basic Course.

    Vincent, Kenneth

    Several intermediate performance objectives and corresponding criterion measures are listed for each of eight terminal objectives for a basic welding course. The materials were developed for a 36-week (2 hours daily) course developed to teach the fundamentals of welding shop work, to become familiar with the operation of the welding shop…

  8. Pulsed TIG welding of pipes

    Killing, U.

    1989-01-01

    The present study investigates into the effects of impulse welding parameters on weld geometry in the joint welding of thin-walled sheets and pipes (d=2.5 mm), and it uses random samples of thick-walled sheets and pipes (d=10 mm), in fixed positions. (orig./MM) [de

  9. Friction welding method

    Ishida, Ryuichi; Hatanaka, Tatsuo.

    1969-01-01

    A friction welding method for forming a lattice-shaped base and tie plate supporter for fuel elements is disclosed in which a plate formed with a concavity along its edge is pressure welded to a rotating member such as a boss by longitudinally contacting the projecting surfaces remaining on either side of the concavity with the rotating member during the high speed rotation thereof in the presence of an inert gas. Since only the two projecting surfaces of the plate are fused by friction to the rotary member, heat expansion is absorbed by the concavity to prevent distortion; moreover, a two point contact surface assures a stable fitting and promotes the construction of a rigid lattice in which a number of the abovementioned plates are friction welded between rotating members to form any desired complex arrangement. The inert has serves to protect the material quality of the contacting surfaces from air during the welding step. The present invention thus provides a method in which even Zircaloy may be friction welded in place of casting stainless steel in the construction of supporting lattices to thereby enhance neutron economy. (K. J. Owens)

  10. Single-step brazing process for mono-block joints and mechanical testing

    Casalegno, V.; Ferraris, M.; Salvo, M.; Rizzo, S.; Merola, M.

    2007-01-01

    Full text of publication follows: Plasma facing components act as actively cooled thermal shields to sustain thermal and particle loads during normal and transient operations in ITER (International Thermonuclear Experimental Reactor). The plasma-facing layer is referred to as 'armour', which is made of either carbon fibre reinforced carbon composite (CFC) or tungsten (W). CFC is the reference design solution for the lower part of the vertical target of the ITER divertor. The armour is joined onto an actively cooled substrate, the heat sink, made of precipitation hardened copper alloy CuCrZr through a thin pure copper interlayer to decrease, by plastic deformation, the joint interface stresses; in fact, the CFC to Cu joint is affected by the CTE mismatch between the ceramic and metallic material. A new method of joining CFC to copper and CFC/Cu to CuCrZr alloy was effectively developed for the flat-type configuration; the feasibility of this process also for mono-block geometry and the development of a procedure for testing mono-block-type mock-ups is described in this work. The mono-block configuration consists of copper alloy pipe shielded by CFC blocks. It is worth noting that in mono-block configuration, the large thermal expansion mismatch between CFC and copper alloy is more significant than for flat-tile configuration, due to curved interfaces. The joining technique foresees a single-step brazing process: the brazing of the three materials (CFC-Cu-CuCrZr) can be performed in a single heat treatment using the same Cu/Ge based braze. The composite surface was modified by solid state reaction with chromium with the purpose of increasing the wettability of CFC by the brazing alloy. The CFC substrate reacts with Cr which, forming a carbide layer, allows a large reduction of the contact angle; then, the brazing of CFC to pure copper and pure copper to CuCrZr by the same treatment is feasible. This process allows to obtain good joints using a non-active brazing

  11. Single-step brazing process for mono-block joints and mechanical testing

    Casalegno, V.; Ferraris, M.; Salvo, M.; Rizzo, S. [Politecnico di Torino, Materials Science and Chemical Engineering Dept., Torino (Italy); Merola, M. [ITER International Team, llER Joint Work Site, Cadarache, 13 - St Paul Lez Durance (France)

    2007-07-01

    Full text of publication follows: Plasma facing components act as actively cooled thermal shields to sustain thermal and particle loads during normal and transient operations in ITER (International Thermonuclear Experimental Reactor). The plasma-facing layer is referred to as 'armour', which is made of either carbon fibre reinforced carbon composite (CFC) or tungsten (W). CFC is the reference design solution for the lower part of the vertical target of the ITER divertor. The armour is joined onto an actively cooled substrate, the heat sink, made of precipitation hardened copper alloy CuCrZr through a thin pure copper interlayer to decrease, by plastic deformation, the joint interface stresses; in fact, the CFC to Cu joint is affected by the CTE mismatch between the ceramic and metallic material. A new method of joining CFC to copper and CFC/Cu to CuCrZr alloy was effectively developed for the flat-type configuration; the feasibility of this process also for mono-block geometry and the development of a procedure for testing mono-block-type mock-ups is described in this work. The mono-block configuration consists of copper alloy pipe shielded by CFC blocks. It is worth noting that in mono-block configuration, the large thermal expansion mismatch between CFC and copper alloy is more significant than for flat-tile configuration, due to curved interfaces. The joining technique foresees a single-step brazing process: the brazing of the three materials (CFC-Cu-CuCrZr) can be performed in a single heat treatment using the same Cu/Ge based braze. The composite surface was modified by solid state reaction with chromium with the purpose of increasing the wettability of CFC by the brazing alloy. The CFC substrate reacts with Cr which, forming a carbide layer, allows a large reduction of the contact angle; then, the brazing of CFC to pure copper and pure copper to CuCrZr by the same treatment is feasible. This process allows to obtain good joints using a non

  12. Friction stir welding tool and process for welding dissimilar materials

    Hovanski, Yuri; Grant, Glenn J; Jana, Saumyadeep; Mattlin, Karl F

    2013-05-07

    A friction stir welding tool and process for lap welding dissimilar materials are detailed. The invention includes a cutter scribe that penetrates and extrudes a first material of a lap weld stack to a preselected depth and further cuts a second material to provide a beneficial geometry defined by a plurality of mechanically interlocking features. The tool backfills the interlocking features generating a lap weld across the length of the interface between the dissimilar materials that enhances the shear strength of the lap weld.

  13. Interfacial Microstructure and Shear Strength of Brazed Cu-Cr-Zr Alloy Cylinder and Cylindrical Hole by Au Based Solder

    Zaihua Li

    2017-07-01

    Full Text Available Au-Ge-Ni solder was chosen for brazing of the Cu-Cr-Zr alloy cylinder and a part with a cylindrical hole (sleeve below 550 °C. The Au based solder was first sintered on the surface of the cylinder and then brazed to the inner surface of the sleeve. The effects of the heating process, the temperature and the holding time at the temperature on the microstructure of the sintered layer on the surface of the cylinder, the brazed interfacial microstructure, and the brazed shear strength between the cylinder and the sleeve were investigated by scanning electron microscope, energy dispersive X-ray spectroscopy analysis, and tensile shear tests. By approach of side solder melt feeding and brazing under proper parameters, the voids and micro cracks due to a lack of enough solder melt feeding are greatly lessened and the brazed shear strength of 100 MPa is ensured even with large clearances around 0.01 mm.

  14. Modelling Polymer Deformation and Welding Behaviour during 3D Printing

    McIlroy, Claire; Olmsted, Peter

    2016-11-01

    3D printing has the potential to transform manufacturing processes, yet improving the strength of printed parts, to equal that of traditionally-manufactured parts, remains an underlying issue. The most common method, fused deposition modelling, involves melting a thermoplastic, followed by layer-by-layer extrusion of the material to fabricate a three-dimensional object. The key to the ensuring strength at the weld between these layers is successful inter-diffusion. However, as the printed layer cools towards the glass transition temperature, the time available for diffusion is limited. In addition, the extrusion process significantly deforms the polymer micro-structure prior to welding and consequently affects how the polymers "re-entangle" across the weld. We have developed a simple model of the non-isothermal printing process to explore the effects that typical printing conditions and amorphous polymer rheology have on the ultimate weld structure. In particular, we incorporate both the stretch and orientation of the polymer using the Rolie-Poly constitutive equation to examine how the melt flows through the nozzle and is deposited onto the build plate. We then address how this deformation relaxes and contributes to the thickness and structure of the weld. National Institute for Standards and Technology (NIST) and Georgetown University.

  15. Plasma Processes of Cutting and Welding

    1976-02-01

    TIG process. 2.2.2 Keyhole Welding In plasma arc welding , the term...Cutting 3 3 4 4 4 2.2 Plasma Arc Welding 5 2.2.1 Needle Arc Welding 2.2.2 Keyhole Welding 5 6 3. Applications 8 93.1 Economics 4. Environmental Aspects of...Arc Lengths III. Needle Arc Welding Conditions IV. Keyhole Welding Conditions v. Chemical Analyses of Plates Used - vii - 1. 2. 3. 4. 5. 6. 7. 8.

  16. Friction Stir Welding Process: A Green Technology

    Esther T. Akinlabi; Stephen A. Akinlabi

    2012-01-01

    Friction Stir Welding (FSW) is a solid state welding process invented and patented by The Welding Institute (TWI) in the United Kingdom in 1991 for butt and lap welding of metals and plastics. This paper highlights the benefits of friction stir welding process as an energy efficient and a green technology process in the field of welding. Compared to the other conventional welding processes, its benefits, typical applications and its use in joining similar and dissimilar materia...

  17. Weld Nugget Temperature Control in Thermal Stir Welding

    Ding, R. Jeffrey (Inventor)

    2014-01-01

    A control system for a thermal stir welding system is provided. The control system includes a sensor and a controller. The sensor is coupled to the welding system's containment plate assembly and generates signals indicative of temperature of a region adjacent and parallel to the welding system's stir rod. The controller is coupled to the sensor and generates at least one control signal using the sensor signals indicative of temperature. The controller is also coupled to the welding system such that at least one of rotational speed of the stir rod, heat supplied by the welding system's induction heater, and feed speed of the welding system's weld material feeder are controlled based on the control signal(s).

  18. Thermal Stir Welding: A New Solid State Welding Process

    Ding, R. Jeffrey

    2003-01-01

    Thermal stir welding is a new welding process developed at NASA's Marshall Space Flight Center in Huntsville, AL. Thermal stir welding is similar to friction stir welding in that it joins similar or dissimilar materials without melting the parent material. However, unlike friction stir welding, the heating, stirring and forging elements of the process are all independent of each other and are separately controlled. Furthermore, the heating element of the process can be either a solid-state process (such as a thermal blanket, induction type process, etc), or, a fusion process (YG laser, plasma torch, etc.) The separation of the heating, stirring, forging elements of the process allows more degrees of freedom for greater process control. This paper introduces the mechanics of the thermal stir welding process. In addition, weld mechanical property data is presented for selected alloys as well as metallurgical analysis.

  19. Numerical simulation of welding

    Hansen, Jan Langkjær; Thorborg, Jesper

    Aim of project:To analyse and model the transient thermal field from arc welding (SMAW, V-shaped buttweld in 15mm plate) and to some extend the mechanical response due to the thermal field. - To implement this model in a general purpose finite element program such as ABAQUS.The simulation...... stress is also taken into account.Work carried out:With few means it is possible to define a thermal model which describes the thermal field from the welding process in reasonable agreement with reality. Identical results are found with ABAQUS and Rosenthal’s analytical solution of the governing heat...... transfer equation under same conditions. It is relative easy tointroduce boundary conditions such as convection and radiation where not surprisingly the radiation has the greatest influence especially from the high temperature regions in the weld pool and the heat affected zone.Due to the large temperature...

  20. Milestones in welding technology

    Dolby, Richard E.

    2013-09-01

    Sir Alan's PhD thesis describes his research into cracking during arc welding of armour steels. Throughout his career, he had a strong interest in defects of all types, how they formed in metallic structures and how the larger ones could be detected and sized by non-destructive techniques. He was also vitally concerned with how defects impacted on the engineering integrity of welded structures, particularly the risk of fracture in nuclear plant. This study presents a view of some of the major milestones in global welding technology that took place over the 60 or more years of Sir Alan's career and highlights those where he had a personal and direct involvement.

  1. Welding technologies for nuclear machinery and equipment

    Kobayashi, Masahiro; Yokono, Tomomi.

    1991-01-01

    The main welding methods applied to nuclear machinery and equipment are shielded metal arc welding, submerged arc welding, MAG welding and TIG welding. But in the last 10 years, in order to improve the reliability required for the welding of nuclear machinery and equipment, the welding technologies aiming at the reduction of heat input, the decrease of the number of welding pass and the automatic control of welding factors have been applied for the main purpose of bettering the quality and excluding human errors. The merits and the technology of narrow gap, pulsed MAG welding and melt-through welding are explained. As the automation of TIG welding, image processing type narrow gap, hot wire TIG welding and remote control type automatic TIG welding are described. For the longitudinal welding of active metal sheet products, plasma key-hole welding is applied. Since the concentration of its arc is good, high speed welding with low heat input can be done. For the stainless steel cladding by welding, electroslag welding has become to be employed in place of conventional submerged arc welding. Arc is not generated in the electroslag welding, and the penetration into base metal is small. (K.I.)

  2. Mechanized hyperbaric welding by robots

    Aust, E.; Santos, J.F. dos; Bohm, K.H.; Hensel, H.D.

    1988-01-01

    At the GKSS-Forschungszentrum investigations are carried out on mechanized welded test plates produced under working pressure between 10 to 110 bar in breathable TRIMIX-5-atmosphere. The welds are performed by a modified industrial robot, which was adapted in its components to withstand these severe conditions. Variations on the welding parameters were made to maintain a stable arc as well as to provide on indication of the effect of the variables on the mechanical properties of the welded joint. During all tests the robot showed a very good function. Good reliable welds were achieved meeting the requirements according API II04 or BS 4515-1984. (orig.) [de

  3. Spot Welding of Honeycomb Structures

    Cohal, V.

    2017-08-01

    Honeycomb structures are used to prepare meals water jet cutting machines for textile. These honeycomb structures are made of stainless steel sheet thickness of 0.1-0.2 mm. Corrugated sheet metal strips are between two gears with special tooth profile. Hexagonal cells for obtaining these strips are welded points between them. Spot welding device is three electrodes in the upper part, which carries three welding points across the width of the strip of corrugated sheet metal. Spot welding device filled with press and advance mechanisms. The paper presents the values of the regime for spot welding.

  4. Understanding Friction Stir Welding

    Nunes, A. C., Jr.

    2018-01-01

    This Technical Memorandum explains the friction stir welding process in terms of two basic concepts: the concentration of deformation in a shear surface enveloping the tool and the composition of the overall plastic flow field around the tool from simple flow field components. It is demonstrated how weld structure may be understood and torque, drag, and lateral tool forces may be estimated using these concepts. Some discrepancies between computations and accompanying empirical data are discussed in the text. This work is intended to be helpful to engineers in diagnosing problems and advancing technology.

  5. Method of manufacturing borosilicate glass solidification products

    Tanaka, Tsuneya.

    1986-01-01

    Purpose: To obtain glass solidification products efficiently in a dry process from medium and high level radioactive liquid wastes discharged from PWR type reactors. Method: Boric acid-containing radioactive liquid wastes generated from primary coolants of PWR type reactors are evaporated to condensate as the pre-treatment. The concentrated liquid wastes are supplied to a drum type rotary kiln. While on the other hand, usual glass frits are introduced into the kiln. The liquid wastes are dried in the rotary kiln, as well as B 2 O 3 and the glass frits in the liquid wastes are combined into glass particles. In this case, since the kiln is rotated, no glass particles are deposited on the wall of the kiln. Then, the glass particles are introduced for melting into a high frequency melting furnace made of metal. The melting temperature is set to 1100 - 1150 deg C. The molten borosilicate glass is recovered from the bottom of the melting furance, contained in a canister and cooled for several hours, and then a cover is welded to the canister. (Ikeda, J.)

  6. Laser hybrid brazing of oxide ceramics for high temperature gas sensing applications in (V)HTRS

    Heilmann, F. [Robert Bosch GmbH, Stuttgart (Germany). Corporate Research and Advance Engineering; Technische Univ. Dresden (Germany). Chair of Hydrogen- and Nuclear Engineering; Rixecker, G. [Robert Bosch GmbH, Stuttgart (Germany). Corporate Research and Advance Engineering; Boerner, F.D.; Lippmann, W.; Hurtado, A. [Technische Univ. Dresden (Germany). Chair of Hydrogen- and Nuclear Engineering

    2009-07-01

    It has been shown that the use of halogen lamps to assist laser brazing reduces total energy and joining time. For parts with specific geometries not suitable for a rotation process, an assistive heating with halogen lamps might be even more beneficial, to alleviate temperature gradients and transients. Forsterite-based ceramics are highly suitable as a joining partner for ZrO{sub 2}, especially in a laser brazing process based on volume heating. By adding Fe{sub 2}O{sub 3} to the raw powder mixture, the absorptivity of the forsterite ceramic can be tuned with an optimum at 0.1 wt.% Fe, reducing the necessary laser energy input even more. (orig.)

  7. Determinants of the quality of brazed joints of nickel-based superalloys

    Katarzyna Strzelczak

    2017-10-01

    Full Text Available In the aerospace industry, passenger safety depends on proper quality control at each production stage. The main responsibility for the correct operation of the aircraft lies within a gas turbine. A proper and rigorous selection of the gas turbine construction material is required, and in a further step, the method of joining the construction parts. Nickel superalloys due to the high heat resistance, strength and creep resistance at high temperatures, toughness and corrosion resistance, are very often used for the construction of a gas turbine engine. In the next step, the selection of joining method is necessary. This method must be able to achieve high-quality connections, resistant to work at high temperatures and corrosive environments. The most effective bonding method that meets the above conditions is brazing. In this study non-destructive (visual test and destructive (metallographic test of brazed joint of Inconel 718 and Inconel 625 were conducted.

  8. High heat flux test of tungsten brazed mock-ups developed for KSTAR divertor

    Song, J.H. [National Fusion Research Institute, Daejeon (Korea, Republic of); Kim, K.M., E-mail: kyungmin@nfri.re.kr [National Fusion Research Institute, Daejeon (Korea, Republic of); Hong, S.H.; Kim, H.T.; Park, S.H.; Park, H.K.; Ahn, H.J. [National Fusion Research Institute, Daejeon (Korea, Republic of); Kim, S.K.; Lee, D.W. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-11-01

    The tungsten (W) brazed flat type mock-up which consists of W, OFHC-Cu (oxygen-free high conductive copper) and CuCrZr alloy has been designed for KSTAR divertor in preparation for KSTAR upgrade with 17 MW heating power. For verification of the W brazed mock-up, the high heat flux test is performed at KoHLT-EB (Korea High Heat Load Test Facility-Electron Beam) in KAERI (Korea Atomic Energy Research Institute). Three mock-ups are tested for several thousand thermal cycles with absorbed heat flux up to 5 MW/m{sup 2} for 20 s duration. There is no evidence of the failure at the bonding joints of all mock-ups after HHF test. Finite element analysis (FEA) is performed to interpret the result of the test. As a result, it is considered that the local area in the water is in the subcooled boiling regime.

  9. Electric strength of metal-ceramic brazed units of thermionic energy converters in cesium vapours

    Belousenko, A.P.; Vasilchenko, A.V.; Nikolaev, Y.V.

    1989-01-01

    The investigation of electric strength characteristics of the hollow metal-ceramic brazed units of thermionic energy converters with the insulator 1 = 10-50 mm from polycrystal aluminum oxide at the temperature T = 450-750 degrees and the cesium vapour pressure P Cs = 10 - 1 -10 3 Pa has been carried out. The experimental dependencies of the break-down voltage of the brazed units on the temperature, parameter P Cs · 1 and the value of surface electric resistance of the insulators are given as well as the empiric equations obtained with the help of experimental data for calculating the break-down voltage. A mechanism of ceramic insulator influence on electric strength characteristics of the cesium gap is investigated. A breakdown model explaining this influence is proposed

  10. Evaluation of mechanically alloyed Cu-based powders as filler alloy for brazing tungsten to a reduced activation ferritic-martensitic steel

    Prado, J. de, E-mail: javier.deprado@urjc.es; Sánchez, M.; Ureña, A.

    2017-07-15

    80Cu-20Ti powders were evaluated for their use as filler alloy for high temperature brazing of tungsten to a reduced activation ferritic/martensitic steel (Eurofer), and its application for the first wall of the DEMO fusion reactor. The use of alloyed powders has not been widely considered for brazing purposes and could improve the operational brazeability of the studied system due to its narrower melting range, determined by DTA analysis, which enhances the spreading capabilities of the filler. Ti contained in the filler composition acts as an activator element, reacting and forming several interfacial layers at the Eurofer-braze, which enhances the wettability properties and chemical interaction at the brazing interface. Brazing thermal cycle also activated the diffusion phenomena, which mainly affected to the Eurofer alloying elements causing in it a softening band of approximately 400 μm of thickness. However, this softening effect did not degrade the shear strength of the brazed joints (94 ± 23 MPa), because failure during testing was always located at the tungsten-braze interface. - Highlights: •W-Eurofer brazed joints, manufactured using Cu-based mechanically alloyed powders as filler is proposed. •The benefits derivate from the alloyed composition could improve the operational brazeability of the studied system. •Tested pre-alloyed fillers have a more homogeneous melting stage which enhances its spreading and flowing capabilities. •This behaviour could lead to work with higher heating rates and lower brazing temperatures.

  11. Microstructure Evolution During Stainless Steel-Copper Vacuum Brazing with a Ag/Cu/Pd Filler Alloy: Effect of Nickel Plating

    Choudhary, R. K.; Laik, A.; Mishra, P.

    2017-03-01

    Vacuum brazing of stainless steel and copper plates was done using a silver-based filler alloy. In one set of experiments, around 30-µm-thick nickel coatings were electrochemically applied on stainless steel plates before carrying out the brazing runs and its effect in making changes in the braze-zone microstructure was studied. For brazing temperature of 830 °C, scanning electron microscopy examination of the braze-zone revealed that relatively sound joints were obtained when brazing was done with nickel-coated stainless steel than with uncoated one. However, when brazing of nickel-coated stainless steel and copper plates was done at 860 °C, a wide crack appeared in the braze-zone adjacent to copper side. Energy-dispersive x-ray analysis and electron microprobe analysis confirmed that at higher temperature, the diffusion of Cu atoms from copper plate towards the braze-zone was faster than that of Ni atoms from nickel coating. Helium leak rate of the order 10-11 Pa m3/s was obtained for the crack-free joint, whereas this value was higher than 10-4 Pa m3/s for the joint having crack. The shear strength of the joint was found to decrease considerably due to the presence of crack.

  12. Welding method by remote handling

    Hashinokuchi, Minoru.

    1994-01-01

    Water is charged into a pit (or a water reservoir) and an article to be welded is placed on a support in the pit by remote handling. A steel plate is disposed so as to cover the article to be welded by remote handling. The welding device is positioned to the portion to be welded and fixed in a state where the article to be welded is shielded from radiation by water and the steel plate. Water in the pit is drained till the portion to be welded is exposed to the atmosphere. Then, welding is conducted. After completion of the welding, water is charged again to the pit and the welding device and fixing jigs are decomposed in a state where the article to be welded is shielded again from radiation by water and the steel plate. Subsequently, the steel plate is removed by remote handling. Then, the article to be welded is returned from the pit to a temporary placing pool by remote handling. This can reduce operator's exposure. Further, since the amount of the shielding materials can be minimized, the amount of radioactive wastes can be decreased. (I.N.)

  13. Ultrasonic inspection of austenitic welds

    Tomlinson, J R; Wagg, A R; Whittle, M J [N.D.T. Applications Centre, CEGB, Manchester (United Kingdom)

    1980-11-01

    The metallurgical structure of austenitic welds is described and contrasted with that found in ferritic welds. It is shown that this structure imparts a marked elastic anisotropy in the ultrasonic propagation parameters. Measurements of variations in the apparent attenuation of sound and deviations in the beam direction are described. The measurements are interpreted in terms of the measured velocity anisotropy. Two applications of the fundamental work are described. In the first it is shown how, by using short pulse compression wave probes, and with major modification of the welding procedure, a stainless steel fillet weld in an AGR boiler can be inspected. In the second application, alternative designs of a transition butt weld have been compared for ease of ultrasonic inspection. The effects of two different welding processes on such an inspection are described. Finally, the paper examines the prospects for future development of inspection and defect-sizing techniques for austenitic welds. (author)

  14. Visualization of Spot- welding Resistance

    Michal Černý

    2016-01-01

    Full Text Available This contribution devotes to monitoring of processes running during joining of steel sheets by incadescent so called point welding using non-destructive trial method – acoustic emission (AE. The joining process is detailed described within experimental measuring from the point of view of metallurgic effects runnig during weld creation (records obtained by means of AE method. It takes into consideration quality of joined steels within welding data of steel producer. Steel welding (determined by chemical composition during mechanical verification and firmness of welds consider results of measurement AE and fracture effect of point joints. The measurement also demonstrates conclusion about connection of metallurgic processes with material wave effects (AE measurement and their impact on firmness of joint at steel with guaranteed welding, difficult welding and at their potential combination.

  15. Fast brazing development for the joining of the beryllium armor layer for the ITER First Wall panels

    Buodot, C.; Boireau, B.; Lorenzetto, P.; Macel, D.

    2006-01-01

    In order to reduce cost and manufacturing time induction brazing is being developed as an alternative to Hot Isostatic Pressing for the joining of the beryllium armor onto the copper alloy heat sink material for the manufacture of First Wall panels for the ITER Blanket. The copper alloy that is currently adopted by ITER is a Copper Chromium Zirconium alloy. Its good mechanical properties are obtained by precipitation hardening by means of an ageing heat treatment at a temperature of about 480 o C. In order to avoid over-ageing and keep acceptable mechanical properties, brazing at higher temperatures must therefore be done as fast as possible. The flat geometry of a panel is not familiar for induction process; nevertheless, a development work was done validating the feasibility of joining beryllium tiles onto a copper chromium zirconium flat surface of a panel by induction brazing process. The development was done in 2 stages: validation of the capability of the induction process to realise a heat cycle on a dummy panel and in parallel, validation of the brazing parameters giving acceptable mechanical results on the beryllium CuCrZr joint. A flat pancake inductor was manufactured and tested on a dummy panel in an induction brazing vessel manufactured for this purpose. Several heating cycles were done with the aim of defining a cycle that gives uniform temperature at the interface of all the beryllium tiles on the entire panel surface. These cycles gave us a temperature range in which the brazing can be performed. A special device for brazing small mock up was also manufactured. This was for the metallurgical characterisation program. Many brazing samples where done and mechanically characterised. Unfortunately, this first metallurgical stage led to unacceptably low shear test values. A complete analysis of this non conformance put in evidence that the bad results were due to the braze material that was not adapted to this process. By changing the braze material

  16. High-power comparison among brazed, clamped and electroformed X-band cavities

    Spataro, B., E-mail: bruno.spataro@lnf.infn.it [INFN-LNF, Via E. Fermi 40, 00044 Frascati, Rome (Italy); Alesini, D.; Chimenti, V. [INFN-LNF, Via E. Fermi 40, 00044 Frascati, Rome (Italy); Dolgashev, V. [SLAC, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); Higashi, Y. [KEK 1-1 Oho, Tsukuba, Ibaraki, 305-0801 (Japan); Migliorati, M.; Mostacci, A. [University of Rome Sapienza, Department of Fundamental and Applied Science for Engineering, Via A. Scarpa 14, 00185 Rome (Italy); Parodi, R. [INFN-Genova, Via Dodecaneso 33, 16146 Genova (Italy); Tantawi, S.G.; Yeremian, A.D. [SLAC, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States)

    2011-11-21

    We report the building procedure of X-band copper structures using the electroforming and electroplating techniques. These techniques allow the deposition of copper layers on a suitable die and they can be used to build RF structures avoiding the high temperature brazing step in the standard technique. We show the constructed prototypes and low power RF measurements and discuss the results of the high power tests at SLAC National Accelerator Laboratory.

  17. Large Area Active Brazing of Multi-tile Ceramic-Metal Structures

    2012-05-01

    metallurgical bonds. The major disadvantage of using active brazing for metals and ceramics is the high processing temperature required that results in...steels) and form strong, metallurgical bonds. However, the high processing temperatures result in large strain (stress) build-up from the inherent...metals such as titanium alloys and stainless steels) and form strong, metallurgical bonds. However, the high processing temperatures result in large

  18. Synchronous separation, seaming, sealing and sterilization (S4) using brazing for sample containerization and planetary protection

    Bar-Cohen, Yoseph; Badescu, Mircea; Sherrit, Stewart; Bao, Xiaoqi; Lindsey, Cameron; Kutzer, Thomas; Salazar, Eduardo

    2018-03-01

    The return of samples back to Earth in future missions would require protection of our planet from the risk of bringing uncontrolled biological materials back with the samples. This protection would require "breaking the chain of contact (BTC)", where any returned material reaching Earth for further analysis would have to be sealed inside a container with extremely high confidence. Therefore, the acquired samples would need to be contained while destroying any potential biological materials that may contaminate the external surface of the container. A novel process that could be used to contain returning samples has been developed and demonstrated in a quarter scale size. The process consists of brazing using non-contact induction heating that synchronously separates, seams, seals and sterilizes (S4) the container. The use of brazing involves melting at temperatures higher than 500°C and this level of heating assures sterilization of the exposed areas since all carbon bonds (namely, organic materials) are broken at this temperature. The mechanism consists of a double wall container with inner and outer shells having Earth-clean interior surfaces. The process consists of two-steps, Step-1: the double wall container halves are fabricated and brazed (equivalent to production on Earth); and Step-2 is the S4 process and it is the equivalent to the execution on-orbit around Mars. In a potential future mission, the double wall container would be split into two halves and prepared on Earth. The potential on-orbit execution would consist of inserting the orbiting sample (OS) container into one of the halves and then mated to the other half and brazed. The latest results of this effort will be described and discussed in this manuscript.

  19. Experimental Results For Hydrocarbon Refrigerant Vaporization In Brazed Plate Heat Exchangers at High Pressure

    Desideri, Adriano; Schmidt Ommen, Torben; Wronski, Jorrit; Quoilin, Sylvain; Lemort, Vincent; Haglind, Fredrik

    2016-01-01

    In this contribution, the experimental heat transfer coefficient  and the pressure drop measured during HFC refrigerants vaporization inside small brazed plate heat exchanger (PHE) at typical evaporation temperature for organic Rankine cycle systems for low thermal energy quality applications are presented. Scientific work focusing on the heat transfer in PHEs has been carried out since the late 19th century. More recent publications have been focusing on vaporization and condensation of ref...

  20. Experimental results for hydrocarbon refrigerant vaporization in brazed plate heat exchangers at high pressure

    Desideri, Adriano; Rhyl Kaern, Martin; Ommen Schmidt, Torben; Wronski, Jorrit; Quoilin, Sylvain; Lemort, Vincent; Haglind, Fredrik

    2016-01-01

    In recent years the interest in small capacity organic Rankine cycle (ORC) power systems for harvesting low quality waste thermal energy from industrial processes has been steadily growing. Micro ORC systems are normally equipped with brazed plate heat exchangers which allows for efficient heat transfer with a compact design. An accurate prediction of the heat transfer process characterizing these devices is required from the design phase to the development of model- based control strategies....

  1. Elastic-plastic-creep analysis of brazed carbon-carbon/OFHC divertor tile concepts for TPX

    Chin, E.; Reis, E.E.

    1995-01-01

    The 7.5 MW/m 2 heat flux requirements for the TPX divertor necessitate the use of high conductivity carbon-carbon (C-C) tiles that are brazed to annealed copper (OFHC) coolant tubes. Significant residual stresses are developed in the C-C tiles during the braze process due to large differences in the thermal expansion coefficients between these materials. Analyses which account for only the elastic-plastic strains developed in the OFHC tube may not accurately characterize the behavior of the tube during brazing. The elevated temperature creep behavior of the copper coolant tubes intuitively should reduce the calculated residual stresses in the C-C tiles. Two divertor tile concepts, the monoblock and the archblock, were analyzed for residual stress using 2-D finite element analysis for elastic-plastic-creep behavior of the OFHC tube during an assumed braze cooldown cycle. The results show that the inclusion of elevated temperature creep effects decrease the calculated residual stresses by only about 10% when compared to those analyses in which only elastic-plastic behavior of the OFHC is accounted for. The primary reason that creep effects at higher temperatures are not more significant is due to the low yield stress and nearly flat-top stress-strain curve of annealed OFHC. Since high temperature creep plays less of a role in the residual stress levels than previously thought, future scoping studies can be done in an elastic-plastic analysis with confidence that the stresses will be within approximately 10% of an elastic-plastic-creep analysis

  2. Recent Corrosion Research Trends in Weld Joints

    Kim, Hwan Tae; Kil, Sang Cheol; Hwang, Woon Suk

    2007-01-01

    The increasing interest in the corrosion properties of weld joints in the corrosive environment is placing stringent demands on the manufacturing techniques and performance requirements, and the manufacture employs the high quality and efficiency welding process to produce welds. Welding plays an important role in the fabrication of chemical plants, nuclear power plant, ship construction, and this has led to an increasing attention to the corrosion resistant weld joints. This paper covers recent technical trends of welding technologies for corrosion resistance properties including the COMPENDEX DB analysis of welding materials, welding process, and welding fabrications

  3. Welding technology transfer task/laser based weld joint tracking system for compressor girth welds

    Looney, Alan

    1991-01-01

    Sensors to control and monitor welding operations are currently being developed at Marshall Space Flight Center. The laser based weld bead profiler/torch rotation sensor was modified to provide a weld joint tracking system for compressor girth welds. The tracking system features a precision laser based vision sensor, automated two-axis machine motion, and an industrial PC controller. The system benefits are elimination of weld repairs caused by joint tracking errors which reduces manufacturing costs and increases production output, simplification of tooling, and free costly manufacturing floor space.

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

    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.

  5. Heating and thermal control of brazing technique to break contamination path for potential Mars sample return

    Bao, Xiaoqi; Badescu, Mircea; Sherrit, Stewart; Bar-Cohen, Yoseph; Campos, Sergio

    2017-04-01

    The potential return of Mars sample material is of great interest to the planetary science community, as it would enable extensive analysis of samples with highly sensitive laboratory instruments. It is important to make sure such a mission concept would not bring any living microbes, which may possibly exist on Mars, back to Earth's environment. In order to ensure the isolation of Mars microbes from Earth's Atmosphere, a brazing sealing and sterilizing technique was proposed to break the Mars-to-Earth contamination path. Effectively, heating the brazing zone in high vacuum space and controlling the sample temperature for integrity are key challenges to the implementation of this technique. The break-thechain procedures for container configurations, which are being considered, were simulated by multi-physics finite element models. Different heating methods including induction and resistive/radiation were evaluated. The temperature profiles of Martian samples in a proposed container structure were predicted. The results show that the sealing and sterilizing process can be controlled such that the samples temperature is maintained below the level that may cause damage, and that the brazing technique is a feasible approach to breaking the contamination path.

  6. Preparation of W/CuCrZr monoblock test mock-up using vacuum brazing technique

    Singh, Kongkham Premjit; Khirwadkar, Samir S.; Bhope, Kedar; Patel, Nikunj; Mokaria, Prakash K.; Mehta, Mayur

    2015-01-01

    Development of the joining for W/CuCrZr monoblock PFC test mock-up is an interest area in Fusion R and D. W/Cu bimetallic material has prepared using OFHC copper casting approach on the radial surface of W monoblock tile surface. The W/Cu bimetallic material has been joined with CuCrZr tube (heat sink) material with the vacuum brazing route. Vacuum brazing of W/Cu-CuCrZr has been performed @ 970 °C for 10 mins using NiCuMn-37 filler material under deep vacuum environment (10 -6 mbar). Graphite fixtures were used for OFHC copper casting and vacuum brazing experiments. The joint integrity of W/Cu-CuCrZr monoblock mock-up on W/Cu and Cu-CuCrZr has been checked using ultrasonic immersion technique. Micro-structural examination and Spot-wise elemental analysis have been carried out using HR-SEM and EDAX. The results of the experimental work will be discussed in the paper. (author)

  7. Vacuum brazing of metals (1961); Brassure sous vide des metaux (1961)

    Lapujoulade, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1961-07-01

    We have studied brazing in vacuum aiming its application for the making of containers and apparatus meant for high vacuum (p < 10{sup -8} torr). We first define the wettability of a brazing alloy on a metal and we remind the influence of the various parameters which act on this wettability (nature of the solid, of the liquid, geometrical and physicochemical state of the surface, metallurgical reactions occurring at the interface, temperature, time). We give then the results of the tests carried out in order to determine the conditions of wettability in vacuum of some brazing alloys on metals which can be used for the above mentioned apparatus (stainless steel, aluminium, bronze, titanium, zirconium, kovar, nickel, copper). (author) [French] Nous avons etudie la brasure sous vide en vue de son application a la construction d'enceintes et apparelilage destines a l'obtention des vides eleves (p < 10{sup -8} torr). Nous definissons d'abord la mouillabilite d'une brasure sur un metal et nous rappelons l'influence des differents parametres qui agissent sur cette mouillabilite (nature du solide, du liquide, etat geometrique et physico-chimique de la surface, reactions metallurgiques a l'interface, temperature, temps). Nous donnons ensuite les resultats des essais effectues dans le but de determiner les conditions de mouillabilite sous vide de certaines brassures sur des metaux utilisables dans les constructions mentionnees ci-dessus (acier inoxydable, bronze d'aluminium, titane, zirconium, kovar, nickel, cuivre). (auteur)

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

    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...

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

    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.

  10. 49 CFR 192.225 - Welding procedures.

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Welding procedures. 192.225 Section 192.225... BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Welding of Steel in Pipelines § 192.225 Welding procedures. (a) Welding must be performed by a qualified welder in accordance with welding procedures...

  11. Integrated sensors for robotic laser welding

    Iakovou, D.; Aarts, Ronald G.K.M.; Meijer, J.; Beyer, E.; Dausinger, F; Ostendorf, A; Otto, A.

    2005-01-01

    A welding head is under development with integrated sensory systems for robotic laser welding applications. Robotic laser welding requires sensory systems that are capable to accurately guide the welding head over a seam in three-dimensional space and provide information about the welding process as

  12. ICT diagnostic method of beryllium welding quality

    Sun Lingxia; Wei Kentang; Ye Yunchang

    2002-01-01

    To avoid the interference of high density material for the quality assay of beryllium welding line, a slice by slice scanning method was proposed based upon the research results of the Industrial Computerized Tomography (ICT) diagnostics for weld penetration, weld width, off-centered deviation and weld defects of beryllium-ring welding seam with high density material inside

  13. Sensor integration for robotic laser welding processes

    Iakovou, D.; Aarts, Ronald G.K.M.; Meijer, J.; Ostendorf, A; Hoult, A.; Lu, Y.

    2005-01-01

    The use of robotic laser welding is increasing among industrial applications, because of its ability to weld objects in three dimensions. Robotic laser welding involves three sub-processes: seam detection and tracking, welding process control, and weld seam inspection. Usually, for each sub-process,

  14. Glass compositions

    France, P W

    1985-05-30

    A fluoride glass for use in the production of optical fibres has an enhanced D/H ratio, preferably such that OD:OH is at least 9:1. In the example, such a glass is prepared by treating with D/sub 2/O a melt comprising 51.53 mole per cent ZrF/sub 4/, 20.47 mole per cent BaF/sub 2/, 5.27 mole per cent LaF/sub 3/, 3.24 mole per cent AlF/sub 3/, and 19.49 mole per cent LiF.

  15. Numerical analysis of weld pool oscillation in laser welding

    Cho, Jung Ho [Chungbuk National University, Cheongju (Korea, Republic of); Farson, Dave F [The Ohio State University, Columbus (United States); Hollis, Kendall; Milewski, John O. [Los Alamos National Laboratory, Los Alamos (United States)

    2015-04-15

    Volume of fluid (VOF) numerical simulation was used to investigate melt flow and volumetric oscillation of conduction-mode pulsed laser weld pools. The result is compared to high speed video stream of titanium laser spot welding experiment. The total simulation time is 10ms with the first 5 ms being heating and melting under constant laser irradiation and the remaining 5 ms corresponding to resolidification of the weld pool. During the melting process, the liquid pool did not exhibit periodic oscillation but was continually depressed by the evaporation recoil pressure. After the laser pulse, the weld pool was excited into volumetric oscillation by the release of pressure on its surface and oscillation of the weld pool surface was analyzed. The simulation model suggested adjusting thermal diffusivity to match cooling rate and puddle diameter during solidification which is distinguishable from previous weld pool simulation. The frequency continuously increased from several thousand cycles per second to tens of thousands of cycles per second as the weld pool solidified and its diameter decreased. The result is the first trial of investigation of small weld pool oscillation in laser welding although there have been several reports about arc welding.

  16. Deconvoluting the Friction Stir Weld Process for Optimizing Welds

    Schneider, Judy; Nunes, Arthur C.

    2008-01-01

    In the friction stir welding process, the rotating surfaces of the pin and shoulder contact the weld metal and force a rotational flow within the weld metal. Heat, generated by the metal deformation as well as frictional slippage with the contact surface, softens the metal and makes it easier to deform. As in any thermo-mechanical processing of metal, the flow conditions are critical to the quality of the weld. For example, extrusion of metal from under the shoulder of an excessively hot weld may relax local pressure and result in wormhole defects. The trace of the weld joint in the wake of the weld may vary geometrically depending upon the flow streamlines around the tool with some geometry more vulnerable to loss of strength from joint contamination than others. The material flow path around the tool cannot be seen in real time during the weld. By using analytical "tools" based upon the principles of mathematics and physics, a weld model can be created to compute features that can be observed. By comparing the computed observations with actual data, the weld model can be validated or adjusted to get better agreement. Inputs to the model to predict weld structures and properties include: hot working properties ofthe metal, pin tool geometry, travel rate, rotation and plunge force. Since metals record their prior hot working history, the hot working conditions imparted during FSW can be quantified by interpreting the final microstructure. Variations in texture and grain size result from variations in the strain accommodated at a given strain rate and temperature. Microstructural data from a variety of FSWs has been correlated with prior marker studies to contribute to our understanding of the FSW process. Once this stage is reached, the weld modeling process can save significant development costs by reducing costly trial-and-error approaches to obtaining quality welds.

  17. Welding in nuclear engineering

    1982-01-01

    The 3rd international conference 'Welding in nuclear engineering', organized in 1978 by the Deutscher Verband fuer Schweisstechnik e.V., was, like the two foregoing conferences in 1970 and 1974, an absolute success. The noteworthy echo to this meeting in the international technical world - the number of 650 participants from 26 countries is self-evidence - and this fact, was for the Deutscher Verband fuer Schweisstechnik e.V. occasion and at the same time an obligation now to follow in the same way, the meeting that was started 12 years ago, by organizing the international conference 'Welding in nuclear engineering'. The conference this year offers in addition to the two plenary session lectures, 34 short reports and a further 28 single contributions in the form of two poster-sessions. Unfortunately, it was again not possible to accept all the papers submitted because the conference was limited to 2 days only. Nevertheless, the papers will offer a representative cross-section through the total range of welding engineering. In particular, the poster session, which take place for the first time within the scope of a meeting organized by the Working Group 'Welding in Nuclear Engineering', should contribute to the aim that this time again the discussions will form the main point of the conference. (orig./RW) [de

  18. Welding. Student Learning Guide.

    Palm Beach County Board of Public Instruction, West Palm Beach, FL.

    This student learning guide contains 30 modules for completing a course in welding. It is designed especially for use in secondary schools in Palm Beach County, Florida. Each module covers one task, and consists of a purpose, performance objective, enabling objectives, learning activities keyed to resources, information sheets, student self-check…

  19. Thermal Stresses in Welding

    Hansen, Jan Langkjær

    1998-01-01

    Studies of the transient temperature fields and the hereby induced deformations and stressses in a butt-welded mild steel plate modelledrespectively in 2D plane stress state (as well as plane strain state) and in full 3D have been done. The model has been implemented in the generalpurpose FE...

  20. State Skill Standards: Welding

    Pointer, Mike; Naylor, Randy; Warden, John; Senek, Gene; Shirley, Charles; Lefcourt, Lew; Munson, Justin; Johnson, Art

    2005-01-01

    The Department of Education has undertaken an ambitious effort to develop statewide occupational skill standards. The standards in this document are for welding programs and are designed to clearly state what the student should know and be able to do upon completion of an advanced high-school program. The writing team determined that any statewide…

  1. Elementary TIG Welding Skills.

    Pierson, John E., III

    The text was prepared to help deaf students develop the skills needed by an employed welder. It uses simplified language and illustrations to present concepts which should be reinforced by practical experience with welding skills. Each of the 12 lessons contains: (1) an information section with many illustrations which presents a concept or…

  2. The Characteristics of Welding Joint on Stainless Steel as a Candidate of High Level Waste Canister

    Aisyah; Herlan-Martono

    2000-01-01

    High level waste is the waste generated from reprocessing of the spent fuels. This type of waste is vitrified with borosilicate glass to become waste-glass. This waste glass is contained in a canister made of austenitic stainless steel. The canister material is subjected to be welded during fabrication and utilization. The character of the welding joint that is the function of the electrical current used in the welding process have been studied. The strength of the joint is tested mechanically i.e.: the tensile strength and hardness test. The result shows that the higher the current used in welding process, the better the strength of the joint and as well the tensile strength. The optimum current is 110 A. From the hardness test, it was figured that the length of the HAZ area is 14 mm. The material in HAZ area is the hardest compared to the others, it is due to the appearance of the chrome-carbide. The welding of the canister with such a condition, during fabrication as well as during the utilization of the canister for the container of the high level waste with the PWHT process gives better result. (author)

  3. Effect of Pin Geometry on the Mechanical Strength of Friction-Stir-Welded Polypropylene Composite Plates

    Kordestani, F.; Ashenai Ghasemi, F.; Arab, N. B. M.

    2017-09-01

    Friction stir welding (FSW) is a solid-state welding process, which has successfully been applied in aerospace and automotive industries for joining materials. The friction stir tool is the key element in the FSW process. In this study, the effect of four different tool pin geometries on the mechanical properties of two types of polypropylene composite plates, with 30% glass and carbon fiber, respectively, were investigated. For this purpose, four pins of different geometry, namely, a threaded-tapered pin, square pin, four-flute threaded pin, and threaded-tapered pin with a chamfer were made and used to carry out the butt welding of 5-mm-thick plates. The standard tensile and Izod impact tests were performed to evaluate the tensile strength and impact toughness of welded specimens. The results indicated that the threaded-tapered pin with a chamfer produced welds with a better surface appearance and higher tensile and impact strengths. The tests also showed that, with the threaded-tapered pin with a chamfer, the impact strength of the glass- and carbon-fiber composite welds were about 40 and 50%, respectively, of that of the base materials.

  4. Galvanic corrosion of beryllium welds

    Hill, M.A.; Butt, D.P.; Lillard, R.S.

    1997-01-01

    Beryllium is difficult to weld because it is highly susceptible to cracking. The most commonly used filler metal in beryllium welds is Al-12 wt.% Si. Beryllium has been successfully welded using Al-Si filler metal with more than 30 wt.% Al. This filler creates an aluminum-rich fusion zone with a low melting point that tends to backfill cracks. Drawbacks to adding a filler metal include a reduction in service temperature, a lowering of the tensile strength of the weld, and the possibility for galvanic corrosion to occur at the weld. To evaluate the degree of interaction between Be and Al-Si in an actual weld, sections from a mock beryllium weldment were exposed to 0.1 M Cl - solution. Results indicate that the galvanic couple between Be and the Al-Si weld material results in the cathodic protection of the weld and of the anodic dissolution of the bulk Be material. While the cathodic protection of Al is generally inefficient, the high anodic dissolution rate of the bulk Be during pitting corrosion combined with the insulating properties of the Be oxide afford some protection of the Al-Si weld material. Although dissolution of the Be precipitate in the weld material does occur, no corrosion of the Al-Si matrix was observed

  5. In-field Welding and Coating Protocols

    2009-05-12

    Gas Technology Institute (GTI) and Edison Welding Institute (EWI) created both laboratory and infield girth weld samples to evaluate the effects of weld geometry and hydrogen off-gassing on the performance of protective coatings. Laboratory made plat...

  6. Perspectives of special welding methods. 1

    Herden, G.; Buness, G.; Wiesner, P.

    1976-01-01

    Laser, electron, ion, and light beam welding as well as plasma arc welding are considered to be special fusion welding methods. The stage of development and possible future applications of these methods are described. (author)

  7. Improvements in and relating to welding

    Taylor, B.D.

    1979-01-01

    This invention concerns apparatus for use in welding, particularly welding which must be effected in a predetermined, for example, inert atmosphere, e.g. the welding of reactive materials such as zircaloy, titanium, magnesium, aluminium, etc. (U.K.)

  8. Welding for the CRBRP steam generators

    Spalaris, C.N.; Ring, P.J.; Durand, R.E.; Wright, E.A.

    1979-01-01

    The rationale for selecting weld design, welding procedures and inspection methods was based upon the desire to obtain the highest reliability welds for the CRBRP steam generators. To assure the highest weld reliability, heavy emphasis was placed on the control of material cleanliness and composition substantially exceeding the requirements of the ASME Code for 2-1/4Cr--1Mo. The high tube/tubesheet weld quality was achieved through close material control, an extensive weld development program and the selection of high reliability welding equipment. Shell and nozzle weld fabrication using TIG, MIG, and submerged arc procedures are also being controlled through precise specifications, including preheat and postheat programs, together with radiography and ultrasonic inspection to ascertain the weld quality desired. Details of the tube/tubesheet welding and shell welding are described and results from the weld testing program are discussed

  9. Measurement of residual stresses in welded sample of dissimilar materials

    Mansur, Tanius Rodrigues; Gomes, Paulo de Tarso Vida; Scaldaferri, Denis Henrique Bianchi; Martins, Geraldo Antonio Scoralick; Atanazio Filho, Nelson do Nascimento

    2008-01-01

    The welding of dissimilar metals has several applications in the industry. Especially in the nuclear industry, this joint type, common between carbon steel and stainless steel, it is always reason of analysis and special cares tends in view the need to maintain the integrity of the equipment. Residual stresses are introduced in the material as a result of processes as welding, machining, sanding and polishing that can to produce deformation in the proximities of the surface of the material. Residual compressive stresses can be introduced in the material through the jetting process (bombardment of the surface for small glass spheres, dry sand or steel). That procedure allows a fine subsurface layer to suffer yielding, compressing the superficial layer and reducing the formation of areas of concentration of traction stresses, increasing the resistance of the material to the fatigue. The welding process introduces residual stresses due to the geometry resulting from the fusion of the material welded and of the heterogeneous cooling. Besides the microstructural alteration and chemical composition of the material in the affected area for the heat, introduced by the welding, it is also had the effect of the discontinuity of the passes and the formation of bubbles and emptiness that can contribute to the cracks nucleation, reducing the resistance to the fatigue. In the great majority of the times residual stresses are harmful and there are many documented cases which US these stresses went predominant factors for the failure for fatigue. A particularly dangerous aspect of the residual stresses is that their presence is not usually observed, what usually happens with an applied load to the structure. The knowledge of the surface residual stresses is important to predict the emergence of failure when the component or structure is requested. In nuclear power plants it is common to welding of piping of stainless steels with mouthpieces of carbon steel of pressure vases of

  10. Developments in welding and joining methods of metallic materials

    Pilarczyk, J.

    2007-01-01

    The impact of the welding technology on the economy development. The welding and joining methods review. The particular role of the laser welding and its interesting applications: with filler metal, twin spot laser welding, hybrid welding process, remote welding. The fiber lasers. The high intensity electron beams applications for surface modification. The TIG welding with the use of the active flux. Friction welding, friction stir welding and friction linear welding. (author)

  11. An investigation on mechanical properties of steel fibre reinforced for underwater welded joint

    Navin, K.; Zakaria, M. S.; Zairi, S.

    2017-09-01

    Underwater pipelines are always exposed to water and have a high tendency to have corrosion especially on the welded joint. This research is about using fiber glass as steel fiber to coat the welded joint to determine the effectiveness in corrosion prevention of the welded joint. Number of coating is varied to determine the better number coating to coat the pipeline. Few samples were left without immersion in salt water and few samples are immersed into salt water with same salinity as sea water. The material sample is prepared in dog bone shape to enable to be used in Universal Tensile Machine (UTM). The material prepared is left immersed for recommended time and tested in Universal Tensile Machine. Upon analyzing the result, the result is used to determine the breakage point whether broken on the welded joint or different place and also the suitable number of coating to be used.

  12. Welding wire pressure sensor assembly

    Morris, Timothy B. (Inventor); Milly, Peter F., Sr. (Inventor); White, J. Kevin (Inventor)

    1994-01-01

    The present invention relates to a device which is used to monitor the position of a filler wire relative to a base material being welded as the filler wire is added to a welding pool. The device is applicable to automated welding systems wherein nonconsumable electrode arc welding processes are utilized in conjunction with a filler wire which is added to a weld pool created by the electrode arc. The invention senses pressure deviations from a predetermined pressure between the filler wire and the base material, and provides electrical signals responsive to the deviations for actuating control mechanisms in an automatic welding apparatus so as to minimize the pressure deviation and to prevent disengagement of the contact between the filler wire and the base material.

  13. Fundamental Laser Welding Process Investigations

    Bagger, Claus; Olsen, Flemming Ove

    1998-01-01

    In a number of systematic laboratory investigations the fundamental behavior of the laser welding process was analyzed by the use of normal video (30 Hz), high speed video (100 and 400 Hz) and photo diodes. Sensors were positioned to monitor the welding process from both the top side and the rear...... side of the specimen.Special attention has been given to the dynamic nature of the laser welding process, especially during unstable welding conditions. In one series of experiments, the stability of the process has been varied by changing the gap distance in lap welding. In another series...... video pictures (400 Hz), a clear impact on the seam characteristics has been identified when a hump occurs.Finally, a clear correlation between the position of the focus point, the resultant process type and the corresponding signal intensity and signal variation has been found for sheets welded...

  14. INERT GAS SHIELD FOR WELDING

    Jones, S.O.; Daly, F.V.

    1958-10-14

    S>An inert gas shield is presented for arc-welding materials such as zirconium that tend to oxidize rapidly in air. The device comprises a rectangular metal box into which the welding electrode is introduced through a rubber diaphragm to provide flexibility. The front of the box is provided with a wlndow having a small hole through which flller metal is introduced. The box is supplied with an inert gas to exclude the atmosphere, and with cooling water to promote the solidification of the weld while in tbe inert atmosphere. A separate water-cooled copper backing bar is provided underneath the joint to be welded to contain the melt-through at the root of the joint, shielding the root of the joint with its own supply of inert gas and cooling the deposited weld metal. This device facilitates the welding of large workpieces of zirconium frequently encountered in reactor construction.

  15. Metals welding by using laser

    Al-Qaisy, R.A.W.

    1991-01-01

    In the present work, same welding ''conduction limited type'' under atmospheric conditions was performed using pulsed Ng:YAG laser to weld; low carbon steel (LCS), stainless steel (304) (SUS304), stainless steel (303) (SUS303), and brass. Microstructure of welded zone, heat affected zone (HAZ), and the laser energy on penetration depth and effective diameter were studied. Tensile test, micro-hardness, and surface roughness of welded and parent metals were also dealt with. Melting efficiency was worked out and an under vacuum seam welding of low carbon steel has been accomplished. Finally spot welding of aluminium tungsten, and platinium wires were employed using different layer energies. 34 tabs.; 82 figs.; 51 refs.; 1 app

  16. Corrosion of carbon steel welds

    Daniel, B.

    1988-09-01

    This report assesses the factors which cause preferential attack to occur in carbon steel fusion welds. It was concluded that the main factors were: the inclusion content of the weld metal, the potential of the weld metal being less noble than that of the parent, and the presence of low-temperature transformation products in the heat-affected zone of the weld. These factors should be minimized or eliminated as appropriate so that the corrosion allowances determined for carbon steel waste drums is also adequate for the welds. An experimental/theoretical approach is recommended to evaluate the relative corrosion resistance of welds prepared from BS 4360 grade 43A steel to that of the parent material. (author)

  17. Glass: Rotary Electric Glass Furnace

    Recca, L.

    1999-01-29

    Compared to conventional gas-fired furnaces, the new rotary electric furnace will increase energy efficiency while significantly reducing air emissions, product turnaround time, and labor costs. As this informative new fact sheet explains, the thousand different types of glass optical blanks produced for the photonics industry are used for lasers, telescopes, cameras, lights, and many other products.

  18. A New Vacuum Brazing Route for Niobium-316L Stainless Steel Transition Joints for Superconducting RF Cavities

    Kumar, Abhay; Ganesh, P.; Kaul, R.; Bhatnagar, V. K.; Yedle, K.; Ram Sankar, P.; Sindal, B. K.; Kumar, K. V. A. N. P. S.; Singh, M. K.; Rai, S. K.; Bose, A.; Veerbhadraiah, T.; Ramteke, S.; Sridhar, R.; Mundra, G.; Joshi, S. C.; Kukreja, L. M.

    2015-02-01

    The paper describes a new approach for vacuum brazing of niobium-316L stainless steel transition joints for application in superconducting radiofrequency cavities. The study exploited good wettability of titanium-activated silver-base brazing alloy (CuSil-ABA®), along with nickel as a diffusion barrier, to suppress brittle Fe-Nb intermetallic formation, which is well reported during the established vacuum brazing practice using pure copper filler. The brazed specimens displayed no brittle intermetallic layers on any of its interfaces, but instead carried well-distributed intermetallic particles in the ductile matrix. The transition joints displayed room temperature tensile and shear strengths of 122-143 MPa and 80-113 MPa, respectively. The joints not only exhibited required hermeticity (helium leak rate high vacuum but also withstood twelve hour degassing heat treatment at 873 K (suppresses Q-disease in niobium cavities), without any noticeable degradation in the microstructure and the hermeticity. The joints retained their leak tightness even after undergoing ten thermal cycles between the room temperature and the liquid nitrogen temperature, thereby establishing their ability to withstand service-induced low cycle fatigue conditions. The study proposes a new lower temperature brazing route to form niobium-316L stainless steel transition joints, with improved microstructural characteristics and acceptable hermeticity and mechanical properties.

  19. Synthesis and characterization of Ni-Mo filler brazing alloy for Mo-W joining for microwave tube technology

    Frank Ferrer Sene

    2013-04-01

    Full Text Available A brazing process based on Ni-Mo alloy was developed to join porous tungsten cathode bottom and dense molybdenum cathode body for microwave tubes manufacture. The Ni-Mo alloy was obtained by mixing and milling powders in the eutectic composition, and applied on the surface of the components. The brazing was made at 1400 °C by using induction heating in hydrogen for 5 minutes. Alumina surfaces were coated with the binder and analyzed by Energy Dispersive X-rays Fluorescence. The brazed samples were analyzed by Scanning Electron Microscopy coupled to Energy Dispersive Spectroscopy. Stress-strain tests were performed to determine the mechanical behavior of the joining. The quality of the brazing was evaluated by assuring the presence of a "meniscus" formed by the Ni-Mo alloy on the border of the tungsten and molybdenum joint, the absence of microstructural defects in the interface between the tungsten and molybdenum alloys, and the adhesion of the brazed components.

  20. Experimental evaluation of brazed molybdenum-graphite bonds for the divertor of the NET/ITER nuclear fusion device

    Smid, I.; Linke, J.; Nickel, H.; Kny, E.; Reheis, N.; Kneringer, G.; Bolt, H.

    1995-01-01

    Composites consisting of plasma-facing carbon material brazed to molybdenum (TZM) substrates are a promising system for the divertor of the Next European Torus (NET) and the International Thermonuclear Experimental Reactor (ITER). Isotropic graphite and a refractory metal (molybdenum or TZM, a high temperature alloy of molybdenum), two dissimilar substrate materials, yet closely matched in their thermal expansivities, were joined with the use of four different high-temperature brazes: Zr, 90Ni-10Ti, 90Cu- 10Ti, and 70Ag-27Cu-3Ti (compositions in wt%). A summary is given of experiments on mechanical strength, heat transfer capability, structural changes, and failure modes under high heat loads of brazed bonds. Tensile-strength tests on the brazing interface prove the suitability of the brazes up to their melting point. The expected enhancement in thermal contact compared with graphite is confirmed. Passively cooled tiles of dimensions 25 mm x 25 mm were subjected to thermal cycling in electron-beam simulations. Heat fluxes of up to 10 MW m -2 were applied. (author)