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in subjects: "Brazing"

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Metals and Ceramics Division. Annual progress report, ending June 30, 1980

Research is reported concerning: (1) engineering materials, including materials compatibility, mechanical properties, nondestructive testing, pressure vessel technology, and welding and brazing; (2) fuels and processes consisting of ceramic technology, fuel cycle technology, fuels evaluation, fuel fabrication and metals processing; and (3) materials science which includes, ceramic studies, physical metallurgy properties, radiation effects and microstructural analysis, metastable and superconduc… more

Date: September 1, 1980

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Brazing techniques for side-coupled electron accelerator structures

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. … more

Date: January 1, 1986

Creator: Hansborough, L. D.; Clark, W. L.; DePaula, R. A.; Martinez, F. A.; Roybal, P. L.; Wilkerson, L. C. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Fabrication and tuning techniques for side-coupled electron accelerator structures

Beginning in 1979, Los Alamos entered into a collaboration with the National Bureau of Standards (NBS) to develop an advanced cw microtron accelerator. The accelerating structures (one 0.9-m-long, one 2.7-m-long, and two 4.0-m-long) containing a total of 184 accelerating cavities have been fabricated and tuned to the 2380-MHz operating frequency. New methods simplified the fabrication of these structures and eliminated several furnace-brazing steps. These fabrication methods, lathe-mounted tuni… more

Date: January 1, 1986

Creator: Hansborough, L. D.; Clark, W. L.; DePaula, R. A.; Martinez, F. A.; Roybal, P. L.; Wilkerson, L. C. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Failure mechanisms of polycrystalline diamond compact drill bits in geothermal environments

Over the past few years the interest in polycrystalline diamond compact (PDC) drill bits has grown proportionately with their successful use in drilling oil and gas wells in the North Sea and the United States. This keen interest led to a research program at Sandia to develop PDC drill bits suitable for the severe drilling conditions encountered in geothermal fields. Recently, three different PDC drill bits were tested using either air or mud drilling fluids: one in the laboratory with hot air,… more

Date: September 1, 1981

Creator: Hoover, E. R. & Pope, L. E.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Fabrication and tuning of the SNS CCL hot model

A full-scale powered model of the SNS CCL was completed in August 2001. The manufacturing processes and tuning procedures used in the CCL Hot Model formed the basis of the main manufacturing contract for the SNS CCL system later placed in private industry. In this paper we summarize the design basis for the CCL and the manufacturing and process steps required to fabricate and of the various tooling and lifting and handling fixtures utilized in the process at the various machining, brazing, weld… more

Date: January 1, 2003

Creator: Bultman, N. K. (Nathan K.); Billen, J. H. (James H.); Chen, Z. (Zukun); Richards, D. R. (Daniel R.); Young, L. M. (Lloyd M.) & Hopkins, S. M. (Steve M.)

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Low-cycle fatigue behavior of oxygen-free high-conductivity copper at 300/sup 0/C in high vacuum

In-vacuum fatigue tests were performed on commercially-pure OFHC copper and 35% Au-65% Cu brazing filler metal at 300/sup 0/C. Excessive recrystallization due to exposure in the 1025/sup 0/C brazing temperature cycle was detrimental to the fatigue life of the base metal; cold work was beneficial to the fatigue resistance. Triple-point cracking and grain boundary sliding were the prevailing modes of fatigue failure observed in the full-size specimens. However, a mixed morphology of ductile and c… more

Date: January 1, 1983

Creator: Liu, K. C. & Loring, C. M., Jr.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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An Overview of Current and Past W-UO[2] CERMET Fuel Fabrication Technology

Studies dating back to the late 1940s performed by a number of different organizations and laboratories have established the major advantages of Nuclear Thermal Propulsion (NTP) systems, particularly for manned missions. A number of NTP projects have been initiated since this time; none have had any sustained fuel development work that appreciably contributed to fuel fabrication or performance data from this era. As interest in these missions returns and previous space nuclear power researchers… more

Date: June 1, 2007

Creator: Burkes, Douglas E.; Wachs, Daniel M.; Werner, James E. & Howe, Steven D.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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

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 m… more

Date: January 1, 1987

Creator: Santella, M.L. & Moorhead, A.J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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

A brazing process has been developed wherein several hundred stamped AM-350 stainless steel sheet metal components, wire components and machined bar components were simultaneously joined together to fabricate about 400 grids of different sizes for the LWBR fuel rod support system. High temperature (2110F +- 20F) vacuum brazing was employed using Ni--Cr--Si braze alloy filler metal in the form of paste. Techniques employed in the assembly, braze alloy application and fixturing of grids to achiev… more

Date: February 1979

Creator: Ebejer, L.P.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Advanced solar receiver development

Ceramic receivers for advanced solar Brayton and advanced solar Stirling thermal power systems are considered which utilize impingement jet cooled silicon carbide ceramic dome heat exchanger modules in conjunction with a cavity receiver geometry to heat a pressurized gaseous heat transfer fluid to temperatures in the range from 1800 to 2400/sup 0/F. Conceptual designs of single and multiple-dome ceramic cavity receivers are presented and analyzed and a combined analytical and experimental progr… more

Date: January 1, 1979

Creator: Jarvinen, P. O.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Development of large rectangular ceramic insulators for ion accelerators for the neutral-beam program

The need for structures that are resistant to damage for 14 MeV neutrons, are bakeable, and that can be closely packed together, has resulted in the intensive development of rectangular brazed ceramic insulators for ion accelerators. The development of two candidate materials, machinable glass ceramic and alumina, is described along with the ceramic-to-metal brazing techniques developed for each material. The microstructures of the brazed joints are examined and the results of microprobe studie… more

Date: March 1, 1979

Creator: Paterson, J.A.; Koehler, G.W. & Duffy, T.J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Design and use of polycrystalline diamond compact drag bits in the geothermal environment

The potential for utilizing polycrystalline diamond compact (PDC) cutters to provide high performance bits has been recognized by the drilling industry. New bit designs suitable for geothermal drilling are being developed based on the results of single cutter laboratory tests and analytical analyses. A new bonding technique for attaching the cutters to the bit body has been developed. Bits using this new technique have been built and tested with promising results. The results of single cutter t… more

Date: January 1, 1979

Creator: Varnado, S. G.; Huff, C. F. & Yarrington, P.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Metals and Ceramics Division annual progress report, October 1, 1978-June 30, 1979

Research is reported concerning: (1) engineering materials including materials compatibility, mechanical properties, nondestructive testing, pressure vessel technology, and welding and brazing; (2) fuels and processes consisting of ceramic technology, fuel cycle technology, fuels evaluation, fuels fabrication and metals processing; and (3) materials science which includes, ceramic studies, physical metallurgy and properties, radiation effects and microstructural analysis, metastable and superco… more

Date: September 1, 1979

Creator: Peterson, S. (ed.)

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Thermodynamics of copper-nickel alloys containing aluminum, silicon, titanium, and chromium relative to their use in ceramic brazing

By varying the copper-to-nickel ratio the activity coefficients of Al, Si, Ti, and Cr can be varied over a wide range. Thus to a degree one can tailor the behavior of such alloys for usefulness in brazing ceramics. Further, considerable amounts of these active elements can be present while the ability of carbon to reduce the surface oxide film in a high-vacuum system is retained. The critical aluminum concentrations required to prevent the formation of SiO/sub 2/, TiO, or Cr/sub 2/O/sub 3/ by r… more

Date: November 1, 1984

Creator: Williams, R. O.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Selected advances in materials research

Several findings emanating from materials research that should have a beneficial impact on technological advancement in the future are described. The report deals with the GRAPHNOL, a new class of high-temperature brazing alloy for joining refractory components, gel-sphere-pac process for manufacture of nuclear fuel, and noble-metal fuel cladding for service in radioisotope thermoelectric generators designed to provide auxiliary power aboard spacecraft for planetary exploration.

Date: January 1, 1979

Creator: Cunningham, J. E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Direct use geothermal applications for brazed plate heat exchangers

Brazed plate heat exchanger were placed in three geothermal fluids (Klamath Falls, OR; Boise, ID; and Pagosa Springs, CO) to determine the effect of H[sub 2]S on braze material. Based on subsequent analysis, it appears that the rate of corrosion of the braze material is much slower than corrosion of copper tube materials in the same fluids. Minimum expected life of the heat exchangers based on these corrosion rates is reported to be 12 years in fluids of less than 1 ppm H[sub 2]S and 10 years i… more

Date: January 1, 1992

Creator: Rafferty, K.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Metallurgical study for University of California Lawrence Livermore Labs. [SS 304 to 21-6-9]

Characteristics of several braze alloys (AMI-915, AMS-4772, AMI-935, AMI-937, BNI-6, BAG-18, etc.) were evaluated. Combinations of 304 SS and 21-6-9 were fabricated into T-sections. Lap shear tests and composite coupon tests were also made. Results indicate that AMS-4772, AMI-935, and AMI-915 should provide acceptable mitigator brazes. Suitable brazes can be performed in either vacuum or hydrogen without affecting the strength at the braze joint. (DLC)

Date: unknown

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

State-of-the-art survey of joinability of materials for OTEC heat exchangers

Literature and industrial sources were surveyed to assess, on the basis of apparent economics and reliability, the joinability of both shell-and-tube and compact ocean thermal energy conversion (OTEC) heat exchangers. A no-leak requirement is mandatory to prevent mixing seawater and the ammonia working fluid. The operating temperature range considered is 7 to 28/sup 0/C (45 to 82/sup 0/F). Materials evaluated were aluminum, titanium, copper--nickel, AL-6X austenitic stainless steel, singly and … more

Date: December 1, 1978

Creator: Beaver, R. J.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Elevated temperature creep properties for selected active metal braze alloys

Active metal braze alloys reduce the number of processes required for the joining of metal to ceramic components by eliminating the need for metallization and/or Ni plating of the ceramic surfaces. Titanium (Ti), V, and Zr are examples of active element additions which have been used successfully in such braze alloys. Since the braze alloy is expected to accommodate thermal expansion mismatch strains between the metal and ceramic materials, a knowledge of its elevated temperature mechanical pro… more

Date: February 1, 1997

Creator: Stephens, J. J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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High temperature grain growth and oxidation of Fe-29Ni-17Co (Kovar{trademark}) alloy leads

One important application for the Fe-29Ni-17Co (Kovar{trademark}) alloy in wire form is in brazed feed through assemblies which are integral parts of vacuum electronic devices. Since Cu metal brazes are performed at process temperatures of about 1100{degrees}C, there is opportunity for significant grain growth to occur during the brazing operation. Additional high temperature exposure includes decarburization of the Fe-29Ni-17Co alloy wire in wet hydrogen for 30 min. at 1000{degrees}C prior to … more

Date: December 31, 1993

Creator: Stephens, J. J.; Greulich, F. A. & Beavis, L. C.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Fabrication of the APS Storage Ring radio frequency accelerating cavities

Specification, heat treatment, strength, and fatigue life of the Advanced Photon Source (APS) Storage Ring 352-MHz radio frequency (RF) accelerating cavity copper is discussed. Heat transfer studies, including finite element analysis, and configuration of water cooling is described. Requirements for and techniques of machining are considered. Braze and electron beam joint designs are compared. Vacuum considerations during fabrication are discussed.

Date: July 1, 1993

Creator: Primdahl, K.; Bridges, J.; DePaola, F.; Kustom, R. & Snee, D.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Residual stresses in material processing

Material manufacturing processes often introduce residual stresses into the product. The residual stresses affect the properties of the material and often are detrimental. Therefore, the distribution and magnitude of residual stresses in the final product are usually an important factor in manufacturing process optimization or component life prediction. The present paper briefly discusses the causes of residual stresses. It then adresses the direct, nondestructive methods of residual stress mea… more

Date: September 1, 1994

Creator: Kozaczek, K. J.; Watkins, T. R.; Hubbard, C. R.; Wang, Xun-Li & Spooner, S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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New applications for high average power beams

The technology base formed by the development of high peak power simulators, laser drivers, FEL`s, and ICF drivers from the early 60`s through the late 80`s is being extended to high average power short-pulse machines with the capabilities of supporting new types of manufacturing processes and performing new roles in environmental cleanup applications. This paper discusses a process for identifying and developing possible commercial applications, specifically those requiring very high average p… more

Date: August 1, 1993

Creator: Neau, E. L.; Turman, B. N. & Patterson, E. L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Reactions and microstructure at ceramic/metal interfaces

Reactions of Ti and Zr with AlN, Al{sub 2}O{sub 3} and mullite were studied. The substrates were selected to represent a simple nitride (AlN), a simple oxide (Al{sub 2}O{sub 3}), and a complex oxide (mullite). The activities of the Ti and Zr were varied by dissolving them at 1 and 5 wt.% in the 72Ag-28Cu eutectic composition, which is otherwise unreactive with the ceramics. Reactions were studied by measuring the variation of the alloy contact angle on the ceramic with time at temperature and b… more

Date: December 31, 1993

Creator: Tomsia, A. P. & Loehman, R. E.

Item Type: Article

Partner: UNT Libraries Government Documents Department