Cold Spray: A New Technology
A new solid-state spray process (Fig. 1) is quickly being adopted by many industries. Cold spray is capable of providing restoration, sealing, surface modification, wear resistance, thermal barriers, corrosion protection, heat dissipation, rapid prototyping, near net shapes, aesthetic coatings, and many other applications without the undesirable effects of process temperatures or metallurgical incompatibilities among materials.
Cold spray is capable of producing
coatings or components made of
metals, cermets, polymers, or composites. Its ability to prevent
thermal effects such as oxidation, vaporization, melting,
recrystallization, grain growth, and residual thermal stresses makes
this new process unique for preserving the original characteristics of
the feedstock materials. It is especially attractive for the processing
of advanced industrial materials, such as those based on
Optimize the Robotic Process?
Robotic welding systems are a fixture in industries where speed and repeatability are required to maintain a high volume of production. Companies invest large amounts of capital on robotics expecting a very fast payback and, in many cases, they achieve it. This return on investment can be attributed to both the robot itself and the welding consumable that is used. The automotive and metal fabrication industries, specifically, have become two of the biggest consumers for this technology.
The following is a classic robotic "widget" scenario: Acme Widgets runs welding consumable type A in its robotic welding cells and produces 500 parts per shift.
Online Filler Metal Help
Whether we're writing procedures, inspecting welds, or purchasing filler metals, we all need to research data related to the selected filler material. There is free software out there to help welding engineers, inspectors, and buyers determine the necessary data. It is called fnumbers.com (www.fnumbers.com), and it is provided by C-spec, Concord, Calif.
Industry's many ways of classifying filler metals can be a bit cumbersome at times. Fnumbers.com can make the process of referring to an American Welding Society (AWS) classification from a Unified Numbering System (UNS) number or a trade name, and finding F-numbers and A-numbers much easier — all it takes is a click of a mouse.
Corrosion Testing of Austenitic Stainless Steel Weldments
There are significant differences in testing and evaluating the corrosion resistance of stainless steel welds compared to carbon steel, low-alloy steel, copper-based alloy, and aluminum alloy welds.
Some of the major differences in evaluating stainless steel are its susceptibility to severe intergranular attack (IGA), stress corrosion cracking (SCC), and crevice corrosion. Accurately testing for the susceptibility for each of these conditions has been problematic over the years.
Determining Corrosion Behavior Is Not Easy
The common practice of assuming that weight loss is relatively uniform over the full area of the specimen in calculating a corrosion rate is reasonable for carbon steel and other materials, but results in unusually low and misleading corrosion rates for stainless steel. This is due to the fact that corrosion of stainless steel is typically not uniform, but highly localized.
A. H. Tuthill
THE AMERICAN WELDER Obelisk Stands Sentry to Honor Heroes
M. R. Johnsen
School Builds Its Reputation on Students' Successes
A. R. Neilson
Temperature-Indicating Methods Are Tested
R. K. Wiswesser
Selecting the Right Type of Portable Wire Feeder
WELDING RESEARCH SUPPLEMENT
Experimental Study Determines the Electrical Contact Resistance in
Resistance Welding (.pdf)
Characterization of a Double-Sided Friction Stir Weld on a
Superaustenitic Stainless Steel (.pdf)
The American Welder
Welding Journal (ISSN 0043-2296) is published monthly by the American Welding Society for $90.00 per year in the United States and possessions, $130 per year in foreign countries: $6.00 per single issue for AWS members and $8.00 per single issue for nonmembers. American Welding Society is located at 550 NW LeJeune Rd., Miami, FL 33126-5671; telephone (305) 443-9353. Periodicals postage paid in Miami, Fla., and additional mailing offices. POSTMASTER: Send address changes to Welding Journal, 550 NW LeJeune Rd., Miami, FL 33126-5671.
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WELDING JOURNAL - May 2005, Volume 84, Number 5