Operated by Los Alamos National Security, LLC for the U.S. Department of Energy's NNSA UNCLASSIFIED Modernizing Welding Capability Paul F. Moniz 1 , Stanley Pierce 1 , Jesse N. Martinez 2 , John L. Brown 2 , Edwin M. Serrano 2 , Alan Hoff 2 , Andrew Thronas 2 , and Benny Rose 2 1 Manufacturing Engineering and Technologies, Actinide Engineering and Science and 2 Nuclear Component Operations Heat Source Technologies LA-UR-15-21288
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Operated by Los Alamos National Security, LLC for the U.S. Department of Energy's NNSA
UNCLASSIFIED
Modernizing Welding Capability
Paul F. Moniz1, Stanley Pierce1, Jesse N. Martinez2, John L. Brown2, Edwin M. Serrano2, Alan Hoff2, Andrew Thronas2, and Benny Rose2
1Manufacturing Engineering and Technologies, Actinide Engineering and
Science and 2Nuclear Component Operations Heat Source Technologies
LA-UR-15-21288
Operated by Los Alamos National Security, LLC for the U.S. Department of Energy's NNSA
UNCLASSIFIED
Purpose The Los Alamos Actinide Engineering and Science team uses automated Gas Tungsten Arc welding (GTAW) processes to encapsulate plutonium oxide into various container configurations and materials. Materials used in the encapsulation and packaging processes are alloys of Iridium, Platinum, Cobalt, Tantalum, and Stainless Steel.
Welding is a critical part of the manufacturing process, and robust control of the process is essential in providing a safety class container that can be handled outside a controlled environment, and meet stringent safety and performance requirements during launch and space operation.
Slide 2
Operated by Los Alamos National Security, LLC for the U.S. Department of Energy's NNSA
UNCLASSIFIED
Current Welding System • The current welding system uses a DOS based computer to control
welding current and travel speed. Simplistic electro-pneumatic controls are used for weld torch coarse positioning. Fine adjustments of the torch are accomplished by the operator manually adjusting hand screws. These fine adjustment create system variability from operator to operator.
• The single most important variable created is “arc gap”. This is the gap between the electrode tip and the work piece or part to be welded. The operator variability can be as much as 0.004”.
• The current system can not compensate for changes in the arc gap caused by run out in the fixture/tooling which has been as much as 0.008”. This compounded by the operator variability can be extremely problematic in welding processes with arc gap sensitivities such as welding Iridium.
Slide 3
Operated by Los Alamos National Security, LLC for the U.S. Department of Energy's NNSA
UNCLASSIFIED
Slide 4
Why Modernize – The current systems are obsolete and spare parts are
no longer available. – Current systems have limited control functionality. – Process improvements are needed.
• Square wave pulse control technology. • Apply additional engineering controls on the process mitigating