WELDABILITY OF TANTULUM ALLOYS.
Abstract
The factors which might affect the ductility of fusion welds in Ta alloys include: interstitial impurities, welding parameters, alloying elements, and weldment microstructure. Studies showed that base-material alloy content and interstitial-impurity content are most important. In general, machine fusion welds in Ta alloys with a total alloy content (Hf, Mo, W, Re) greater than 13 atomic % will have a room-temperature minimum bend radius greater than 2t in the as-welded condition. The interstitial content of Ta alloy sheet should be less than 100 ppm by wt total of O2, N2, and H2 with a C content of about 50 ppm or less if fusion welds are to be ductile at room temperature. The 2t bend transition temperature of fusion welds in Ta-5W-2.5Mo and Ta-10W-2.5Mo is less than -320 F if the welds are stress relived 1 hr at 1500 F. Tensile joint efficiencies of from 86 % at room temperature to 88% at 3500 F can be obtained with fusion welds in Ta-5W-2.5Mo and Ta-10W-2.5Mo, but the joint efficiencies of welds in Ta-17W are lower. A severe exposure of 10 hr at 3500 F impaired the ductility of both base material and welds in the Ta-10W-2.5Mo alloy. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1965
- Accession Number
- AD0474223
Entities
People
- D. C. Martin
- P. A. Kammer
- R. E. Monroe
Organizations
- Battelle Memorial Institute