Weldability of Formable Sheet Titanium Alloy - Ti-15V-3Cr-Al-3Sn

Abstract : Gas-Tungsten-Arc (GTA) and Electron Beam (EB) fusion welding process parameters were established for Ti-15V-3Cr-3Al-3Sn alloy sheet in 0.050-, 0.100- and 0.300-inch thicknesses. The material, purchased from Timet, was characterized by mechanical testing in the following conditions: solution annealed and solution annealed and aged at 900 and 950 F for eight hours. Solution annealed material is very ductile and formable. Aging response of base metal shows that 150 to 170 ksi minimum yield strengths can be achieved. GTA and EB welds were made using a square butt joint configuration in the 0.050- and 0. 100-inch thickness. A 'V' joint configuration was used to weld 0.100-inch thick material wire using the GTA process. 0.300-inch material was welded with the EB process only. All weldments were made using production equipment and there were no anomalies in welding this material. X-ray and dye penetrant tests showed that weldments were crackfree and within porosity limits. Bend and tensile tests made on weldments in the as-welded condition were very ductile and compared favorably to the ductility of solution annealed base metal. Aging response of welded specimens, tensile tested in both longitudinal and transverse directions, was similar to base metal and properties compared favorably to base metal properties. Notched tensile strengths, fracture toughness, and crack growth rates all indicate that Ti-15V-3Cr-3Al-3Sn weldments are satisfactory for structural applications.