Notched Tensile Fracture of Ti-6A1-4V Laser Welds at Elevated Temperatures

摘要

Notched tensile tests of Ti-6A1-4V laser welds, which were subjected to post-weld heat treatments (PWHTs) at 482 or 704°C, were carried out in air at 25,150,300 and 450C. The results were compared with those of mill-annealed base metal (MB) specimens tested at same temperatures. In general. the notched tensile strength (NTS) of all specimens decreased with increasing temperature. The results indicated the NTS of the MB specimen was obviously higher than that of the welds at room temperature, but became much lower at 450°C. It was deduced the presence of thicker grain boundary a promoted intergranular fracture at elevated temperature accounted for the decreased NTS of the weld with the PWHT at 704°C.