Research on Work Hardening Type Superplastic Deformation Behavior of FSW Titanium Alloy

摘要

The combination of FSW and SPF processing is one of the most attractive fabrication method for the larger structures and integrate substructure to reduce the part count of aircraft assemblies and costs. One purpose of the SPF technology development is to decrease the forming temperature and increase the forming rate, then reduce cost and enhance the efficiency. Maybe FSW could supply another way to achieve this besides reduce the grain size by traditional rolling process. The purpose of this study was to indicate some new results of the superplasticity of weld nugget for the Ti-6Al-4V alloy. It was found that the temperature has no much effect on the superplastic tensile elongation of the weld nugget, and deformation rate had the contrary effects on the superplasticity to the traditional results, the elongation would be higher with the higher deformation rate. The mechanism would be discussed with the analysis of the microstructure by SEM. The tensile properties were tested after SPF process with a 60% strain.