Weld zone characteristic and mechanical performance of in situ titanium matrix composites using gas tungsten arc welding (GTAW)

Abstract

In situ TiBw and La2O3 reinforced titanium matrix composites were successfully fusion welded by the gas tungsten arc welding (GTAW) process and the weldability and feasibility for composites were studied, and uniform and defect free welds were produced with sound welding parameters. Microstructural observations showed that the joint has a distinctly identified weld zone characteristic. In addition, the distribution and size of TiBw in the weld became much more homogeneous and smaller. Moreover, the welded joints exhibited good mechanical properties at ambient temperature and the strength equal to the base metal at elevated temperature. The fracture mechanism of TiBw in the weld also was investigated.