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

Abstract

In situ TiB_w 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 TiB_w 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 TiB_w in the weld also was investigated.

Keywords:

• Gas tungsten arc welding
• Mechanical properties
• Scanning electron microscopy
• TiB whisker
• titanium matrix composites
• Microstructure

We would like to acknowledge a financial support provided by the Dawn Program of Shanghai Education Commission under grant no. 10SG15, 973 Program under grant no. 2012CB619600 and Shanghai Science and Technology Committee under grant no. 10JC1407500.