Effects of tool wear on the microstructure evolution and mechanical properties of friction stir welded TA5 alloy

A Co-based tool was employed to weld TA5 alloy to investigate the effects of tool wear on the microstructure evolution and mechanical properties. Results showed that both dense diffusion and loose cracked layers were detected near the surface of as-worn tool, indicating the occurrences of both diffusional wear and abrasive wear. The stir zone (SZ) was divided into the contaminated zone (CZ) and non-contaminated zone (NCZ) according to whether...