Mechanical and Corrosion Behavior of AZ31 Mg and Cu–8Zn Alloy FSW Joint Prepared With and Without Zn Interlayer
摘要
Friction Stir Welding (FSW) is an established method for joining dissimilar metals. The present research work evaluates and compares the mechanical and corrosion behaviour of AZ31 Mg and Cu-8Zn alloy FSW joints to that of the base alloys. For the FSWs, 3 mm-thick plates of AZ31 Mg alloy and Cu-8Zn alloy were used, both with and without a Zn interlayer. The tool rotating speed of 1200 rpm and the traversal speed of 20 mm/min were part of the process parameters. The microstructural study revealed that FSW sample without Zn interlayer shows presence of defect like voids, whereas defect free weld joint was obtained with Zn interlayer. Material flow behavior and grain size variation were also evaluated. Microhardness test showed that hardness increased due to grain refinement in the stir zone compared to the base material for both with and without the Zn interlayer. The XRD analysis revealed the formation of intermetallic compounds like MgZn and MgZn2. The corrosion behaviour of FSW joints and base alloys were performed in a 3.5 wt% NaCl solution. FSW samples had a higher tendency to corrode as compared to base alloys. The FSW performed with Zn interlayer (FSW-CZM) has shown lower corrosion rate compared to FSW performed without Zn interlayer (FSW-CM).