Incorporation of SiC particles in FS welded zone of AZ31 Mg alloy to improve the mechanical properties and corrosion resistance

The solid-state nature of the friction stir welding (FSW) process leads to several advantages over fusion welding methods as problems associated with cooling from the liquid phase are avoided. This process eliminates many of the defects associated with fusion welding techniques such as shrinkage, solidification cracking and porosity. In general, FSW has been found to produce a low number of defects and is very tolerant of variations in parameters and materials. Nevertheless, physical and chemical properties of the weld zone developed during FSW are a primary concern. In this study, the mechanical properties and corrosion behavior of the weld zone resulting after FSW are investigated and improved by addition of SiC particles. AZ31 magnesium alloy sheets were FS welded and simultaneously processed by incorporation of SiC particles. Mechanical properties and corrosion behavior of FS welded specimens were compared with those of FS welded and processed specimens. The results showed that the addition of SiC particles during FSW considerably improved the mechanical properties and corrosion resistance of the weld zone. Based on the obtained results, incorporation of SiC hard particles in the microstructure of weld zone produced by FSW is highly recommended.