Improving the Microstructure and Mechanical Properties of Aluminium Alloys Joints by Adding SiC Particles During Friction Stir Welding Process

This study experimentally investigates the influence of adding SiC on microstructure and mechanical properties of the aluminium alloys welded joints. The SiC particles have been directly added into a zone of friction stir welding (FSW) to make (AA6061–AA2024) SiC composites material. Results show that the effect of adding SiC particles on microstructure refines the grain size in the stir zone by preventing its growth during FSW process. The adding of SiC particles has a significant effect on the thermomechanical zone resulting from restricting the growth of grains. Results indicated that the microhardness of FSW joints is increased from 44 to 86 HV by adding 9.2% SiC particles as compared to that obtained without including SiC under the same welding conditions. It has been observed that the tensile strength is enhanced when the amount of SiC particles are increased by up to 6.9%.