The Effects of SiC Particle Addition as Reinforcement in the weld Zone during Friction Stir Welding of Magnesium Alloy AZ31B

Abstract

Welding of magnesium alloys influence a great effect on magnesium application expansion, especially in marine and aerospace where large-size, complex components are required. Due to specific physical properties of magnesium, its welding requires great control. In general, the solid-state nature of friction stir welding (FSW) process has been found to produce a low concentration of defects. Mechanical properties of  friction stir welded joints are decreases than base material, so to enhance the mechanical properties of welded portion, In the present research additional SiC particulates were incorporated in the weld interface of friction stir welding of Magnesium alloy AZ31B. Silicon Carbide has been added as reinforcement by creating separate geometry, at the edges where the welding is interface with 4 different volume proportions such as 10%, 15%, 25% and 30%. Tool Steel of H13 grade has been used as friction stir welding tool. Rotational Speed of 1400 RPM and Transverse Speed of 25 mm/min were selected. Joined Mg Alloy AZ31B alloy plates were evaluated for their mechanical properties under two different conditions, i.e in the un-reinforced welded condition and reinforced welded conditions. The results of the study revealed that the mechanical properties of the SiC particulates added Mg alloy AZ31B welded joints are superior in all four proportions of SiC, compared to un-reinforced Mg alloy AZ31B welded joints. Microstructural examination of the welded joints was conducted using Optical microscope and revealed that distribution of SiC particles producing increased weld strength. The comparison of the microstructures and mechanical properties of unreinforced Friction stir welded AZ31 with those of SiC reinforced FS-welded joints showed that the addition of SiC particles decreased the grain size and increased the strength.