Microstructural Evolution of a Cast ZK60 Mg Alloy/SiCp Surface Composites Induced by Friction Stir Process

In the fabrication of light weight structural materials, the as-cast ZK60 magnesium alloy plays a vital role in the replacement of aluminum alloy. As the wear and friction properties are poor for magnesium alloys, it is very much essential to adopt surface engineering to enhance these properties. Friction stir processing is one of the promising thermo-mechanical processing techniques that alters the grain refinement and surface properties of the material. This investigation is made to understand the impacts of tool traverse speed ranges from 5 to 25 mm/min in cast ZK60 and FSPed/ZK60/SiCp magnesium alloy friction stir processed zone formation. It is found that the FSP made by using the high tool traverse speed of 10 mm/min exhibited higher hardness (121.2HV) and uniform particle distribution in the processed zone. This may be attributed to the dispersion and grain boundary strengthening. Also, this study is further proceeded to transient temperature distribution during FSPed/ZK60 Mg alloy by using Finite Element method. From simulation, the maximum temperature determined is 462 degrees C, which is notably less compared to the melting temperature of the plate.