Effect of tool diameter ratio of tapered cylindrical profile pin on wear characteristics of friction stir processing of Al-Si alloy reinforced with SiC ceramic particles

Friction stir processing is demonstrated to effectively enhance the surface and bulk properties of aluminum composites fabricated via the stir casting route. This process is performed below the melting point of the base material wherein common conventional fabrication problems such as solidification, liquidation cracking, and porosity are eliminated to a significant extent. Five different tools with varying tool diameter ratios are experimented on while maintaining tool rotational and traverse speeds and axial force constant. In this investigation, the hardness and wear characteristics of the LM25 aluminum alloy reinforced with 5% silicon carbide particles composite is studied. It is concluded that the tool with a tool diameter ratio of 3.0 resulted in a defect-free processing zone, refined grains, and a minimum particle size enhancing the wear resistance and hardness as compared to that for other values of a tool diameter ratio.