Influence of hybrid pin profile on enhancing microstructure and mechanical properties of AA5052/SiC surface composites fabricated via friction stir processing
Jainesh Sarvaiya, Dinesh Singh
Abstract
In friction stir processing (FSP), conventional pin tools like square and threaded cylindrical pins require multipass to produce defect-free and homogenous reinforcement particle dispersion. Thus, the effectiveness of the hybrid pin profile in a single pass was investigated in the current work to produce surface composites. The hybrid pin profile combines the features of square and threaded pins. The drilled blind holes were filled with SiC particles in the AA5052-H32 alloy. A pinless rotating tool was moved over the blind holes to avoid the spattering of inserted SiC particles during FSP. Thereafter, the FSP was performed using threaded, square, and hybrid pin tools. The mechanical and microstructural characteristics of the developed surface composites were studied. The results revealed that the hybrid pin tool uniformly distributed SiC particles due to lateral downward material movement and pulsating action. The hybrid pin tool produced smaller grain size of 9.32 µm than the conventional pin tool (i.e. 12.28 and 17.52 µm). The hybrid pin tool obtained the highest microhardness of 117 HV and tensile strength of 216.34 MPa. Using a hybrid tool saves processing time by half while attaining high mechanical properties that favour FSP commercialization.