Assessment of Mechanical and Tribological Behavior of AA6061 Reinforced with B4C and Gr Hybrid Metal Matrix Composites

Abstract

Aluminum alloy (AA6061)-based hybrid metal matrix composites (HMMCs) are manufactured using a dual stir casting method, with varying volume percentages of B4C (5%, 10%, and 15%) and Gr (10%, 15%, and 20%) incorporated. The resulting HMMC and reinforcement elements are uniformly dispersed within the main matrix, forming a mechanically mixed layer with interfacial reactions. This layer reduces wear loss and friction coefficient compared to AA6061, especially with higher amounts of B4C and Gr, as they demonstrate little aggregation of reinforced material. The presence of Gr particles enabled the impact of different wear parameters (applied load, sliding speed, and distance) to be combined. Micro-hardness studies demonstrate that the hardness of HMMC increases as the volume fraction of reinforced particles and sliding distance increase. The compression test revealed a 22% improvement over AA6061. As a result, adding reinforcing materials to the matrix contributes to inducing greater strength by increasing wear resistance with a Gr-imparted lubrication effect.