Dry Sliding-Friction and Wear Behavior of Hot-Extruded Al6061/Si3N4/Cf Hybrid Metal Matrix Composite

The effects of reinforcement addition and hot extrusion on the microstructures, micro hardness, friction, and wear behavior of aluminum (Al) hybrid composite were investigated. Al6061 dispersed with electroless nickel-coated Si3N4 (6 wt.%) and copper-coated carbon fiber (Cf) (1 wt.%) hybrid composites was developed through stir casting followed by hot extrusion. Optical micro-structural studies confirmed that the size of reinforcements decreased, and their orientations were in the extrusion direction. The decrease in the grain size (29%) of hybrid composites was larger than that in the grain size of matrix alloys under hot-extruded conditions. The synthesized hot-extruded Al6061 hybrid composite exhibited a lower coefficient of friction (51%) and high wear resistance (39%) compared with the hot-extruded Al6061 base alloy.