Study of wear behavior and mechanical mixed layer on artificial aged Al6061 composite reinforced with B₄C particles

Present study emphases on the enhancement in hardness and wear resistance of Al6061 composite reinforced with boron carbide particles of various weight percentage (2, 4 and 6) in peak aged condition during artificial aging. The effect of artificial aging treatment with different aging temperatures of 100, 150 and 200°C was also investigated. Presence of B₄C particles in Al6061 alloy accelerating the aging process and thus attain higher strength. These particles provide more sites for the nucleation of fine precipitates. These fine precipitates anchor lattice strain to deform the matrix to increase hardness and wear resistance of materials. The combined effect of B₄C and artificial aging at lower temperature shows improvement in hardness by 150-175% and wear resistance by 100% due to the precipitation of secondary solute rich phase of alloying elements and dislocation mobility hindrance. Tribolayer or mechanically mixed layer was observed due to the transfer of material from rotating disc surface to the wear surface of composite, which is believed to be effect of friction and oxidation on iron particles. The results were correlated with the unreinforced Al6061 alloy. The analysis of the unreinforced alloy worn sample surface doesn't show presence of iron in the mechanically mixed layer.