Tribological Characterization of Stir-cast Aluminium-TiB2 Metal Matrix Composites

The present study considers friction and wear of aluminium matrix composites reinforced with TiB₂ micro particles processed through the stir casting method rather than in-situ techniques adopted by earlier studies. Different weight percentages of TiB₂ powders having average sizes of 5 - 40 micron were incorporated into molten LM4 aluminium matrix by stir casting method. The friction and wear behavior were studied for Al-TiB₂ composites prepared according to specific dimensions by using a block-on-roller type multi-tribotester at room temperature. Normal loads of 25 - 75 N and rotational speed of 400 – 600 rpm were used for determination of friction and wear behavior. It is found that friction and wear decrease with increase in percentage of TiB₂ reinforcement in the composite, while friction and wear increase with applied load and speed. Scanning electron microscopy studies the reveal presence of both abrasive and adhesive wear mechanisms with abrasive wear being predominant.