Dry Sliding Wear Behavior of Aluminum 6063 Composites Reinforced with TiB 2 Particles

Abstract

The influence of titanium diboride (TiB 2) loading on the dry sliding wear characteristics of aluminum 6063 matrix alloy-titanium diboride (Al/TiB 2) composite materials has been assessed using a pin-on disc wear tester at different loads. The composites with 5 and 10 wt% of fine TiB 2 particles were fabricated using stir casting technique. For comparison, as-cast of the base alloy were made under the same processing applied for Al/TiB 2 composites. The hardness of the composite materials was measured using Brinell hardness tester. Scanning electron microscopy (SEM) was used to analyze the wear surfaces of samples. The results indicate that fine TiB 2 particles markedly improved the wear performance of the aluminum 6063 matrix alloy. The coefficient of friction decreases with increase in the amount of TiB 2 , but this effect was more pronounced in dry sliding. Hardness of composites increased with increasing TiB 2 loading. The wear rates increase with increase in load and dependent upon TiB 2 loading in the base alloy. Among the composites tested, Al/TiB 2 composites containing 10 wt% TiB 2 exhibited superior wear resistance over the base alloy and 5 wt% Al/TiB 2 composites. These observations were correlated in terms of the TiB 2 loading in base alloy which resulted in the variations of the hardness.