Dry sliding wear behavior of Al-SiO2 composites

Abstract

Al-base composites with different amount of silica (5, 10, 15 and 20 wt.%) were developed using powder metallurgy route and compacts were sintered at 550 °C for 2 h. XRD analysis of all compositions was conducted for phases and amount of the second phase present. Morphology of the composites shows quite uniform distribution of the SiO2 particles but at higher percentage of SiO2 particles the clustering starts. Mechanical properties such as uniaxial compressive strength (UCS) and hardness were evaluated and it is seen that among all compositions, composite with 10 wt.% SiO2 has maximum UCS and hardness. Wear behavior of all composites was studied with sliding distance, applied loads, sliding velocity and composition. All composites show a linear increase in cumulative wear with distance and load. Wear rate with load increases continuously for all compositions, however, composite with 10 wt.% SiO2 revealed minimum wear rate with distance, sliding velocity and loads. Wear rate with sliding velocity increases sharply after attaining minima at 3 m/s sliding velocity. SEM analysis of wear tracks is in agreement with wear results. Al-10 wt.%SiO2 also shows minimum wear coefficient values for all loads, however, wear coefficient decreases with load for all compositions.