The effect of Ni and Zr additions on hardness, elastic modulus and wear performance of Al-SiCp composite

The strive for lightweight in the automotive industry points to aluminium metal matrix composites as substitutes of cast iron in brake discs. The wear performance of the material is critical, besides suitable mechanical resistance and thermal properties. The present study investigated the wear behaviour of Al-Si alloys reinforced with silicon carbide particles. The matrix alloy was added with nickel and zirconium, and nanoindentation was performed to determine intermetallic phases' hardness and elastic modulus. The addition of 20 wt% carbides determined an elastic modulus 35–40 % higher than the matrix alloys. Wear rate was in the 2–8 * 10-5 mm3/N * m range for all materials. The tribo-layer had a critical role in the wear performance, as the coefficient of friction decreased during wear.