Studies on machinability of Al/Sip + SiCp composite materials

This paper presents the experimental results on the machinability of silicon and silicon carbide particles (SiCp) reinforced aluminium matrix composites (Al/Sip + SiCp) during milling process using a carbide tool. The total volume fraction of the reinforcements is 65 vol%. The milling forces, flank wear of the tool and the machined surface quality of composites with different volume fraction of SiCp were measured during experiments. The machined surfaces of composites were examined through SEM. The results showed that the flexural strength and Vickers hardness are improved when certain volume fraction of silicon particles are replaced by silicon carbide particles with the same volume fraction and particle size and the effect of SiCp on machinability is optimal when 9 vol% silicon particles in Al/Sip was replaced by silicon carbide particles with the same volume fraction and the same particle size. Cracks and pits were found on the machined surfaces of composites due to the intrinsic brittleness of silicon particles.