Effect of cutting environment and heat treatment on the surface roughness of drilled Al/SiC MMC

In the last decades, the use of metal matrix composites (MMCs) has increased enormously in many engineering applications such as aerospace, automotive, marine and railway. Such materials are known as difficult to machine materials due to the presence of very hard and abrasive reinforcements. The purpose of this study is to determine the influence of the cutting parameters, cutting environment and heat treatments on the surface roughness after drilling A 356/15 SiC MMCs. Experiments were conducted at different cutting speeds, feed rates, heat treatments (as-received, solution annealed and aged) and cutting environments (MQL, compressed air and dry). Improved surface roughness values were obtained with increased cutting speeds and decreased feed rates. The surface roughness using the MQL technique was lower than the surface roughness obtained for the other cutting environment. The optimal machining parameter combination has been obtained and the cutting conditions in terms of the cutting speed of 15 m x min(-1), the feed rate of 0.1 mm x rev(-1) and the cutting environment MQL represent applicable solutions for the annealed materials.