Experimental study of surface integrity during end milling of Al/SiC particulate metal-matrix composites

The quality of the components produced during end milling of Al/SiC particulate metal-matrix composites (PMMCs) is important as it influences the performance of the finished part to great extent. Hence, the estimation of surface integrity can cater to the requirements of performance evaluation. Therefore, an understanding of surface integrity provides many opportunities to avoid failures, enhance component integrity and reduce overall costs. This paper presents the results of an experimental research on end milling of Al/SiC PMMC. The aim of the investigation is to enhance the knowledge about the machinability of Al alloy reinforced with SiC using TiAlN coated carbide end mill cutters. Investigations on surface quality and the extent of sub-surface damage of machined Al/SiC PMMC and Al alloy were carried out at different levels of cutting conditions. The comparison of Al/SiC PMMC and Al alloy on the basis of surface integrity (surface roughness, residual stress, microstructure and microhardness) was tried out in order to know the machinability of two materials. The results show that the presence of the reinforcement enhances the machinability in terms of both surface roughness and lower tendency to clog the cutting tool, when compared to a non-reinforced Al alloy. The results would serve to understand the end milling machining process better; provide inputs that can ensure better machining of Al/SiC PMMC and thus expected to lead technological and economical gains with the use of Al/SiC PMMC in various industrial applications by replacing Al alloys. (C) 2008 Elsevier B.V. All rights reserved.