THE MACHINABILITY CHARACTERISTICS OF ALUMINOSILICATE FIBER REINFORCED Al ALLOY COMPOSITE

Abstract

Aluminum metal matrix composites (MMCs) reinforced with ceramic constituents have been increasingly used in engineering applications because of their improved properties over those of nonreinforced alloys. The full application of such MMCs is, however, cost sensitive because rapid tool wear during machining leads to high machining costs. In this paper, the machinability of LM.13 Al alloy reinforced with 25% by volume fraction of aluminosilicate fibers using multicoated carbides having different restricted contact (RC) type rake faces and polycrystalline cubic boron nitride (PCBN) tools is presented. A quantitative description of the mode of action of RC tools is given based on a simple model for cutting. The two tool materials were compared with respect to number of response parameters. The results show that PCBN outperforms the multicoated carbides in machining these materials. The plethora of advantages offered by RC tools is not realized in machining MMC material as they are heterogeneous in nature.