Drilling of Al2219/B4C/Gr metal matrix hybrid composites

Abstract

MMCs are new group of materials which offer superior properties over alloys. MMCs are very difficult to machine by HSS tool due abrasive nature of carbide particles. During machining of MMCs higher thrust force and poor surface finish is obtained because of abrasive nature of ceramic particles. This paper reports the influence of cutting parameters such as feed and speed during the drilling of Al2219 matrix, mono composite Al2219+8%B4C and hybrid composite Al2219+8%B4C+3%Gr.The composites are prepared by liquid metallurgy route. Experiments were conducted with TiN coated HSS drill bit. The experiment was conducted for various speeds 1000, 1500 and 2000 rpm and feeds 0.1, 0.2 and 0.3mm/rev. The influence of thrust force and surface roughness is studied at various feed rate and speed for base alloy, mono composite and hybrid composite. From the experiment it is concluded that thrust force and surface roughness increases with increase in feed rate. In hybrid composite lesser thrust force and higher surface roughness is observed as graphite having solid lubricating property when compared with mono composite