CHIP MORPHOLOGY AND HOLE SURFACE TEXTURE IN THE DRILLING OF CAST-ALUMINUM ALLOYS

The effects of cutting fluid and other process variables on chip morph ology when drilling cast aluminium alloys are investigated. The effect s of workpiece material, speed, feed, hole depth, cutting-fluid presen ce and percentage oil concentration, workpiece temperature, drill type and drill overhang are studied using statistically-designed experimen ts. The measured responses of the experiments are the size and the sha pe of the generated chips. The effect of chip size on hole surface fin ish is also examined. The results show that the significant variables affecting chip size include the feed, material, drill type and to a le sser extent, cutting-fluid presence and drill speed. The drilled hole surface is shown to be correlated to chip size. (C) 1998 Published by Elsevier Science S.A. All rights reserved.