Surface integrity of newly developed of Alsi/Aln metal matrix composite during end milling under dry cutting conditions

Abstract

The investigation on surface integrity (surface roughness, microstructure and microhardness) were carried out in order to analyze the cutting parameters affected the surface integrity for better machinability of AlSi/AlN MMC. Five cutting parameters (cutting speed, feed rate, depth of cut, volume fraction of particles reinforcement and type of coated insert) were performed. Two types of coating (TiB2 and TiN/TiCN/TiN) of carbide cutting tools were employed to machine various volume fractions of AlN particles (5%, 7% and 10%) reinforced to AlSi Alloy MMC under dry cutting condition. The results shows that the optimum levels for minimum surface roughness are; A1 (single coating of insert), B3 (cutting speed: 250 m/min), C2 (feed rate: 0.75 mm/tooth), D1 (axial depth: 0.6 mm) and E1 (5% reinforcement). Surface roughness value increases along with increase in volume fraction of reinforcement. Depth of cut is more significant than feed rate and cutting speed in obtaining lower surface roughness. This could be due to the formation of BUE on the rake face of cutting tool at higher Depth Of Cut (DOC). The increases of volume fraction of AlN particles, from 5 to 10% give contribution to the changes of hardness. A surface dislocation is occurred at the highest speed and feed; 250 m/min and 0.9 mm/tooth. This phenomenon happens at high cutting condition due to the highly heat generation which softens the machined surface. © Maxwell Scientific Organization, 2013.