Optimization of Machining Hybrid Metal Matrix Composites Using Desirability Analysis

Abstract

This paper presents the detailed discussions on fabrication of Aluminium - silicon carbide (10% by weight of particles) and boron carbide (5% by weight of particles) Hybrid Metal Matrix Composites (Al/SiC/B4C MMC) using stir casting method. SiC and a B4C particle range from 30μm to 50 μm. The cylindrical rods of diameter 60 mm and length 250 mm are fabricated and subsequently machined using medium duty lathe of 2 kW spindle power to study the machinability issues of Hybrid MMC using Poly Crystalline Diamond (PCD) insert of 1600 grade. The optimum machining parameters have been identified by a composite desirability value obtained from desirability function analysis as the performance index, and significant contribution of parameters can then be determined by analysis of variance. Confirmation test is also conducted to validate the test result. Experimental results have shown that machining performance can be improved effectively through this approach. Results show at higher cutting speeds, good surface finish is obtained with faster tool wear. It is concluded that, tool wear and cutting force are directly proportional to the cutting speed, where as surface roughness is inversely proportional to the cutting speed. Percentage of error obtained between experimental value and predicted value is within the limit.