Optimization of drilling processes of aluminium metal matrix composites using the robust ordinal priority approach

Abstract

In the present-day automobile, aviation, marine, defence and manufacturing industries, aluminium metal matrix composites (Al-MMCs) have found immense applications due to their higher strength-to-weight ratio, toughness, thermal stability, and excellent corrosion and wear resistance properties. Non-uniform metallurgical structure due to presence of agglomerated reinforcement elements in the matrix is responsible for poor machinability of Al-MMCs leading to reduced tool life, poor surface integrity, higher energy consumption, increased cutting force etc. during drilling operations. This paper proposes application of a newly developed multi-criteria decision making tool, in the form of ordinal priority approach (OPA), for solving two parametric optimization problems for drilling operations of Al-MMCs. In this method, the optimal intermix of various drilling parameters is identified based on ordinal preference of the experts with respect to criteria importance and preference of the conducted experiments against each of the criteria. In the first example, a combination of drilling parameters as cutting speed = 87.96 mm/min, feed rate = 0.050 mm/min and point angle = 140° provides compromised values of average surface roughness (Ra), cutting force and torque. On the other hand, in the second example, the most preferred values of thrust force, Ra and burr height can be obtained at an optimal parametric intermix of spindle speed = 2000 rpm, feed rate = 0.2 mm/rev, Al2219 work material and carbide drill bit. The robustness and solution accuracy of OPA while solving parametric optimization problems are also validated against other criteria weight measurement techniques and MCDM tools respectively.