Optimization of drilling process parameters by harmony search algorithm

Titanium alloy find widespread applications in different fields such as in aerospace, bio-medical and electronics due to its superior physical properties (high strength, toughness, corrosion resistance and durability and low density). Further, its biological compatibility makes it useful in a variety of applications in bio-medical engineering. Drilling is one of the important machining processes involved in most of its application fields. In drilling process, it is desirable to obtain good hole quality at minimum thrust. The present work investigates the influence of various control parameters on circularity at entry and thrust force in drilling of titanium alloy using face centered central composite design. The optimal parameters that maximize circularity and minimize thrust force have been obtained by harmony search (HS) algorithm. The fitness value of 2.8878 and 1.0171 for thrust obtain from GA and HS algorithm respectively and fitness of 0.0895 and 0.1143 for circularity at entry according to GA and HS algorithm respectively. The result suggests that HS algorithm is a robust technique as compared to GA in solving the machining problems.