Title: Influence of process parameters on material removal rate and surface roughness in WED-machining of Ti₅₀Ni₄₀Cu₁₀ shape memory alloy

Authors: M. Manjaiah; S. Narendranath; S. Basavarajappa; V.N. Gaitonde

Addresses: Department of Mechanical Engineering, National Institute of Technology Karnataka, Surathkal-575025, Karnataka, India ' Department of Mechanical Engineering, National Institute of Technology Karnataka, Surathkal-575025, Karnataka, India ' Department of Studies in Mechanical Engineering, University B.D.T. College of Engineering, Davangere-577 004, Karnataka, India ' Department of Industrial and Production Engineering, B.V.B. College of Engineering and Technology, Hubli-580 031, Karnataka, India

Abstract: Among the shape memory alloys (SMAs), TiNi SMAs have been typically used as the functional elements in the larger part of the industries due to exceptional properties like super elasticity and shape memory effect. However, traditional machining of these alloys is fairly complex due to these properties. The non-traditional machining process like electric discharge machining (EDM) exhibits outstanding capability in machining of these alloys. The poor selection of machining parameters may cause increased roughness of workpiece and lesser material removal rate. Hence, an effort has been made in the present work to explore the effects of three process parameters, such as pulse on time, pulse off time and servo voltage in wire electric discharge machining (WEDM) of Ti₅₀Ni₄₀Cu₁₀ shape memory alloy (SMA) using zinc coated brass wire electrode on material removal rate and surface roughness using response surface methodology (RSM)-based mathematical models. The experiments were planned as per central composite design (CCD). The investigations revealed that pulse on time and servo voltage have predominant effects in maximising material removal rate and minimising surface roughness. The best combination of the process parameters for multi-response optimisation was obtained through desirability function.

Keywords: wire EDM; electrical discharge machining; WEDM; material removal rate; MRR; surface roughness; surface quality; central composite design; CCD; response surface methodology; RSM; process parameters; titanium alloys; coper; nickel; shape memory alloys; electro-discharge machining; pulse on time; pulse off time; servo voltage; zinc coating; brass wire electrodes; mathematical modelling.

DOI: 10.1504/IJMMM.2016.075461

International Journal of Machining and Machinability of Materials, 2016 Vol.18 No.1/2, pp.36 - 53

Received: 30 Apr 2015
Accepted: 12 Aug 2015
Published online: 23 Mar 2016 *

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