Multi-objective optimization in WEDM process of nanostructured hardfacing materials through hybrid techniques

• Machining of Nanostructured hardfacing material.
• Optimal settings of WEDM parameters are identified.
• Hybrid method modifies GRA for multi-response optimization.
• PCA eliminates the problem of actual weights for the multiple responses.
• Developed models using RSM to find the effects of WEDM parameters on GR grade.

Hardfacing is one of the most efficient and cost-effective ways to scale down operating expense leading to improved performance and reliability of the equipment. Presence of nano-particles in hard facing metal matrix dramatically enhanced surface area to volume ratio resulting in magnificent improvement in conductivity, hardness, heat and wear resistant properties. This paper presents an application of nanostructured hardfacing material for the development of turning tool insert through welding and machining by WEDM process. In order to simultaneously optimize performance characteristics (MRR, machining time and surface roughness), a novel hybrid approach combining grey relational analysis with principal component analysis has been proposed to identify the optimal combination of process parameters in WEDM for machining nanostructured hardfacing materials. The grey relational analysis manifests discharge pulse time a most important parameter for both brass and zinc coated brass wires. Further, mathematical models are developed using response surface methodology to investigate the effects of the WEDM parameters on grey relational grade. As subsequent comparison made in terms of performance characteristics amongst brass and zinc coated brass wire, it is observed that zinc coated brass wire is highly worthy of being chosen especially for machining of nanostructured hardfacing material.