Optimization of Parameters for Material Removal Rate and Surface Roughness in Wire Electric Discharge Grinding (WEDG) for Micro-machining of Cemented Carbide Rods

Abstract

In this work, the machining of cemented carbide rods is carried out in wire electric discharge grinding process. It is a hybrid machining process in which machining of micro-parts can be machined with high accuracy, aspect ratios, and flexibility. The rotary axis is mounted on the WEDM machine to produce micro-rods. The workpiece material cemented carbide is selected since it is widely used for cutting tools in industrial applications. This material is tough to be machined through conventional process. From the literature survey, the following three machining parameters such as the input current (A), pulse-off time (µs), and voltage (V) are considered as the input parameters for the machining process. Experimental trials are conducted based on the Taguchi parametric design by machining an Ø2 mm, and length of 10 mm to Ø400 µm with brass wire of Ø 0.25 mm was used to machine the workpiece material under different sets of parameter combinations. The S/N ratio analysis was carried out to find the optimum machining parameters and significant parameters affecting the material removal rate and surface roughness. ANOVA is used to find the most dominating parameter. Finally, it is concluded experimentally and statistically that the significant parameters affecting the material removal rate and surface roughness is input current. By varying these parameters, machining process of cemented carbide is extended to contour profiles.