Effects of Wire Material on Productivity of WESM-Processed HSS
Advance materials are widely used in aerospace, bio-medical, die and mold making, and nuclear industries. These materials are very precise and difficult-to-machine with conventional way of manufacturing processes such as milling, drilling, boring etc. So, wire electric spark machining (WESM) seems to be better choice to cut such materials in a cost-effective way. The present experimental study discusses the effect of wire materialon material removal rate (MRR) and further optimized values of machining parameters are achieved. Four machining parameters i.e., peak current, servo voltage, spark on time and spark off time are varied up to their four levels while the other machining parameters such as wire tension, wire feed rate, flushing pressure and polarity of wire electrode are kept constant. HSS (High Speed Steel) is used as a workpiece material, while three types of tool-wires i.e., diffused, copper and molybdenum wires are used as a tool electrode. The plan of experiment is based on Taguchi L16 orthogonal array and analysis of variance is used to find significant machining parameter. From result obtained, it is concluded that diffused wire provides more MRR as compare to copper and molybdenum wire. It is also concluded that, spark on time is the significant parameter followed by peak current, spark off time and servo voltage for all type of wires used. As the spark on time and peak current increases, the material removal also increases whereas material removal rate decreases with increase in spark off time and servo voltage.
Keywords - WESM, HSS, MRR, copper wire, Taguchi method