Experimental investigations on machining behavior of waspaloy and synthesis of waspaloy matrix composites

Abstract

Superalloys have been selected as one of the best candidate materials for aerospace application owing to its exceptional properties. Superalloys were classified under three common categories namely nickel based, iron-nickel based and cobalt based which are positioned in the prominent place due to its wide application in the environment where temperature is above 540°C. Waspaloy, Haynes214, Inconel601, Inconel617, Hastelloy series: B, N, S, W and X, Nimonic 75 are some of the nickel-base superalloy. The formation of intermetallic precipitates in some superalloys was the reason for strength retaining ability at high temperature. The dislocation was hindered due to the increase in the volume of precipitates which was the cause for high hardness. Most of the Nickel based superalloys are termed as difficult to machine alloys. The frequent replacement of cutting tools was done during machining these alloys which ultimately affects the productivity of the company. This type of alloys exhibits poor machinability which also makes difficult to machine by conventional means. Waspaloy, nickel based superalloy, has been extensively used in aerospace industry due to its strength retaining capacity at higher temperature, better newlinecorrosion resistance and toughness. In the first investigation, Electrical Discharge Machining (EDM) was selected for the machining the waspaloy plate. The Taiwan make, ECOWIN MIC-640L CNC EDM machine was used for drilling the waspaloy plate. The drill size is 10mm diameter and 4mm depth. The electrolytic pure copper was used as tool. The four process parameters namely peak current; voltage, duty cycle and flushing pressure were selected for the investigations. Each process parameters with three levels were selected newline newline