Investigation on the effect of electrolyte On machining of metal matrix composite Through electro chemical machining

Abstract

Electrochemical machining (ECM) is one of the important machining process for machining alloys and composites. Aluminium composites are gaining importance in aerospace and automobiles industries. The effect of ECM process input parameters namely voltage, electrolyte concentration and duty cycle on Al7075 alloy is studied with acidified infra-red heated electrolyte. The formation of hole depth on the specimen in X-plane and Y-plane were investigated. Based on the experiments the acidified sodium nitrate (NaNO3) heated electrolyte shows better hole depth to the room temperature electrolyte. Based on the preliminary experiments L27 Orthogonal Array (OA) experiments were planned. The input process parameters such as voltage, temperature of the electrolyte, type of tools and the thickness of the work piece is varied and its effect on material removal rate (MRR) and surface roughness (SR) were studied on Al7075 alloy. The results of the experiments are analysed using Technique for order of preference by similarity to ideal solution (TOPSIS) and Analysis of variance (ANOVA). As per the analysis voltage at 7V, electrolyte temperature at 27ºC, aluminium electrode and work piece thickness of 12 mm shows the higher MRR and low SR. newlineFurther two different composition of specimen were prepared i.e., Al 7075 with 5% and 10% mass fraction of boron carbide (B4C) (AMMCand#8223;s). The prepared specimens are machined using ECM by varying one parameter at a time. The input process such as electrolyte temperature, electrolyte concentration, voltage and duty cycle were considered to study the machining speed, diametric overcut (DOC) and Delamination factor (DF). The heated sodium nitrate electrolyte of varying concentration is used in the experiment. The electrolyte is heated with induction heater and the temperature is maintained in closed loop setup newline