Investigation on the Wire Electric Discharge Machining Performance of artificially aged Al6061/B4C composites by Response Surface Method

Abstract

Present research work is focused on investigation of material removal rate in Wire-ED Machining (EDM) of artificially aged Al-6061/ B 4 C reinforced composites with 2-6 wt.% in peak aged condition. Combined effect of B 4 C and artificial aging at 100°C improved the hardness by 20 -170% under as cast and artificially aged condition. Initially the wire EDM experiments are conducted on Al6061 alloy and then the process parameters such as current, pulse-on time (t on ) and pulse-off time (t off ) are optimized to obtain the high material removal rate (MRR). At optimized conditions test samples with various % of B 4 C are machined to study their influence on MRR. The study revealed that current and t off had a significant influence. MRR increased as current is increased and it decreased as t off is increased. Maximum MRR at optimum settings, current : 5.53 A, T off : 10 µs and T on : 36.46 µs is 2.45 mg/min. Considering the limitation of the experimental set up the modified optimum settings (T off : 10 µs, T on : 30 µs and current : 5 A) resulted in average MRR of 2.39 mg/min with deviation of 0.20 mg/min. The study showed that there is no significant difference in MRR and the morphology of the machined surface with respect to test samples of different % of B 4 C particles as reinforcement in Al6061 composite.

Experimental Investigations and Optimum Performance Evaluation of Wire-EDM Characteristics of Aluminium 6061-Magnesite Composites

“…This condition is practically the sam AA-LCM and AA-DBM composites. Spark-cutting energy is correlated with pulse duration [28]. More material me high sparking energy, and the crater size increases.…”

“…More material me high sparking energy, and the crater size increases. Pulse-off time values, ranging fro µs to 62 µs, cause a significant shift in MRR when the cutting speed surpasses 1.7 mm Based on observations, there is a little decrease in MRR at 4-6% of magnesite particles Spark-cutting energy is correlated with pulse duration [28]. More material melts at high sparking energy, and the crater size increases.…”

“…As the travelling wire passes over the molten pool, the surface gets distorted and the wear tracks are formed. The resultant high internal stresses and mismatch strain impact the microstructural properties of the composites [28]. When the alloy plastically deforms to accommodate the reduced volumetric expansion of the reinforcing particulates, a higher dislocation density is generated.…”