Influence of Al203 particle mixed dielectric fluid on machining performance of Ti6Al4V

In this research work, an attempt was made to machine Ti6Al4V titanium alloy utilizing AA6061/10 Gr composite tool. The composite tool was fabricated using stir casting technique and Al2O3 particles of size 5 mu m were incorporated in the dielectric fluid to enhance the machining performance. Experiments were conducted by varying Al(2)0(3) concentration, pulse on time, current, and pulse off time, and the responses Material Removal Rate (MRR), Tool Wear Rate (TWR), and Surface Roughness (Ra) were recorded. Experiments runs were planned using Taguchi orthogonal array. The results revealed that adding powder increases MRR and TWR owing to the excessive heat generation and bridging effect respectively. The best surface finish was attained due to the increase in spark gap and complete flushing of machined debris. Coating of materials over the machined specimen was observed when the parametric value of Ton was higher than 60 mu s under PMEDM conditions. Pits, craters and cracks were observed on the machined topography which was eliminated when 5 g l(-1) of Al2O3 particles were added to dielectric fluid. MEIOT technique was utilized for optimization and it was observed that Ton 15 mu s, Toff 4 mu s and current 7 A and powder concentration of 10 g l(-1) results in best machining performance.