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

Abstract

In this research work, an attempt was made to machine Ti6Al4V titanium alloy utilizing AA6061/10Gr composite tool. The composite tool was fabricated using stir casting technique and Al2O3 particles of size 5µm were incorporated in the dielectric fluid to enhance the machining performance. Experiments were conducted by varying Al203 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 60s under PMEDM conditions. Pits, craters and cracks were observed on the machined topography which was eliminated when 5g/l of Al2O3 particles were added to dielectric fluid. MEIOT technique was utilized for optimization and it was observed that Ton 15µs, Toff 4µs and current 7A and powder concentration of 10g/l results in best machining performance.

Impact of SiC Particle Incorporated Dielectric Medium on Machining Performance of AA7050/SiC/Al2O3 Hybrid Composites

“…23 The concurrent effect of powder concentration and Ton has very minimum impact on the MRR of hybrid composites. 24 Under unmixed dielectric circumstances with increased Ton, no change in MRR was found; however, when 5 g l −1 SiC particles were added to the dielectric fluid, MRRs of 68.80 mg min −1 and 70.53 mg min −1 were measured, respectively. When machined AA7050/8Al 2 O 3 /8SiC hybrid composites under 5 g l −1 PMEDM dielectric condition a 35% improvement in MRR was attained owing to the bridging effect.…”

Electric Discharge Machining of Inconel 718 Under a Distinct Dielectric Medium

“…20 Particle agglomeration and heterogeneous reinforcement distribution throughout the matrix material generate uncontrollable sparks and inadequately flushed machined debris. 21 Powder metallurgy, casting and in situ fabrication are the various techniques adopted to attain the uniform distribution of particles. 22,23 Of the various production techniques stir casting was cost effective and suitable for mass production.…”