Experimental investigation on effects of machining parameters on the performance of Ti-6Al-4V micro rotary parts fabricated by LS-WEDT

Abstract

The low speed wire electrical discharge turning (LS-WEDT) is firstly proposed to fabricate the Ti-6Al-4V micro rotary workpiece in this study. The surface quality, sub-surface damages and machining efficiency of LS-WEDT process are discussed. The single factor experiments and orthogonal experiments are respectively conducted to analyze effects of speed parameters and peak current on surface roughness (Ra), material removal rate (MRR), surface morphology and the white layer of the TC4 micro rotary workpiece machined by LS-WEDT. Experimental results indicated that the most important factors affecting the Ra and MRR in LS-WEDT respectively are the peak current and feeding speed, and the rotating speed and feeding speed have significant interactive effect on Ra and MRR. Besides, the low feeding speed can cause surface burning and the high rotating speed will elongate craters. Furthermore, the surface oxidation of TC4 workpiece machined by LS-WEDT is far more serious than the surface alloying and Ti3O and Ti6O can be detected on the machined surface. Moreover, the serrated white layer can be observed and gradually becomes continuous and thin with the decrease of peak current. Finally, large amounts of oxygen and less copper elements can be detected on the top of the white layer and longitudinal cracks.