Effects of disc milling parameters on the physical properties and microstructural characteristics of Ti6Al4V powders

In this study, the mechanical disc milling was applied to the production of Ti6Al4V powders from the recycling titanium alloy machining scraps. The present study covers the effects of the milling speed and milling time on the characteristics of recycled powders such as particle size, morphology, crystal phases, and oxygen content. The scraps and produced powders were sequentially characterized by XRD, SEM, particle size and elemental oxygen analyses. The results indicated that the milling parameters had a significant effect on the particle size and morphologies of Ti6Al4V powders. The particle size of flaky powders decreased when the milling speed increased from 800 to 1400 rpm for a milling time of 4 min., and the milling time increased from 4 to 24 min. for a milling speed of 1200 rpm. The results showed that the average mean particle sizes (d(50)) are approximately 330 and 211 mm after milling for 4 min at 1400 rpm and for 24 min at 1200 rpm, respectively. Based on the XRD results, a significant change in the phase content was not recorded. Overall, our study demonstrated that the applied milling process is quite effective to produce micron-sized powders from the Ti6Al4V scraps in a short time. (C) 2017 Elsevier B.V. All rights reserved.