Effect of Mo Addition on the Mechanical and Wear Behavior of Plasma Rotating Electrode Process Atomized Ti6Al4V Alloy

Abstract

In the current study, the effect of Mo content (1-10 wt.%) on the microstructure, hardness, bending and wear properties of Ti6Al4V-xMo alloys was investigated. The pre-alloyed and Plasma Rotating Electrode Process (PREP) atomized Ti6Al4V alloy powders and elemental Mo particles were mechanically mixed for 45 min in a zirconia jar. A uniaxial vacuum hot pressing was applied at 950°C for 30 min under 50 MPa pressure. The Ti6Al4V-xMo alloys were prepared metallographically and characterized by optical and scanning electron microscopy. The chemical composition of the different zones in the structure was determined using energy-dispersive x-ray (EDX) analysis. Mo appeared among the TiAl64V alloy particles and caused the formation of different diffusion zones. The formation of grain boundary α was effectively prevented, and instead, fine α’ and β zones were formed. Various phases formed along the particle boundaries of the Ti6Al4V alloy, and effective improvements in hardness, bending and wear resistance were obtained. However, the highest Mo content caused a decrease in mechanical properties. Ti6Al4V-5Mo alloy showed superior hardness and wear resistance.