High-Carbon Ferrochrome Effects on Microstructure and Mechanical Properties of Powder Metallurgy Titanium Alloys

In this paper, the powder metallurgy method was employed to prepare titanium alloys with high-carbon ferrochrome (HCFeCr). With the HCFeCr addition, the size of the β grains decreased and the lamellae of the α phase became thinner. The TiC strengthening phase precipitated at the grain boundaries, resulting in the inhibition of the β grain growth and hardness enhancement. In addition, Fe and Cr as β-stabilizing elements existed in the enriched β-Ti phase, which increased the β phase amount. The strength improvement was attributed to grain size optimization and strengthening phase formation. With the 9 wt.% HCFeCr addition, the corresponding Vickers hardness increased to 480 HV, which is 60% higher than the Ti6Al4V alloy. The tensile and yield strength was 1228 and 1140 MPa, respectively. The addition of HCFeCr can effectively enhance the strength and hardness while reducing the cost. This is a promising additive to obtain low-cost Ti alloys with high mechanical properties.