Effect of Fe or Cr Addition on the Strengthening Ti-6Al-4V Alloy by Metal Injection Molding

Abstract

It has been found that the strengthening of sintered Ti-6Al-4V alloy compacts were available by addition of fine Mo powder, because of microstructural modification on the sintered compacts. In this study, the metal injection molding process has been applied to strengthen Ti-6Al-4V alloy compacts by addition of fine Fe or Cr powders. Fe and Cr are the same beta stabilizing element as Mo and are more cost effective powders as compared to Mo powder. The microstructures of sintered compacts were consisted of acicular alpha phases and intergranular beta phases. The tensile strength of sintered compacts was increased with increasing Fe or Cr contents, and the effect of Fe addition for strengthening the sintered compacts was larger than Cr addition. Eventually, the tensile strength of sintered compacts added 2mass% of Fe was improved to be 980MPa with 14.8% of elongation, and the compacts added 4mass% of Cr showed the excellent tensile strength of 1030MPa with 15.1% of elongation.