Fabrication of high strength Ti alloy compacts by metal injection molding

Abstract

Ti and its alloys show the excellent characteristics such as low density, high strength, high corrosion resistance and high biocompatibility. Therefore, they have been widely used for various industrial and medical applications. However, they have poor workability, it is difficult to produce the complicate shaped and precise parts. Therefore, the metal injection molding (MIM) is hoped to be a suitable technique for fabricating the complex shaped Ti or its alloy parts with low cost. In our previous studies, it was found that the strengthening of sintered Ti-6Al-4V alloy compacts were available by addition of Fe or Cr powders because of their solution strengthening of beta phase. In this study, the metal injection molding process has been applied to fabricate high strength Ti alloy compacts using mixed elemental powders. The alloy composition was replaced V with Fe, Cr or Mo in Ti-6Al-4V alloy. Eventually, more than 1100 MPa of strength and 8 % of elongation were achieved in Ti-6Al-12.5Mo alloy compact by MIM process.