Fabrication of Ti-6Al-7Nb Alloys by Metal Injection Molding

Abstract

The metal injection molding process was applied to produce Ti-6Al-7Nb alloys using 3 types of mixed powders. The first is a mixture of Ti and Al-Nb pre-alloyed powders, the second is a mixture of Ti, Ti-Al alloy and Nb powders, and the third is a mixture of elemental powders of Ti, Al and Nb. The sintered compacts using the first and second powders showed higher density and mechanical properties than the compacts using the third powder which showed many large pores formed due to the dissolution of Al particles during the sintering steps. Eventually, the compacts using a mixture of Ti+Al-Nb or Ti+Ti-Al+Nb powders showed tensile strength of above 800MPa and elongation of above 10%, which are similar to the properties of wrought materials.