Developing of New Titanium Alloys by Powder Metallurgy for Aerospace Applications 2003-01-3605
Titanium alloys parts are ideally suited for advanced aerospace systems because of their unique combination of high specific strength at both room temperature and moderately elevated temperature, in addition to excellent general corrosion resistance. Despite these attractive features, use of titanium alloys in engines and airframes is limited by cost. The alloys processing by powder metallurgy eases the obtainment of parts with complex geometry and probably, cheaper. In this work, results of the Ti-6A1-4V, Ti-6Al-7Nb and Ti-13Nb-13Zr alloys production are presented. Samples were produced by mixing of initial metallic powders followed by uniaxial and cold isostatic pressing with subsequent densification by sintering at 1500 C, in vacuum. Sintered samples were characterized for phase composition, microstructure and microhardness by X-ray diffraction, scanning electron microscopy and Vickers indentation, respectively. Density was measured by Archimedes method. It was shown that the samples were sintered to high densities and presented homogeneous microstructure. Processing parameters were optimized in order to reduce the interstitial pick-up (O,C,N and H) and to minimize grain growth during sintering.