Mechanical and Microstructural Characterization of a Titanium-based Ti-6Al-2Cr-2Ni Alloy Produced by SPS Sintering for Use in the Aerospace Industry

Abstract

Titanium-based alloys are widely applied in the aerospace industry thanks to their excellent strength-to-weight ratio, good corrosion resistance and thermal stability. In this study, a Ti-6Al-2Cr-2Ni alloy was elaborated by Spark Plasma Sintering (SPS), a technique derived from powder metallurgy that enables rapid, controlled densification. Sintering was carried out at 1000 °C under 30 MPa for 8 minutes in an inert atmosphere. A thermal annealing treatment at 550 °C was then applied to optimize microstructure and mechanical properties. Microstructural characterization by scanning electron microscopy (SEM), combined with EDS elemental analysis, revealed a significant reduction in porosity and progressive homogenization of the alloying elements after treatment. X-ray diffraction (XRD) confirmed the presence of a majority of α-Ti phase, associated with intermetallic compounds. Mechanically, Vickers microhardness measurements showed an increase in hardness after annealing, while instrumented indentation enabled Young's modulus to be reliably determined. These results indicate that the Ti-6Al-2Cr-2Ni alloy developed by SPS is a promising alternative to standard alloys such as Ti-6Al-4V, offering improved microstructural controllability, interesting mechanical properties and thermal optimization potential for advanced aerospace applications.