Abstract

Engineering grade intermetallic TiAl based alloys has been established as high performance alloys when compared to more traditional super alloys and other Ni based alloys thanks to excellent density/performance ratio.

Objective: This study aims to investigate new selected alloys compositions toward their use as structural materials for automotive and aeronautic industry.

Methods: Nominal compositions of Ti-45Al-5Nb-4V-0.5Mo-0.1Si, Ti-45Al-5Nb-4V-0.5Mo-0.5Si and Ti-45Al-5Nb-4V-0.3Si (at %) were casted and heat treated resulting in y and a/y microstructure analyzed using scanning electron microscopy. To determine formability and mechanical behaviour at elevated temperature, hot compression tests were conducted at 1323 K and strain rate of 0.05 s−1 on deformation dilatometer DIL A/D 805.

Results: Microstructure imaging before and after deformation and stress strain curves were obtained. DRX (DXR) evidence was further explicated by exploitation of experiment data and calculation of dynamic recrystallization volume fraction of DRXed phases.

Conclusion: Results shows that mechanical performance of intermetallic TiAl alloys are microstructure depended. Casted Ti-45Al-5Nb-4V-0.5Mo-0.1Si alloy have promising mechanical performance and is subject to improvement toward application.

Keywords: Titanium aluminides, Intermetallics, TiAl, Microstructure, Electron microscopy, Hot compression test, Dynamic softening, Recrystallization, Compression behavior