Microstructure and Mechanical Behaviour of NbTiAl based alloys doped with low additions of silicon.

Z. Zhao (1) , A. Denquin (1) , S. Drawin (1) , J. Barreau (1)

1 ONERA - The French Aerospace Lab [Palaiseau]

Nb-base refractory intermetallic materials have potential interest for high temperature applications thanks to their low density and high temperature strength. While advanced intermetallics in monolithic form have limited prospects for providing the required balance of properties for use at high temperatures, two-phase or multicomponent intermetallic systems composed of a ductile, Nb-base refractory phase in equilibrium with one or more silicide intermetallics show promise for further development as structural materials. In the present paper, Nb-base refractory alloys based on Nb-35Ti-15Al (at.%) were doped with small amount of Si (1 and 2 at% of silicon) addition to improve its high temperature strength by keeping an acceptable ductility at room temperature. The samples were prepared by arc-melting starting from pure elements (99.99%). The silicon addition effects on the microstructural features were investigated by using X Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) techniques. Its effects on the mechanical properties were assessed by compression tests at ambient and high temperatures. Compression tests show the beneficial effect of the Si addition on strength.

Keywords: NIOBIUM SILICIDE; NIOBIUM ALUMINIDE; PHASE TRANSFORMATION; COMPRESSION TEST

Domains: Chemical Sciences; Material chemistry

Z. Zhao, A. Denquin, S. Drawin, J. Barreau. Microstructure and Mechanical Behaviour of NbTiAl based alloys doped with low additions of silicon.. THERMEC 2013, Dec 2013, LAS VEGAS, United States. ⟨hal-01057810⟩