Production of low oxygen contamination orthorhombic Ti-Al-Nb intermetallic foil

摘要

Aerospace industries continue the search for high performance materials, and recent years have seen rapid developments being made in the capabilities of Ti-AI based intermetallic alloys. Interest in these alloys is caused by their attractive combination of strength and density, but major drawbacks include brittleness at low temperature and sensitivity to interstitial contamination. Development of a relatively new class of ailoys was stimulated in 1988 by the discovery of Banerjee et al. [1] of a Ti-Al-Nb orthorhombic (O) phase based on the Ti2AlNb composition. Alloys close to this stoichiomeiry can have microstructures containing O phase, ordered cubic ftyand ordered hexagonal a2, depending on the exact composition and processing route. Promising mechanical properties, in comparison with conventional a2 based alloys, have been measured by Rowe [2], and results indicate that the best candidates for further development are based on O + p0 two phase alloys.