Deformation structures in cold rolled Nb-(10--16) at.% Al solid solutions

Alloys based on the refractory intermetallic compound Nb3Al have recently become of interest for applications at very high temperatures (1,000--1,600 C) in the new generation of aircraft propulsion systems. This compound has an A15 structure, a density of 7.29 g/cm3 and forms by a peritectic reaction from the liquid below 1,960 C. Moreover, it exists in a two-phase equilibrium with a b.c.c. Nb-Al solid solution over a wide composition range between ∼9 and 18 at.% Al. Recent results have shown that monolithic Nb3Al is quite strong and displays superior creep resistance above 1,000 C, although it is very brittle at low temperatures. With regard to the latter, it has been shown recently that improved toughness at ambient temperatures can be achieved by the presence of the Nb solid solution as a second phase. However, apart from some recent work, limited studies of transformations and deformation characteristics of binary solid solutions have been reported. In this paper, results of such a study of Nb-(10--16)Al alloys are reported