INVESTIGATION OF THE STRENGTH AND DUCTILITY RELATIONSHIIPS IN TITANIUM-ALUMINUM ALLOYS BETWEEN 6 AND 15% ALUMINUM FOR APPLICATION AT ELEVATED TEMPERATURES

摘要

An investigation of the strength and ductility relationships in a series of Ti-Al alloys varying from 6 to 15% aluminum was carried out. The activation energy for the embrittlement reaction in a Ti-8A1 alloy was found to be about 34,000 cal/mol, which is compatible with present knowledge of diffusion of aluminum or interstitial elements. More com¬plete evidence was obtained that striations represent sub-boundaries that form as a result of the beta-alpha transformation and at which micro segregation occurs. Striations can be eliminated by cold working and recrystallizing, or by quenching and recrystallizing. Rapid quench¬ing results in a martensitic structure which exhibits high resistance to embrittlement on subsequent aging at 750°F in a T1-8A1 alloy.