High temperature mechanical properties of a submicrocrystalline Ti–47Al–3Cr alloy produced by mechanical alloying and hot isostatic pressing

• Published in: Journal of alloys and compounds Vol. 313; no. 1; pp. 201 - 208
• Main Authors: Shagiev, M.R., Senkov, O.N., Salishchev, G.A., Froes, F.H.
• Format: Journal Article
• Language: English; Russian
• Published: Lausanne Elsevier B.V 15.12.2000; Elsevier
• Subjects: A. Intermetallics, nanostructures; B. Mechanical alloying, powder metallurgy; D. Mechanical properties; B. Mechanical alloying, powder metallurgy; A. Intermetallics, nanostructures; D. Mechanical properties
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/S0925-8388(00)01167-1

High temperature tensile properties of a TiAl-based alloy with a submicrocrystalline structure were studied in the temperature range of 800 to 1200°C and the strain rate range of 10 −4 to 3×10 −1 s −1. The alloy was produced by hot isostatic pressing of an amorphous mechanically alloyed powder and contained two phases, TiAl and Ti 2AlN; the latter resulted from contamination of the powder with nitrogen during mechanical alloying. Two temperature ranges with different behavior were distinguished. In the temperature range of 800 to 950°C, the stress exponent, n=6, and the activation energy of deformation, Q=497 kJ mol −1, were typical to a climb controlled deformation mechanism. In the temperature range 1000 to 1200°C, the stress exponent, n=3, and the activation energy, Q=347 kJ mol −1, were determined together with high elongation indicating superplastic behavior.