Temperature and composition dependence of the elastic constants of Ni3Al

• Published in: Metallurgical and materials transactions. A, Physical metallurgy and materials science Physical metallurgy and materials science, 1999-09, Vol.30 (9), p.2403-2408
• Main Authors: PRIKHODKO, S. V, CARNES, J. D, ISAAK, D. G, YANG, H, ARDELL, A. J
• Format: Article
• Language: English
• Subjects: Applied sciences; Condensed matter: structure, mechanical and thermal properties; Elasticity, elastic constants; Exact sciences and technology; Mechanical and acoustical properties of condensed matter; Mechanical properties of solids; Metals. Metallurgy; Physics
• ISSN: 1073-5623; 1543-1940
• DOI: 10.1007/s11661-999-0248-9

The stiffness constants, c(ij), of monocrystalline Ni3Al of three different compositions, 23.2, 24.0, and 25.0 at. pct Al, were measured over the temperature range from 300 to 1100 K using the rectangular parallelepiped resonance method. The bulk modulus, as well as the shear modulus, Young's modulus, and Poisson's ratio for randomly oriented polycrystalline stoichiometric Ni3Al, were derived from the stiffness constants. The data indicate that c(44) is essentially independent of composition, decreasing slightly with increasing temperature for all three alloys. The values of c(11) and c(12), however, decrease with increasing Al content, the difference being small at room temperature but becoming larger at higher temperatures. We find that c(11) and c(12) are not as sensitive to Al concentration as is implied by previous results. A comparison of different shear moduli of Ni3Al and the saturated Ni-Al solid solution in equilibrium with it indicates that the ordered phase is generally elastically stiffer than the solid solution over the range of temperatures at which coarsening of the Ni3Al precipitate has been heavily investigated. (Author)