A comparative study of microstructure, mechanical and fracture properties of Ni3Al-based intermetallics produced by powder metallurgy and standard melting and casting processes

• Published in: Journal of materials science 1996-06, Vol.31 (12), p.3213-3222
• Main Authors: BOZIC, D, ILIC, N, MITKOV, M, JOVANOVIC, M. T, ZDUJIC, M
• Format: Article
• Language: English
• Subjects: Applied sciences; Exact sciences and technology; Fractures; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/BF00354671

A comparative study of the microstructure, mechanical properties, and fractography of Ni3Al macro- and microalloyed intermetallics produced by powder metallurgy (PM) and standard vacuum melting and casting processes has been carried out. Non-porous PM compacts were obtained by vacuum hot pressing of powders produced either by gas atomization or by a rotating electrode process. All materials showed a positive temperature dependence of the compression yield strength. The maximum strength was attained between 600 and 700 C; then a decrease occurred. With increase in temperature the ductility of all materials slightly decreased to a minimum and then abruptly increased. Values of mechanical properties of PM compacts were higher than those of as-cast material. There is a correlation between the fracture morphology and the ductility of Ni3Al, i.e. the higher ductility corresponds to transgranular fracture, while the minimum ductility is a consequence of intergranular fracture. (Author)