화학공학소재연구정보센터
Journal of Materials Science, Vol.31, No.12, 3213-3221, 1996
A Comparative-Study of Microstructure, Mechanical and Fracture Properties of Ni3Al-Based Intermetallics Produced by Powder-Metallurgy and Standard Melting and Casting Processes
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 degrees C, then the decrease occurs. 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.