Structure and mechanical properties of Ni3Al intermetallic, fabricated by spark plasma sintering of mechanically activated "Ni - Al" powder mixtures

The structure and mechanical properties of Ni3Al intermetallic are studied. The materials are fabricated according to different schemes, which combined mechanical activation of Ni and Al powders, self-propagating high temperature synthesis (SHS) and spark plasma sintering (SPS). It is found that Ni3Al intermetallics, fabricated by SPS using three different routes, have relative density of about 97 % and high values of mechanical properties compared to similar materials, obtained by conventional methods. Microhardness of the sintered samples range from 6100 to 6300 MPa. The value of flexural strength of all sintered samples is equal to 800 MPa. Spark plasma sintering of 86.71 % wt. Ni and 13.29 % wt. Al powders at 1100 degrees C leads to the formation of the material with the highest level of tensile strength equal to 400 MPa. This process was the most fast and efficient. It combines the chemical interaction of reagents with the sintering process.