Effect of partial mechanical alloying on the self-propagating high-temperature synthesis of Ni₃Si

Self-propagating high-temperature synthesis (SHS) is a new method for economical processing of intermetallic compounds and ceramic materials, as well as composites based on them. On the other hand, mechanical alloying is an effective method for producing highly metastable and, therefore, reactive metal powders. In this paper an overview of partial mechanical alloying is given. The effect of partial mechanical alloying on the self-propagating high-temperature synthesis of Ni₃Si-compounds is studied. The influence of alloying time on powder characteristics, e.g. particle size distribution, is given. The effect of alloying time on the properties of Ni–Si composite powders and on the characteristics of the SHS process, e.g. propagation rate, is reported. Ni₃Si was chosen as the object for this study because of its corrosion and high-temperature oxidation resistance. Like other L12-type compounds, the strength of Ni₃Si shows an anomalous behaviour as a function of temperature, therefore, it has potential for high-temperature applications.