SELF-PROPAGATING HIGH-TEMPERATURE SYNTHESIS OF NI3AL

Combustion synthesis of the Ni3Al intermetallic was studied using the self-propagating high-temperature synthesis (SHS) mode. Since the reaction wave propagates rather quickly through the sample in SHS, a successful application of this process requires an understanding of the influence of processing variables on its dynamics, and on the phase composition and microstructure of the product. Thus, the effects of green density, ignition power, preheating temperature, and the particle sizes of aluminum and nickel were investigated. In addition, nickel particles with different morphology were used. It was found that higher green density, lower ignition power and higher preheating temperature lead to fully reacted product with a well-developed microstructure. The reactant particle sizes and their morphology also significantly influence the product properties. The obtained results are helpful in understanding the mechanism of formation of Ni3Al.