SHS (Self-sustained high-temperature synthesis) of intermetallic compounds: effect of process parameters by computer simulation

The very wide temperature ranges and the many different chemical and phase transformation steps experienced by an SHS process make the search for a unifying theory impractical and a numerical approach highly desirable. The work describes an investigation of the Al+Ni→AlNi SHS by a computer simulation method developed by the Authors and based on a finite difference numerical engine coupled to a detailed description of several assumed reaction steps. The model includes Al melting, Ni diffusion-controlled dissolution (and possibly Ni melting), nucleation and precipitation of AlNi, and eutectic deposition. The results are discussed from the point of view of feasibility of the process, transition from self-propagating to thermal explosion behavior, and influence of process variables such as reactant grain sizes, diffusion coefficient, initial composition, and thermal conductivity.