Interface Reactions Between the Metal Melt and the Filter Surface Activated by a Spark Plasma Sintering Process

Abstract

AbstractThe reactions between newly developed filter materials and metal melts containing various inclusions were analyzed under laboratory conditions. For the melt production, a Spark Plasma Sintering (SPS) apparatus was utilized. The SPS process provides very high heating rates, which emulate the thermo-shock during a real filtration process, and variable reaction times, which allows to simulate both, short and long filtration processes. The short-time filtration processes are relevant for die-casting, where one ton of a steel passes the filter in approx. 15 s, the long-term ones for continuous casting taking several hours. In the SPS process, the convection of the steel melt is suspended, which makes the interpretation of the interfacial reactions and reaction kinetics more straightforward and trustworthy. Furthermore, the SPS process allows speeding up the reaction diffusion kinetics by using tiny diffusion couples having the form of powder mixtures that contain the metal or alloy and the functional filter material under study. In such samples, the equilibrium state that is suitable for a direct comparison with the results of thermodynamic simulations can be achieved very quickly.