The effects of induction heating rate on properties of Ni–Al based intermetallic compound layer coated on ductile cast iron by combustion synthesis

Applying brittle intermetallic compound coating on metals can enlarge the range of their use. In this instance, the properties of the coating layer are influenced by the constituent phases of intermetallic compound coating layer. In this study, the mixtures of Ni and Al powder have been reacted at different heating rates in an induction furnace in order to obtain the intermetallic compound coating layer with a single phase structure on a ductile cast iron. The microstructures and mechanical properties of the coating layer are investigated and the effects of heating rate in the induction furnace on the properties of intermetallic compound coating layers are evaluated. It was found that the ignition temperature and the maximum temperature increase significantly with increasing heating rate. It was also found that the coating layer is composed of single phase NiAl corresponding to the initial composition of mixed powder and adhesion qualities with substrate are improved with increasing heating rate.