In Situ TiC-Reinforced Steel Matrix: Heterogeneous Nucleation and Formation Mechanism of Divorced Eutectic TiC

Divorced eutectic TiC (TiC_E) influences the mechanical properties of TiC-reinforced wear-resistant steels. However, there is a lack of information with respect to the heterogeneous nucleation, growth, and formation mechanism of divorced TiC_E. To this end, the morphology, orientation, and origin of the divorced TiC_E in TiC-reinforced wear-resistant steel are thoroughly examined. Combined with the calculated planar disregistry between primary TiC (TiC_P) and divorced TiC_E and their actual orientation relationship examined using the electron backscatter diffraction (EBSD) technique, it is indicated that TiC_P serves as the preferred heterogeneous site for divorced TiC_E during solidification. The precipitation mechanism for the divorced TiC_E on the TiC_P is put forward and accounts for why the direction of [100] is the preferential growth direction.