First-principle and experimental investigation into the interfacial characters of Ti-doped ZTA and high chromium cast iron

Abstract

Ti doping can improve the interfacial wettability and bonding condition between ZTA ceramic and high chromium cast iron (HCCI), but the underlying mechanism is still unclear. Therefore, the effects of Ti doping on the interfacial characters between ZTA and HCCI were investigated by experiment and first-principles calculations. Results of XRD, SEM, and high-temperature drop test indicate the presence of Ti at the interface and its effect on the formation of interfacial diffusion layer to improve the interface wettability and bonding obviously. The heat of segregation and work of adhesion obtained by first-principle calculations shows that the improvement in interface wettability and bonding is due to the promotion of dopped Ti atoms on the diffusion of Fe, Al, and Zr elements, but not the diffusion of Ti itself. Further investigation from the electronic level reveals that the doped Ti changes the charge distribution and orbital hybridization, and thus makes the formation or enhancement of strong ionic bonds and covalent bonds at the interface, improving the bonding strength and wettability of interfaces in ZTA/HCCI. The findings of this research can offer new insights into the modification of ceramics and enlarge the application of advanced ceramic materials.