Development of Microstructure of Interface Between Mo Coating and Ti Alloys at Elevated Temperature
In order to improve the poor scouring resistant and oxidation resistant abilities of titanium alloys at elevated temperature, the halide-activated pack molybdenum cementation process was applied to prepare the protecting coating for titanium alloys. The morphology, microstructure, element distribution of the coating were investigated by OM,SEM and EDS and XRD analysis, respectively. The Mo diffusion coating was formed on titanium substrate above 900℃.The thickness of coating increases with increasing temperature. When it is heated at 1050℃ for 6 hours, the thickness of diffusion layer is about 370μm.The crack between the coating and the substrate is dispelled. The coating consists of Mo、β(Ti)、α"(Ti) and α′(Ti), which distribute from outside to inside. The phase composition and microstructure of the surface of titanium alloys are changed. The poor performance of resisting elevated oxidation is improved to a certain extent.