Composite material of cermets made by SHS
(School of Higher Vocational Technology, Anshan University of Science and Technology, Anshan 114044, China)
Abstract: Based on self-propagating high temperature synthesis （SHS） technology, the ceramic coating with thickness of 2.5mm on the surface of carbon steel and square steel tube was produced under gravity condition. The phase compositions of the coating were determined by X-ray diffractometry. The microstructure of the coating, interfacial structure and hardness between coating and steel body were analyzed by optics microscopy and scanning electron microscopy. The wear resistance of the ceramic coating was investigated. The results show that the combine between ceramic coating and metal base body is firm. There are few air vents and good densification in the coating. Ceramic coating is mainly made up α- Al2O3 base body phase and FeO-Al2O3 spinelle phase. SiO2 exists together with the crystallization quartz phase in the ceramic coating. The hardness（HV 0.2） of composite can reach 1500. The wearability of ceramic coating is eight times higher than that of hardened steel No.45 of HRC50.
Key words: ceramic coating； gravitational separation； SHS method； hardness