Microstructure of matrix and wear resistance of ceramic layer of TiC/Fe surface gradient composites

In this paper,the joining of gray cast iron (HT300) and titanium plate with the thickness of 0.25 mm was performed by the method of pouring. The sample was isothermally kept in vacuum tube furnace at 1 138℃ for 8 h,and cooled in furnace to room temperature. TiC particulates reinforced surface gradient composite was prepared on the iron matrix of cast iron surface by the in-situ technology. Microstructure analysis, microhardness and wear-resistance test were carried out on the recombination region. The experimental results show that the TiC particulates reinforced surface gradient composite is composed of three layers. The difference between the three layers lies in the different sizes and different shapes of TiC particulates. The microhardness decreases gradually from composite layer (C region) to pearlite region. The maximum microhardness appears in the high density ceramic layer (C region). Therefore,wear experiment was further performed to study wear-resistance of the high density ceramic layer of the surface gradient composite. Apparently, the wear-resistance of high density ceramic layer is enhanced greatly in comparison with gray cast iron.