SiC/YSiC composite coating on matrix graphite sphere prepared by pack cementation and molten salt

SiC/YSiC composite coating was prepared on the surface of matrix graphite sphere by pack cementation and molten salt process to improve the anti-oxidation property of the matrix graphite. According to the experiment results, the composition of the composite coatings prepared with different Y content is the same. While, the crushing model and strength is different. The maximum crushing strength is 1716.2 N when Y content is 1 g. The different coating structure were analyzed according to the results. The coating is composed of inner original SiC layer and outer new formed Si layer when Y content is 0.25 g. When the addition of Y were 0.5 g and 0.75 g, the coating consists of a newly formed YC2 layer inside, a SiC layer in the middle and an external Si layer. The final coating structure is composed of SiC layer and residual Si and YC2 layers when Y content is 1 g.