三维网络SiC_n/20Cr钢复合材料的界面固相反应及显微组织

采用真空-气铸法制备了SiCn/20Cr钢复合材料,并对SiC/20Cr钢复合材料的界面进行了研究.结果表明:SiC和20Cr在复合材料的界面产生较强固相反应,SiC分解出的Si与Fe结合生成Fe-Si化合物,SiC分解出的C以石墨态沉积下来.固相反应的区域由碳化硅反应区、金属反应区和碳沉积区组成.碳元素在碳沉积区的沉积形态与沉积点到SiC的距离有关.TEM证实了金属反应区的产物为(Cr,Fe)23C6及Fe3Si,其中Fe3Si的形成为SiC的分解提供了热力学驱动力.

Solid-Phase Reaction and Microstructure of Interface of 3D Meshy SiC_n/20Cr Steel Composite

The interface of the SiC_n/20Cr Steel composite material fabricated via vacuum-gas casting process was investigated with XRD and EDS(energy-dispersive spectroscopy analyzer)attached to SEM.The result revealed that an intensive solid-phase reaction occurs on the composite's interface between SiC and 20Cr steel,then SiC decomposed into Si that forms Fe-Si compound with Fe and C that precipitated in graphite form.The solid-phase reaction zone is composed of three zones,i.e.the metal,silicon carbide and carbon precipitation zones.The precipitating form of C in carbon precipitation zone relates to the distance between tne precipitation position and silicon carbide.The(Cr,Fe)_(23)C_6 and Fe_3Si is the products from metal reaction zone are verified by transmission electron microscope(TEM),of which the formation of Fe_3Si provides thermodynamically the driving force for the decomposition of SiC.