SiC/Ni3Al界面固相反应

使用扫描电子显微镜、电子能谱仪、X射线衍射仪对经1 050 ℃等温热处理10 h的SiC/Ni3Al界面固相反应层的成分分布、微结构及相组成等进行了研究.结果表明:SiC/Ni3Al界面固相反应层由Ni5.4Al1Si2、石墨态C及NiAl构成,反应物原子(Si,C,Ni和Al)在反应层中连续分布,均呈现下坡扩散的特征.反应层由随机C沉积区(random carbon precipitation zone,R-CPZ)及无碳沉积区(carbon precipitation free zone,C-PFZ)两个亚层构成.其中,R-CPZ靠近SiC侧,主要由Ni5.4Al1Si2构成,片状和颗粒状的石墨态C随机地分布其中;C-PFZ靠近Ni3Al侧,主要由Ni5.4Al1Si2及NiAl构成,不含有石墨态C.

INTERFACIAL SOLID STATE REACTION BETWEEN Ni3Al AND SiC

The microstructure and the element distributions of the reaction zone in interface SiC/Ni3Al composite annealed at 1 050 ℃ for 10 h were studied using a scanning electron microscope with an energy dispersive spectrometer and X-ray diffractometer. The results show that the reaction zone on the interface of SiC/Ni3Al consists of Ni5.4Al1Si2, graphitic carbon and NiAl. The reactant atoms, i.e., Si, C, Ni, and Al, are distributed uniformly in the reaction zone through downhill diffusion. The reaction zone is composed of two sub-zones: the random carbon precipitation zone (R-CPZ) and the carbon precipitation free zone (C-PFZ). The R-CPZ, adjacent to the SiC side face, contains the Ni5.4Al1Si2 matrix with the plate/sphere-like graphitic carbon precipitates randomly distributed. The C-PFZ, adjacent to the Ni3Al side face, contains Ni5.4Al1Si2 and NiAl without the graphitic carbon precipitates.