Guo Mengqiu, Cui Yongjing, Wang Changliang, Jiao Jian, Bi Xiaofang, Tao Chunhu
School of Materials Science and Engineering, Beihang University, Beijing 100191, China.
AECC Beijing Institute of Aeronautical Materials, Beijing 100095, China.
Materials (Basel). 2023 Jun 15;16(12):4407. doi: 10.3390/ma16124407.
In this study, silicon coating was deposited on melt-infiltrated SiC composites using atmospheric plasma spraying and then annealed at 1100 and 1250 °C for 1-10 h to investigate the effect of annealing on the layer. The microstructure and mechanical properties were evaluated using scanning electron microscopy, X-ray diffractometry, transmission electron microscopy, nano-indentation, and bond strength tests. A silicon layer with a homogeneous polycrystalline cubic structure was obtained without phase transition after annealing. After annealing, three features were observed at the interface, namely β-SiC/nano-oxide film/Si, Si-rich SiC/Si, and residual Si/nano-oxide film/Si. The nano-oxide film thickness was ≤100 nm and was well combined with SiC and silicon. Additionally, a good bond was formed between the silicon-rich SiC and silicon layer, resulting in a significant bond strength improvement from 11 to >30 MPa.
在本研究中，采用大气等离子喷涂在熔体渗透碳化硅复合材料上沉积硅涂层，然后在1100℃和1250℃下退火1 - 10小时，以研究退火对该涂层的影响。使用扫描电子显微镜、X射线衍射仪、透射电子显微镜、纳米压痕和结合强度测试对微观结构和力学性能进行评估。退火后获得了具有均匀多晶立方结构的硅层，且无相转变。退火后，在界面处观察到三个特征，即β - 碳化硅/纳米氧化物膜/硅、富硅碳化硅/硅和残余硅/纳米氧化物膜/硅。纳米氧化物膜厚度≤100 nm，且与碳化硅和硅结合良好。此外，富硅碳化硅与硅层之间形成了良好的结合，使结合强度从11 MPa显著提高至>30 MPa。
