2009•Journal of Xi'an Petroleum InstituteRequires access
Preparation of SiC/Cr-Al-Si coating for C/C composites by two-step pack cementation method
Min Huang, Kezhi Li, Hejun Li, Fu Qiangang, Yu Wang, Sheji Luo
Open publisher page 2 citations
Abstract
SiC/Cr-Al-Si anti-oxidation coating on the surface of carbon-carbon composites is prepared by two-step pack cementation method.The phase compositions,microstructure and element distribution on the section of samples of the received SiC/Cr-Al-Si coating are studied by XRD,SEM,and the isothermal oxidation test of samples in air is finished at 1 500℃.The study results show that a SiC/Cr-Al-Si coating of 120 mm thickness is obtained,which consists of mainly three phases of SiC,AlCr2Si and Al4Si2C.Compared with the SiC coating prepared by one-step pack cementation method,the SiC/Cr-Al-Si coating prepared by two-step pack cementation method shows better oxidation resistance.The weight loss of the carbon-carbon sample with SiC/Cr-Al-Si coating is less than 5% after oxidizing for 12 hours.There are microcracks in the SiC/Cr-Al-Si coating,which is thought the main reason why the received SiC/Cr-Al-Si coating failed.In the secondary pack cementation,Cr-Al-Si diffuses into SiC coating but not covers on SiC coating,which is though the other reason why the received SiC/Cr-Al-Si coating failed.