料浆烧结法制备改性Si-Cr-Ti高温抗氧化涂层的研究  

Study of Preparation of High-temperature and Anti-oxidized Modified Si-Cr-Ti Coating by Slurry Sintering

作　　者：肖来荣[1] 蔡志刚[1] 易丹青[1] 向朝建[1] 

机构地区：[1]中南大学材料科学与工程学院,湖南长沙410083

出　　处：《稀有金属与硬质合金》2005年第2期23-27,共5页Rare Metals and Cemented Carbides

基　　金：教育部博士点基金资助项目(200105330033)

摘　　要：采用料浆烧结法制备了C—103铌合金上的改性Si—Cr—Ti高温抗氧化涂层,在涂层料浆中添加活性元素Zr和稀土氧化物Y2O3。进行了1200℃静态抗氧化实验,室温～1200℃的热震实验,1200℃间断氧化增重实验。利用扫描电镜(SEM)、能谱(EDS)和X射线(XRD)等分析研究了涂层的形貌、结构、元素分布、相分布等。结果表明:涂层由两层组成,其外层是涂层主体,由复杂的(Nb,Cr,Ti,Zr)Si2相组成;中间扩散过渡层为致密的NbSi2相和少量Nb5Si3相共存。加改性元素Zr和稀土氧化物Y2O3能增加涂层的致密度和扩散过渡层宽度,改善涂层体系的抗氧化性能。扩散形成的过渡层与基体、涂层主体层之间的界面平直;过渡层本身致密,且能有效阻止裂纹的进一步扩展和氧向基体的扩散。The high-temperature anti-oxidized Si-Cr-Ti coating improved on C-103 niobium alloy is prepared by slurry sintering with the addition of active Zr element and Y_2O_3.Static anti-oxidization test at 1 200 ℃,thermal shock test from room temperature up to 1 200℃ and intermittent oxidization weighting test at 1 200℃ were made.Investigation is made into the morphology, structure,and element distribution and phase distribution of the coating by SEM,EDS,and XRD.The results showed that the coating consists of tow layers.The out layer,the main body of the coating,is made of the complex phase of(Nb,Cr,Ti,Zr)Si_2, the inner layer,the intermediate diffusion transition layer,is made of the dense NbSi_2 phase and associated with minor amount of Nb_5Si_3.The addition of modified Zr and Y_2O_3 can increase the density of the coating and widen the diffusion transition layer to improve the anti-oxidation properties of the coating system with flat interface between the diffusion transition layer and the substrate/main body of the coating.The diffusion transition layer is dense and can effectively prevent the further extension of cracks and oxygen diffusion into the substrate.

关 键 词：料浆烧结 铌合金 改性Si—Cr—Ti 高温抗氧化涂层 

分 类 号：TF125.242[冶金工程—粉末冶金]