摘要
采用电子束和真空自耗电弧熔炼法制备Nb-40Ti-7Al(质量分数,%)合金,利用料浆熔烧法在合金表面制备Si-Cr-Ti涂层,研究在1 400℃下合金与涂层的氧化行为。通过X射线衍射(XRD)、扫描电镜(SEM)、能谱分析(EDS)及电子探针微区分析(EPMA)研究基体与涂层氧化前后的组织形貌变化及成分分布。结果表明:Nb-40Ti-7Al合金在1 400℃氧化1～11 h后,氧化产物均主要为TiNb2O7、TiO2、Al2O3;氧化前,涂层主要由(Nb,Ti,Cr,Al)Si2主体层与(Ti,Nb,Al)5Si3过渡层组成,高温氧化后涂层表面形成含有Al2O3、TiO2的SiO2阻挡层;合金与涂层的氧化行为均遵循抛物线规律,合金在1 400℃氧化11 h的单位面积质量增量为161.98 mg/cm2,而涂覆涂层后单位面积质量增量降至9.56 mg/cm2,表明Si-Cr-Ti涂层具备良好的高温抗氧化性能。
The Nb-40Ti-7Al （mass fraction, %） alloy was prepared by electron beam melting and vacuum self-consuming arc melting, and then prepared the Si-Cr-Ti coating on the surface of the alloy in the way of stuff paste melting. Oxidation behavior of the alloy matrix and coating at 1 400℃ studied, including the change of morphology and composition during the oxidation process, by means of XRD, SEM, EDS, and EPMA. The results show that the oxidation products of the alloy are mostly TiNb207, TiO2 and A1203 during the oxidation time of lh-llh at 1 400 ~C. The coating is mainly composed of the subject layer of （Nb, Ti, Cr, A1）Si2 and transition layer of （Ti, Nb, AI）sSi3 before oxidation, and then the barrier layer of A1203, SiO2 and TiO2 formed on the surface of the coating after oxidation. The oxidation behavior of alloy and coating follows the law of parabola. After coating, the mass gain of the matrix decreased from 161.98 mg.cm-3 to 9.56 mg.cm 2, and the coating was complete, showing that it has good anti-oxidation ability at high temperature.
出处
《粉末冶金材料科学与工程》
EI
北大核心
2013年第1期94-101,共8页
Materials Science and Engineering of Powder Metallurgy
基金
湖南省科技攻关项目(05JT1065)
