【摘要】 采用SiO2溶胶-凝胶-旋涂法对TiAl基合金表面进行涂膜。900℃循环氧化测试结果表明,TiAl基合金经SiO2溶胶两次涂膜并热处理后,其抗高温氧化性能得到了显著提高,未涂膜试样氧化一个循环(8h)后增重2.333mg/cm2,涂膜热处理试样氧化40个循环(320h)增重仅为0.6071mg/cm2。XRD和SEM对试样表层的组织结构分析及形貌观察表明,涂层主要由SiO2、Al2O3、Ti5Si3、TiSi2和Ti2Al构成,由表及里分别为SiO2层-Al2O3层-Al2O3+钛硅化合物层-Ti2Al层-TiAl片层组织基体。更多还原

【Abstract】 The sol-gel derived silica films were obtained on TiAl-based alloy by spin coating processing.Cyclic oxidation tests at 900℃ show that the oxidation resistance of TiAl-based alloy is promoted greatly when SiO₂ films are coated twice on surface of the alloy after heat treatment.The mass gain of uncoated TiAl-based alloy is 2.333mg/cm² after one oxidation cycle（8h）,while the mass gain of the twice-coated one is only 0.6071mg/cm² even after 40 oxidation cycles（320h）.The microstructure and morphology of the coated TiAl-based alloy specimens are characterized by XRD and SEM/EDS.The results show that the coatings are composed of SiO₂,Al₂O₃,Ti₅Si₃+TiSi₂ and Ti₂Al,from the outer to the inner.更多还原