(1. 北京航空航天大學 材料科學與工程學院，北京 100191；
2. 中國商用飛機有限責任公司，上海 200232；
3. 中國人民公安大學 繼續(xù)教育學院，北京 100076)
摘 要: 采用熱重分析(TG)、X射線衍射(XRD)、透射電鏡(TEM)及能譜分析(EDS)等方法，研究Nb-Si-Ti(15%~ 26%，摩爾分數(shù))-Hf-Al-Cr多元合金、Nb-Ti(0~50%)二元合金在1250 ℃大氣中的高溫氧化行為。通過Ti含量變化對合金氧化產(chǎn)物種類及氧化物PBR值的影響，探討Ti含量對Nb基合金高溫抗氧化性能的作用。結(jié)果表明：隨著Ti含量的增加，合金的高溫氧化產(chǎn)物從Nb2O5、Ti2Nb10O29、TiNb2O7和TiO2依次過渡。通過計算發(fā)現(xiàn)：Nb基合金的氧化產(chǎn)物Nb2O5、Ti2Nb10O29、TiNb2O7及TiO2的PBR值隨著Ti含量的升高依次減小。氧化產(chǎn)物PBR值的下降，可以有效地降低Nb基合金氧化膜的生長應(yīng)力、提高氧化膜的完整性、增大氧化膜的失效周期，提高Nb基合金的高溫抗氧化性能。
關(guān)鍵字: 高溫合金；Nb基合金；高溫抗氧化性能；氧化產(chǎn)物
（1. School of Materials Science and Engineering, Beihang University, Beijing 100191, China;
2. Commercial Aircraft Corporation Ltd. of China, Shanghai 200232, China;
3. College of Extended Education, People’s Public Security University of China, Beijing 100076, China）
Abstract:The high temperature oxidation behaviors of Nb-Si-Ti(15%-26%, mole fraction)-Hf-Al-Cr and Nb-Ti (0-50%) alloys at 1250 ℃ were analyzed utilizing oxidation weight gain method. The scale morphology and composition were studied by X-ray diffractometry (XRD), transmission electron microscopy (TEM) and EDS analysis. The relationships among the Ti content and the oxidization products and their Pilling-Bed-Worth ratio (PBR, φ) values were further studied. The results show that as the Ti content in the Nb-based alloys increases, the oxidization products transform from Nb2O5 to Ti2Nb10O29 first, then to TiNb2O7 and finally to TiO2. Their corresponding PBR values decrease in sequence. With the decrease of PRB values, the growth stress decreases, the integrity improves and failure cycle lengthens in the oxide film. Therefore, the high temperature oxidation resistance of the Nb-based alloys is significantly improved.
Key words: superalloy; Nb-based alloy; high temperature oxidation resistance; oxidization product
