气体氮化γ-TiAl合金的抗高温氧化性能研究  

Study on the high temperature oxidation resistance of gas nitridedγ-TiAl alloy

作　　者：李强[1] 杜三才 缪煜清[2] 李荣斌[3] LI Qiang;DU Sancai;MIAO Yuqing;Li Rongbin(School of Mechanical Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China;School of Materials and Chemistry,University of Shanghai for Science and Technology,Shanghai 200093,China;Shanghai Engineering Research Center of Hot Manuscripturing,Shanghai Dianji University,Shanghai 201306,China)

机构地区：[1]上海理工大学机械工程学院,上海200093 [2]上海理工大学材料与化学学院,上海200093 [3]上海电机学院上海大件热制造工程技术研究中心,上海201306

出　　处：《有色金属材料与工程》2024年第5期26-32,共7页Nonferrous Metal Materials and Engineering

基　　金：上海电机学院上海大件热制造工程技术研究中心开放基金(18DZ2253400)。

摘　　要：γ-TiAl基合金抗高温氧化性较差限制了其在高温场景下的应用,提高其抗高温氧化性能对高温合金的研究与应用具有重要意义。以Ti-48Al-2Cr-2Nb合金为研究对象,将其置于管式炉中分别在800、900、1000℃下进行气体氮化2 h。采用光学显微镜观察显微组织,采用X射线衍射仪分析物相组成,测试维氏硬度,分析900℃下的高温氧化行为。结果表明,随着氮化温度的升高,合金基体片层组织逐渐粗化,表面膜层增厚,维氏硬度升高。在空气中高温氧化128 h后,800℃和900℃氮化后样品的质量增加仅为未氮化样品的25.3%和28.9%,表明800℃和900℃氮化后的样品具有良好的抗氧化能力。由于1000℃氮化样品因膜层存在裂纹,高温氧化时膜层和基体会与氧发生反应生成氧化物,导致质量增加显著。900℃下氮化处理能够显著提高Ti-48Al-2Cr-2Nb合金的表面维氏硬度,增强合金的抗氧化能力。The poor high-temperature oxidation resistance ofγ-TiAl-based alloys limits their applications in high-temperature environments.Enhancing their oxidation resistance is of significant importance for the researches and applications of superalloys.Ti-48Al-2Cr-2Nb alloy was taken as the research object in this study,and subjected to gas nitriding in a tubular furnace at the temperatures of 800,900,1000℃for 2 hours,respectively.The microstructure was observed by optical microscopy,the phase composition was analyzed by X-ray diffractometer,the Vickers hardness was measured,and the high-temperature oxidation behavior at 900℃was analyzed.The results indicate that with the increase of nitriding temperature,the lamella structure of the alloy matrix gradually coarsens,the surface layer thickens,and the Vickers hardness increases.After high-temperature oxidation in air for 128 hours,the weight gains of the samples nitrided at 800℃and 900℃were only 25.3%and 28.9%of that of sample without nitriding,indicating that the samples nitrided at 800 and 900℃have good antioxidant capacity.Due to the presence of cracks in the film layer of the 1000℃nitrided sample,the film layer and substrate react with oxygen to form oxides during high-temperature oxidation,resulting in a significant increase in weight.Nitriding treatment at 900℃can significantly improve the surface Vickers hardness of Ti-48Al-2Cr-2Nb alloy and enhance its oxidation resistance.

关 键 词：Γ-TIAL合金 气体氮化 显微组织 维氏硬度 高温氧化 

分 类 号：TG146.23[一般工业技术—材料科学与工程]