铼含量微量调整对第三代镍基单晶高温合金组织和高温持久性能的影响  

Effects of Minor Re Adjustment on Microstructure and High-temperature Stress Rupture Properties of the Third Generation Ni-based Single Crystal Superalloy

作　　者：方向[1,2] 张剑 赵云松[1] 杨振宇[1] 许剑伟 吴庆辉[1] 姜华 骆宇时[1] 

机构地区：[1]北京航空材料研究院先进高温结构材料重点实验室,北京100095 [2]中国航发湖南动力机械研究所,株洲412000

出　　处：《机械工程材料》2018年第1期33-38,43,共7页Materials For Mechanical Engineering

摘　　要：制备了名义成分为Ni-9Ta-6Al-6W-4Co-2Cr-0.4Mo-xRe(x分别为6.2,6.8,质量分数/%)的两种单晶高温合金,研究了铼含量对合金铸态显微组织和相转变温度以及热处理态显微组织和高温持久性能的影响。结果表明:微量增加铼后,铸态合金的凝固偏析程度和γ+γ′共晶组织含量均增加,固溶过程中共晶组织快速溶解的峰值温度提高;热处理态合金中的γ′相尺寸略微减小,持久加载过程中拓扑密排相的析出量增加;铼的微量增加显著改变了铼和铬的成分分配比,增强了固溶强化效果,明显提高了合金的高温持久性能。Two single crystal superalloys with nominal composition of Ni-9Ta-6Al-6W-4Co-2Cr-0.4Mo-xRe（x was 6.2,6.8,respectively,mass fraction/%）were prepared.The effects of Re content on the microstructure and phase transition temperature of the as-cast alloys and on the microstructure and high-temperature stress rupture property of the heat-treated alloys were investigated.The results show that a slight increase of Re content resulted in the increase of the solidification segregation degree and theγ＋γ′eutectic structure content in the as-cast alloys.The peak temperatures of rapid dissolution of eutectic structure increased during the solid solution process.The size ofγ′phase in the heat-treated alloys decreased slightly and the topological close-packed phase formation increased in the stress rupture process.The minor increase of Re changed the element partitioning ratios of Re and Cr significantly,improved the solid solution strengthening effect and increased the high-temperature stress rupture properties of the alloys strikingly.

关 键 词：第三代镍基单晶高温合金 铼 显微组织 高温持久性能 

分 类 号：TG132.3[一般工业技术—材料科学与工程]