一种新型三代含锇镍基单晶高温合金的析出相演化规律  

Precipitation phase evolution of a new third-generation Ni-based single crystal superalloy containing osmium

作　　者：于静毅 张利军[1] 周科朝[1] 黄再旺 YU Jingyi;ZHANG Lijun;ZHOU Kechao;HUANG Zaiwang(State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China)

机构地区：[1]中南大学粉末冶金国家重点实验室,长沙410083

出　　处：《粉末冶金材料科学与工程》2024年第2期109-117,共9页Materials Science and Engineering of Powder Metallurgy

基　　金：国家重点研发计划项目(2018YFB0704100)。

摘　　要：铼和钌在镍基单晶高温合金中的应用常受限于其含量和相稳定性,寻找能同时代替铼和钌的新元素具有重要意义。本研究设计了一种具有高含量锇的新型镍基单晶高温合金,采用传统Bridgman技术制备铸态单晶合金,并对合金进行固溶时效处理,通过光学显微镜和扫描电子显微镜研究合金的析出相演化规律。结果表明:铸态合金中锇和钨偏析于枝晶干区域,而铝、钽、钛则偏析于枝晶间区域,即使经过长时间的固溶热处理,锇和钨仍有轻微的偏析。由于枝晶区域的元素偏析,一次时效处理后枝晶间的γ′相比枝晶干的γ′相更易转变为立方形,二次时效处理使析出相的尺寸和体积分数略微增大,形状从立方形向圆形转变。The application of Re and Ru in Ni-based single crystal superalloys is often limited by their content and phase stability,and it is important to search for new elements that can replace Re and Ru at the same time.In this study,a new type of Ni-based single crystal superalloy with high content of Os was designed,the cast single crystal alloy was prepared by the traditional Bridgman technique,and the alloy was subjected to solution aging treatment,the precipitation phase evolution of the alloy was investigated by optical microscopy and scanning electron microscopy.The results show that Os and W in the as-cast alloy segregate in the dendrite core region,while Al,Ta,and Ti segregate in the inter-dendritic region,even after a long time of solution heat treatment,there is still a slight segregation of Os and W.Due to the elemental segregation in the dendritic region,theγ′phase in the inter-dendritic region is more likely to be transformed into a cubic shape than that in the dendrite core after the primary aging treatment,and the secondary aging treatment can slightly increase the size and volume fraction of the precipitated phase,and transform the shape from cubic to round.

关 键 词：镍基单晶高温合金 元素偏析 枝晶 固溶热处理 时效处理 γ′析出相 

分 类 号：TG131[一般工业技术—材料科学与工程]