一种含铼和碳的镍基单晶高温合金显微组织的研究

Microstructure of Re and C-containing Ni-Based Single Crystal Superalloy

研究了一种含铼和碳的镍基单晶高温合金的铸态和热处理态的显微组织。结果表明:合金铸态组织中枝晶干和枝晶间区域的γ'相呈近立方状,枝晶间区域析出了少量的共晶相和MC型碳化物;合金经固溶处理后,共晶相完全消除,显微偏析得到明显改善。经标准热处理后,枝晶干和枝晶间的γ'相立方度提高,枝晶干区域γ'相的体积分数和尺寸都小于枝晶间区域的,其体积分数和尺寸分别为61%,0.32μm和68%,0.41μm,而碳化物的形貌和尺寸无明显变化。合金经1095℃/100h处理后,枝晶干析出了一定量富集Re和W的TCP相。

Microstructure of an as-cast and heat-treated Ni-based single crystal superalloy containing Re and C was investigated.The results show that γ＇ precipitates in dendrite core and interdendritic region have the same morphology with nearly cuboidal shape in the as-cast alloy.In the meantime,some eutectics and MC carbides exist in the interdendritic region.The eutectic was ruled out after solution heat treatment,as well as microsegregation was improved distinctly.The study of alloy after standard heat treatment showed that the γ＇ precipitates shape were regularly cuboidal shape,and the size and volume fraction were 0.32μm,61% and 0.41μm,68% in dendrite core and interdendritic region,respectively.The size and morphology of carbide have no change after heat treatment.TCP phases enriched in Re and W precipitated after 1095℃ /100h in the dendrite core.