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对所设计的四种Ni-Al-C-Ti(Hf,Nb,Ta)四元镍基合金分别在相同的工艺条件下进行定向凝固。组织结构分析表明,它们的凝固组织和相变特性均与工业高温合金相似,可作为研究工业高温合金的模型合金。上述四元镍基合金的凝固组织具有以下特点:(1)碳化物形成元素的枝晶偏析按Hf、Nb、Ti、Ta减小;(2)TiC和HfC具有大体相似的形态,呈不规则块状:而NbC和TaC则呈发达的汉字体状,这种差别是引起工业高温合金中MC碳化物形态变化的根本原因;(3)含Ti和含Hf合金中的γ-γ′共晶数量多于含Nb和含Ta合金。
Four designed Ni-Al-C-Ti (Hf, Nb, Ta) quaternary nickel-based alloys were respectively subjected to directional solidification under the same process conditions. Tissue structure analysis shows that their solidification microstructure and phase transition characteristics are similar to industrial superalloys, which can be used as a model alloy for the study of industrial superalloys. The solidification microstructure of the four-element nickel-based alloy has the following characteristics: (1) the dendritic segregation of the carbide-forming elements decreases according to Hf, Nb, Ti and Ta; (2) TiC and HfC have an approximately similar morphology Massive: while NbC and TaC are developed Chinese characters, this difference is caused by industrial carbide MC carbide morphology changes in the root causes; (3) containing Ti and Hf alloy γ-γ ’eutectic More than Nb and Ta alloys.