镍基高温合金快速凝固粉末颗粒中MC型碳化物相的研究

对等离子旋转电极雾化（PREP）法制备的FGH95镍基高温合金粉末中碳化物的形态、结构、成分及其稳定性进行了实验研究，分析了粉末颗粒凝固过程中的热学参数和非平衡溶质分配对碳化物形成过程的影响．结果表明：快速凝固FGH95合金粉末中亚稳MC型碳化物形态的几何完整度随粉末颗粒尺寸减小由规则形态向复杂形态变化，不同尺寸粉末颗粒中碳化物的形态和数量决定于凝固过程中热学参数的变化和非平衡溶质分配系数的不同．亚稳MC型碳化物在加热作用下发生分解及合金元素再分配，其形态由复杂形状为主转变为规则形态的稳定MC型碳化物．

RESEARCH ON MC TYPE CARBIDE IN NICKEL-BASED SUPERALLOY POWDERS DURING RAPID SOLIDIFICATION

The morphology, structure and composition of carbide in FGH95 nickel-based superalloy powders prepared by plasma rotating electrode processing (PREP) and the carbide stability were investigated experimentalloy. The effects of thermal parameters and non-equilibrium solute partition on the process of carbide formation during solidification are also analyzed. The results indicate that the geometry integrity of metastable MC type carbide in rapidly solidified FGH95 alloy powders changed from regular morphology into diversified morphology with decreasing the powder size. The carbide morphology and quantity in different sizes powder particles depended upon the changes of thermal parameters and non-equilibrium partition coefficient during solidification. The decomposition of MC type carbide precipitated during rapid solidification and redistribution of alloy elements in MC took place under heat treatment, and the metastable MC type carbide transformed into stable MC type carbide with regular morphology.