熔体过热处理技术及其在镍基高温合金中的应用研究进展

镍基高温合金是先进航空发动机高温叶片不可或缺的关键核心材料,目前通过合金化来提高其承温能力已趋于极限。研究表明,材料熔体结构对合金凝固过程、凝固组织、性能以及成形质量具有重要的影响。熔体结构的变化能够直接导致熔体特性发生改变,进而对性能产生影响,然而在实际合金的制备过程中,熔体结构的作用通常被忽略。熔体过热处理技术通过利用合金熔体的遗传效应,将高温熔体的结构保留到低温熔体,从而大幅提高合金性能。系统介绍了熔体过热的原理、主要处理技术以及如何通过X射线衍射和物性参数测量来确定熔体过热处理参数,重点介绍了熔体过热处理技术在优化高温合金凝固组织和提升性能方面的应用,最后提出了熔体过热处理技术发展的方向和面临的挑战。

Progress on Melt Overheating Treatment Technology and Its Application in Ni-based Superalloys

Ni-based superalloy, as one of the most key core materials indispensable to manufacture turbine blades in advanced aero engines, has been limited to further improve temperature capability by alloying. Melt structure has important influence on solidification process, solidification microstructure, properties and forming quality of the alloy. Change of melt structure induced variation of melt properties directly and further performance change. However, effect of the melt structure was generally ignored during the preparation of alloy. Due to heredity effect of alloy melt, the melt structure at high temperature was retained to that at low temperature by melt overheating treatment technology, and the performance was thus promoted substantially. Principle of melt overheating, major processing technology and determination of melt overheating parameters by X-ray diffraction and measurement of physical property parameters were introduced systematically. Application of melt overheating treatment in microstructure optimization and performance promotion of Ni-based superalloys was reviewed. Finally, challenges and future development orientation of melt overheating treatment were proposed.