The upgrading of aircraft engines and the continuous improvement of turbine blade performance have put forward increasingly high requirements for the development level of investment casting technology. The stability of the organizational structure of components, especially the low defect density requirement for single crystal blades, requires crucibles and refractory materials to have high chemical stability. The reaction mechanism at the melt mold interface and the diffusion control of oxygen atoms are the research focuses of shell materials; The complex and precise internal cavity structure of high-performance hollow turbine blades urgently requires breakthroughs in core size accuracy, strength, and removal performance. Deepening the research on the relationship between ceramic composition, body structure, and performance, and forming a systematic strengthening technology, is an important way to improve the comprehensive performance of the core and shell. The future development directions of investment casting technology in China include the following.
1) Develop new refractory material systems with better high-temperature resistance and chemical stability, summarize the influence mechanism of doping modification on the interface reaction between the shell and the melt, and promote the application of low-cost modified oxide ceramic shells based on calcium oxide.
2) The application of additive manufacturing technology in blade cavity design can regulate the microstructure of the core, reduce shrinkage rate, increase porosity, improve the removal performance of zirconium based, yttrium based and other ceramic cores, and enhance the comprehensive performance of existing composite shells and composite ceramic cores.
3) Develop low-cost, high stability, non-toxic and harmless adhesives, and comprehensively evaluate the effects of different types of adhesives on the high-temperature strength stability, thermal shock resistance, micro particle morphology, and surface roughness of the shell.