熔模铸造型壳用材料研究进展

近年来，随着熔模铸造发展需求的不断提升，我国工业上更多地追求精密铸件，特别是在航空航天领域，这促使着精密铸件向大型化、复杂化、薄壁化、智能化发展，而铸件质量60%与铸造过程中制备的型壳有关。基于此，综述了现阶段熔模铸造型壳用材料的研究进展，从耐火材料、黏结剂、添加剂3个方面总结了其目前的使用和改进情况。介绍了锆系耐火材料、CaO、Y2O3及电熔刚玉几种氧化物面层和背层耐火材料熔融石英、高岭土的应用，现阶段耐火材料的选择更多是根据不同的铸件需求来考虑的，耐火材料的搭配使用和复合耐火材料能够更好地提升型壳质量。对硅溶胶、硅酸乙酯、水玻璃3种黏结剂目前遇到的应用问题进行了分析，改进后的硅溶胶得到了更多学者认可，而硅酸乙酯和水玻璃各自有硅溶胶所不具备的优点，根据需求搭配使用更能体现三者各自的优点。总结了添加剂中常用细化剂、消泡剂、矿化剂的作用及其使用情况，现阶段添加剂的使用研究更为重要，合理地使用添加剂对整个制壳过程起到举足轻重的作用。目前我国的智能铸造发展还不是很成熟，尤其是在型壳制备方面，而未来绿色铸造和智能铸造是值得研究的重点方向。

Research Progress of Materials for Investment Casting Molding Shells

With the development demand of investment casting increasing, in recent years, there is more pursuit of precision castings in China, especially in aerospace, which promotes the development of precision castings to be large, complex, thin-walled and intelligent. And 60% of casting quality is related to the shell prepared in the casting process. Based on this, the research progress of investment casting shell materials at the present stage was summarized, and the current use and improvement were summarized in terms of refractory materials, binders and additives. The application of zirconium refractories, CaO, Y2O3 and fused quartz and kaolin in surface and back layer refractories of fused alumina were introduced. At present, the selection of refractories is more considered according to different casting needs. The combination of refractories and composite refractories can better improve the quality of shells. The current application problems on three kinds of binder, namely silica sol, ethyl silicate, sodium silicate, were analyzed. The improved silica sol has been recognized by more scholars. Ethyl silicate and sodium silicate respectively have the advantages that silica sol does not have. Using them in a combined way according to the needs can reflect their own advantages. The functions and applications of refiners, defoaming agents and mineralizing agents commonly used in additives were summarized. At present, the research on the use of additives is more important. Reasonable use of additives will play a pivotal role in the whole process of shell making. At present, the development of intelligent casting in China is not mature, especially in the aspect of the shell preparation. The green casting and intelligent casting are the key directions worthy of research in the future.