基于立体光固化3D打印的一体化石膏铸型的高温力学性能研究

机匣是航空发动机的重要承力构件，向大型化、整体化、匣体/管道一体化方向发展，对现有加工技术提出挑战。基于立体光固化3D打印的一体化石膏铸型制备方法，为机匣类轻质合金零件的精密铸造提供新思路。铸造用光固化树脂材料的烧失温度高、发气量大，这对石膏型材料的高温力学性能提出更高要求。因此，在确定石膏型力学性能的关键温度基础上，研究石膏型力学性能随温度的变化规律，探讨膏水比、填料比等对石膏型力学性能的影响机理，发展同化学组分晶须增强石膏型的方法。在此基础上，将石膏铸型500℃高温弯曲强度提高至2 MPa以上，并实现薄壁机匣样品（含有内径3 mm管路）的铸造。

Study on High Temperature Mechanical Properties of Integrated Gypsum Molds Based on Vat Photopolymerization

The casing is an important bearing component of the aero-engine, and it is developing towards large-scale, integrated, and casing/pipe integration, posing challenges to existing processing technologies. Based on Vat photopolymerization, a popular process of 3D printing, the preparation method of integrated gypsum mold is proposed, providing a new method for rapid precision casting of complex lightweight alloy parts. However, the photocurable resin for casting has a high temperature for ignition lost and a large amount of gas generation, which puts higher requirements on the high temperature mechanical properties of the gypsum mold. Therefore, based on the determination of the critical temperatures for gypsum mechanical properties, the change laws of mechanical properties with temperatures are studied, and the influence mechanism of paste/water ratio and paste/filler ratio on the mechanical properties is discussed. Method to enhance gypsum by whiskers with same chemical component is developed. An integrated gypsum mold is made with bending strength of over 2 MPa in the high temperature of 500℃, from which a thin-walled aluminum alloy casing sample is cast with pipes with inner diameters of 3 mm.