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

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.