本文利用差热分析、热失重、红外光谱分析等方法以及扫描电镜和自制的变形—断裂模拟装置等研究了酚醛树脂的特性,探讨了影响壳型用覆膜砂的力学性能和热稳定性的因素。文中还分析了覆膜砂在常温和高温下的变形—断裂机理,指出其热稳定性是影响壳型铸件尺寸精度的首要因素。 In this paper, the properties of phenolic resin were studied by means of differential thermal analysis, thermogravimetry, infrared spectroscopy, scanning electron microscopy and self-made deformation-fracture simulator. The influences of the mechanical properties and thermal stability factor. The deformation and fracture mechanism of coated sand at normal temperature and high temperature are also analyzed. It is pointed out that thermal stability is the primary factor affecting the dimensional accuracy of shell castings.