某光学元件兼做真空容器密封件,在真空压力作用下多次发生破裂。采用缩比件压裂试验的方法分析破裂原因,并且找到了改进方案。试件的破裂压力和破裂形态表明,元件在真空压力作用下,磨削表面的微裂纹扩展,是造成元件破裂的原因,属于典型的脆性断裂。光学元件的材料是典型的脆性材料,做受力结构件时,结构应该尽量简化,且承力部位要在抛光处理的表面上。 An optical element also serves as a vacuum container seal, ruptured several times under the effect of vacuum pressure. The reason of fracture was analyzed by shrinkage test of shrinkage ratio, and the improvement was found. The rupture pressure and rupture morphology of the specimen indicate that the microcrack expansion of the grinding surface under the action of vacuum pressure is the cause of the rupture of the component and belongs to the typical brittle fracture. Optical components of the material is a typical brittle material, to do the force structure, the structure should be as simple as possible, and bearing parts to be polished on the surface.