一种光学元件脆性断裂的试验分析

Experimental Study on the Brittle Fracture of an Optical Element

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 is a seal of vacuum container. It is broken by the atmosphere pressure many times. For analysing the cause of the fracture, some fracturing experiments are tested. The experimental resuhs show that the growing micro-cracks in the grinding surface are the reason for the fracture. It is a brittle fracture so typically. Due to the material of the optical element is brittle, so any element structure should be as simple as possible if it is a force structural parts, and the load-bearing surface must he a polished surface.