铍青铜弹簧片应力腐蚀断裂研究

Stress Corrosion Fracture of Beryllium Bronze Spring Flake

目的研究传感器微动开关弹簧片应力腐蚀的机理,找到断裂原因。方法对弹簧片进行断口形貌观察、能谱成分分析,并进行产品模拟腐蚀实验。结果传感器内部意外进入雨水,在工作温度下形成湿热环境,开关盒中的游离氨在此环境下释放出来,在开关盒内部形成潮湿氨气氛,铍青铜弹簧片工作时凹面一侧承受静拉应力作用,从而在潮湿氨和拉应力共同作用下发生应力腐蚀开裂。结论通过采用无氨酚醛塑料制备开关盒,弹簧片的应力腐蚀得到了有效预防。

Objective To research the mechanism for stress corrosion of spring flake for microswitch of sensor and find out the cause of fracture. Methods Morphological observation of fracture, analysis of energy spectrum, and corrosion simulation of product were carried out. Results Free ammonia was released from switch box at the working temperature in the moist heat cir-cumstance which is caused by rainwater entering the sensor accidentally. The concave side of beryllium bronze spring flake was under tensile stress when it worked, so the spring flake fractured by stress corrosion. Conclusions Through using non-aminon phenolic plastic producing switch box, the stress corrosion of spring flake is effectively prevented.