聚变堆真空室用标准螺纹紧固件防咬死铜镀层麻点原因分析

Cause analysis on pits of anti-seizing copper coating on standard threaded fastener applied to vacuum chamber of fusion reactor

为降低托卡马克聚变堆运行时真空室内标准螺纹紧固件咬死的风险,在其表面电镀防咬死铜镀层。在工艺验证过程中,电镀后经真空烘烤的螺栓、螺母标准件表面出现了麻点。为了确定麻点产生的原因,从螺纹紧固件的制造、清洗、电镀等各方面进行实验探究,根据镀层成分分析,确定了麻点是有机物碳化所致,并通过对比实验验证了分析结果,继而提出相应的解决措施。

In order to reduce the risk of seizing phenomenon occurring on standard threaded fastener used in vacuum chamber during the operation of tokamak fusion reactor, an anti-seizing copper coating was electroplated on the surface of fastener. During the process of coating verification test, some pits appeared on the surfaces of the copper-coated standard threaded fasteners after vacuum baking. Some comparative experiments were conducted to study the manufacturing, cleaning,and electroplating processes of threaded fasteners, and the elemental composition of copper coating was analyzed. It was showed that the formation of pits was caused by the carbonization of organic contaminants. Some corresponding solutions were given.