碳纤维复合材料/金属机械连接接头疲劳绝缘特性研究

Research on Fatigue Insulation Characteristics of CFRP/Metal Mechanical Connection Joint

为了解决碳纤维复合材料(CFRP)/金属连接结构在海水环境和疲劳载荷联合作用下的电化学腐蚀问题,采用全浸腐蚀测量方法,测试了CFRP与金属钢板分别在3.5%(质量分数)NaCl溶液中的自腐蚀电位,提出了5种CFRP/金属结构绝缘连接方案,并分别开展两阶段拉-拉疲劳绝缘特性试验研究。结果表明:在螺钉表面涂刷螺纹绝缘胶(方案I)或喷涂绝缘环氧粉末涂层材料(方案Ⅱ)均不能有效抑制CFRP/金属连接区域的电化学腐蚀行为;螺钉表面绝缘环氧粉末涂层耐疲劳磨损性能优于螺纹绝缘胶,在JN-1型环氧密封胶泥保护作用下,方案Ⅳ连接接头绝缘疲劳性能优于方案Ⅲ;在方案Ⅳ基础上,在其连接区域内增设尼龙套筒(方案Ⅴ),同样具有良好的绝缘疲劳性能,且效果更佳。

In order to solve the electrochemical corrosion problem of carbon fiber reinforced polymer(CFRP)/metal connection structure under the combined action of seawater environment and fatigue load, the self-corrosion potential of CFRP and metal plate in 3.5%(mass fraction) NaCl solution was measured by full immersion corrosion measurement method. Five schemes of CFRP/metal mechanical insulation connection were proposed, and the two-stage tension-tension fatigue insulation characteristics test were studied. Results showed that the electrochemical corrosion behavior of CFRP/metal joint area could not be effectively inhibited by coating the screw surface with thread insulating adhesive(scheme Ⅰ) or spraying insulating epoxy powder coating material(scheme Ⅱ). The fatigue wear resistance of insulation epoxy powder coating on screw surface was better than that of thread insulation adhesive. Under the protection of JN-1 epoxy sealant, the insulation fatigue performance of scheme Ⅳ connection joint was better than that of scheme Ⅲ connection joint. On the basis of scheme Ⅳ, nylon sleeve(scheme Ⅴ) was added in the connection area, which also had good insulation fatigue performance, leading to better effect.