激光制备石墨烯/镍/铜触头材料及其性能研究

Study on the fabrication and properties of graphene/nickel/copper contact materials by laser method

为改善抗电弧烧蚀能力差导致铜合金触头电寿命不足的问题,本文采用激光法在镍镀层增强紫铜表面原位制备大面积石墨烯,形成石墨烯/镍/铜复合材料,提高Cu基触头的使用寿命.设置电沉积电流5 mA,沉积90 s后在铜表面引入平均厚度为25~27μm的Ni过渡层,改善Cu对激光的高反射、高导热问题.通过旋涂石墨碳源在镍过渡层表面,设置纳秒激光功率1.5 W,脉宽150 ns,扫描速度10 mm/s,加工3次,频率250 KHz后进行辐照,在铜镍过渡层表面成功制备了石墨烯独立涂层.对复合材料进行了理论分析和实验验证,取得了相应最优参数下的相关性能数据.结果表明,石墨烯/Ni/Cu复合触头硬度为245.45 HV,是紫铜的3.17倍;接触电阻0.096 mΩ符合国家标准;摩擦系数0.083 7是紫铜的0.73倍;500℃时复合材料导热系数为1 178 W/(m·K),是紫铜的3.43倍.同时,复合材料具有良好的抗氧化性能.本文为新型铜合金触头的制备提供了新的思路和实验基础.

To improve the problem of insufficient electrical life of Cu alloy contacts due to poor resistance to arc ablation,this paper uses the laser method to prepare large-area graphene in situ on the surface of purple copper to prepare graphene/Ni/Cu composite contact materials and improve the service life of copper-based contacts.The electrodeposition current was set at 5 mA and a nickel transition layer with an average thickness of 25~27μm was introduced on the Cu surface after 90 s of deposition to improve the high reflection and thermal conductivity of the Cu to the laser.The graphene freestanding coating was successfully prepared on the surface of the Cu-Ni transition layer by spin-coating a graphite carbon source on the surface of the nickel transition layer,setting a nanosecond laser power of 1.5 W,pulse width of 150 ns,scanning speed of 10 mm/s,processing three times and irradiating at a frequency of 250 KHz.The composites were theoretically analysed and experimentally verified,[JP2]and relevant performance data were obtained for the corresponding optimum parameters.The results showed that the hardness of the graphene/Cu composite contact was 245.45 HV[JP],3.17 times that of Cu,the contact resistance was 0.096 mΩin accordance with national standards,the coefficient of friction was 0.0837,0.73 times that of Cu,and the thermal conductivity of the composite was 1178 W/(m·K)at 500℃,3.43 times that of Cu,while the composite had good oxidation resistance.This paper provides a new idea and experimental basis for the preparation of new copper alloy contacts.