母排散热涂层的制备及性能研究

Preparation and Performance of Thermal Dissipation Coatings for Bus Bars

针对母排在静态空气环境中散热性能较差的问题,采用镍铬尖晶石相作为辐射填料、碳纳米管(CNTs)作为导热填料制备母排散热涂料,研究填料的含量和温度对涂层发射率和热导率的影响,并对散热涂层的微观形貌、附着力、散热性能以及涂层厚度对散热效果的影响进行表征。结果表明:涂层的发射率随着辐射填料的加入而提升,随温度的升高略有下降,当镍铬尖晶石的含量达16%时,涂层的发射率已基本趋于稳定,达到0. 93,在此基础上加入4%的CNTs,涂层内形成连续的导热网络,涂层热导率达到1. 96 W/(m·K),涂层在母排上的附着力为5～8 MPa。当电流温升稳定时,涂覆散热涂层后的铝排温升较裸排降低30. 3 K,较涂覆纯树脂涂层的铝排降低6. 3 K;涂覆散热涂层后的铜排温升较裸排降低22. 5 K,较涂覆纯树脂涂层的铜排降低5. 8 K,散热性能明显提升,并且散热涂层厚度<200μm时,其厚度对母排散热效果没有影响。

Due to the poor thermal dissipation performance of bus bars in the static air en- vironment,using nickel cadmium spinel phase as radiation filler,carbon nanotubes (CNTs) as thermal conductive filler to prepare thermal dissipation coatings for bus bars.The influence of filler content on coatings emissivity and thermal conductivity was researched,and the microstructure and adhesive of coatings,heat dissipation performance and the influence of coating thickness on the heat dissipation were characterized.Results showed that the emissivity of coatings increased with the increase of the radiation fillers content,and slightly decreased with the increase of the temperature.The emissivity of coating was basically stable at 0.93 when the content of nickel cadmium spinel reached 16 wt.%.On this bas thermal conductivity in the coatings was formed with adding 4 wt S, % a continuous network of CNTs.The thermal conductivity of coating was 1.96 W/(inK),the adhesion of coating on the bus bar was 5-8 MPa. The temperature rise of the aluminum bus bar with applying thermal dissipation coating was 30.3 K lower than that of the bare bus bar,and 6.3 K lower than that of the aluminum bus bar coated with pure resin coating.The temperature rise of the copper bus bar with applying ther- mal dissipation coating Was 22.5 K lower than that of the bare bus bar,and 5.8 K lower than that of the copper bus bar coated with pure resin coating.The thermal dissipating performance improved significantly.The thickness had no effect on bus bar thermal dissipation when coating thickness was less than 200 μm.