石墨/镍基金属钎涂层界面结构分析及性能

Microstructures analysis and performance research of graphite/nickel-based brazing coating

电机行业中石墨有重要的作用,在镍基焊料中加入适量活性金属,并通过创新的钎涂方法制备石墨表面的钎焊层,以实现石墨与电机换向器中铜转子更牢固的连接,使得原本与铜直接接触的石墨电刷的磨损量大大降低.通过DSC,XRF,SEM,EDS,XRD,超声C-扫描探伤以及电阻测试等试验检测钎焊层的性能.结果表明,钎料自身生成了金属间化合物,并且钎料中的Si和Cr元素与石墨生成了碳化物,从而使得钎料与石墨之间形成了牢固的冶金结合,样品经钎涂后不影响其作为电刷材料的导电性.

Graphite is playing an important role in motor industry. A moderate amount of active metals were added into nickel-based solder,an innovative coating method was used to prepare the brazing layer on the surface of graphite,which realized the firmer connection between graphite and copper rotor in the motor commutators,and reduced the abrasion loss of the graphite brush which directly contact with copper originally. By using the DSC,XRF,SEM,EDS,XRD,ultrasonic C-inspection and resistance test,the performances of the brazing layer were analyzed. It is shown that not only the solder itself generated the intermetallic compounds,but also Si and Cr in the solder reacted with graphite turned into carbide,which made a strong metallurgical bond between graphite and solder,which does not affect its electrical conductivity as the brush after brazing.