高速电机转子用AuGe10Ni1.5Cu钎料的研究

AuGe10Ni1.5Cu0.5 solder used for high velocity motor rotor

针对用作高速电机转子导条及端环材料的高强度CuCrZrRE合金存在"550℃退火软化"的缺陷,采取"真空熔铸+等温轧制+精密轧制"方式制备一种新型的AuGeNiCu钎料。利用差热分析仪、光学显微镜和X-射线衍射仪,结合电阻率、润湿性和力学性能测试,研究轧制对钎料组织及强度的影响,考察Cu含量对其润湿性能的影响。结果显示:钎料AuGe10Ni1.5Cu0.5熔化温度为368~544.4℃,满足550℃以下钎焊温度要求;经过多次轧制后,钎料合金组织显著细化,其强度随轧制箔片厚度减小而提高;钎焊接头电阻率为3.61×10-6Ω·cm,与CuCrZrRE基体形成"等电阻率"接头,当AuGe10Ni1.5钎料所含Cu的质量分数增加至0.5%时,其铺展面积是不加铜钎料的1.67倍,润湿性显著改善;钎料AuGe10Ni1.5Cu0.5与母材CuCrZrRE间的钎焊接头剪切强度约为110.5 MPa,完全满足电机转子服役要求。

In order to overcome 550 ℃ softening characteristics of high strength CuCrZrRE alloy used for conducting bar and end collar of high velocity motor rotor, a new type of AuGeNiCu solder was developed by the method of vacuum molten casting as well as isothermal rolling and precision rolling. The effect of rolling on the microstructure and the strength of soldering foils and the effect of copper content on wettability were studied by using differential thermal analyzers （DTA）, optical microscopy （OM）, X- ray diffractometer （XRD） and testing machine for resistivity, wettability and mechanical properties. The result shows that the melting temperature of AuGe10Ni1.5Cu0.5 solder is from 368 to 544.4 ℃ , which meets the requirements of soldering temperature below 550 ℃. The microstructure of soldering alloy is significantly refined and the strength of soldering foils increases with the decrease of the thickness of rolling foils. The resistivity of soldering joint is 3.61 × 10^-6Ω· cm, which equals to that of CuCrZrRE base metal. The spreading area on CuCrZrRE base metals at 0.5%Cu contained in AuGelONi1.5 solder is 1.67 times than that without copper, and the wettability is markedly improved. The shear strength of the soldering joints is about 110 MPa, which entirely meets the operating strength requirements of high velocity motor rotor.