微电机换向器用内氧化法AgCuONiO电接触材料的结构及性能研究

Structure and Properties of Internal Oxidized AgCuONiO Electrical Contact Materials Applied to Micro-motor Commutator

内氧化银基合金具有优良的导电性和耐磨性,已成为一种重要的电接触材料并成功应用于微电机换向器领域。本文利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、显微硬度仪(MHT)以及寿命试验分别对微电机换向器用AgCu4Ni0.3合金内氧化前后的结构及性能进行了研究。结果表明,AgCu4Ni0.3合金在700℃、0.5 atm氧分压下氧化3 h后完全氧化,氧化产物CuO、NiO颗粒均匀弥散分布于氧化层基体中,增强了合金的热稳定性;AgCu4Ni0.3合金的软化温度由氧化前的250℃提高到400℃。寿命试验表明,相比AgCuNi/TU1材料,AgCuONiO/TU1复合材料制成的换向器具有更高的耐磨损性能,在电接触材料领域具有广泛的应用前景。

The internal oxidized Ag-based alloys have become an important kind of electrical contact materials and been successfully used in micro-motor commutator field due to their excellent electrical conductivity and abrasion resistance. The structure and properties of internal oxi- dized AgCu4Ni0.3 alloys were respectively studied by the means of XRD, SEM, MHV and life testing. Results show that the AgCu4Ni0.3 alloy is fully oxidized after being oxidized at 700℃ for three hours in 0.5 atm oxygen atmosphere. The CuO and NiO particles distribute in the ma- trix uniformly, so that the thermal stability of the alloy is enhanced. Compared with that of the AgCu4Ni0.3 alloy before oxidized （about 250 ℃）, the softening temperature of the oxidized Ag- Cu4Ni0.3 alloy is improved almost to 400℃. Life testing shows that the commutator made with AgCuONiO/TU1 clad strips has higher abrasive resistance, which can be used as the electrical contact materials widely.