航空光电雷达电机换向器激光沉积再制造

Remanufacturing of the Aviation Photoelectric Radar Motor Commutator by Laser Deposition

航空光电雷达电机换向器部位使用的纯铜材料在服役中容易发生表面损伤,传统红外激光沉积纯铜材料过程中激光吸收率较低。采用蓝光激光器对纯铜电机换向器失效部位进行送粉式激光沉积修复(所用粉末为Cu-15Sn),研究蓝色激光工艺参数对修复形貌及修复区组织性能的影响。采用光学显微镜、扫描电镜及附带能谱仪、显微硬度计、微型摩擦磨损试验仪表征和测试修复区的微观组织、显微硬度及耐磨性能。结果表明:蓝光激光可以在较宽的工艺参数窗口范围获得良好的修复层。修复层为典型的枝晶结构,由铜固溶体枝晶和铜锡金属间化合物共晶组成;平均显微硬度为铜基体硬度的2.24倍,修复区相对耐磨性为基体的2.37倍。修复区相对于基体硬度和耐磨性提升的原因在于快速凝固条件下形成的细小非均匀枝晶结构(固溶体和金属间化合物的混合结构)和固溶强化效应。铜基体和修复区磨损机制均为磨粒磨损、氧化磨损及黏着磨损。其中修复区主要为粘着磨损和氧化磨损,铜基体为粘着磨损和轻微氧化磨损。研究结果能够为电机换向器部位纯铜材料的高效修复提供数据支撑和理论基础,推进蓝色激光沉积再制造技术在有色金属加工领域的应用。

The pure copper material used in the commutator of photoelectric radar motor is prone to surface damage in service.The laser absorption rate of pure copper material deposited by traditional infrared laser is low.Blue laser is used to remanufacture the failed part of motor commutator made of pure copper(the powder used was Cu-15Sn).The effects of laser processing parameters on the repair morphology and microstructure-properties of the repaired zone are studied.The microstructure,microhardness and wear resistance of the repaired area are characterized and tested by optical microscope,scanning electron microscope,energy dispersive spectrometer,microhardness tester and micro friction and wear test instrument.The results show that blue laser can obtain good repair layer in a wide range of processing parameter window.The repair layer is a typical dendrite structure,which is composed of copper solid solution dendrite and copper-tin intermetallic compound eutectic.The average microhardness of the repaired layer is 2.24 times that of the copper substrate,and the relative wear resistance of the repaired area is 2.37 times that of the substrate.The reason for the improvement of hardness and wear resistance of the repaired area relative to the matrix is the fine non-uniform dendrite structure(mixed structure of solid solution and intermetallic compound)and solid solution strengthening effect formed under the condition of rapid solidification.The wear mechanism of copper substrate and repaired zone is abrasive wear,oxidation wear and adhesive wear.The repair area is mainly adhesive wear and oxidation wear,and the copper substrate is adhesive wear and slight oxidation wear.The research results can provide data support and theoretical basis for the efficient repair of pure copper material in the motor commutator,and promote the application of blue laser deposition remanufacturing technology in the field of non-ferrous metal processing.