WC颗粒增强镍基涂层改善制动盘组织与磨损性能

为提高汽车制动盘耐磨和高温氧化性能,延长其使用寿命,采用激光熔覆技术在中碳钢表面制备了以WC颗粒为增强相的Ni基复合涂层.借助SEM和XRD等表征手段对制动盘表面涂层进行了组织和物相分析,利用维氏硬度计测试了制动盘表面涂层截面显微硬度分布,通过摩擦磨损实验研究了制动盘表面涂层的磨损性能.研究表明,制动盘表面涂层主要由γ-（Ni,Fe）固溶体、均匀分布WC颗粒和碳化物抗磨损相组成.涂层平均显微硬度HV0.2670,显微硬度值波动较小较为平稳,证明涂层组织比较均匀.在多种强化效果共同作用下,制动盘表面涂层的磨损量与基材相比明显减小,仅为基材的20％,抗磨损性能显著提高.

WC Particles Reinforced Nickel-based Coating to Improve the Morphology and Wear Performance of the Brake Disc

In order to improve the car brake disc wear-resistant and high temperature oxidation resistance and prolong it＇s service life, WC particles reinforced Ni-base coatings were fabricated by laser cladding on medium carbon steel surface. The microstructures and phase composition of the coating were analyzed by means of scanning electron microscopy （SEM） and X-Ray diffraction （XRD）. The cross-section micor-hardness of the cladding layer measured by Vickers hardness tester, and the abrasion performance of the cladding characterized through the friction and wear experiments. The research shows that the phase of the laser cladding coatings is mainly composed of carbides and ~ - （Ni, Fe）solid solution,uniformly distributed WC particles and wear-resistant carbide phase composition. The average micro-hardness of the coating is HV0.2670, the mierohardness values less volatile relatively stable,prove coating microstructures more uniform. Under the combined action of a variety of reinforcing effect, the amount of wear of the brake disc surface coating than the substrate is significantly reduced, only 20% of the substrate, and to significantly improve the abrasion resistance.