牙轮钻头钢激光熔覆金属陶瓷复合涂层的组织与性能

Microstructure and Properties of Metal Ceramic Composite Coatings Fabricated by Laser Cladding on Roller Bit Steel

在清除了渗碳层的15MnNi4Mo牙轮钻头钢表面熔覆不同质量配比的WC-Co50复合涂层,为牙轮钻头的修复提供一种新思路。运用OM、SEM和XRD分析了该涂层的微观组织和物相组成;利用显微硬度计和磨损实验机测得了不同质量配比涂层的显微硬度和磨损性能。结果表明,Co50+20%WC与Co50+40%WC试样涂层表面形貌良好,无裂纹与气孔等缺陷。该涂层主要由Co、Co4W2C、FeNi3、WC、W2C和Ni2.9Cr0.7Fe0.36等物相组成。三种试样涂层的平均硬度和耐磨性基本都达到了磨损前水平,硬度最高达778.71 HV0.2,最低磨损失重1.7 mg,可满足牙轮钻头再制造要求。

WC-Co50 composite coatings with different mass ratios were fabricated on the surface of 15MnNi4Mo roller bit steel after clearing the carburized layer,which can provide a new idea for the repair of the roller bit.The microstructure and phase composition of the laser cladding coatings were analyzed by OM,SEM and XRD.The microhardness and wear properties of the coatings with different composition ratios were measured by microhardness and wear testers.The results show that Co50+20%WC and Co50+40%WC samples present good surface morphologies.The coatings are free of defects such as cracks and pores.The coatings are mainly composed of Co,Co4W2C,FeNi3,WC,W2C and Ni2.9Cr0.7Fe0.36.The average hardness and wear resistance of the three kinds of samples are all basically at the pre-wear level.The highest hardness and the lowest wear loss are 778.71 HV0.2 and 1.7 mg,respectively,which can meet the remanufacturing requirements of the roller bit.