CeO_(2)改性对感应熔覆自润滑复合涂层性能的影响

Effect of CeO_(2) modification on properties of induction cladding self-lubricating composite coatings

利用高频感应熔覆技术在35CrMo钢表面制备CeO_(2)改性镍基自润滑复合涂层。借助光学显微镜(OM)、X射线衍射仪(XRD)、硬度计、摩擦磨损试验机、电化学工作站等研究了不同CeO_(2)含量对涂层微观组织、硬度、耐磨性和耐蚀性的影响,并分析了磨损机制。结果表明:适量CeO_(2)可改善复合涂层的组织、细化晶粒、减少缺陷。复合涂层主要物相为γ-Ni、Cr_(23)C_(6)、TiB_(2)和h-BN等。随着CeO_(2)含量增加,复合涂层的硬度、耐磨性和耐蚀性均先增加后降低。添加2 mass%CeO_(2)后,复合涂层的硬度最大,为711.1 HV0.2,摩擦系数和磨损量均最小,分别为0.39和43.2 mg,其磨损机制为粘着磨损和轻微的磨粒磨损。当CeO_(2)含量为1 mass%时,复合涂层的自腐蚀电位为-0.34187 V,自腐蚀电流密度为5.4μA/cm^(2),耐蚀性最佳。

CeO_(2) modified nickel-based self-lubricating composite coatings were prepared on the surface of 35CrMo steel by high-frequency induction cladding technology.The effects of different CeO_(2) content on microstructure,hardness,wear resistance and corrosion resistance of the composite coatings were studied by means of optical microscope(OM),X-ray diffraction(XRD),hardness tester,friction and wear tester and electrochemical workstation,and the wear mechanism was analyzed.The results show that an appropriate amount of CeO_(2) can improve the microstructure,refine the grain and reduce the defects of the composite coatings.The main phases of the composite coatings areγ-Ni,Cr_(23)C_(6),TiB_(2) and h-BN.With the increase of CeO_(2) content,the hardness,wear resistance and corrosion resistance of the composite coatings first increase and then decrease.After adding 2 mass%CeO_(2),the maximum hardness of the composite coatings is 711.1 HV0.2,and the friction coefficient and wear amount are the smallest,which are 0.39 and 43.2 mg,respectively.The wear mechanism is adhesive wear and slight abrasive wear.When the CeO_(2) content is 1 mass%,the self-corrosion potential of the composite coatings is-0.34187 V,the self-corrosion current density is 5.4μA/cm^(2),and the corrosion resistance is the best.