稀土金属Y对真空熔结Ni基涂层显微组织和耐磨性的影响

研究了稀土金属Y对真空熔结Ni基合金涂层显微组织及化学组成、硬度和耐磨性的影响.结果表明:稀土金属Y可以改善真空熔结Ni基合金涂层的显微组织,阻碍针状相的析出,细化球状相,减轻碳钢母材中Fe对Ni基合金涂层的"稀释"作用,降低Ni60涂层中Fe的含量,提高Ni、Cr元素的含量;与此同时,稀土金属Y可明显提高Ni60涂层的硬度和耐磨性,降低摩擦系数,使Ni60涂层由微观犁沟和微观断裂剥落磨损形式转变为单一的微观犁沟磨损.

Effect of Rare Earth Metal Yttrium on Microstructure and Wear Resistance of Vacuum Fusion Sintered Ni-Based Coating

The effect of rare earth metal yttrium on the microstructure, chemical composition, hardness, and wear resistance of vacuum fusion sintered Ni-based coatings was studied. Thus the elemental compositions and phase compositions of the alloy coatings were determined using an energy dospersive X-ray analyzer and an X-ray diffractometer, respectively. The friction and wear behaviors of the coatings were evaluated on an MM-200 test rig in a lock-on-ring configuration under oil-lubricated condition. The worn surface morphologies of the coatings were observed using a scanning electron microscope. The results showed that the rare earth metal yttrium was beneficial to improving the microstructure of Ni60 coating, restraining the precipitation of the needle-shaped phase, and making the size of the sphere-shaped decreased. Moreover, yttrium helped to alleviate the dilution function of the Fe atom from the steel matrix to the Ni-based alloy coating, while it was able to decrease the Fe content and increase the Ni and Cr contents of the coating. Besides, yttrium contributed to greatly increasing the hardness and wear resistance and decrease the friction coefficient of the Ni60 coating, while it led to a transformation of the micro-plowing and micro-peeling wear modes of the Ni60 coating to micro-plowing.