稀土对真空熔结镍基金属陶瓷复合层成分和硬度分布的影响

Effect of Rare Earth on Component and Microhardness Distribution of Vacuum Fusion Sintered Ni-Based Metal-Ceramic Composite Coating

研究了真空熔结镍基金属陶瓷复合涂层纵截面的微观组织形态、化学组成、相结构,及合金元素与显微硬度的分布特征。结果表明:稀土(Ce+La)消除了Ni60+WC涂层中的针状相,改变了析出相的分布形态,增加了熔合带的宽度。稀土改变了涂层的化学组成,提高了Ni、Cr、Si和W的含量;降低了Fe的含量。Ni60+WC+RE涂层还析出了新的Cr3Ni5Si2相。两种Ni60+WC复合涂层显微硬度的最大值都出现在距涂层表面的0.2mm处,稀土明显地提高了复合涂层的显微硬度。

The microstructure, chemical composition, phase structure, and distributing characteristics of alloy elements and microhardness of vacuum fusion sintered Ni-based metal-ceramic composite coatings were studied. The results show that the addition of rare earth elements (Ce+La) changes the morphology and distribution of the precipitated phases, and increases the fusion zone width of interface and the needle phase disappears in the Ni60+WC eating. Rare earth elements change the chemical composition of coating, and increase the contents of Ni, Cr, Si and W of coating and decrease Fe content of the coating. New phase Cr3Ni5Si2 is precipitated form Ni60+WC+RE coating. Microhardness values of two kinds of coating reach their maximum values at 0.2 mm from the coating surface, and rare earth elements (Ce+La) can apparently enhance the microhardness of Ni-based metal-ceramic composite coating.