不同Cr3C2成分的激光熔覆Cr3C2/Ni涂层组织

Microstructure of laser cladding CrC/Ni coating with different CrC content

采用优化的工艺参数制备了不同Cr3C2成分的Cr3C2/Ni熔覆层,研究了不同Cr3C2含量及粒径对激光熔覆Cr3C2/Ni涂层组织的影响。结果表明:随着Cr3C2含量增加,熔覆层的组织更加细密,当Cr3C2含量超过20 mass%时,熔覆层有较多Cr的碳化物产生,且熔覆层中二次枝晶生长明显;Cr3C2含量达到30 mass%时,熔覆层底部存在较多未熔解的碳化物,熔覆层硬度值出现较大波动;Cr3C2粒径范围从45~109μm减小到15~45μm,熔覆层中二次枝晶消失,Cr3C2粒径范围为5~15μm时,熔覆层组织弥散程度较高;Cr3C2粒径的减小可以提高熔覆层的耐磨性并减少其硬度波动。

The Cr3C2/Ni cladding coating with different Cr3C2 content was prepared by optimized process parameters, and the effect of different Cr3C2content and particle size on microstructure of the laser cladding Cr3C2/Ni coating was studied. The results show that with the increase of Cr3C2 content, the structure of the cladding coating is finer and denser. When the Cr3C2 content is more than 20 mass%, more Cr carbides are produced in the cladding coating, and the secondary dendrite growth is obvious in the cladding coating. When the Cr3C2content reaches 30 mass%, there are more undissolved carbides at the bottom of the cladding coating, and the hardness of the cladding coating fluctuates greatly. When the particle size of the Cr3C2 decreases from 45-109 μm to 15-45 μm, the secondary dendrites disappear in the cladding coating. When the particle size range of the Cr3C2 is 5-15 μm, the microstructure dispersion of the cladding coating is the highest. The decrease of the Cr3C2particle size can improve the wear resistance of the cladding coating and reduce its hardness fluctuation.