(1．安徽工业大学 激光加工研究中心, 马鞍山 243002；
2．Department of Materials Science and Engineering,
The Changwon National University,
9 Sarium-dong, Changwon 641-773, South Korea；
3．Division of Engineering, Colorado School of Mine,
Golden, CO 80401, USA)
摘 要: 运用激光熔覆技术在16Mn钢表面制备了钴基合金涂层(Co55)、 含20%SiCp(体积分数, 下同）的钴基合金涂层(CoSiC)以及含20%B4Cp钴基合金涂层(CoB4C), 比较研究了合金涂层的组织、相结构、 显微硬度及滑动磨损性能。 结果表明： 合金涂层由涂层结合区的胞状共晶组织及涂层区的树枝状亚共晶组织组成, CoSiC涂层及CoB4C涂层的树枝晶比Co55涂层的更细小； B4Cp及SiCp在熔覆过程中完全熔解， 其分解出的B, C, Si与涂层中的合金元素结合形成了更多的化合物, Co55涂层由/γ/-Co和（Cr, Fe）7C3组成, CoSiC涂层由γ-Co, Cr7C3, Cr23C6, CoSi2, Cr3Si和Si2W组成, CoB4C涂层由γ-Co, Cr7C3, Cr23C6, CrB, CrB2和Fe23(C, B)6组成； 3种激光熔覆涂层的显微硬度及耐磨性由高到低的顺序为CoB4C→CoSiC→Co55。 对涂层的强化机理进行了分析。
关键字: 激光熔覆； 钴基合金； SiC； B4C； 组织； 耐磨性
B4Cp and SiCp
（1．Research Center for Laser Processing,
Anhui University of Technology, Maanshan 243002, China；
2．Department of Materials Science and Engineering,
The Changwon National University,
9 Sarium-dong, Changwon 641-773, South Korea；
3．Division of Engineering, Colorado School of Mine, Golden, CO 80401, USA）
Abstract:The laser surface cladding technique was used to form Co-based alloy coating, 20% SiCp Co-based composite coating (CoSiC) and 20% B4Cp Co-based composite coating (CoB4C) on the 16Mn steel substrate by 5kW CO2 continuous wave laser. Microstructure, phase constitution, micro-hardness and sliding wear properties of the coatings were studied. The results show that the microstructures of the coatings are consisted of the cellular eutectic structures of bonding zone and the dendrites of coating zone. The dendrites of CoSiC and CoB4C coatings are much finer than that of Co55 coating. SiCp and B4Cp are completely dissolved in Co-based alloy during laser cladding processing, and more eutectic compounds exist in the CoSiC and CoB4C coatings. Co55 coating is consisted of γ-Co and （Cr, Fe）7C3, but CoB4C is consisted of γ-Co, Cr7C3, Cr23C6, Fe23(C, B)6 and CrB and CoSiC coating is consisted of γ-Co, Cr7C3, Cr23C6, CoSi2, Cr3Si and Si2W. Microhardness and sliding wear resistance of the three coatings are in the order of CoB4C→CoSiC→Co55 from high to low. The strengthen mechanism of the coatings is simplify analyzed.
Key words: laser cladding; Co-based alloy coating; B4C; SiC; microstructure; wear resistance
