材料期刊网

目的：证明活性剂SiO2的加入能够改善钴基硼化物层的宏观形貌、硬度、耐磨损性能、微观组织结构及物相组成。方法以Q235钢为母材,Co60和B4 C为熔覆材料,SiO2为活性剂,利用活性氩弧熔覆技术制备B4 C质量分数为8%的钴基硼化物复合涂层。分析活性剂SiO2的加入对熔覆层截面尺寸的影响,并测定熔覆层的硬度,分析熔覆层的微观结构及相组成。通过磨损试验,对比分析基体、常规熔覆层及活性熔覆层的耐磨损性能。结果添加活性剂后,熔覆层的微观组织结构发生了改变,生成的物相增多。物相分析表明,常规熔覆层含有Co2B,Mn2B,CrB2等相,活性熔覆层中除此之外,还含有W3CoB3, Cr3 B4,Cr3 C2,Co2 SiO4等新相。活性熔覆层的硬度为常规熔覆层的1.13倍,耐磨粒磨损、粘着磨损、冲蚀磨损性能分别为常规熔覆层的1.57,1.37,1.49倍。结论添加活性剂SiO2后,熔覆层与基体结合更好,微观组织得到细化和均匀化,硬度和耐磨损性能都得到提高。

Objective To prove that the added active agents SiO2 can improve the macro-morphology, hardness, wear resist-ance, microstructure and physical phase of cobalt-based boride layer. Methods The cobalt-based composite cladding layer contai-ning 8% B4 C was fabricated on the surface of Q235 steel with the active argon arc cladding technology, using Co60 and B4 C as the basic materials, and SiO2 as the active agent. The effects of the addition of SiO2 on the size of the cladding layer cross section were analyzed, and then the hardness of the cladding layer was determined, and the microstructure and phase composition of the clad-ding layer were analyzed. The wear resistance of the substrate, the conventional cladding layer and the active cladding layer was studied by wear tests. Results The results showed that the microstructure of the cladding layer was changed, and the phases formed were increased after adding the active agent. Phase analysis showed that Mn2 B, CrB2 and Co2 B existed in the conventional cladding layer, whereas the active cladding layer contained not only Mn2 B, CrB2 and Co2 B, but also W3 CoB3 , Cr3 B4 , Cr3 C2 and Co2 SiO4 . In addition, the hardness of the active cladding layer was increased by 1. 13 times, and the wear resistance, adhesive wear and ero-sion resistance were improved by 1. 57, 1. 37 and 1. 49 times as compared with the conventional cladding layer. Conclusion After adding the active agent SiO2 in the coating layer, a better bonding between the cladding layer and the substrate was obtained, and the microstructure of the cladding layer was refined and became more uniform, moreover, the hardness and wear resistance of the coating were both improved.