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采用激光熔覆技术,在1Cr18Ni9Ti基材上,“原位”合成了以MoNiSi及Co_3MoSi Laves相为增强相的镍基和钴基复合材料涂层。利用OM,XRD、SEM、TEM等研究了涂层的显微组织和微结构,并考察了涂层的显微硬度、耐磨损性能和高温抗氧化性能。结果表明,镍基、钴基激光熔覆涂层显微组织分别为MoNiSi分布在镍基固溶体基体上和初生Co_3Mo_2Si分布在Co固溶体和Co_3Mo_2Si共晶基体上。两种合金的强化相均为具有密排六方晶体结构的MgZn_2型Laves相、且固溶大量合金元素Cr;固溶体相均为面心立方晶体结构,Cr、Si、Mo等合金元素固溶含量很高。镍基、钴基激光熔覆涂层的平均显微硬度分别为650HV_(0.2)和1000HV_(0.2)。与不锈钢和镍基高温合金相比,Laves相增强激光熔覆复合材料涂层具有优良的耐磨和抗高温氧化综合性能。
Using laser cladding technology, Ni-based and cobalt-based composite coatings with MoNiSi and Co_3MoSi Laves phases as reinforcing phases were synthesized in-situ on 1Cr18Ni9Ti substrate. The microstructure and microstructure of the coating were investigated by OM, XRD, SEM and TEM. The microhardness, wear resistance and high temperature oxidation resistance of the coating were also investigated. The results show that the microstructures of Ni-based and Co-based laser cladding coatings are MoNiSi distributed on the Ni-based solid solution matrix and the nascent Co_3Mo_2Si distributed on the Co solid solution and Co_3Mo_2Si eutectic matrix, respectively. The strengthening phases of the two alloys are all MgZn 2 -type Laves phases with a hexagonal close-packed structure and a large amount of alloying elements Cr are solid solution; the solid solution phases are all face-centered cubic crystal structures, and the alloying elements such as Cr, Si, high. The average microhardness of Ni-based and Co-based laser cladding coatings are 650HV_ (0.2) and 1000HV_ (0.2), respectively. Compared with stainless steel and nickel-based superalloy, Laves phase enhanced laser cladding composite coating has excellent wear resistance and high temperature oxidation comprehensive performance.