塑料模具钢表面激光熔覆W_xC/Ni基合金涂层的组织及性能  

Microstructure and properties of laser clad Ni-based tungsten carbide alloy layer on a plastic mould steel

作　　者：赵先锐[1,2] 左敦稳[2] 程虎[1] 李勤涛[1] 戴晟[1,2] 冯尚申[1] 

机构地区：[1]台州学院,浙江台州318000 [2]南京航空航天大学机械工程学院,江苏南京210016

出　　处：《材料热处理学报》2013年第4期177-181,共5页Transactions of Materials and Heat Treatment

基　　金：浙江省教育厅科研计划项目(Y201119602);航空科学基金(2010ZE52056);浙江省工量刃具检测与深加工技术研究重点实验室开放基金(ZD201201)

摘　　要：采用TJ-HL-5000横流CO2连续激光器在2738塑料模具钢表面制备了WxC/Ni基合金涂层。利用金相显微镜、SEM、EDS、XRD、显微硬度计以及摩擦磨损试验机等检测设备研究了激光熔覆涂层组织及性能。XRD分析结果表明,熔覆层的主要物相有γ-Ni、W2C、WC、M23C6(M=Cr,Ni,Mo,W)、NiCr和Cr2O3等。金相显微镜、SEM和EDS分析结果表明,结合区为良好冶金结合,结合区为FeNiCrW合金,厚度为20μm左右;基体对熔覆层合金的稀释度很低;熔覆层从界面向外依次分布着平面晶区、细等轴晶区、粗树枝晶区以及表面细晶区。显微硬度计结果表明,熔覆层的硬度值平均约900 HV1,是基体硬度的2.8倍左右。摩擦磨损试验结果表明,与基体相比熔覆层的耐磨性有了很大提高。The W_xC/Ni-based alloy layer was successfully coated onto 2738 plastic mould steel surface by using a TJ-HL-5000 transverse- flow CO2 continuous laser. Microstructure and mechanical properties of the coatings were investigated by metallographic microscope, SEM/ EDS, XRD, Vickers microhardness tester and friction-abrasion testing machine. XRD results show that the clad layer consists of WC, γ- nickel, Ni4B3, Cr7C3, W2C, M23 C6 （M = Cr, Ni, Mo, W）, NiCr and Cr203 phases. SEM and EDS results indicate that the metallurgical bonding is formed between the cladding coating and the steel substrate, and the interface zone is FeNiCrW alloy with thickness of 20 μm or so. From the interface to surface, the clad coatings consist of plane crystal layer, fine equiaxial crystal layer, coarse dendrite layer and surface fine-grain layer. The results of Vickers microhardness tesing show that the average micro-hardness of the laser clad coating is about 900 HV1, which is 1.8 times higher than that of the steel substrate. The results of friction-wear test indicate that the wear resistance of the steel with clad layer is improved significantly compared with the substrate.

关 键 词：2738钢 激光熔覆 Ni基碳化钨合金 显微组织 

分 类 号：TG174.4[金属学及工艺—金属表面处理]