热流密度对高速钢刀具多道熔覆WC/Co陶瓷层组织与性能的影响  

Effect of Heat Flux on Microstructure and Properties of High-speed Steel Cutter WC/Co Ceramic Layer by Laser Multiple-channel Cladding

作　　者：陈翔[1] 张德强[2] 李金华[2] 郭海华 姚芳萍[2] 朴若华 CHEN Xiang;ZHANG Deqiang;LI Jinhua;GUO Haihua;YAO Fangping;PU Ruohua(Engineering Training Center,Liaoning University of Technology,Liaoning Jinzhou 121001,China;School of Mechanical Engineering and Automation,Liaoning University of Technology,Liaoning Jinzhou 121001,China;Training Center,Dalian Economic and Trade School,Liaoning Dalian 116000,China)

机构地区：[1]辽宁工业大学工程实践教学部,辽宁锦州121001 [2]辽宁工业大学机械工程与自动化学院,辽宁锦州121001 [3]大连市经济贸易学校实训中心,辽宁大连116000

出　　处：《表面技术》2024年第13期207-219,共13页Surface Technology

基　　金：辽宁省教育厅高等学校基本科研项目(LJKMZ20220967)。

摘　　要：目的研究高速钢刀具表面激光多道熔覆WC/Co陶瓷层时,热流密度对熔覆层道次间的影响规律,以及多道熔覆层制备时的参数选择。方法建立多道单层激光熔覆理论模型,并利用模拟仿真和实验的方法,以热流密度作为评价指标,对激光热源的不同参数和熔覆层组织与性能进行耦合分析。结果当热流密度小于24.06×10^(6) W/m^(2)时,熔覆层内形成细长的枝状晶。当热流密度在36.09×10^(6)~39.82×10^(6) W/m^(2)变化时,熔覆层内形成以胞状、枝状为主要强化相的多晶体混合组织。当热流密度大于44.11×10^(6) W/m^(2)时,熔覆层组织形成稳态的块状结构。不同热流密度下,熔覆层的物相组织均由Fe_(3)W_(3)C、Co_(3)W_(3)C、Mo_(3)Co_(3)C、W_(2)C、WC、Cr_(3)Mo、(Cr,Fe)_(7)C_(3)和多种间隙化合物组成。结论当第n道熔覆层制备完成后,受到后续第n+1道熔覆层制备时热流密度的影响较大,而此后道次的影响较小。熔覆层内部组织形态随着热流密度的增加从细长的枝状晶向胞状晶转变,再逐渐形成稳态块状晶。熔覆层内各位置的显微硬度值随着热流密度的增加而先增大,随后逐渐减小。较大的热流密度会导致基材参与熔覆的质量增加,但降低了基材的抗弯曲强度,加大了熔覆层及基材断裂的可能性。当热流密度为36.09×10^(6) W/m^(2)时,是一组较为理想的工艺参数选择。It is an advanced technology of surface modification,repair and remanufacturing by laser cladding,which has an incomparable advantage over traditional cutter repair methods in surface modification and damage remanufacturing of cutting tools.Cermet powder can effectively increase the hardness of cladding layer,so that it can meet the basic hardness requirements of cutter.WC/Co cermet powder is one of the ideal materials for cutter repair.The work aims to study the effect mechanism of the heat flux on the multi-channel cladding layer and the selection of parameters in the preparation of multi-channel cladding layer by laser on multi-channel WC/Co ceramic cladding layer on the surface of high-speed steel cutter.By establishing the theoretical model,the COMSOL Multiphysics was used to conduct simulation analysis on the multi-channel laser cladding process and the temperature field of the multichannel model,and the YLR-3000 fiber laser processing system was adopted to prepare WC/Co single-layer multi-channel ceramic cladding layer on 45 mm×30 mm×10 mm high-speed steel cutter surface by coaxial powder feeding process.The samples were cut by wire cutting and the microstructure of cladding section was observed and analyzed by Axio Vert.A1 inverted metallographic microscope.The microstructure of cladding layer was analyzed by S-3000N scanning electron microscope(SEM)and NORAN-QUESTⅡenergy dispersive spectrometer(EDS).The hardness of cladding layer was measured by HVS-1000 microhardness tester.The phase characterization was analyzed by D/MAX-2500 X-ray diffractometer.The multi-factor laser process parameters were coupled and the morphology,structure and properties of cladding layer were analyzed by the heat flux(qn).The correctness of the theoretical model was verified by simulation analysis,and the effect law of heat flux between adjacent channels of single-layer and multi-channel cladding layer was obtained.By the simplified experiment,the effect law of heat flux was found that when the nth cladding layer was prepare

关 键 词：激光熔覆 热流密度 WC/Co陶瓷熔覆层 显微组织 高速钢刀具 多道熔覆 

分 类 号：TH142.2[一般工业技术—材料科学与工程] TG174.4[机械工程—机械制造及自动化]