碳含量对激光熔覆CoCrFeMnNiC_(x)高熵合金涂层摩擦磨损和耐蚀性能的影响

Effects of Carbon Content on Friction and Wear Behavior and Corrosion Resistance of Laser Cladding CoCrFeMnNiC_(x) High Entropy Alloy Coatings

采用激光熔覆技术在45钢基体上制备了不同碳含量(等摩尔比)的CoCrFe MnNiCx(x=0,0.03,0.06,0.09,0.12,0.15)高熵合金涂层。通过X射线衍射(XRD)、扫描电镜(SEM)、HVS-1000A型显微硬度计、RST5000型电化学工作站、UMT-2型摩擦磨损试验机等表征和测试手段研究了不同碳含量对激光熔覆CoCrFe MnNiCx高熵合金涂层物相结构、显微硬度、摩擦磨损及耐腐蚀性能的影响。结果表明,当碳含量x由0逐渐增加至0.09时,高熵合金相结构由FCC固溶体转变为FCC固溶体和M23C6相共存,合金微观组织变得细小;熔覆层硬度由183.20 HV0.2增加至223.48 HV0.2;涂层的摩擦因数降低,耐磨性能变强;腐蚀电位由-469 m V增大至-348 m V,腐蚀电流密度由14.95μA·cm-2减小为2.29μA·cm-2,耐腐蚀性增强。当碳含量x由0.09逐渐增加至0.15时,合金相结构再次转变为FCC固溶体,且合金微观组织恢复粗大状态;熔覆层硬度与耐腐蚀性降低,但耐磨性能却先减弱后增强。合金在碳含量为0.09时,硬度最高且耐腐蚀性能最强;在碳含量为0.15时,耐磨性最强。

CoCrFe MnNiCx(x=0,0.03,0.06,0.09,0.12,0.15)high entropy alloy coatings with different carbon content(equimolar ratio)were prepared by laser cladding on 45 steel substrate.The effects of different content of carbon on the phase structure,microhardness,friction and wear resistance of laser cladding CoCrFe MnNiCx high entropy alloy coatings were studied by means of X-ray diffraction(XRD),scanning electron microscopy(SEM),HVS-1000 A microhardness tester,RST5000 electrochemical workstation and UMT-2 friction and wear tester.Results show that when the C content x increases from 0 to0.09,the phase structure of the high entropy alloy changes from FCC solid solution to the coexistence of FCC solid solution and M23 C6 phase,and the microstructure of the alloy becomes fine.The hardness of the cladding layer increases from 183.20 HV0.2 to 223.48 HV0.2.The friction coefficient decreases,and the wear resistance becomes stronger.The corrosion potential increases from-469 m V to-348 m V,and the corrosion current density decreases from 14.95μA·cm-2 to 2.29μA·cm-2.When the C content x increases from 0.09 to 0.15,the phase structure of the alloy transforms into FCC solid solution again,and the microstructure of the alloy returns to coarse state.The hardness and corrosion resistance of the cladding layers decrease,but the wear resistance first weakens and then increases.The hardness and corrosion resistance of the alloy are the highest when the carbon content is 0.09,and the wear resistance is the strongest when the carbon content is 0.15.