表面技术2025，Vol.54Issue(3)：90-100,11.DOI:10.16490/j.cnki.issn.1001-3660.2025.03.007
Mo含量对激光熔覆CoCrW涂层摩擦磨损行为的影响
Effect of Mo Content on the Friction and Wear Behavior of Laser Cladding CoCrW Coating
摘要
Abstract
As a new type of green surface modification technology,laser cladding uses high-energy laser beam to prepare high-performance coatings on the metal surface.Compared to other technologies,the coatings prepared by laser cladding technology show a higher bonding to the substrate.Adding different elements in powder can further enhance the mechanical properties and oxidation and wear resistance of the laser cladding coatings.Among the alloying elements,Mo element can improve the high temperature strength and corrosion resistance of alloys.The work aims to prepare CoCrW coatings with different Mo contents(≥ 10％)by laser cladding technology,and systematically investigate the effects of different Mo contents(0％,10％,20％and 30％)on the microstructure,mechanical properties,and tribological properties of the coatings. GH4169 was selected as the substrate materials and ground by sandpaper.Different contents(0％,10％,20％and 30％mass fraction)of Mo were added in CoCrW as a cladding powder.4 kW fiber laser(YLS-4000)was used for laser cladding of pre-positioned powder.During the cladding process,the laser power was 1.4 kW,the scanning speed was 800 mm/min,the spot diameter was 4 mm,the overlap rate was 50％,and the powder thickness was 2.5 mm.The sample was cut by wire cutting,the cross section was polished and corroded with HCl(2 mL)+C2H5OH(2 mL)+CuCl2(0.1 g)solution.Scanning electron microscope(JEOL JSM-5600LV),energy disperse spectroscope(JSM-5600LV)and X-ray diffraction(PANalytical Empyrean)were adopted to evaluate the physical phase and elemental composition,and Vickers hardness measurement(MH-5-VM)and friction testing machine(Rtec-3000F)were utilized to assess and evaluate the hardness distribution and tribological properties of the coatings. The coatings showed a uniform and dense microstructure and formed a metallurgical bond to the substrate.Co-based coatings were mainly composed of y-Co and carbide phase.During the laser cladding process,the microstructure of the coatings gradually transformed from the large dendrite in the middle region to the fine columnar and cellular crystal near the top.The content of carbide phase rose with the increase of Mo content,resulting in a remarkable increase in micro-hardness to 954HV0.2 when Mo content was 30％.Under the condition of reciprocating friction,the average friction coefficients and wear rates of four coatings sliding against Si3N4 showed a similar trend,namely initially rising and then decreasing as temperature changes.As the temperature rose from room temperature to 400 ℃,the hardness of the coatings decreased.There was no effective lubricating phase at this temperature range.Consequently,it is worth noting that the friction coefficient and wear rate increase from room temperature to 400 ℃.When the testing temperature is above 600 ℃,the elements in the coatings begin to oxidize,and the oxide layers are gradually dense from 600 ℃ to 800 ℃.The synergistic effect of the oxides causes a considerable decrease in both the friction coefficient and wear rate.Among the four coatings,M3 coating(30％Mo content)exhibits the best tribological properties from room temperature to 800 ℃.As the content of Mo element increases,it can be found that the synergistic effect of solid solution and hard phase strengthening obviously improves tribological properties of coatings.Mo element promotes the formation and densification of oxide glaze layer at high temperature,which improves the wear behavior of the coatings more significantly.关键词
激光熔覆/CoCrW/Mo含量/摩擦学性能/磨损机制Key words
laser cladding/CoCrW/Mo content/tribological properties/wear mechanism分类
矿业与冶金引用本文复制引用
罗兰,路世盛,胥卫奇,文泽东,王凌倩,周健松..Mo含量对激光熔覆CoCrW涂层摩擦磨损行为的影响[J].表面技术,2025,54(3):90-100,11.基金项目
中国科学院战略性先导科技专项(XDB 0470302) （XDB 0470302）
中国科学院材料磨损与防护重点实验室青年基金(SYSQY-2023-1) Strategic Priority Research Program of the Chinese Academy of Sciences(XDB 0470302) （SYSQY-2023-1）
Youth Fund of Key Laboratory of Science and Technology on Wear and Protection of Materials(SYSQY-2023-1) （SYSQY-2023-1）
