| 引用本文: | 田峰,段海涛,潘邻,许鑫宇,秦江林,魏琴琴,罗国强.CrN/TiAlN多层涂层的微观结构和摩擦磨损性能[J].中国表面工程,2024,37(3):232~241 |
| TIAN Feng,DUAN Haitao,PAN Lin,XU Xinyu,QIN Jianglin,WEI Qinqin,LUO Guoqiang.Microstructural, Frictional, and Wear Properties of CrN / TiAlN Multilayer Coatings[J].China Surface Engineering,2024,37(3):232~241 |
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| 摘要: |
| 特种装备车辆往往在高速、高冲击等复杂环境下运行，底盘选装密封件表面容易被磨损造成密封失效，在密封工作面制备硬质涂层是提高服役寿命、延长维修周期的重要方法。采用物理气相沉积法在 45#钢表面制备单层 CrN 涂层和不同过渡层厚度的多层 CrN / TiAlN 涂层，用 X 射线衍射仪、扫描电子显微镜、表面轮廓仪、纳米压痕仪和往复式摩擦磨损试验机， 研究涂层的微观结构、机械性能和摩擦磨损性能。结果表明单层 CrN 涂层厚度为 0.87 μm, 其硬度和模量最小为 19.49 GPa 和 160.53 GPa。CrN / TiAlN 多层涂层的硬度和模量明显提高，且随过渡层厚度增加而增大，4CrN / TiAlN 涂层的硬度和模量可达到 39.86 GPa 和 386.72 GPa。在空气环境下的摩擦磨损试验中，单层 CrN 涂层被快速破坏；CrN / TiAlN 多层涂层的平均摩擦因数随着过渡层厚度的增加先增大后减小，最大磨损深度和磨痕截面积不断下降。4CrN / TiAlN 涂层具有最优摩擦磨损性能，其平均摩擦因数为 0.792 5，磨痕截面积为 315.09 μm2 ，磨损机理为磨粒磨损和少量粘着磨损。提高过渡层厚度能够降低基体的塑性变形，降低涂层与基体的物理性能差异，减少涂层开裂并提高涂层摩擦磨损性能。通过调控过渡层厚度获得性能优异的 CrN / TiAlN 多层涂层，研究成果可应用于车辆旋转密封件上，显著提高密封工作面耐磨损性能。 |
| 关键词: 45#钢 CrN 涂层 CrN / TiAlN 多层涂层 耐磨性 磨损机制 |
| DOI：10.11933/j.issn.1007-9289.20230919003 |
| 分类号:TG174 |
| 基金项目: |
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| Microstructural, Frictional, and Wear Properties of CrN / TiAlN Multilayer Coatings |
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TIAN Feng1，2，DUAN Haitao2，PAN Lin2，XU Xinyu3，QIN Jianglin1，WEI Qinqin3，LUO Guoqiang3
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1.State Owned Wuhan Xinyu Machine Factory, Wuhan 430060 , China ；2.State Key Laboratory of Special Surface Protection Materials and Application Technology,Wuhan Research Institute of Materials Protection, Wuhan 430030 , China ；3.State Key Lab of Advanced Technology for Materials Synthesis and Processing,Wuhan University of Technology, Wuhan 430070 , China
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| Abstract: |
| Special equipment vehicles often operate under high-speed, high-impact, or other adverse environmental conditions. The surface of a rotary shaft seal on the chassis of this type of vehicle is prone to wear and tear, which can lead to sealing failure. An important method for extending the service life and prolonging the maintenance interval is the preparation of hard coatings on the working surfaces of seals. The aim of this study is to improve the wear resistance and extend the service life of rotating axes. The rotary shaft on the vehicle chassis is generally made of 45# steel. Therefore, we prepared hard coatings with different structures on a 45# steel substrate that was ground, polished, and cleaned using ultrasound and alcohol in advance. A single-layer CrN coating and multilayer CrN / TiAlN coatings with thicknesses of support layers were prepared on the 45# steel via physical vapor deposition. The microstructure, mechanical properties, and friction and wear properties of the coatings were analyzed using X-ray diffractometry, scanning electron microscopy, surface profilometry, nanoindentation, and reciprocating tribometry. The single-layer CrN coating was 0.87 μm thick, with hardness of 19.49 GPa and an elastic modulus of 160.53 GPa at a minimum. The multilayer CrN / TiAlN coatings had significantly higher hardness and elastic modulus values, which increased with the thickening of the support layer. The hardness and elastic modulus of the 4CrN / TiAlN coatings reached 39.86 and 386.72 GPa, respectively. The main reason for the increased hardness of the CrN / TiAlN multilayer coatings was Al doping. The addition of Al can refine the grain and cause crystal lattice distortion of nitride, which increases the resistance to dislocation movement and generates fine crystal strengthening and solid solution strengthening effects. In the friction and wear tests in an air atmosphere, the single-layer CrN coating was soon worn. With an increase in the thickness of the support layer, the average friction coefficient of the multilayer CrN / TiAlN coatings initially increased and then decreased, and the cross-sectional area of the wear scar and the maximum wear depth decreased. The 4CrN / TiAlN coatings exhibited optimal frictional abrasion performance, with an average friction coefficient of 0.792 5 and a cross-sectional area of wear scar of 315.09 μm2 . The wear mechanisms of the 4CrN / TiAlN coatings were abrasive and slight adhesive wear. Increasing the thickness of the support layer could reduce the plastic deformation of the substrate, bridge the difference in the physical properties between the coatings and the substrate, decrease coating cracks, and improve the frictional and wear performance of the coatings. Multilayer coatings can strengthen the binding force between the film and substrate and reduce the residual stress in the coating. In multilayer structures, the interface between the two layers prevents dislocation glide, stress concentration, and cracking and detachment of the coating. It is easier to control the thickness of CrN / TiAlN multilayer coatings prepared via physical vapor deposition than that of conventional electroplated chromium coatings. Moreover, the former yields a significantly better surface hardness and modulus and is a more efficient and eco-friendly preparation process than the latter. With excellent wear resistance, multilayer coatings enable a rotary shaft seal to provide a long-term sealing effect under complex environmental conditions and high-speed rotation, thus extending the service life of the seal. In this study, we obtained CrN / TiAlN multilayer coatings with outstanding performance by controlling the coating thickness. These findings are expected to significantly improve the wear resistance of the working surface of the rotary shaft seals of vehicles. |
| Key words: 45# steel CrN coating CrN / TiAlN multilayer coating wear resistance wear mechanism |
