| 引用本文: | 杨宇,杨发展,姜芙林,黄珂,刘朝伟.内部结构非对称织构对材料表面的润滑性能分析[J].中国表面工程,2024,37(1):240~253 |
| YANG Yu,YANG Fazhan,JIANG Fulin,HUANG Ke,LIU Chaowei.Analysis of the Lubricating Properties of the Internal Structure Asymmetric Microtexture on the Material Surface[J].China Surface Engineering,2024,37(1):240~253 |
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| 摘要: |
| 织构对材料表面的减摩降磨具有积极效果，但内部结构对称织构在摩擦方向和润滑方式上较为单一。为研究内部结构非对称织构对加工润滑特性的影响以及在改善材料表面摩擦性能方面的激励机制，通过研究对称织构和两种内部结构非对称织构的正、反向摩擦行为，对比润滑油在各织构单元体的压力分布、流速和流迹线来分析织构内部结构的对称性对润滑性能的影响。利用飞秒激光以倾斜加工的工艺制备内部结构非对称织构，并进行摩擦磨损试验。结果证明：织构内部结构的对称特征直接影响润滑油的流速和流迹线状态，进而影响油膜的承载力，而流速越大空化效应越剧烈，且流迹线越向涡旋中心集中，惯性效应越强。在内部结构非对称织构正反两个方向的摩擦中，正向摩擦的润滑性能要优于反向摩擦的润滑性能，且无论是正向摩擦还是反向摩擦，织构沟槽呈现直角时的润滑性更加优异，内部结构非对称织构的加工工艺可以增加表面硬度， 有利于降低摩擦因数。 |
| 关键词: 非对称织构 Fluent 仿真分析 流体动压润滑 倾斜加工工艺 摩擦因数 |
| DOI：10.11933/j.issn.1007-9289.20230223002 |
| 分类号:TG156；TB114 |
| 基金项目:山东省自然科学基金(ZR2018PEE011) |
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| Analysis of the Lubricating Properties of the Internal Structure Asymmetric Microtexture on the Material Surface |
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YANG Yu1,2, YANG Fazhan1,2, JIANG Fulin1, HUANG Ke1, LIU Chaowei1
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1.School of Mechanical and Automotive Engineering, Qingdao University of Technology,Qingdao 265200 , China;2.Key Laboratory of Energy Conservation and Pollution Control of Industrial Fluids of Ministry of Education,Qingdao University of Technology, Qingdao 265200 , China
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| Abstract: |
| Microtexture has been proven to have an important role in wear reduction and lubrication of material surfaces, but the internal structure of a symmetric microtexture is more homogeneous in terms of friction direction and lubrication mode. Therefore, studying the symmetry of the internal structure of a microtexture is vital. This study investigated the effect of the internal-structure asymmetric microtexture on the process lubrication characteristics and incentive mechanism to improve the material surface friction properties. Two lubrication states, the internal-structure symmetric and asymmetric groove microtextures, were simulated using the fluid–solid coupling method. By simulating the forward and reverse friction behavior of the symmetric microtexture and two internal-structure asymmetric microtextures, we determined the microtexture parameters and friction direction when the internal-structure asymmetric microtexture reached the optimal lubrication state and analyzed the effect of the symmetry of the internal structure of the microtexture on the cavitation and inertia effects by studying the pressure distribution, flow rate, and flow traces of the lubricant in the microtexture unit. The internal structure of the asymmetric microtexture was prepared via a tilting process using a femtosecond laser, and frictional wear experiments were conducted using an MPT-20 wear tester. The results showed that the internal-structured asymmetric microtexture exhibited better lubricity and friction performance under the conditions of lubricant inertia effect and cavitation effect, and the internal-structure asymmetric microtexture had better performance in forward friction lubrication. Comparing the pressure distribution graphs, flow velocity graphs, and flow traces of the asymmetric microtextures of the two internal structures, we observed that the lubricity of the microtexture grooves was superior when the grooves had right angles, both for forward and reverse friction; the best internal-structure asymmetric microtexture had an oil-film bearing capacity of 146 227 Pa and the fastest flow rate of 6.695 m / s. The inclined machining process was beneficial for improving the microhardness and wear resistance of the material surface. The average microhardness of the machined surface was 1 766.70 HV, which was approximately 11.9% higher. Additionally, a significant reduction in the wear rate with multilevel bonded wear on the unprocessed surfaces was observed, whereas the laser-processed surfaces had a smaller wear area and less bonded wear, and the degree of surface strengthening increased with increasing inclination. The wear rate of the asymmetric surface microtexture of the optimal internal structure was 10.08×10?3 mm3 / (N·m) and the friction factor was 0.0932, which was a reduction of the friction factor of approximately 13.1%. The results proved that the symmetrical characteristics of the internal structure of the microtexture directly affect the flow velocity and the state of the flow traces of the lubricant, which consequently affects the bearing capacity of the oil film. The greater the flow velocity, the more intense the cavitation effect, and the more complex the flow traces, the more concentrated the vortex center, and the stronger the inertia effect. The friction factor of the surface with an internal-structure asymmetric microtexture was smaller than that of the surface with a symmetric microtexture, and the friction factor of the right-angle microtexture was the smallest. The processing of an internally structured asymmetric microtexture can increase surface hardness, and a laser-induced periodic nanostructure (LIPSS) facilitates a reduction in the friction factor. The experimental results matched the simulation results, laying the foundation for the application of internal-structure asymmetric microtextures in the manufacturing industry and enriching the types of material surface microtextures. |
| Key words: asymmetrical texture Fluent simulation analysis hydrodynamic pressure lubrication tilt processing process friction factor |
