| 引用本文: | 涂传坤,曹均,朱旻昊,叶佩青,谢京杉.润滑介质及基体对不同厚度PTFE/PI-PAI涂层的摩擦性能[J].中国表面工程,2024,37(1):225~239 |
| TU Chuankun,CAO Jun,ZHU Hao,YE Peiqing,XIE Jingshan.Tribological Properties of PTFE / PI-PAI Coatings with Different Thickness under Different Lubricating Medium and Substrate[J].China Surface Engineering,2024,37(1):225~239 |
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| 摘要: |
| 船舶发动机轴瓦在受到炮弹攻击后处于极端工况，造成轴瓦失效破坏。传统的电镀镀层和磁控溅射薄膜因存在高污染、 高成本等缺点，目前亟须寻求新的解决方案来提高轴瓦在极端工况下的耐磨性能。针对轴瓦因炮击而处于极端工况，设计了 ZrO2 填充 PTFE / PI-PAI 的涂层材料，采用液体喷涂工艺在 A370 铝合金和 CuPb22Sn2.5 铜合金基体表面制备三种不同厚度涂层，研究涂层在不同润滑介质下的摩擦学性能。结果表明，涂层的摩擦学性能受到涂层硬度、润滑介质及基体支撑作用影响， 涂层的硬度及弹性模量随厚度的增加呈现递减的趋势。涂层越厚，基体的支持作用越小。在油润滑工况下，铜合金基体上涂层摩擦因数及磨损率均小于铝合金，润滑油是涂层摩擦性能最主要影响因素。在海水工况下，涂层主要表现为磨粒磨损，并出现明显的犁沟现象。铜合金基体上涂层的摩擦因数高于铝合金，海水腐蚀和高频往复摩擦带来的冲刷作用是摩擦性能主要影响因素。在干摩擦工况下，涂层以黏着磨损为主。涂层的硬度受到基体支撑的影响，高频往复运动中硬质对磨球与硬质基体夹击软质涂层和接触压力是摩擦性能主要影响因素。通过涂层与合金摩擦因数对比，可知 30 μm 涂层能够大幅度地降低轴瓦材料的摩擦因数，有利于提高船舶发动机轴瓦在极端工况的摩擦学性能。阐明了基体对不同厚度自润滑涂层的支撑机理， 分析了涂层在极端工况下受到轰击后的摩擦学性能，确定了船舶发动机轴瓦涂层的最佳设计厚度。 |
| 关键词: 涂层厚度 润滑介质 基体支撑 摩擦行为 磨损机制 |
| DOI：10.11933/j.issn.1007-9289.20230313001 |
| 分类号:TG156；TB114 |
| 基金项目:国家自然科学基金（52005273）；浙江省自然科学基金（LQ20E050007）；宁波市揭牌指挥重点研发计划（2022Z050）；湖南省科技创新项目（2022RC4016） |
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| Tribological Properties of PTFE / PI-PAI Coatings with Different Thickness under Different Lubricating Medium and Substrate |
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TU Chuankun1, CAO Jun1,2, ZHU Hao2, YE Peiqing1,3, XIE Jingshan4
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1.College of Mechanical Engineering and Mechanics, Ningbo University, Ningbo 315211 , China;2.College of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 315016 , China;3.College of Mechanical Engineering, Tsinghua University, Beijing 100084 , China;4.Zhongyuan Inner Parts Group Bearing Co., Ltd., Mengzhou 454750 , China
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| Abstract: |
| As ships are attacked by shells or come in contact with reefs, the engine compartment experiences extreme working conditions, such as oil lubrication, seawater corrosion, and even dry sliding wear. To improve the tribological performance of a ship's engine bearing under extreme working conditions and ensure the smooth return of the ship after damage, we designed a polymer coating consisting of PTFE / PI-PAI and ZrO2. Three different coatings of different thicknesses were prepared using liquid spraying on the surfaces of the A370 aluminum alloy and CuPb22Sn2.5 copper alloy. The tribological performance of these coatings with different lubricating media was studied. The performance of the coatings was evaluated based on their physical phase composition, microstructure morphology, element distribution, bond strength between the coating and substrate, nano-hardness, Young's modulus, and frictional wear behavior. The tribological properties of the coatings were investigated using various lubricating media. The results showed that the physical phase and solid distribution of the coatings were not influenced by variations in the coating thickness. The hardness and elastic moduli of the coatings decreased with increasing coating thickness, and the hardness of the coating on the copper alloy substrate was higher than that on the aluminum alloy substrate. The thicker the coating, the less supported the action of the hard substrate. Compared with coating under 20 μm thickness, the supporting effect of coating under 50 μm thickness on the aluminum alloy and copper alloy substrate was increased by 1 297.78% and 1 767.98%, respectively. The coefficients of friction (CoFs) and wear rates of the coatings on the copper alloy substrate under oil-lubricated conditions were lower than those on the aluminum alloy substrate. The wear rate of the coatings decreased with increasing coating thickness. The maximum variation in the CoFs of the coatings with different thicknesses on different substrates was only 3.33%. Oil lubrication is a key factor resulting in these frictional properties. Abrasive wear and significant plowing were observed under corrosive seawater conditions. The CoFs of the coatings on the copper alloy substrate were higher than those of the coatings on the aluminum alloy substrate. Seawater corrosion and the effect of seawater scouring during high-frequency reciprocating frictional movements were the main factors influencing frictional performance. The wear mechanism of the coating under dry sliding was primarily adhesive wear. The coating entered stable wear at 600 s under dry sliding wear, which occurred later than under seawater conditions. Adhesive wear is the main reason for this observation. The hardness of the coating was influenced by the supporting action of the substrate. The tribological performance of the copper alloy coating was better than that of the aluminum alloy coating. The pinch action from the high-frequency reciprocating motion of the hard grinding ball to the soft coating on the hard substrate and the contact pressure were the main factors. The marine engine bearing had the best tribological performance under the coating with 30 μm thickness prepared on the copper alloy substrate. Compared with the CoF of the copper substrate, the CoFs of the coatings under dry sliding wear and seawater decreased by 72.16% and 36.07%, respectively. The tribological performance of marine engine bearings under extreme conditions can be improved using this coating. In this study, the support mechanism from the substrate to self-lubricating coatings with different thicknesses was elucidated. The tribological performance of the coating under extreme conditions was analyzed, and the optimum coating thickness on a marine engine bearing was determined. |
| Key words: coating thickness lubricating medium substrate support frictional behavior wear mechanism |
