| 摘要: |
| 采用超音速等离子喷涂技术在45CrNiMoVA钢表面制备Mo涂层，利用场发射扫描显微镜（SEM）、X射线能谱分析仪（EDS）观测涂层显微形貌与组织成分，分析了载流摩擦中的电接触模型及电弧成因，利用滑动式摩擦试验机研究了电流强度对涂层粗糙度、表面温升及摩擦磨损性能的影响。结果表明：制备的Mo涂层组织致密、氧化程度低，与基体结合方式为“机械铆合”；随电流增加，摩擦副间电弧能量急剧升高，起弧率与表面粗糙度先降低，后上升。其中收缩电阻和微电容产生的自感电动势促进了电弧形成；摩擦副表面的温升由摩擦热、焦耳热、电弧热共同决定，与电流强度呈正相关；摩擦因数受表面粗糙度、材料剪切强度、表面膜等因素共同影响，随电流增加呈下降趋势。此外，载流条件下会出现黏着磨损、氧化磨损、电弧烧蚀等磨损，加剧了涂层剥落与磨粒磨损，但形成的摩擦膜可以有效保护涂层，降低磨损率。 |
| 关键词: 超音速等离子喷涂 Mo涂层 载流摩擦磨损 电弧 |
| DOI：10.11933/j.issn.1007-9289.20181218001 |
| 分类号:TG174.442;TG115.58 |
| 基金项目:北京市自然科学基金（2152031） |
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| Current-Carrier Tribological Properties of Mo Coating Deposited by Supersonic Plasma Spraying |
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HUI Yang, LIU Guimin, YAN Tao, DU Linfei, LIU Ming
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Department of Equipment Maintenance and Remanufacturing Engineering, Academy of Army Armored Forces, Beijing 100072, China
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| Abstract: |
| Mo coatings were prepared on the surface of steel 45CrNiMoVA by supersonic plasma spraying. Microstructure and composition of the coatings were observed by scanning electron microscopy (SEM) and X-ray energy dispersive spectrometry (EDS). Electric contact model and arc formation in the current-carrying friction were analyzed. Effects of current intensity on coating roughness, surface temperature rise and friction and wear properties were studied by sliding friction tester. The results show that the Mo coating presents a dense microstructure and with low oxidation degree, and the bonding mode between the coating and the substrate is "mechanically riveted". As the current increases, the arc energy between the friction pairs increases sharply, and the arcing rate and surface roughness first decrease and then rise. The self-induced electromotive force generated by the shrinkage resistor and the microcapacitor promotes arc formation. The temperature rise of the friction pair surface is determined by the friction heat, the Joule heat, and the arc heat, and is positively correlated with the current intensity. The friction coefficient which is affected by surface roughness, material shear strength, surface film and other common factors decreases with the increase of the current. In addition, adhesion wear, oxidation wear, arc ablation and other wear mechanisms appear under the current condition, which aggravate spalling and abrasive wear of the coating. The formed friction film can effectively protect the coating and reduce the wear rate. |
| Key words: supersonic plasma spraying Mo coating current-carrier friction and wear arc |
