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2.
3.
One of the new physical methods that provides much information about the processes going on in a friction contact zone in real time is acoustic emission (AE). Basic experimental results of AE in friction are presented and analysed. Using AE signals we can get an indication about the state of the friction processes, about the quality of solid and liquid layers on the contacting surfaces in real time, sometimes about intensity of wear, changing of wear and friction regimes and so on. The influence of sliding velocity, load, roughness and some physical and mechanical properties of the body on the parameters of AE are also given. Some attention to the practical implementation of these techniques for control of capability for work of friction pairs in real conditions are given. Modern methods and devices enable condition monitoring of sliding and rolling bearings. 相似文献
4.
A lubrication-flow model for a free film in a corner is presented. The model, written in the hyperbolic coordinate system
ξ = x
2 −y
2, η = 2xy, applies to films that are thin in the η-direction. The lubrication approximation yields two coupled evolution equations
for the film thickness and the velocity field which, to lowest order, describes plug flow in the hyperbolic coordinates. A
free film in a corner evolving under surface tension and gravity is investigated. The rate of thinning of a free film is compared
to that of a film evolving over a solid substrate. Viscous shear and normal stresses are both captured in the model and are
computed for the entire flow domain. It is shown that normal stress dominates over shear stress in the far field, while shear
stress dominates close to the corner.
This revised version was published online in October 2005 with corrected page numbers. 相似文献
5.
The breakdown processes of oil films under quasi-static loading have been investigated by using a newly developed steel-oil-mercury system. The relationship between the thickness and breakdown ratio of a hexadecane film is represented by a single master curve independently of the indentation speed, indentation load, and temperature. The master curve shows that the breakdown process of hexadecane includes two stages; one is the decrement of the thickness without breakdown and the other is the decrement of the thickness with a drastic progress of breakdown. By solving a small amount of fatty acid in hexadecane, the thickness increases and the breakdown ratio decreases noticeably; a multilayer residual film supporting normal load is formed between two metal surfaces. Experiments at different temperatures reveal a negative relationship between the temperature and thickness of residual film, which indicates that the residual film is organized by physical interaction rather than chemical interaction. At least under a lower concentration, the residual film appears to consist of not only fatty acid molecules but also hexadecane molecules. 相似文献
6.
冷成型模具低温锌系磷化 总被引:4,自引:1,他引:3
研制出适用于冷成型模具高硬度表面的低温锌系磷化工艺。其中磷化液含Zn(H2 PO4 ) 2 ·2H2 O 6 0g/L ,Zn(NO3) 2 ·6H2 O 90g/L ,NaNO2 1.5g/L ,稀土促进剂 0~ 1.0g/L ,游离酸度 4~ 6点 ,总酸度 70~ 75点。该磷化液在 4 0℃下 ,处理 30~ 4 0min后可获得厚约 10 μm的磷化膜。性能测试表明 ,其减摩、润滑性能良好 ,摩擦系数约降 0 .1,与未处理试样相比磨损量下降 96 % ,附着力 1级。 相似文献
7.
高温润滑涂层设计的系统考虑 总被引:3,自引:0,他引:3
航天、航空、核能等尖端技术迫切要求使用耐高温润滑涂层,以保护金属构件的表面,增加发动机、推进器的工作效率和输出功率,80年代国际摩擦学界根据工业和国防的需要将高温润滑涂层和耐磨材料定为摩擦学学科发展的重要研究方向之一。本文对高温润滑涂层设计中遇到的典型环境、涉及到的关键问题、未来发展的途径等问题作了阐述。 相似文献
8.
10.
阐述了冶金设备齿轮减速器润滑问题的重要性,分析了齿轮润滑的主要状态和润滑对齿轮传动的影响,简述了冶金设备齿轮减速机的工作特点及对润滑油性能的要求和选用。 相似文献