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表面粗糙度对微动摩擦特性的影响 总被引:4,自引:0,他引:4
通过实验研究,探讨了表面粗糙度对微动摩擦特性影响的作用。表面粗糙高时接触表面之间的摩擦系数会有明显增加,在微动状态下表面粗糙度对表面磨损影响不大。 相似文献
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表面轮廓仪传递函数对超光滑表面粗糙度测量的影响 总被引:4,自引:0,他引:4
表面粗糙度是表征光学元件表面质量的一个重要指标,这使得人们不断致力于改进表面粗糙度的测量技术,以提高其测量精度.然而很多实验表明,在对超光滑表面粗糙度进行测量时,对于同一个表面,不同类型的表面轮廓仪通常会给出不同的结果,这使得测量结果之间的可比性成为问题.针对这种情况,本文运用线性系统理论方法,分析了表面轮廓仪的带宽对表面粗糙度测量的影响,并用离散傅里叶变换方法计算了表面粗糙度测量值随表面轮廓仪带宽的变化.结果表明,表面轮廓仪的带宽对表面粗糙度测量有着重要影响,轮廓仪的带宽越宽,则给出的测量值越大,也越接近真实值.因此对两种不同类型的轮廓仪测得的结果一般不能直接进行比较,除非两者具有相同的带宽. 相似文献
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超疏水表面具有减阻效果,在提高管道传输效率、降低水下航行体和微流体器件中流动阻力等方面有着广阔的应用前景。介绍超疏水表面的制备、滑移理论以及减阻特性的研究,讨论微尺度下表面润湿性、表面微结构和流场流动状态对壁面减阻的影响,对超疏水壁面减阻的物理机制进行总结,并指出气体层不连续模型和气穴模型是分别适用于光滑疏水表面和带微结构超疏水表面的减阻模型。介绍超疏水表面减阻特性的一些应用,提出将超疏水表面应用到微流体系统中面临的问题,如微通道壁面疏水性的制备及其减阻效果的耐久性。 相似文献
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基于磨粒表面信息的磨损表面特征评估 总被引:2,自引:0,他引:2
建立了基于磨粒表面信息的磨损表面评估方法。首先选择合理的磨粒和磨损表面特征参数,通过识别磨粒类型,获得磨损过程中具有典型性和代表性的磨粒类型,然后选取这些具有代表性的磨粒类型,得到磨粒的表面特征向量,进而来研究磨损表面和磨粒表面的映射关系,实现基于磨粒表面信息的磨损表面特征评估。实例表明,根据磨粒表面特征评估磨损表面特征是可行的。 相似文献
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介绍工程陶瓷超精加工降低加工表面粗糙度的原理及超精加工工艺参数对已加工表面粗糙度的影响 相似文献
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自由曲面的透视纹理映射研究 总被引:2,自引:0,他引:2
从纹理映射的基本方法出发,分析传统多边形纹理映射存在的不足,提出了自由曲面的透视变换纹理映射.首先介绍透视变换和透视纹理映射原理,并简要分析其在自由曲面纹理映射中的应用.由于多边形纹理映射的精度问题及自由曲面表达的多样性,因此在自由曲面纹理映射中,选择双三次 Bezier面片逼近自由曲面.然后详细介绍了透视纹理映射的算法步骤:先得到纹理空间参数与对象空间坐标之间的对应关系,通过计算对象空间坐标与屏幕空间之间关系,确定纹理空间与屏幕空间的对应关系.最后提出了纹理走样的处理方法.该方法不仅可以应用于自由曲面纹理映射,还可有效地应用到多面体、自由形体表面的纹理映射. 相似文献
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Influence of the artificial saliva storage on 3‐D surface texture characteristics of contemporary dental nanocomposites 下载免费PDF全文
ŞTEFAN ŢĂLU MIROSLAW BRAMOWICZ SLAWOMIR KULESZA TIJANA LAINOVIĆ MARKO VILOTIĆ LARISA BLAŽIĆ 《Journal of microscopy》2016,264(2):198-206
The aim of this study was to analyse the influence of the artificial saliva on a three‐dimensional (3‐D) surface texture of contemporary dental composites. The representatives of four composites types were tested: nanofilled (Filtek Ultimate Body, FUB), nanohybrid (Filtek Z550, FZ550), microfilled (Gradia Direct, GD) and microhybrid (Filtek Z250, FZ250). The specimens were polymerised and polished by the multistep protocol (SuperSnap, Shofu). Their surface was examined, before and after 3 weeks’ exposure to artificial saliva storage. The surface texture was analysed using the atomic force microscope (AFM). The obtained images were processed to calculate the areal autocorrelation function (AACF), anisotropy ratio Str (texture aspect ratio), and structure function (SF). The log–log plots of SF were used to calculate fractal properties, such as fractal dimension D, and pseudo‐topothesy K. The analysis showed changes in surface anisotropy ratio Str values, which became higher, whereas the Sq roughness (root‐mean‐square) reduced after the artificial saliva storage. All the samples exhibited bifractal structure before the saliva treatment, but only half of them remained bifractal afterwards (GD, FZ250), whereas the other half turned into a monofractal (FUB, FZ550). The cube‐count fractal dimension Dcc was found to be material‐ and treatment‐insensitive. 相似文献
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The friction and wear behaviour of boundary lubricated sliding surfaces is influenced by the surface texture. By introducing controlled depressions and undulations in an otherwise flat surface, the tribological properties can be improved. Lubricant can then be supplied even inside the contact by the small reservoirs, resulting in a reduced friction and a prolonged lifetime of the tribological contact.In the present paper, well-defined surface textures were produced by lithography and anisotropic etching of silicon wafers. The wafers were subsequently PVD coated with thin wear resistant TiN or DLC coatings, retaining the substrate texture. The size and shape of the depressions were varied and evaluated in reciprocating sliding under dry and boundary lubricated conditions. 相似文献
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纹理触觉再现技术的研究现状及发展 总被引:1,自引:0,他引:1
物体一个非常重要的触觉特征是它具有表面纹理信息,人们可以通过触摸物体获得这种感觉.在虚拟现实或遥操作领域,将虚拟的或远地的物体的纹理信息再现并作用于操作者手部,不仅可以增强系统的临场感,而且可以帮助操作者识别不同特性的虚拟物体.触觉再现技术近几年已成为虚拟现实和遥操作领域研究的前沿技术,文中介绍了当今世界上仅有的几种可以再现纹理触觉的方法,并比较他们各自的优缺点.最后,指出纹理触觉再现技术的发展思路. 相似文献
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Studies on friction and transfer layer: role of surface texture 总被引:2,自引:0,他引:2
Friction influences the nature of transfer layer formed at the interface between tool and metal during sliding. In the present investigation, experiments were conducted using “Inclined Scratch Tester” to understand the effect of surface texture of hard surfaces on coefficient of friction and transfer layer formation. EN8 steel flats were ground to attain surfaces of different textures with different roughness. Then super purity aluminium pins were scratched against the prepared steel flats. Scanning electron micrographs of the contact surfaces of pins and flats were used to reveal the morphology of transfer layer. It was observed that the coefficient of friction and the formation of transfer layer depend primarily on the texture of hard surfaces, but independent of surface roughness of hard surfaces. It was observed that on surfaces that promote plane strain conditions near the surface, the transfer of material takes place due to the plowing action of the asperities. But, on a surface that promotes plane stress conditions the transfer layer was more due to the adhesion component of friction. It was observed that the adhesion component increases for surfaces that have random texture but was constant for the other surfaces. 相似文献
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工件表面纹理间距提取的一种新方法 总被引:1,自引:0,他引:1
表面质量是机械产品的一个重要指标,如何准确高效地提取衡量工件表面质量的评定参数是当前一个重要的研究方向。研究了一种基于快速傅里叶变换(FFT)方法从工件表面图像提取纹理间距参数,该方法具有精度高,方法简单等优点。 相似文献
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Jeong-du Kim Dal-ho Lee Keun-bum Lee 《The International Journal of Advanced Manufacturing Technology》2005,27(3-4):274-280
In order to make clear the effects of mirror grinding conditions on the ground surfaces in the surface mirror grinding of
sintered carbide adopting an in-process electrolytic dressing method, experiments are conducted to measure the vibration signals
of the workpiece during grinding and the profile of the ground surface. It is found that components with low frequency vibration
signals have a very close relation to the undulation of a ground surface and components with high frequencies to the surface
roughness . 相似文献
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The effect of partial texture surface on flow field of journal bearing is investigated experimentally using a visualization apparatus, which was less reported before. The visualization results show that there is a speeding‐up phenomenon in the movement of lubricant when lubricant flows from smooth surface region to dimple surface region, and the rising ratio of lubricant speed increases with the rotational speed of journal shaft. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献