The area of contact between stationary and between moving surfaces
The area of contact between stationary and between moving surfaces
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DOI：
10.1098/rspa.1939.0005
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发表时间：
1939-02-01
影响因子：
--
通讯作者：
Tabor, D
中科院分区：
文献类型：
--
作者：
Bowden, FP;Tabor, D
当两个平面放在一起时，紧密接触的面积必须比表观面积小得多。即使表面被非常仔细地抛光并尽可能平坦，山丘和山谷仍然会出现在表面上。上表面将支撑在这些不规则结构上，并且大区域将被与分子的尺寸相比更大的距离分开。我们对这些不规则的大小和表面的平整度知之甚少。光学方法不能揭示远小于半个光波长的不规则性。质子的散射（Knauer和Stern，1929）或电子的衍射（Thomson，1934; Finch，Quarrell和Wilman，1935）可以给出小部分表面结构的信息，但这些方法不能揭示孤立峰的存在，也不能显示大面积表面的平坦程度。由于即使用最精细的技术也很难制备出在1 ~ 2 000埃范围内平整的表面，我们可以预期，对于大多数表面来说，紧密接触的面积，即表面在分子引力范围内的面积，将非常小。对真实的接触面积的一些了解对于完全理解摩擦机制是必不可少的，本文描述了一种估计静止和运动表面接触面积的方法。
When two plane surfaces are placed together the area of intimate contact must be very much less than the apparent area. Even if the surfaces are very carefully polished and are made as flat as possible, hills and valleys will still be present on the surface. The upper surface will be supported on these irregularities, and large areas will be separated by a distance which is great compared with the dimensions of a molecule. We do not know very much about the size of these irregularities nor the degree of flatness of the surfaces. Optical methods cannot reveal irregularities much smaller than half a wave-length of light. The scattering of protons (Knauer and Stern 1929) or the diffraction of electrons (Thomson 1934; Finch, Quarrell and Wilman 1935) can give information about the structure of a small portion of the surface, but these methods would not reveal the presence of isolated peaks nor show how flat are the surfaces over a large area. Since it is difficult, even with the most refined technique, to prepare surfaces which are flat to within one or two thousand angstroms, we may expect that the area of intimate contact, that is, the area over which the surfaces are within the range of the molecular attraction, will, for most surfaces, be very small. Some knowledge of the real area of contact is essential for any complete understanding of the mechanism of friction, and this paper describes an attem pt to estimate this area for both stationary and for moving surfaces.