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首页> 外文会议>Society of Tribologists and Lubrication Engineers annual meeting amp; exhibition 2009 >Thermodynamics, a bridge links chemistry and mechanics in surface frictional contact, and its application for blank preparation in coining industry
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Thermodynamics, a bridge links chemistry and mechanics in surface frictional contact, and its application for blank preparation in coining industry

机译：热力学，在表面摩擦接触中联系化学和力学的桥梁，及其在压模行业中毛坯制备中的应用

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As tribologists some times we had difficulties to explain a simple tribologic phenomenon well. In some cases, a tribologic theory conflicts with basic mechanisms in other fields, because in all of our studies, we ignored a very important physical parameter, entropy. Here are the examples.rnWhen we conducted a very simple dry pin on disk sliding wear test with steel samples, after a few rotations at low speed, we could found a layer of oxide debris on the wear track. We could not explain why so many reaction products were formed. According to Arrhennius equation, the predicted reaction products between oxygen and steel are much less than the oxide debris on the wear track. Without other way, we explained this phenomenon as: the material was activated by the sliding contact stress.rnWhen we ran a ball on three flats wear test with the 52100 steel, we could see many wear grooves and ridges on the worn disk surface. Then, we explained the phenomena as abrasive wear, and assumed that these wear grooves were formed by the hard particles plowing. However, when we examined the ball, we could also found the similar grooves and ridges that were matched with the ridges and grooves on the disks. The conformity of these ridges and grooves may be as high as 80% of the contact area.rnIn industry application, we often added different additives in base oils. For example, to reduce the coefficient of friction, we added oleic acid. To reduce wear rate, we added ZDDP. When compared the test results, we found that the low friction of oleic acid caused a high wear rate, but a higher friction of ZDDP reduced the wear rate. These results conflict with our normal tribologic principles: higher friction causes higher wear.rnDuring ceramic grinding, we used a diamond to grind a relative softer material such as silicon nitride. The diamond tips were worn to flat in a very fast manner. Diamond is the hardest material in the world, how does it was worn by a material of which the hardness is much less than diamond?rnFor an EHD oil film thickness optical interferometry measurement, we used a ball against a rotating glass disk. On the contact surface of the glass, there was a thin metal semi reflective film, such as Cr. When the thickness of the EHD film was thick, the theoretical predictions matched the measured values. However, when the thickness reduced to the nano-level, the thickness was different to the predicted values.
机译：作为摩擦学家，有时我们很难很好地解释一个简单的摩擦学现象。在某些情况下，摩擦学理论与其他领域的基本机制相冲突，因为在我们的所有研究中，我们都忽略了非常重要的物理参数熵。下面是示例。当我们对钢样品进行磁盘上的非常简单的干销滑动试验时，在低速旋转几圈后，我们会在磨损轨道上发现一层氧化物碎片。我们无法解释为什么会形成这么多反应产物。根据Arrhennius方程，氧气和钢之间的预测反应产物比磨损轨迹上的氧化物碎片少得多。不用其他方法，我们将这种现象解释为：材料是由滑动接触应力激活的。当我们在52100钢的三个平面上对球进行磨损测试时，在磨损的磁盘表面上会看到许多磨损槽和脊。然后，我们将这种现象解释为磨料磨损，并假设这些磨损槽是由硬质颗粒的耕作形成的。但是，当我们检查球时，我们还可以发现与圆盘上的凸脊和凹槽相匹配的相似的凸脊和凹槽。这些隆起和凹槽的一致性可能高达接触面积的80％。在工业应用中，我们经常在基础油中添加不同的添加剂。例如，为了降低摩擦系数，我们添加了油酸。为了降低磨损率，我们添加了ZDDP。当比较测试结果时，我们发现油酸的低摩擦导致较高的磨损率，而ZDDP的较高摩擦则降低了磨损率。这些结果与我们通常的摩擦学原理相冲突：更高的摩擦力会导致更高的磨损。在陶瓷研磨过程中，我们使用金刚石来研磨相对较软的材料，例如氮化硅。钻石尖端以非常快速的方式被磨平。金刚石是世界上最坚硬的材料，硬度比金刚石低得多的材料会如何磨损金刚石？对于EHD油膜厚度光学干涉测量，我们将球放在旋转的玻璃盘上。在玻璃的接触表面上，有薄金属半反射膜，例如Cr。当EHD膜的厚度较厚时，理论预测与测量值相符。但是，当厚度减小到纳米水平时，厚度与预测值不同。

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