Abstract Infrared microscopy is used to obtain through-thickness oil temperature measurements from EHL contacts between different surface materials (steel, silicon nitride and zirconia) for the lubricants Santotrac 50 and PAO4. The measurement technique was first adapted to overcome focussing issues due to the partially transparent zirconia surface. Results were used to infer in-contact rheological behaviour of the lubricants. Santotrac 50 shows significant shear localisation under all conditions with the position of the shear heating zone being highly affected by the contact surfaces' thermal properties. For PAO4, the shear profile depends on the contact surfaces’ thermal properties with moderate to high surface conductivities favouring uniform shearing, whereas highly insulating surfaces (zirconia) cause shear localisation at the surface for both lubricants. These results are used to interpret friction measurements and show how the thermal properties of surfaces can be used to control rheology and friction. This paper is prefaced by a review of thermal EHL theory upon which our analysis is based.

中文翻译：

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使用红外显微镜研究 EHL 流变学和摩擦中的热效应

摘要 红外显微镜用于从润滑油 Santotrac 50 和 PAO4 的不同表面材料（钢、氮化硅和氧化锆）之间的 EHL 接触中获得全厚度油温测量值。由于部分透明的氧化锆表面，该测量技术首先适用于克服聚焦问题。结果用于推断润滑剂的接触流变行为。Santotrac 50 在所有条件下都显示出显着的剪切局部化，剪切加热区的位置受接触面热性能的影响很大。对于 PAO4，剪切剖面取决于接触表面的热特性，具有中等至高的表面电导率，有利于均匀剪切，而高度绝缘的表面（氧化锆）会导致两种润滑剂在表面发生剪切局部化。这些结果用于解释摩擦测量，并展示如何使用表面的热特性来控制流变和摩擦。本文首先回顾了我们的分析所基于的热 EHL 理论。