This work explores experimentally the effects of DC electrical currents on lubricant film thickness alteration in lubricated sliding steel contacts in the boundary and mixed regime as measured by ultrasound. The experiments were performed in a two-electrode cell-based pin-on-disk tester instrumented with ultrasonic transducers. Unelectrified and electrified tribological tests were conducted on steel flat-on-flat contacts under various speeds and loads using both a mineral base oil and a gear oil. Film thickness, coefficient of friction (CoF), and electrical contact resistance (ECR) were measured during short experiments (30 s) in unelectrified and electrified (1.5 and 3 A) conditions. The results suggest that film thickness, CoF, and all ECR are altered by passing DC currents through the contact. In particular, film thickness increased and decreased, respectively, by applying electricity at the different speeds and loads tested. These alterations were majorly ascribed to oil viscosity decrease by local heat and surface oxidation caused by electrical discharge and break down at the interface.

这项工作通过实验探讨了超声波测量的直流电流对边界和混合状态下润滑滑动钢触点润滑膜厚度变化的影响。实验是在配备超声波换能器的基于两电极电池的钉盘测试仪中进行的。使用矿物基础油和齿轮油在不同速度和负载下对钢平对平接触进行非带电和带电摩擦学测试。在不通电和通电（1.5 和 3 A）条件下的短时间实验（30 秒）中测量了薄膜厚度、摩擦系数 (CoF) 和接触电阻 (ECR)。结果表明，通过接触点传递直流电流会改变薄膜厚度、CoF 和所有 ECR。特别是，通过以不同的测试速度和负载通电，薄膜厚度分别增加和减少。这些变化主要归因于局部热量引起的油粘度降低以及放电引起的表面氧化和界面处的分解。