Fibre-reinforced thermosets and thermoplastics containing PTFE are commonly used in marine and hydropower applications due to their self-lubricating ability in both dry and water lubricated contacts. The constant development of such composite bearings over the last decades make them even more attractive in these fields of application, due to their low maintenance cost and long service life. Their tribological performance is usually estimated by extrapolation of short, accelerated tests, which may induce risks of inaccurate or even incorrect interpretation.

In this work, reciprocating dry sliding behaviour of these materials against stainless steel is investigated under typical hydropower conditions. The aim is to study the wear and friction behaviour and the development of transfer layers during long sliding tests, corresponding to years of operation. In order to mimic operational shutdowns, the tests are stopped every 20 h and the counter surfaces are examined using 3D optical interferometry and SEM to study development of surface topography and transfer layers.

Test results show that the wear rates of both materials decrease significantly with time. For the thermoplastic, COF decreases with time due to accelerated material transfer observed after 80 h. In contrast, much less material transfer is observed for the fibre-reinforced thermoset, which shows its highest transfer amount after 20 h. Surface analysis indicates severe abrasive wear of the counter surface caused by the wear debris from steel and reinforcements in the material and is accompanied by simultaneous COF increase for the thermoset. Cross-sectional analysis reveals thinner transfer layers and higher wear of the steel in the middle of the wear tracks, where the sliding speed and number of load cycles are highest. These findings contribute to a more accurate interpretation of results obtained than that of short time tests regarding the tribological performance of these materials. As a direct conclusion, the selection of counter surface material can be crucial.

含有 PTFE 的纤维增强热固性塑料和热塑性塑料因其在干润滑和水润滑接触中的自润滑能力而常用于船舶和水电应用。由于其低维护成本和长使用寿命，这种复合轴承在过去几十年中的不断发展使其在这些应用领域更具吸引力。它们的摩擦学性能通常通过简短的加速测试外推来估计，这可能会导致不准确甚至错误解释的风险。

在这项工作中，研究了这些材料在典型水电条件下对不锈钢的往复干滑动行为。目的是研究磨损和摩擦行为以及长时间滑动测试期间转移层的发展，对应于多年的操作。为了模拟操作停机，测试每 20 小时停止一次，并使用 3D 光学干涉仪和 SEM 检查反面，以研究表面形貌和转移层的发展。

测试结果表明，两种材料的磨损率均随时间显着降低。对于热塑性塑料，由于 80 小时后观察到的材料转移加速，因此 COF 会随时间降低。相比之下，纤维增强热固性材料的材料转移要少得多，在 20 小时后表现出最高的转移量。表面分析表明，由钢材和材料中的增强材料产生的磨损碎屑引起的反面严重磨损，同时伴随着热固性材料的 COF 增加。横截面分析显示，在滑动速度和负载循环次数最高的磨损轨迹中间，钢的传递层更薄，磨损程度更高。这些发现有助于更准确地解释所获得的结果，而不是关于这些材料的摩擦学性能的短时间测试。作为一个直接的结论，反面材料的选择至关重要。