Correlation between Scratching and Macroscopic Sliding Properties of Polymer/Metal-Pairs based on Mechanism Analysis

聚合物和金属之间滑动接触的摩擦和磨损主要取决于金属配对体的粗糙度。粗糙度与聚合物表面的相互作用有助于摩擦，并导致犁削、材料转化和转移膜形成。在单微凸体划痕实验中研究了其基本机制。我们的项目探讨了微观划痕实验揭示的机制和宏观摩擦学标准测试结果之间的联系。在该项目的第一阶段，我们通过多道划痕，使用由宏观测试的钢对体制作的单个微凸体，建立了不同长度和速度尺度之间的定量联系。将微观现象和宏观测试联系起来的进一步成功策略包括新颖的高分辨率平钉实验和整个玻璃化转变温度的测量。在项目的延续中，我们建议在三个关键方面扩展该方法。我们将揭示聚合物材料中的内部摩擦，即热机械本体性质，对摩擦和磨损的影响。我们将阐明不同的聚合物在单一的粗糙水平的转移膜的润滑功能的转移膜的粗糙和光滑的区域的钢表面的相关机制。最后，我们将讨论摩擦能量输入和温度一般与磨损的聚合物表面的粘弹性和由此产生的磨损性能。我们的项目建立在萨尔布吕肯的INM -莱布尼茨新材料研究所纳米摩擦学小组和凯撒大帝大学复合材料工程主席的互补专业知识的基础上。该项目的成功不仅将有助于理解聚合物-钢摩擦学中的关键机制，从而合理设计新的聚合物摩擦材料，而且还将建立可应用于这些系统之外的多尺度摩擦学的新方法。

Friction and wear of sliding contacts between polymers and metals depend critically on the roughness of the metal counterbody. The interaction of roughness asperities with the polymer surface contributes to friction and leads to ploughing, material transformation, and transfer film formation. The underlying mechanisms are investigated in single-asperity scratching experiments. Our project explores the connection between the mechanisms revealed by microscopic scratching experiments and the results of macroscopic standard tests in tribology. In the first phase of the project, we have established quantitative links between the different length and velocity scales by means of multi-pass scratching, using single micro-asperities crafted from the steel counter body of macroscopic tests. Further successful strategies for linking microscopic phenomena and macroscopic tests included novel high-resolution pin-on-flat experiments and measurements across the glass transition temperature. In the continuation of the project, we propose to extend the approach with three key aspects. We will reveal the influence of internal friction in the polymeric materials, i.e. of the thermo-mechanical bulk properties, on friction and wear. We will clarify the transfer film mechanisms of different polymers at the single asperity level in correlation to the lubricating function of transfer films on rough and smooth areas of the steel surface. Finally, we will address the frictional energy input and temperature in general in relation to the viscoelasticity of worn polymer surfaces and the resulting wear performance. Our project builds on the complementary expertise in the Nanotribology Group of the INM - Leibniz Institute for New Materials, Saarbrücken, and the Chair of Composite Engineering at the University of Kaiserslautern. The successful project will not only contribute to the understanding of key mechanisms in polymer-steel tribology and thus to a rational design of new polymeric tribomaterials, but also establish novel methods in multi-scale tribology which can be applied beyond these systems.