Friction and wear of metals are critically influenced by the microstructures of the bodies constituting the tribological contact. Understanding the microstructural evolution taking place over the lifetime of a tribological system therefore is crucial for strategically designing tribological systems with tailored friction and wear properties. Here, we focus on the single-crystalline High-Entropy Alloy CoCrFeMnNi that is prone to form twins at room temperature. Deformation twins feature a pronounced orientation dependence with a tension-compression anisotropy, a distinct strain release in an extended volume and robust onset stresses. This makes deformation twinning an ideal probe to experimentally investigate the complex stress fields occurring in a tribological contact. Our results unambiguously show a grain orientation dependence of twinning under tribological load. It is clearly shown, that twinning cannot be attributed to a single crystal direction parallel to a sample coordinate axes. With deformation twins in the microstructure, stress field models can be validated to make them useable for all different tribological systems.

金属的摩擦和磨损很大程度上受到构成摩擦接触体的微观结构的影响。因此，了解摩擦系统在整个生命周期内发生的微观结构演变对于战略性地设计具有定制摩擦和磨损特性的摩擦系统至关重要。在这里，我们重点关注在室温下容易形成孪晶的单晶高熵合金 CoCrFeMnNi。变形孪晶具有明显的方向依赖性、拉压各向异性、扩展体积中明显的应变释放以及强大的起始应力。这使得变形孪生成为实验研究摩擦接触中发生的复杂应力场的理想探针。我们的结果明确显示了摩擦载荷下孪晶的晶粒取向依赖性。清楚地表明，孪晶不能归因于平行于样品坐标轴的单晶方向。通过微观结构中的变形孪晶，可以验证应力场模型，使其可用于所有不同的摩擦学系统。