Role of layer thickness and grain size contrast in rolling contact fatigue of coarse/fine-grained layered materials: A crystal plasticity study
Xiaochong Lu, Xikai Yu, Zixu Guo, Xiaohua Zhang, Guglielmo Vastola, Daniele Dini, Yilun Xu, Yong‐Wei Zhang
Abstract
Heterogeneous layered materials combine high strength and ductility, offering improved damage tolerance under tribological loading. Among the key microstructural factors, layer thickness and grain size contrast have a critical influence on the mechanical behavior during rolling contact fatigue (RCF). A crystal plasticity finite element (CPFE) model was developed to simulate rolling contact responses in coarse-grained (CG)/fine-grained (FG) layered structures. The simulations reveal that layer thickness modulates strain localization, dislocation activity, and damage evolution in a sliding-orientation-dependent manner. FG layers serve as barriers to strain transmission and suppress damage propagation from adjacent CG layers. Furthermore, dislocation partitioning at CG/FG interfaces promotes strain delocalization and enhances RCF resistance. These findings provide mechanistic insights for optimizing layered microstructure design for advanced tribological applications.