Atomic insights into the deformation mechanism of an amorphous wrapped nanolamellar heterostructure and its effect on self-lubrication

The evolution of pearlite into an amorphous wrapped nanolamellar heterostructure (AWNH) within the tribolayer is an important process for the formation and stabilization of a nanocomposite self-lubricating surface. Here, experimental characterizations were performed to show that an AWNH was an intermediate product of transformation of pearlite to oxide nanoparticles and played a supporting role as a self-lubricating layer of the substrate. Furthermore, the molecular dynamics simulation method was used to analyze the wear properties and load-bearing capacities of four different microstructures to reveal the unique AWNH deformation mechanism and its effect on the self-lubrication behavior. The results showed that the AWNH exhibited a low friction and good wear resistance, which could be ascribed to its high hardness, high plasticity, and outstanding interface deformation coordination ability. The shear bands were restricted by the nanolamellar structure, and the shear transition zone that formed at the interfaces caused the plastic deformation to be uniformly distributed, which provided favorable conditions for supporting the self-lubricating layer. The results of this study provide theoretical guidance for analyzing the deformation mechanisms and tribological behaviors of AWNHs and help to optimize self-lubricating material design.