Dislocation-grain boundary interactions: recent advances on the underlying mechanisms studied via nanoindentation testing

To comprehend the mechanical behavior of a polycrystalline material, an in-depth analysis of individual grain boundary (GB) and dislocation interactions is of prime importance. In the past decade, nanoindentation emerged as a powerful tool to study the local mechanical response in the vicinity of the GB. The improved instrumentation and test protocols allow to capture various GB-dislocation interactions during the nanoindentation in the form of strain bursts on the load-displacement curve. Moreover, the interaction of the plastic zone with the GB provides important insight into the dislocation transmission effects of distinct grain boundaries. Of great importance for the analysis and interpretation of the observed effects are microstructural investigations and computational approaches. This review paper focused on recent advances in the dislocation-GB interactions and underlying mechanisms studied via nanoindentation, which includes GB pop-in phenomenon, localized grain movement under ambient conditions, and an analysis of the slip transfer mechanism using theoretical treatments and simulations.

Automated summary

In order to understand the mechanical behavior of polycrystalline materials, a detailed analysis of the interactions between individual grain boundaries and dislocations is essential. Nanoindentation has emerged as a powerful tool for studying the local mechanical response near the grain boundaries. The improved instrumentation and testing protocols have enabled the capture of various grain boundary-dislocation interactions during nanoindentation in the form of strain bursts. This review focuses on recent advancements in studying dislocation-grain boundary interactions and the underlying mechanisms via nanoindentation.