Metal nanomaterials undergo changes in mechanical properties due to variations in grain size

With the rapid development of nanotechnology, an increasing number of metal nanomaterials are being applied in modern society. This paper primarily investigates the Hall-Petch relationship in metal crystals, which is a physical law describing the correlation between grain size and yield strength in metal nanomaterials. According to this relationship, the grain size influences the yield strength of the materials. At the nanoscale, this relationship may alter, exhibiting the inverse Hall-Petch effect, where further reducing the grain size paradoxically decreases the material’s yield strength. This paper also explores various mechanical properties of metal nanomaterials, including deformation and fracture mechanisms, and discusses their yield strength, plastic deformation, and fatigue performance. Additionally, the article analyses various strengthening mechanisms in metal nanocrystals, combining them with the Hall-Petch relationship to deepen the understanding of the impacts brought by changes in grain size. This provides new insights for optimizing material preparation techniques and improving mechanical properties through the control of microstructures.