Experimental Evaluation of Specimen Size Effect on the Bending Deformation of Polycrystalline Copper

Abstract

With an increase in the relative grain size to the macrostructure, the collective behavior of the crystal grains will affect the macroscopic deformation field. Experimental quantification and theoretical modeling of the development of such a micro- to macroscopic non-uniform deformation are important to optimize the manufacturing process of the miniaturized metal parts in various small-sized devices. To investigate the relative size effect on the mechanical behavior of the polycrystalline material, the interaction between the microstructure-induced non-uniform deformation and the macroscopic boundary condition-induced non-uniform deformation of polycrystalline copper was evaluated. The development of the strain distribution was measured by the digital image correlation (DIC) method. A non-uniform deformation depending on the macroscopic boundary condition was observed in the specimen with smaller grains, whereas the microscopic non-uniform deformation affected the macroscopic non-uniform deformation in the specimen with larger grains.