Sizes effect on the tensile behaviors of H65-IF-H65 laminated metal composites

The H65 brass alloy-interstitial free steel-H65 brass alloy (H65-IF-H65) laminated metal composites (LMCs) of 0.12 mm thickness and 1-9 mm gauge widths were prepared by rolling combined with annealing. The electron back scatter diffraction (EBSD), digital image correlation (DIC) technology, conventional tensile testing, in-situ tensile testing and SEM were used to analysis the effect of specimen width on the mechanical behavior of the H65-IF-H65 LMC. The results show that the H65-IF interface is mechanical bonded without elements diffusion during the annealing process. As the gauge width gradually reduced from 9 mm to 1 mm, the tensile strength and yield strength remain basically unchanged, meanwhile the total, the uniform, and the non-uniform elongations decrease from 30.3%, 23.4% and 6.9% to 20.3%, 18.8% and 1.5%, respectively. The work hardening ability also decreases rapidly. Moreover, the strain of the H65-IF-H65 LMCs is gradually concentrated. On the tensile fracture, the width of the dimple band and the number and size of dimples within it also decrease significantly, which indicates a significant size effect. The main reason of sample sizes effect on the tensile behaviors of H65-IF-H65 LMCs is that the interaction of shear stress is inhibited with the decrease of the gauge width. The cracks are more likely to spread rapidly in the single shear band and result in a decreased ductility.