Microstructural and mechanical evolution of alpha-brass sheets during accumulative roll bondingThursday (29.09.2016) 15:00 - 15:15 Part of:
Accumulative Roll Bonding (ARB) is an interesting method to produce metal/metal compound sheet materials. For many material combinations the thickness of the individual metal sheets has to differ significantly. In this study we investigate the deformation behavior of two different α-brass alloys (CuZn15 and CuZn37) during ARB. Moreover, we study the subsequent formation of symmetric compound sheets formed from these two alloys. Longitudinal sections (RD-ND plane) of the metal sheets were investigated both by optical microscopy and scanning electron microscopy to estimate the homogeneity of grain refinement during different numbers of ARB cycles. Tensile testing was performed on samples oriented parallel to the rolling direction in order to evaluate the associated changes in mechanical properties resulting from grain refinement and work hardening.
The homogenous CuZn37 sheets suffer from massive deformation localization and exhibit shear bands that pass through the entire cross section of the sample already at low numbers of ARB cycles. In contrast, the brass/brass compounds are characterized by a nearly ideally layered microstructure with only slight necking of both layer types even at the final stages of ARB. The influence of these different types of deformation on the macroscopic mechanical properties of the produced metal sheets are discussed in detail.