Influence of grain boundary modification on color transition behavior of Cu-Al-Zn-Sn alloys with low stacking fault energy

Abstract

In this study, we investigated the color transition mechanism of Cu-5Al-5Zn-1Sn (in wt%) alloy during cold-rolling and annealing processing by analyzing the correlation between microstructural characteristics and optical transition behavior. Single-phase Cu alloys have limited solubility which restrict on controlling their optical properties. Therefore, we propose a novel strategy for modulating the optical properties of single-phase Cu alloys. Cu alloys with low stacking fault energy (SFE) exhibit highly dense twin defects and dislocations when subjected to severe plastic deformation. In addition, annealed low SFE samples contain unique grain boundary structure, with different energies according to atomic structure and misorientation angle, which influences the density of states and electronic structure of the alloys. Consequently, the optical transition energy of the samples is affected by the grain boundary energy, which this influence to the chromaticity of the samples. These findings provide a new approach for adjusting the color of the alloys.