Grain Boundary Character Distribution and its Effect on Corrosion Resistance of Copper and Brass

Abstract

The grain boundary character distribution (GBCD) and its effect on the corrosion resistance of copper and brass (H65, H80) after solid solution and cold-rolled annealing were investigated by means of static weight loss method, scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and Electron back-scattered diffraction (EBSD).The possible mechanism of the effect of proportion of low ∑ coincidence site lattice (ΣCSL) on corrosion resistance were discussed preliminary. The results show that the proportion of low ΣCSL of the three kinds of samples after cold rolling and annealing all increase obviously compared with samples in solid solution. The proportions of low ΣCSL( such as Σ3,Σ9 and Σ27 ) of H65 brass,H80 brass and copper increase in turn in the same heat treatment conditions. In addition, it can increase the grain boundary ratio of low ΣCSL up to 67.9% by cold rolling of 6% and annealing at 650°C for 10min; The corrosion experiments show that corrosion resistances of samples after heat treatment are much better than that in solid solution. In the three samples, the corrosion resistance of copper is the best and that of H80 brass is better than that of H65 brass. Key words: copper; brass; GBCD; corrosion resistance