The role of local strains from prior cold work on stress corrosion cracking of α-brass in Mattsson's solution

Multi-analytical approach for an archaeometric study on orichalcum coins

“…The selective dealloying can be justified with the trans-granular stress corrosion, frequently observed in alloys with content of Zn between 20% and 30% (Sieradzki et al, 1987). Indeed, is reported in literature that the local strain due to coldworking could lead the acceleration of the corrosion cracking by stress, deformation of grain boundaries and the trigger of corrosion (Ulaganathan & Newman, 2014). Evolving, the dezincification process in the external layer formed a sponge-type structure, also observed in brass with low content of Sn, such as standard sample representative of archaeological brass (Constantinides et al, 2002).…”

Observations of Corrosion Product Formation and Stress Corrosion Cracking on Brass Samples Exposed to Ammonia Environments

“…In the images of Sample 2 in Figure 8, cracks are shown extending from the hole where strings were used to suspend the samples in solution and from the impressed letter H. Image 2d in Figure 3, and 6c and 6d in Figure 6 show cracking on the tips of the samples and across the engraved letter edges. These were observed after the samples were immersed in Mattsson's solution and are a result of stress concentration at the stamped area and tip of the samples causing dislocation of grain boundaries and tension around the tip of the sample 16 . Also, the anodic reaction occurring at the edge of the sample causes dissolution of the metals.…”

“…The engraved letters on the samples created a compressive stress around the area engraved on the sample which caused inhomogeneous distribution of dislocation movement within the microstructure with a tendency to segregate at grain boundaries, thereby resulting in local strain gradients 16 . The shape (depth and sharpness) of the letter engraved on the samples determined the direction stress will propagate and raised the stress that led to SCC of brass.…”

Effect of cold rolling and annealing temperature to the characteristics of α + β' phases in Cu-29.5Zn-2.5Al alloy produced by gravity casting

“…In order to diminish the risk of cracking and stressinduced corrosion, thermal annealing is traditionally used to recover high residual stress density after cold deformation [10][11]. A good control of annealing temperature and its duration is strictly required to achieve the desired mechanical properties, especially for annealing of duplex brass which has phases with varying SFE values [7].…”