The effect of low strain and annealing iterations on the ductility of alpha-brass

This paper reports a study of the relationship between purpose-designed, it erative multi-stage thermomechanical treatments, grain boundary crystallogr aphy and subsequent ductility in alpha-brass. Grain boundary crystallograph ies were analysed not only in terms of proportions of coincidence site latt ice (CSL) types but also, crucially, as proximity to the exact CSL referenc e structure. The only CSLs that were present in significant proportions wer e Sigma 3s, and those Sigma 3s with intermediate proximity to the exact CSL misorientation were identified as high mobility boundaries. Variation in m obility at a Sigma3 as a function of deviation from the exact CSL configura tion is discussed in detail. For two selected specimens modifying the strai n-annealing regimes resulted in ductilities of 53% and 74% respectively. Th e enhanced ductility in one specimen is probably the result of a combinatio n of strain-induced grain growth and increased proportions of Sigma 3s with intermediate proximity to the exact CSL misorientation.