Rolling and Annealing of Fine Grained 70:30 Brass

Abstract

The rolling textures and microstructures developed in fine grained (2–5 μ m diam.) 70:30 brass are different to those found in coarser grained material. The {111}〈 u v w 〉 γ fibre usually found at medium reductions is not developed but the normal {110}〈112〉 texture still emerges at higher reductions. The microstructures are related to these changes. Although twinning is a deformation mode at low reductions the volume of twins is never large and the twin alignment characteristic of normal brass at ∼70% reduction does not occur. The pattern of shear band development is changed and large areas of the microstructure are featureless at high reductions. Hardness values show an unexpected rise between 60 and 90% reduction and this is attributed to a Stage IV regime of strain hardening. After annealing at 300 and 900℃ the textures are typical of those found in coarser grained material.