The respective influences of grain size and texture on the formability of a 1050 aluminium alloy

In order to clarify the relative influences of texture and grain size on th e plastic response of a 1050 Al alloy, some tensile tests have been perform ed after various annealing treatments (designed to obtain different grain s izes) and initial and final textures have been measured. A micro-macro mode l has then been used in order to suppress the effect of texture from the ma croscopic stress-strain curves. As for the description of textures, it has been shown that most of the obtained textures after annealing can be descri bed as a mixture of rolling and recrystallisation textures (containing main ly the so-called Cube, Brass and Goss orientations) and that there is no cl ear correlation between texture intensity and grain size; after deformation , the Brass component is reinforced at the expense, of the Goss orientation , whereas the evolution of the Cube component depends on the initial scatte r around the various components. Concerning the tensile curves, it is obser ved first that the Hall-Fetch relationship is not always verified (the smal ler the grain size, the higher the yield stress) when the conventional stre ss/strain curves are examined, When the effect of texture is suppressed fro m these curves and 'microstructural' stress/strain curves are plotted, the Hall-Fetch relationship becomes verified and the curve crossing phenomenon, sometimes observed, disappears. It can thus be concluded that the grain si ze is the only microstructural feature affecting the yield stress and that the hardening evolution is more or less independent of the texture evolutio n, (C) 1998 Elsevier Science Ltd. All rights reserved.