Papers by Keyword: Subgrain Structure

Abstract: The effect of ECAP technology on the subgrain structure of coarse-grained pure aluminium is described by means of the orientation imaging microscopy (the selected lower bounds of misorientation (disclination) are
= 2o, 5o, 10o and 15o). Standard profile and intercept counts carried out in three suitably oriented and mutually perpendicular section planes and along 18 systematically oriented directions, resp., are used to examine the subgrain and grain structures after the number of passes N = 2, 4, 8, 12 as well the effect of subsequent annealing (several hours at 473K). The local and overall non-homogeneity and anisotropy of boundary structures have also been evaluated.

Abstract: The development of physically-based models of microstructural evolution during hot deformation of metallic materials requires knowledge of the grain/subgrain structure and crystallographic texture characteristics over a range of processing conditions. A Fe-30wt%Ni based alloy, retaining a stable austenitic structure at room temperature, was used for modelling the development of austenite microstructure during hot deformation of conventional carbon-manganese steels. A series of plane strain compression tests was carried out at a temperature of 950 °C and strain rates of 10 s-1 and 0.1 s-1 to several strain levels. Evolution of the grain/subgrain structure and crystallographic texture was characterised in detail using quantitative light microscopy and highresolution electron backscatter diffraction. Crystallographic texture characteristics were determined separately for the observed deformed and recrystallised grains. The subgrain geometry and dimensions together with the misorientation vectors across sub-boundaries were quantified in detail across large sample areas and the orientation dependence of these characteristics was determined. Formation mechanisms of the recrystallised grains were established in relation to the deformation microstructure.