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A study of recrystallisation texture evolution was performed in an ageable Al-Mg-Si alloy to assess the sheet formability of autobody sheet before age hardening, by using quantitative orientation distribution function (ODF) determination during presolutionising anneal treatments. It was found that preannealing of cold rolled sheet near 250uC results in the largest amount of cube texture upon subsequent solutionising at 560uC. The apparent activation enthalpy is near 2?5 eV if the iron solute content is below 0?5 ppm atomic. The formation of cube oriented grains occurs below 300uC and grain growth above this temperature appears to be inhibited by iron solute drag of the grain boundaries. It was discovered that the volume fraction ratio of the cube and {02 1} ,100. is correlated to the average R value.

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Recent use of nano-indentation to assess work-hardening of complex microstructure of dual phase steels as a function of deformation together with crystal plasticity finite element method to simulate the bulk properties gives rise to the question of the role of crystallite orientation during indentation. Such studies using nano-indentation on µm-sized grains are difficult. To elucidate this effect, Vickers microindentation of cube textured Al capacitor foils were examined. These foils of 106 µm thickness are convenient for small angle X-ray scattering (SAXS) examination and the orientation around the indent can be examined by back-scattered electron diffraction (EBSD). The indentations were carried out with the diagonals parallel to the rolling direction (RD) and 45 ° to it at temperatures from 20 °C (295 K) to 160°C (433 K). The SAXS tests were performed only at 20°C on RD specimens.Keywords: Aluminum, micro-hardness, SAXS, stacking fault tetrahedral, dislocation intersections IntroductionIndentation testing using Vickers hardness with diamond pyramid head has been the standby materials characterization of mechanical properties. Since the discovery of age-hardenable alloys, the great progress is due to the advent of hardness testing to monitor ageing as function of time and annealing temperatures and has become the standard procedure to perform such tests to delineate the optimum hardness for alloy development. As the microstructure of the alloy becomes more complex with multiple hardening precipitates, the indenter size have decreased to micro-and nano-meter scales. Detailed characterization of texture and stored work in damaged volumes using conical indenter have been performed to determine if a simple correlation between hardness and geometric-necessary-dislocation (GND) density exist [1]. The application of such computational analyses was recently illustrated for dual-phase steels [2] in which nano-indentation result was used to correlate to the bulk stress-strain response. However application of such methods to face-centred cubic (fcc) structures may require more statistical testing to assess the crystal orientation dependence of the hardness response. Hardness has been attributed to two main factors; the yield strength due to the size, density and distribution of the embedded nano-particles and the gradients in GND densities around the indent interface. Brown [3] has simulated indentation using Vickers diamond indenter and has developed a circular flow model to predict lattice rotation which could rise as high as 12 °. Such rotations has been observed in Berkovichtip indented matrix of cube oriented copper crystal using Kikuchi line analysis of electron diffraction (TEM) images (14 °) [4] and in conical indented (111) surface of copper crystal (15 °) using EBSD [1]. Although the analytical means for modelling micro-and nano-plastic flow seems to be at hand [2], for aluminum (Al) alloys dynamic recovery can occur during indentation at room temperatures.During the recent work of assessing double Brag...

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