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M: Metallphysik

M 27: Mechanische Eigenschaften IV

M 27.2: Vortrag

Donnerstag, 11. März 2004, 12:00–12:15, H4

Microstructure and Texture Development during Recrystallization of Rolled Molybdenum Sheets — •Carl-Georg Oertel¹, Ingwar Hünsche¹, Werner Skrotzki¹, and Wolfram Knabl² — ¹Dresden University of Technology, Institute of Structural Physics, D-01062 Dresden, Germany — ²PLANSEE Aktiengesellschaft, Technologiezentrum, A-6600 Reutte/Tyrol, Austria

Recrystallization is an important tool to adjust the grain size and texture of polycrystalline materials in order to optimise their properties. In the present work the recrystallization kinetics and the development of texture has been studied on rolled molybdenum sheets as a function of temperature and time. The microstructure was investigated by orientation contrast in a scanning electron microscope. The kinetics of recrystallization displayed in a JMAK plot yields Avrami coefficients decreasing with temperature from 2.5 to 1.1. The activation energy amounts to 4.4 eV, which agrees well with the coefficient of self-diffusion. The textures of the sheet surface and centre layer were measured by X-ray diffraction. The rolling texture in the centre of the sheets is characterised by a strong α -fibre with the rotating cube component {100}<110> dominating. Besides that, there exists a weak γ -fibre. In contrast, the surface layer is characterised by a weak cube component. During recrystallization changes in texture are insignificant. With long annealing times all texture components tend to degrade. The investigations are intended to control the structure parameters in the rolling process in order to optimise the deep-drawing properties of molybdenum sheets.