Characterization of Precipitates in Aluminium Alloy 6013 after Cold-Rolling and Annealing

Abstract

The aim of the present work was to observe changes in precipitations during annealing after cold-rolling. Series of the samples from cold-rolled AA6013 were prepared and compared to undeformed samples. The samples were annealed at the temperatures equal to 260, 490• C for undeformed state and at 280, 360, and 530• C for cold-rolled state. For investigation thin foils were prepared. Chemical composition and crystal structure of precipitates was analysed and described using transmission electron microscopy imaging, X-ray energy-dispersive spectroscopy and selected-area diffraction techniques. The researches indicated that low annealing temperatures caused dissolution of metastable β and Q phases. With increasing temperature there also occurred growth of Q phase. At highest annealing temperatures there were noticed precipitations of β phase again. Microstructural observation also revealed an impact of those particles on recrystallization processes.