EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

The present study investigates the thermal stability of the microstructure of the rapidly solidified ribbon-consolidated Mg97.94Zn0.56Y1.5 alloy. In the as solidified state, the material has a very fine grain structure with an average grain size of around 900 nm. Moreover, dispersive Zn- and Y-rich stacking faults segregated in basal planes can be observed in the microstructure. The alloy is characterized by a weak basal texture with a more pronounced intensity at the (10-10) pole. As a result of these features, the material has shown a superior yield strength of 360 MPa and an elongation of 18%. In order to study its thermal stability, isothermal annealing for 2h in a range of 300 °C - 500 °C was applied. Scanning electron microscopy (SEM), including backscatter electron images (BSE), and electron backscatter diffraction (EBSD) techniques have been used to study the microstructure changes. Furthermore, X-ray measurements were performed for reliable texture analysis. The microstructure was found to be stable with increasing annealing temperature up to 400 °C. With further temperature increase, the growth of the grain size and changes in the texture of the alloy, particularly, redistribution of the intensity at the (10-10) pole, can be related to the recrystallization process. Microstructure changes were correlated with the results of the microhardness measurements.