Microstructure Analysis and Bulk Texture Study in Wide Magnesium Alloy Sheets Processed by Twin-Roll Casting

Abstract

The wide magnesium (Mg) alloy sheets produced by twin-roll casting (TRC) are prone to have an inhomogeneous microstructure and basal texture. Texture has a significant effect on the properties of Mg alloy sheets for the processes after TRC, which can be greatly modified by alloy composition. However, systematic studies on the bulk texture of TRCed Mg alloy sheets using neutron diffraction are lacking. In this study, neutron diffraction was used to explore the bulk textures in different positions of the Mg, Mg–Al–Zn, and Mg–Al–Sn–Zn alloy sheets produced by TRC, besides microstructure and micro-texture analysis using field emission scanning electron microscopy and electron backscattering diffraction. The influence of alloy composition on the microstructure and texture evolution of TRCed Mg alloy sheets is explored and discussed. The TRCed pure Mg sheet possesses a relatively strong basal texture, and the texture distribution is inhomogeneous; while TRCed Mg–Al–Sn–Zn alloy sheets feature much weaker textures and a relatively homogenous distribution in different positions. The present study provides guidance for the control of texture via tailoring alloy compositions, which provides candidate Mg alloys suitable for the TRC process.

Study on Bulk Texture and Mechanical Properties of As-Extruded Wide Mg-Al-Zn Alloy Sheets with Different Al Addition

“…Neutrons only interact with nuclei, so they have a strong ability of penetration in materials [35][36][37], which means that neutron diffraction has the following advantages in texture measurement among these techniques. For example: (1) large samples can be used, thus a high accuracy and good statistics, as well as bulk texture, will be obtained; (2) accurate texture analysis can be achieved for coarse-grained, texture inhomogeneity, multi-phase samples and samples with a small volume fraction of the second phase; (3) texture evolution during a high temperature and tension process can be studied by in situ neutron diffraction.…”