Microstructure and Mechanical Properties of Severely Deformed AX41 Magnesium Alloy

T. Krajňáka, K. Máthis a, J. Gubicza b, J. Stráská a and M. Janeček a aDepartment of Physics of Materials, Faculty of Mathematics and Physics, Charles University, Ke Karlovu 5, 121 16 Prague 2, Czech Republic bDepartment of Materials Physics, Eötvös Loránd University, Budapest, Hungary

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The object of the present paper is the study of mechanical properties and microstructural evolution of AX41 magnesium alloy, severely deformed using a combination of hot extrusion and equal channel angular pressing. Equal channel angular pressing processing was performed at 250°C following route Bc. Mechanical properties of the ultrafine-grained alloy were investigated in tension at a constant strain rate of 10-4 s-1 at room temperature and 100°C. The dislocation density was determined by X-ray line profiles analysis. Microstructural observations performed by electron backscattering diffraction after 8 passes of equal channel angular pressing revealed very fine and homogeneous microstructure with a grain size of 0.3-6μm. It has been found that the room temperature mechanical properties such as yield stress and tensile strength reach their maximum value even after the first pass which is in good agreement with the evolution of the dislocation density. Further processing by equal channel angular pressing led to the decrease in both the yield strength and the dislocation density, despite the slight grain size refinement.

DOI: 10.12693/APhysPolA.128.768 PACS numbers: 81.40.-z, 61.05.cp, 68.37.Hk, 61.72.Lk, 61.72.Mm