A comparative study on the microstructures and mechanical properties of the Mg-xCa/Mn/Ce alloys and pure Mg

Abstract

A comparative study on the microstructures and mechanical properties of the extruded Mg-xCa/Mn/Ce (x = 0.25, 0.5, 1, 2.0 wt%) alloys and pure Mg has been carried out. It was found that when the addition of Ca, Mn and Ce was more than 0.25 wt%, 0.5 wt% and 0.5 wt% respectively, microstructures with fine grain sizes smaller than 5 μm can be achieved by extruding at 375 ◦C with a extrusion ratio of 30 and a ram speed of 0.8 mm/s. While the grain size of pure magnesium extruded under the same condition was 26.6 μm. The addition of Ca, Mn or Ce has significant effects on the textures of the extruded Mg-xCa/Mn/Ce alloys. The maximum intensity peaks in PF and IPF of Mg are all deviated by a certain degree with the addition of Ca, Mn or Ce. In the 12 extrusion alloys, Mg-0.5Ca、Mg–2Mn and Mg–1Ce exhibited better mechanical properties, whose ultimate tensile strength and elongation are 243.6 MPa, 233.7 MPa, 321.5 MPa and 25.6%, 20.7%, 7.6%. While the ultimate tensile strength and elongation of as-extruded pure Mg is 173.8 MPa and 16.0% respectively. Mg-xCa and Mg-0.25Ce alloys with weak texture showed weaker tension-compression asymmetry. The experimental results showed that it is feasible to prepare fine grained (<5 μm) Mg-xCa/Mn/Ce alloys with much improved mechanical properties using conventional extrusion.