Textural evolution and improved ductility in Zn-0.2Mg-0.8Mn (wt%) alloys at different extrusion temperatures

Zn-0.2Mg-0.8Mn (wt%) alloys were prepared by indirect extrusion at different temperatures. With decreasing the extrusion temperature from 300 degrees C to 150 degrees C, these alloys exhibited a fully dynamic recrystallized microstructure with an average grain size of 2 mu m. The second phases Mg2Zn11 and MnZn13 were distributed at grain boundaries along the extrusion direction and the texture transformed from < 10<(1)over bar>0 >parallel to ED (extrusion direction) basal texture to non-basal texture with basal planes tilted away from ED about 10 degrees similar to 25 degrees. The refined grain size and the second phases contributed to the high yield strength of 330-350 MPa, while the textural transformation made substantial contribution to the increase of elongation from 12% to 33%. During the tensile deformation, dislocation slip was the main deformation mode. The non-basal texture was beneficial to accommodate more dislocations and/or LAGBs and to improve the ductility of the Zn-Mg-Mn alloys. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

By decreasing the extrusion temperature, Zn-0.2Mg-0.8Mn alloys exhibited fully dynamic recrystallization, with a texture transformation contributing to an increase in elongation. The refined grain size and second phases also contributed to the high yield strength of the alloy.