Microstructure, Texture and Mechanical Properties of Extruded Mg-Zn-Zr Mg Alloy Profiles

The microstructures, texture and mechanical properties of large scale ZK60 magnesium alloy profiles were systematically investigated by XRD diffraction, microstructure observation and tensile testing at room temperature. The results indicate that there are mainly two phases in the extruded ZK60 Mg alloy, i.e. α-Mg and MgZn2, while a small amount of Mg2Zn11 and Zn2Zr3 phases were also observed. Initial coarse grains were significantly refined and broken down along the extrusion direction (ED), and partially dynamic recrystallization (DRX) also takes place during the hot extrusion process. The basal plane in most grains is aligned to ED and transverse direction (TD) rather than commonly extruded fiber texture. In the tensile test, the samples of 45ED direction exhibit the highest elongation to failure (δ=28% and 23%), and the ED direction reveal the highest ultimate tensile strength (σb =325 MPa and 312 MPa) along middle and side parts, respectively.