Effect of Zr addition on the mechanical properties of as-extruded Mg-Zn-Ca-Zr alloys

Extrudable Mg-6Zn-0.2Ca(-0.8Zr) alloy (mass%) has been developed. The Mg-Zn-Ca-Zr alloy shows excellent mechanical properties in the as-extruded state with the ultimate tensile strength of 357 MPa and elongation to failure of 18%. These properties are related to dynamic recrystallization, texture and precipitation. Dynamically recrystallized grains are pinned by fine precipitates, resulting in very fine grain size. The extruded sample also exhibits a higher average {0 0 0 2} 〈112¯0〉 Schmid factor due to the presence of unrecrystallized regions, leading to texture strengthening. Zr may work as a microalloying element, resulting in fine and dense distribution of a MgZn2 based phase involving Ca and Zr.