Fabrication of extraordinary high-strength magnesium alloy by hot extrusion

Extraordinary high-strength Mg-1.8Gd-1.8Y-0.7Zn-0.2Zr alloy has successfully been fabricated by an ingot metallurgy process with hot extrusion followed by aging. The sample exhibits an ultimate tensile strength of 542 MPa, proof stress of 473 MPa and elongation to failure of 8.0%. These high strengths are achieved as a result of fine precipitates due to the aging and dynamic precipitation at the grain boundaries of dynamically recrystallized grains. These precipitates also substantially enhance the compressive proof stress, resulting in improvement in the yield anisotropy. (C) 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.