Effects of Ca and Sr addition on mechanical properties of a cast AZ91 magnesium alloy at room and elevated temperature

The cast AZ91 magnesium alloy having excellent mechanical properties, such as high strength and high creep resistance was developed by additional elements of Ca and Sr. From the microstructural observations, in order to obtain the fine grained AZ91 magnesium alloys, the optimal concentration of elements, such as Ca and Sr were at least 1.0 and 0.5 wt%, respectively. The present developed cast AZ91 magnesium alloy had fine grain sizes of 19 mu m. The tensile strength and elongation at room temperature were 250 MPa and 3.5%, respectively. The strength at an elevated temperature of 448 K on developed AZ91 magnesium alloy was also drastically larger than that on precious cast magnesium alloys. (c) 2005 Elsevier B.V. All rights reserved.