The effect of grain size on the tensile properties of magnox AL80

Tensile tests were made on wires of Magnox AL80, Mg-Al alloy and unalloyed magnesium at room and liquid nitrogen temperatures. The grain size dependence of the yield and ultimate tensile stresses were investigated. It was found that the Petch relationship, σ_y=σ₀+kd^-1/2, was satisfied even for specimens as slender as 1 or 2 mm diameter, though definite values of σ₀ and k were not obtained. It is thought that the preferred orientation in the wire has an influence on both σ₀ and k. Similar results were also obtained for ultimate tensile stress. The strain rate dependence of the yield and ultimate tensile stresses were also investigated. (author)