摘要 |
PROBLEM TO BE SOLVED: To search a novel addition element having an effect for promoting grain boundary sliding while maintaining fine organization structure for activating non-bottom face dislocation movement, because addition of rare earth elements or micronizing of crystal grain size are often used for enhancing ductility or moldability of a magnesium alloy.SOLUTION: There is provided a Mg-based alloy extension material containing 0.11 mass% or more and 2 mass% or less of Zr and the remainder consisting of Mg with inevitable components, excellent in room ductility and exhibiting average crystal grain diameter of base material of 10 μm or less, a relationship between maximum load stress (σmax) and stress at fracture (σbk) in a stress strain curve figure by a tensile test with constant strain rate of the extension material of (σmax-σbk)/σmax of 0.3 or more and strain rate sensitivity index (m value) of 0.1 or more.SELECTED DRAWING: Figure 3 |