Mg-8%Li系共晶合金の超塑性挙動に及ぼすZr添加の影響
1995 年 45 巻 6 号 p. 333-338
詳細
1995 年 45 巻 6 号 p. 333-338
The effect of Zr addition on superplastic deformation has been investigated using Mg-8mass%Li eutectic alloys containing 0 or 0.2mass%Zr. The (α+β) eutectic structure of these alloys was controlled to produce a fine and equiaxed grain structure by a thermomechanical treatment. Recrystallized structures were refined by the Zr addition. The elongation higher than 500% was obtained for the fine-grained specimen. These specimens showed larger values of m (-0.67), which decreased with structural changes during superplastic deformation. During the superplastic deformation, refinement of the β grains was observed, while grain growth of the α grains was found. Improvement of superplastic behavior due to the Zr addition was considered to be caused by both finer grain structure before loading and suppression of dislocation process by solute atoms of Zr, which result in both uniform deformation and dynamic recrystallization.
