【摘要】 研究变形态Mg 2 .5Nd 0 .5Zn 0 .5Zr合金的超塑变形行为发现 ,3 75℃是该合金的最佳超塑变形温度 ,变形速率在 1× 10 - 2 s- 1 时延伸率达到 3 2 9%;当变形速率提高到 2× 10 - 2 s- 1 时 ,该合金的延伸率仍可达到 2 13 %。分析不同真应变下的组织发现 ,晶粒在变形初期发生动态再结晶 ,晶粒得到破碎而变得细小 ,随着变形程度的增加 ,晶粒长大程度较小更多还原

【Abstract】 The superplasticity behavior of wrought Mg 2.5Nd 0.5Zn 0.5Zr alloy was investigated. The results show that 375 ℃ is the optimal deformation temperature, while the elongation amounts to 329% at the strain rate of 1×10 -2 s -1 . With increasing the strain rate to 2×10 -2 s -1 , the elongation still keeps 213%. The various microstructures show that the grains become fine due to dynamic recrystallization during the initial deformation stage. With the deformation being extended. The grains show a minor growth extent. The fracture surface depicts that mechanism of the superplasticity is controlled by the grain boundary sliding accompanied with cavities interlinked.更多还原