【摘要】 LC4铝合金的常规热轧板材经适当形变热处理后,制得了晶粒尺寸细化到6.8μm的薄板。该材料在445～505℃和10^-3～10^-4秒^-1应变速率的拉伸条件下显示出典型超塑性材料的力学特征。在Ⅱ区内的应变速率敏感指数约为0.5,最大延伸率达500%。由lnε（恒定应力）与1/T间的关系求得此合金的超塑性变形激活能为41.4±2.5K cal/mol。此合金的超塑性变形过程是由金属的体自扩散所控制。更多还原

【Abstract】 Conventional hot-rolled LC4 alloy plate materials with large grain size wereconverted into finely-grained sheets with grain size of 6.8μm by means of a specialthermo-mechanical process. The finely-grained LC4 alloy exhibited typical superplast-icity in the temperature range between 445° to 505℃ at strain rates between 10^-3 to10^-4 sec^-1. The strain rate sensitivity, index in region Ⅱ was about 0.5 and themaximum total elongation. of 500% was obtained. The activation energy for the super-plastic flow of this alloy was 41.3±2.5 Kcal/mol, obtained from the relation betweenlnε_const,δ vs 1/T. The superplastic deformation of this alloy was rate-controlled bylattice self-diffusion.更多还原