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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。
The conventional hot-rolled sheet of LC4 aluminum alloy was heat-treated properly and the sheet with the grain size refined to 6.8 μm was obtained. The material shows the mechanical properties of typical superplastic materials under the stretching conditions of 445 ~ 505 ℃ and 10 ~ (-3) ~ 10 ~ (-4) s ~ (-1) strain rate. In Zone Ⅱ, the strain rate sensitivity index is about 0.5 and the maximum elongation is 500%. From the relationship between lnε (constant stress) and 1 / T, the activation energy of the superplastic deformation of this alloy is 41.4 ± 2.5K cal / mol. The superplastic deformation of this alloy is controlled by the self-diffusion of the metal body.