(哈尔滨工业大学材料科学与工程学院， 哈尔滨 150001)
摘 要: 为研究LY12合金在半固态下的力学行为，使用拉伸与压缩试验测定了LY12合金在不同半固态温区及不同应变速率下的真实应力-真实应变曲线，使用线性回归方法确定了真实应力σ与真实应变速率ε·的关系及变形温度与真实应力的关系。结果表明， LY12合金在半固态温区的拉压变形行为均显示出应变速率敏感性, 其拉压力学行为符合简单的幂函数关系σ＝kε·m。根据试验结果, 推算出了半固态LY12在不同变形温度及应变速率下的幂函数系数k、应变速率敏感性指数m及变形激活能Q 的值，从而获得了半固态LY12合金变形力学行为的定量描述。
关键字: LY12合金；力学行为；半固态；拉压变形
（School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, P.R.China）
Abstract: In order to investigate the mechanical behavior of 2024Al alloy deformation at the semi-solid state, the tensile and compressive experiments were employed to measure its curve of true stress vs true strain at various deformation temperatures and strain rates. Based on the experimental results, the relation of true stress σ and true strain rate ε· and the relation of deformation temperature and true stress were determined using the method of simple linear regression. The results showed that the tensile and compressive deformation behaviors of 2024Al alloy in semi-solid state temperature regions display the sensitivity of strain rate and they could be expressed by a simple power law σ＝kε·m. In addition, the coefficient k of power law, the exponent m of sensitivity of strain rate and the energy Q of plastic deformation were derived based on the experimental results and theoretical analyses. Consequently, the quantitative description of 2024Al alloy deformation in the semi-solid temperature region was obtained.
Key words: 2024 alloy; mechanical behavior; semi-solid state; tension and compression deformation
