3004铝合金的动态应变时效现象

Dynamic Strain Aging of 3004 Aluminum Alloy

选取5．56×10^-5s^-1, 2．78×10^-4s^-1，5．56×10^-4s^-1，5．56×10^-3s^-1四个常用应变速率，在223～773K间隔25℃，以各应变速率对3004铝合金进行系列拉伸试验，探索其中的DSA宏观现象及规律。结果表明，在给定的应变速率下。DSA仅发生在一定的温区。在该温区内，流变应力随温度升高基本保持不变，加工硬化速率出现极大值，应变速率敏感性出现负值。计算得出低温下激活能为48．8kJ／mol，表明3004铝合金中的动态应变时效是Mg溶质原子气团与位错交互作用的结果。

The dynamic strain aging （DSA） macro-phenomenon and regular pattern of 3004 aluminum alloy in tensioning process are investigated at 223 - 773K temperature interval 25K with four normal strain rates of 5.56×10^-5s^-1, 2.78×10^-4s^-1,5.56×10^-4s^-1,5.56×10^-3s^-1. The results show that DSA of 3004 aluminum alloy only occurs at a certain range of temperature at settled strain rate. The stress is not varied with the increase of temperature, and a maximum work-hardening rate and negative insensitivity of strain rate appear in this temperature range. The activation energy is 48.8 kJ/mol from the calculation, so the Mg atom is responsible for the DSA in tensioning process of the 3004 aluminum alloy.