热压缩7075铝合金流变应力特征

Flow Stress Feature of 7075 Al Alloy during Hot Compression Deformation

采用Gleeble-1500热模拟高温压缩变形试验,研究了7075铝合金高温塑性变形时的流变应力行为。结果表明,应变速率和变形温度的变化影响合金稳态流变应力的大小,在变形温度为350～500℃、应变速率为0.01～1s-1的条件下,随变形温度升高,流变应力降低;而随应变速率提高,流变应力增大;应变速率和流变应力之间满足指数关系,温度和流变应力之间满足Arrhenius关系,可用Zener-Hollomon参数描述7075铝合金高温塑性变形时的流变应力行为。

The flow stress feature of 7075 aluminum alloy during high temperature plastic deformation ranging from 300-500℃ and strain rates of 0.01～1s^-1 was studied by the thermal compression using Gleeble-1500 hot-simulator. The results show that both strain rates and deformation temperatures control the flow stress. The flow stress decreases with the increase of temperature, while increases with the increase of strain rates. A hyperbolic sine relationship is found to correlate well the flow stress with the strain rate, and an Arrhenius relationship with the temperature. The flow stress of 7075 aluminum alloy during high temperature deformation can be represented by a Zener-Hollomon parameter.