6082铝合金热变形的本构模型

Constitutive model for hot deformation of 6082 aluminum alloy

利用Gleeble-1500热模拟机,研究6082铝合金在变形温度为300～500℃以及应变速率为0.01～10/s下高温单道次压缩过程的热变形流变应力行为。结果表明：6082铝合金高温单道次压缩下的热变形经历了从应变硬化阶段过渡到稳态变形阶段的过程,其软化机制主要为动态回复。该合金流变应力的大小受变形温度、应变速率的强烈影响,它随变形温度升高而降低,随应变速率提高而增大,说明该合金是一个正应变速率敏感的材料。该合金高温流变应力σ可采用Zener-Hollomon参数的函数来描述,函数表达式中参数A、α和n的值分别为3.97×1011s-1、0.01MPa-1、9.16;其热变形激活能Q为143.89kJ/mol。

The flow stress behavior of 6082 aluminum alloy was studied by single-pass high temperature compression experiment on Gleeble-1500 thermal-mechanical simulator, over a range of temperature of 300-500 ℃ and a range of strain rate of 0.01-10/s. The results demonstrate that the hot deformation behavior of 6082 aluminum alloy exhibits strain-hardening to a steady-state, and the softening mechanism was mainly controlled by dynamic recovery （DRV）. The value of flow stress is significantly affected by deformation temperature and strain rate, which decreases as temperature becomes higher and as strain rate becomes lower, indicating that 6082 aluminum alloy is a positive strain rate sensitive material. The flow stress of this alloy can be represented by Zener-Hollomon parameter function, and values of related parameters A, a and n, are 3.97 × 1 0^11 s^-1, 0.01 MPa^-1 and 9.16, respectively. Its activation energy for hot deformation Q is 143.89 kJ/mol.