摘要：本文通过热模拟压缩试验、金相组织观察以及再结晶动力学模型研究Al-8Zn-2Mg-2Cu合金的静态再结晶行为。建立反应热加工工艺条件、固溶条件与静态再结晶体积分数、再结晶晶粒尺寸的数学模型来预测和控制再结晶。

本文主要实验内容为热变形条件、固溶条件对于静态再结晶速率的影响，通过实验数据分析，我们发现：热变形过程中，Z参数越高、原始组织越细小、应变量越大、固溶温度越高，再结晶速率越高，晶粒尺寸越小且再结晶分数越高。通过Avrami方程建立静态再结晶动力学的最初模型，然后依据实验数据，采用线性拟合的方法来逐步确定其中的参数，最终得到静态再结晶动力学方程。最后，Al-8Zn-2Mg-2Cu合金在热变形时存在动态软化，形成再结晶亚晶和再结晶核心，缩短再结晶形核的孕育期，降低了静态再结晶激活能。

关键字：Al-8Zn-2Mg-2Cu合金；热变形；静态再结晶；动力学方程

Abstract：In this paper, the static recrystallization behavior of Al-8Zn-2Mg-2Cu alloy was studied by thermal simulation compression test, metallographic observation and recrystallization dynamics model. A mathematical model of reaction hot processing conditions, solid solution conditions and static recrystallization volume fraction and recrystallization grain size was established to predict and control recrystallization.

The main experimental content of this paper is the effect of thermal deformation condition, solid solution conditions on static recrystallization rate. Through the experimental data analysis, we found that the higher the Z parameter, the smaller the original structure, the higher the strain, the higher the solution temperature, the higher the recrystallization rate, the smaller the grain size and the higher the recrystallization fraction high. The initial model of static recrystallization kinetics was established by Avrami equation. Then, according to the experimental data, the linear fitting method is used to determine the parameters, and finally the static recrystallization kinetics equation is obtained.Finally, the Al-8Zn-2Mg-2Cu alloy undergoes dynamic softening at the time of thermal deformation to form recrystallized subgrain and recrystallization  core, shorten the incubation period of recrystallization nuclei and reduce the static recrystallization activation energy.

Keywords: Al-8Zn-2Mg-2Cu alloy;Thermal deformation; Static recrystallization; Kinetic equations

目录

第一章绪论 1

1.1引言 1

1.2国内外Al-Zn-Mg-Cu系超高强度铝合金的发展与应用 2

1.2.1国外Al-Zn-Mg-Cu系超高强度铝合金的发展 2

1.2.2国内Al-Zn-Mg-Cu系超高强度铝合金的发展 4

1.3铝合金的制备与工艺 5

1.3.1铝合金的熔铸工艺 5

1.3.2铝合金的形变工艺 6

1.3.3铝合金的热处理工艺 6

1.4主要合金元素在高强铝合金中的作用 8

1.5Al-8Zn-2Mg-2Cu静态再结晶的研究现状与存在的问题 8

1.5.1Johnson-Mehl-Avrami-Kolmogorov方程 8

1.5.2静态再结晶动力学模型 9

1.6研究的目的与内容 10

第二章材料及实验方法 11

2.1实验流程 11

2.2平面应变热压缩