7系铝合金的动态力学性能

摘要

材料在复杂的服役环境中可能受到各种不同载荷的作用，对材料在不同加载条件下力学行为的研究是完善材料开发、应用以及进行新材料及结构设计的基础。目前，国内对7005 铝合金的研究尚处于初级阶段，对于这类新型高性能铝合金在动态加载条件下的力学行为研究仍然十分匮乏。另外，作为目前研究材料动态力学行为最为常用的实验设备——分离式霍普金森压杆（SHPB）和分离式霍普金森拉杆（SHTB）。本实验研究热处理之后的七系铝合金的动态力学性能。首先对7005铝合金分别进行固溶，时效，回归，再时效等不同的热处理工艺在动态应变下力学行为和响应，采用分离式Hopkinson 压杆装置对7005 铝合金试件分别进行动态压缩，利用光学显微镜对压缩后试件进行了微观组织观察。最后结论发现试件在固溶时效。回归温度180℃升温10min保温30min 时在应变为0.013 时才到达应力123.6MPa。（应力随应变变化的最快，但是达到的最大应力在所有试验中时最小的）。

关键词动态加载; 分离式霍普金森压杆; 七系铝合金; 微观组织

Abstract

Materials will be subjected by various loads in complicated application environment; so,studying the mechanical properties of the materials under different loading conditions is the basis for application and design of the materials. At present, the research on 7005 aluminum alloy is just at the starting stage in China, and the research on the mechanical behaviors of 7005 aluminum alloy under different loading conditions is still very scarce. Meanwhile, the split Hopkinson pressure bar (SHPB) and the split Hopkinson tensile bar (SHTB) are the most commonly used test equipments of dynamic mechanics. The dynamic mechanical properties of the seven-series aluminum alloy after heat treatment were studied. Firstly, 7005 aluminum alloy was subjected to different heat treatment processes, such as solid solution, aging, regression and re-aging, respectively. Under dynamic strain, the 7005 aluminum alloy specimens were dynamically compressed by separate Hopkinson bar, The microstructures were observed after compression. Finally, the specimen in solid solution, and the regression temperature 180 ℃（Warming up for ten minutes Hold for ten minutes）shows that the stress reaches 123.6MPa when the strain is 0.013 . (Stress is the fastest change with strain, but the maximum stress reached is the smallest in all trials).

Key words dynamic loading; separate Hopkinson pressure bar; 7××× aluminum alloy; microstructure

目录

摘要 ........................................................................................................................... I Abstract ...................................................................................................................... II 1 绪论 (1)

1.1 课题研究背景 (1)

1.2 铝元素简介 (3)

1.2.1 一系到六系铝合金简介 (3)

1.2.2 七系铝合金发展概述 (4)

1.3 铝合金的热处理工艺 (4)

1.3.1 铝合金固溶工艺 (5)

1.3.2 铝合金时效工艺 (5)

1.3.3 热处理时的沉淀顺序 (7)

1.4 铝合金显微组织 (7)

1.4.1 7xxx系铝合金显微表征技术 (7)

1.4.2 7 xxx系铝合金缺陷及研究方向 (8)

1.5 霍普金森杆技术综述 (8)

1.5.1 霍普金森杆装置的构造 (8)

1.5.2 霍普金森杆装置实验的原理 (9)

1.5.3 霍普金森杆实验的要求 (9)

1.5.4 霍普金森杆的国内外研究现状 (10)

1.6 7xxx系铝合金动态力学性能研究的意义 (11)

2 实验部分 (12)

2.1实验材料的准备 (12)

2.2 7005铝合金的热处理 (12)

2.2.1固溶处理 (13)

2.2.2回归再时效处理 (13)

2.3 试件霍普金森杆实验 (14)

2.3.1 实验材料的准备 (14)

2.3.2 实验装置的连接 (14)

2.3.3 应变片的粘贴与连接 (14)