摘要在生活中运用到的结构材料中，镁合金材料是其中最轻的，随着研究的深入及发现，镁合金已经能够在很多领域运用。特别是变形镁合金，其拥有不错的力学性能，这必然是以后新型镁合金的研究方向。变形镁合金在经过一些处理措施之后，能够使晶粒细化，同时很大程度上改善材料的综合力学性能。不过镁合金用于结构件时，在运用过程中都会受到工作循环次数的影响，为了确保材料的可靠性，要求对镁合金的疲劳寿命进行试验与分析，这样才能清楚的了解其疲劳断裂机理以及失效形式。30712
本课题对AZ31镁合金试样进行ECAP处理和深冷处理，并且通过各项试验对其力学性能和疲劳性能进行分析，得出试样晶粒的尺寸变化以及失效机理对其低周疲劳性能的影响。能够清楚的看出经过ECAP以及深冷处理之后，试样的疲劳寿命得到了加强。
关键词  AZ31镁合金  ECAP  低周疲劳  深冷处理
毕业论文设计说明书外文摘要
Title  the influence of AZ31 magnesium alloy low cycle  Fatigue performance by ECAP and cryogenic processing
Abstract
Used in the structure of the material in our daily life, the magnesium alloy material is one of the most light, with the deepening of the research and found that magnesium alloy have been able to use in many fields. Magnesium alloy, in particular, because of its high strength and good toughness, has become a new development direction of magnesium alloy materials in the future. Magnesium alloy after some processing measures, can make the grain refinement, and largely improve the comprehensive mechanical properties of materials. Magnesium alloys used in structure, however, in the process of use will be affected by the work cycle times, in order to ensure the reliability of the material, requirements to test and analysis of the fatigue life of magnesium alloy, so as to understand its fatigue fracture mechanism and failure modes.
This topic on AZ31 magnesium alloy ECAP treatment and cryogenic treatment were carried out, and through the experiment on the mechanical properties and fatigue properties were analyzed, and concluded that grain size variation and failure mechanism of the influence of the low cycle fatigue performance. Can clearly see the after ECAP, cryogenic treatment, the fatigue life of reinforced.
Keywords  AZ31 magnesium alloy  ECAP  Low cycle fatigue Cryogenic treatment
目   次
1  引言    1
1.1 变形镁合金AZ31研究现状    1
1.1.1 镁和镁合金的特点    1
1.1.2 变形镁合金的性能    2
1.1.3 AZ31镁合金中的合金元素    3
1.2 镁合金的疲劳    4
1.2.1 疲劳概述    4
1.2.2 镁合金的疲劳研究    5
1.3 深冷处理技术    6
1.3.1 深冷处理技术概述    6
1.3.2 深冷处理对疲劳的影响    7
1.4 本课题研究目的及意义    7
1.5 本课题的研究内容    7
2 实验内容    9
2.1 实验材料    9
2.2 实验内容及方法    9
2.2.1 ECAP实验    9
2.2.2 试样制备    9
2.2.3 深冷处理实验    10
2.2.4 静态力学性能实验    11
2.2.5 低周疲劳试验    11
2.2.6 硬度实验    11
3 实验结果和分析    12
3.1 静态力学性能实验结果    12
3.2 金相组织观察    13
3.3 低周疲劳性能    14
3.3.1 ECAP常温和冷冻试样平均应力曲线    14 深冷处理对超细晶AZ31镁合金低周疲劳性能影响:http://www.751com.cn/cailiao/lunwen_26577.html