摘要：镁合金是一种优秀的轻质材料，它具有较低的密度、高比强度等优点，然而镁合金较差的耐腐蚀性限制了它在工业领域的广泛应用，通过累积叠轧技术将耐腐蚀性较好的铝合金包覆在镁合金表面制备出的铝镁叠层材料很好的解决了这个问题，使其在航空航天、电子通信、汽车轮舶等领域具有良好的应用前景。累积叠轧每重复一次就是一次ARB循环道次，理论上可以无限次重复达到材料所需的大变形量。本试验主要通过制作四个ARB道次的Al/Mg/Al复合材料，观察Mg层显微组织的演变以及测量并分析Al层和Mg层随着ARB道次的增加，显微硬度的变化趋势；并对1p和3p的Al/Mg/Al材料进行热处理，研究在不同退火温度与退火时间下硬度的变化趋势以及Mg层显微组织的演变；以及通过扫描电镜观察界面微观组织并绘制线扫面图谱，分析结合界面处的成分组成和结构特性，研究界面结合机理。通过实验结果分析可知：87848

1）随着累积叠轧道次的增加，材料表面的加工硬化层进入到心部，使复合板材的的硬度得到提升，这在一道次叠轧后表现尤为显著。

2）随着累积叠轧道次的增加，材料组织得到明显的细化和均匀化，表现为Mg层的大晶粒数量明显减少，晶粒尺寸变得均匀细小。

3）选取不同温度和时间的退火工艺，Mg层和Al层的硬度均表现为逐渐下降的趋势。

4）随着退火时间的增加，Mg层上出现大量等轴晶，晶粒尺寸变得均匀细小。

5）热处理过程中界面两侧的铝、镁原子会发生相互扩散，随着退火温度和保温时间的延长，界面上会析出中间相，对界面的硬度产生影响。

    总之，累积叠轧技术是一种细化晶粒组织的有效手段，可以有效提升复合材料的硬度，选用适当的热处理工艺防止结合界面上产生影响材料性能的中间相也同样重要。

毕业论文关键词   累积叠轧技术 Mg层显微组织 退火处理 硬度 界面结合机理

毕业设计说明书外文摘要

Abstract Abstract: The magnesium alloy is an excellent lightweight material, it has a low density, high specific strength, etc。, but poor corrosion resistance of magnesium alloy limits its wide application in the industrial field, by accumulative roll technology the good corrosion resistance of aluminum magnesium alloy surface coated aluminum-magnesium prepared laminate a good solution to this problem, so that in the aerospace, electronic communications, automotive wheel ship and other fields with good prospects 。 Accumulative Roll each repetition of the cycle is the first ARB passes theoretically infinitely repeated large deformation reaches the desired material。 This test is mainly produced by four ARB passes of Al/Mg /Al composites, observe the evolution of the microstructure of the Mg layer and measure and analyze the Al layer and the Mg layer increases ARB passes, trends microhardness ; and 1p and Al / Mg / Al material 3p subjected to heat treatment, research trends and the evolution of the Mg layer hardness microstructure at different annealing temperature and annealing time; and microstructure by scanning electron microscopy and draw the line scan interface surface maps, analyze binding component at the interface of the composition and structural characteristics, study interfacial bonding mechanism。 The experimental results analysis shows that:

1) With the cumulative increase Roll passes, hardening the surface layer material into the core section, the hardness of the composite sheet has been improved, which after a second roll-bonding is particularly significant。

2) With the increase of accumulative roll passes, the organization has been significantly refined materials and uniform, showed significant reduction in the number of large grain Mg layer, the grain size becomes uniform and fine。