摘要:随着科技的飞速发展，各行各业都取得了重大的飞跃，对于涉及金属材料的行业对材料的要求越来越高，希望能够质量轻且强度高，并且由于工业发展带来的振动和噪音问题越来越严重，高阻尼材料能够减少振动和噪声的影响。镁和镁合金阻尼性能优良，并且通过一些强化方式能够加强镁合金的力学性能，得到阻尼性能和力学性能都优良镁合金材料广泛应用于航空航天、军用武器和汽车等领域。

本实验研究的材料是Mg-6Gd-2xY-xZn-0.6Zr合金，x值取1、1.5、2、2.5。Y/Zn的值为2:1的固定值，设计出含LPSO结构的稀土镁合金，进而通过改变元素Y和Zn的含量，研究LPSO相含量对镁合金组织的作用，进而研究对力学性能和阻尼性能的影响，得到综合性能优异的镁合金。

通过金相组织观察、SEM和EDS分析、XRD分析、拉伸实验和阻尼测试等实验手段，发现随着LPSO相的增加，镁合金的组织得到了细化，合金中镁基体减少，第二相含量增多，镁合金主要由LPSO相和α-Mg两相组成，即Mg10(Gd,Y)Zn和α-Mg，镁合金的力学性能提高，但阻尼性能降低。

关键词：Mg-Gd-Y-Zn-Zr；LPSO；组织；力学性能；阻尼性能

Abstract:Science and technology develop fast, all walks of life have made a great leap, involving metal materials industry, the increasingly high demand for materials, hope to be light and high strength, and due to industrial development, The problem are vibration and noise getting worse, and the high damping material can solve the problems. Magnesium and magnesium alloy damping performance is excellent, and through some strengthening methods can strengthen the mechanical properties of magnesium alloy, damping and mechanical properties are excellent magnesium alloy materials are widely used in aerospace, military and automotive and other fields.

The experimental study is Mg-6Gd-2xY-xZn-0.6Zr alloy, x is 1,1.5,2 and 2.5.The value of Y / Zn is a fixed value of 2:1, and design rare earth magnesium alloy with LPSO structure. The effects of LPSO content on the microstructure, mechanical properties and mechanical properties of the magnesium alloy were studied by changing the contents of elements Y and Zn. so can get the magnesium alloy with excellent properties.

By means of metallographic observation, SEM and EDS analysis, XRD analysis, tensile test and damping test, it was found that the structure of magnesium alloy was refined with the increase of LPSO phase, the magnesium matrix in the alloy decreased, the second phase in the alloy is increased. Mg alloy is composed of Mg10(Gd, Y) Zn and α-Mg, and the mechanical properties of magnesium alloy are improved, but the damping performance is decreased.

Keywords: Mg-Gd-Y-Zn-Zr; LPSO; microstructure; mechanical properties; damping properties

目 录

第一章  绪论 1

1.1 课题的背景及意义 1

1.2 镁及镁合金 2

1.3 镁及镁合金的应用 3

1.3.1 纯镁的应用 3

1.3.2 镁合金的应用 3

1.4 镁合金的分类 3

1.4.1 高强度镁合金 4

1.4.2 耐蚀镁合金 5

1.4.3 耐热镁合金 5

1.4.4 阻尼镁合金 6

1.5 镁合金的强化方式 8

1.5.1 固溶强化 8

1.5.2 沉淀析出强化 9

1.5.3 弥散强化 9

1.5.4 细晶强化 10

1.5.5 复合强化 10

1.5.6 镁合金中LPSO结构对镁合金的强化作用 10

1.6 稀土镁合金 10

1.6.1 稀土元素的分类及其作用 11

1.6.2 稀土镁合金的分类 11

1.6.3 长周期增强稀土镁合金 11

1.6.4 国内外研究现状 12

1.7 本课题研究内容 13

第二章  合金的制备和实验方法 14

2.1 合金成分的设计 14

2.2 合金的制备 14

2.2.1 实验的原材料 14

2.2.2 熔炼设备和所需药品 14

2.2.3 熔炼工艺 15

2.3 合金的组织结构表征 16

2.3.1 金相组织观察 16