摘要镁合金作为目前工业应用中最轻的金属结构材料,因其强度、比刚度高,良好的电磁屏蔽性能及易于加工、回收等优点,被誉为“21世纪绿色金属工程材料”,并广泛用于汽车、通讯、电子、航空航天等领域。塑性差是镁基合金、铸铝合金等加工与应用上的一个瓶颈,改善塑性也就成为这些材料研究与应用中急需解决的关键技术之一。
本论文对电脉冲轧制工艺要求进行了深入的探讨,并改装了传统的轧机。提出了相应的实验方案。对镁合金板进行不同工艺的条件下电脉冲轧制实验。将轧制后的试样进行了抗拉强度、延伸率等力学性能的测试。并应用金相显微镜等观察轧制前后显微组织的改变,并与传统冷轧后的力学特性、显微组织进行了对比分析。该实验结果表明:
1.电脉冲轧制过程中脉冲电流与变形量密切相关,在一定的脉冲电流范围内,轧制试样的变形能力随着脉冲电流的增大而有所改善。轧件的压下量也有所增加。
2.电脉冲轧制过程中轧制力也会在脉冲电流的作用下有一定程度的降低,极大的降低了轧件的成形条件。
3.异数比也可以提高AZ31镁合金材料的塑性。电脉冲也能提高AZ31镁合金材料的塑性。
4.电脉冲轧制使微观组织结构发生了明显改变,出现了等轴晶粒,某些枝晶被打断,晶粒明显细化。出现了变形中心区域晶粒比边缘变形更明显,晶粒更细的现象。
关键词: 镁合金材料,电塑性效应,电脉冲轧制9469
Magnesium alloy electric plasticity research
Abstract:Magnesium alloy as the lightest metal structural materials for industrial applications, Because of its strength and specific rigidity, good electromagnetic shielding performance and ease of processing, recycling, advantages ,Known as the "21st century green metal engineering materials”,And is widely used in automotive, communications, electronics, aerospace and other fields.Poor ductility of magnesium-based alloys, cast aluminum alloy processing and application of a bottleneck and improve the plasticity of these materials has become an urgent need to address research and application of key technologies.
In this paper, electrical pulses rolling process requires in-depth discussion, and modification of the traditional mill. Proposed the corresponding experimental program. Of magnesium alloy sheet under different process conditions electrical pulse rolling test. After the samples were rolling tensile strength, elongation and other mechanical properties of the test. And other applications microscope microstructure was observed before and after the change of rolling and cold rolling with the traditional mechanical properties, microstructure was analyzed.The experiment results show that the:
1.Electric pulse with the pulse current during the rolling process is closely related to the amount of deformation in a certain range of the pulse current, the rolling deformation the sample pulse current increases with the improvement. The rolling reduction is increased.
2.Electric pulse rolling force during rolling is also the role of the pulse current is reduced to a certain extent, greatly reducing the rolling of the forming conditions.
3.Iso ratio can also increase the plasticity of AZ31 magnesium alloy. Electrical pulses can also improve the plasticity of AZ31 magnesium alloy.
4.Rolling the electrical pulse microstructure changed significantly, there has been fibrous tissue,Some dendrites was interrupted, finer grain size; central region appeared deformed grains deformed than the edge more obvious phenomenon of crystal grains finer.
Key Word: Magnesium alloy material,Electroplastic effect,Electric pulse rolling
目 录
第一章绪论..1
1.1 镁合金特点及成型现状.1 AZ31镁合金材料的电塑性研究+文献综述:http://www.751com.cn/cailiao/lunwen_8200.html