摘要镁合金是目前工业应用中最轻的结构材料，因其强度、比刚度高，良好的电磁屏蔽性能及易于回收等特点，而具有应用于汽车、通讯、电子、航空航天等领域的巨大前景，它被誉为“21世纪绿色金属工程材料。但是由于镁合金是密排优尔方晶系，所以滑移系少，塑性差，难以塑性加工成型，这一点也大大影响了镁合金的应用，所以改善镁合金塑性的研究是一项急需解决的关键技术之一。
本文介绍了通过电脉冲轧制的方法来改善AZ61镁合金板材在发生塑性变形时产生的织构和孪晶，从而提高AZ61镁合金的塑性。本实验分别研究了电流大小为1000A和1200A、占空比为50%和80%、脉冲频率为100HZ和50HZ下的电脉冲轧制以及无电脉冲轧制对AZ61镁合金的作用，然后分析比较了不同工艺下得到的AZ61镁合金板材的力学性能和微观组织，结果表明：22740
1.在电脉冲的作用下，原子能加大，位错攀移运动的增强，出现了动态再结晶现象，并且电脉冲对细化晶粒、推迟孪晶的形成以及弱化织构具有促进作用；
2.脉冲电流对AZ61镁合金具有加热作用，从而促进AZ61镁合金的动态再结晶，改善了AZ61镁合金机械性能；
3.较大的脉冲电流、较小的占空比和较大的脉冲频率，即对AZ61镁合金施加的电流越多，对AZ61镁合金的加热作用越大，促进AZ61镁合金的动态再结晶，改善AZ61镁合金的机械性能；
本实验为AZ61镁合金的塑性加工提出了新思路，并且为AZ61镁合金电塑性加工工艺提供重要参考，对促进AZ61镁合金的应用具有重要意义。
毕业论文关键词：电脉冲轧制；AZ61镁合金；孪晶；织构
Abstract
Magnesium alloy is 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，so it has showed the great prospects to be widely used in automotive, communications, electronics, aerospace and other fields，known as the "21st century green metal engineering materials". Due to their hcp structure ,slip system is less than other structure, so their ducility are very poor and it is hard to be formed. As this seriously affect their applications, improving the plasticity of magnesium alloy has become an urgent need to address research of key technologies.
This artical describes that it can improve the ducility of the AZ61 magnesium alloy through electrostimulated rolling,which can change the twinning and texture when plastic deformation .This experiment has researched the in 1000A and 1200A current size, 50% and 80% duty ratio,100HZ and 50HZ impulse frequency and without the electrical pulses. After analying the mechanical properties and mechanism of microstructure by different rolling technology electrical pulse ,the results with those of conventional rolling were compared.The results show that:
1.Under the effect of electrostimulated rolling,increased atomic energy,enhanced the movement of dislocations,and the phenomenon of dynamic recrystallization is appeared,and the pulse current can refine grain、delay the formation of twinning and weaken texture.
2.Pulse current have a heating effect on AZ61 magnesium alloy,which can promote dynamic recrystallization of AZ61 magnesium alloy,and improve the mechanical properties of AZ61 magnesium alloy;
3.The larger pulse current, the smaller duty cycle and the larger pulse frequency,which means the more current is applied to the AZ61 magnesium alloy, the greater the heating effect on the magnesium alloy AZ61,which can promote dynamic recrystallization of AZ61 magnesium alloy ,and improve the mechanical properties of AZ61 magnesium alloy;
This experiment provides a new idea for plastic processing,and provides an important reference for electric plastic processing technology of AZ61 magnesium alloy,which have an important significance to promote the application of AZ61 magnesium alloy. 电脉冲参数对AZ61镁合金板材孪晶和织构的影响:http://www.youerw.com/cailiao/lunwen_15499.html