摘要近年来，镁合金由于其密度小，比强度和比刚性高等一系列优点， 备受关注，其应用领域已涉及汽车、航空、航天等诸多方面。但由于其为密排优尔方结构，在室温下滑移系少，塑性差，导致其较难进行塑性加工（如冲压）。因此，研究成形温度、晶粒尺寸对于镁合金胀形性能的影响，对改善和加强镁合金的应用具有重要的意义。
本文选用AZ31 镁合金轧制板料为研究对象，改变退火温度和保温时间，对AZ31 镁合金轧制板料进行退火实验。通过 Erichsen胀形实验和金相试验研究了不同晶粒尺寸和变形速率下 AZ31镁合金板的胀形性能及胀形过程中的微观组织变化。 21593
研究结果表明，在胀形过程中，板料的减薄区最严重的位置在距离球形冲头中心 1/3半径处，并且该区域也是裂纹出现的位置。通过胀形试验发现，不同退火温度和退火时间对于 AZ31镁合金板料的影响是不一样的。退火温度为 300oC 和350oC，板料的 Erichsen值随着退火时间的延长而增加；而在退火温度为 400oC
条件下，Erichsen 值随着退火时间先降后升再降。此外，镁合金板料在经过胀形试验后，观察其金相组织，发现组织中有孪晶出现，且 Erichsen 值较高的板料，其组织中孪晶数量较多。因此，孪晶的出现有利于板料胀形性能的改善。
关键词 AZ31镁合金 塑性 成形工艺 胀形
Title The research of bulging performance forAZ31 magnesium alloy sheet
Abstract
In recent years, the researcher are focus on magnesium alloys because of
its small density ,high specific strength and specific stiffness and a
series of advantages, and already applied in various industries, such
as automotive, aviation, aerospace and other industrial fields. At room
temperature, slip system of magnesium and magnesium alloys is less because
of their typical hexagonal close-packed crystal structure, lead to low
plasticity and plastic processing difficult. Therefore, it is significant
to improve and strengthen the application of magnesium alloy that
studying the effects of forming temperature grain size on magnesium alloy
bulging performance.
This article selects the AZ31 magnesium alloy rolling sheet as the
research subject and magnesium alloy sheet annealing experiments is
adopting the conditions of different temperature and time to get different
grain size sheet. By Erichsen bulging experiment and metallographic test,
we study the change of bulging properties and the microstructure in the
process of bulging under different grain size and strain rate of AZ31
magnesium alloy sheet.
The results show that the thinning area of metal sheet is at distances
from the center of the spherical punch 1/3 radius in the bulging process,
and is also the location of the crack appears in the area. By the bulging
experiment, it is found that the influence of different annealing
temperature and time for AZ31 magnesium alloy sheet are not the same. When
the annealing temperature is 300o
C and 350o
C, Erichsen value of metal sheet
is increases with annealing time. And under the condition of the annealing
temperature is 400o
C, Erichsen value is rise and fall after fall first as
the annealing time. In addition, the sheet microstructure after bulging
experiment was observed, and it is found that microstructure have
crystal twinning ,and the number of crystal twinning is more in the higher AZ31镁合金板料胀形性能的研究:http://www.youerw.com/cailiao/lunwen_13861.html