铝合金超塑性差温拉深研究论文.pdf

摘要
超塑性铝合金AA5083具有较高的抗拉强度、抗腐蚀性、可焊接性,广
泛应用于航天、航空,船舶等部门。
铝合金AA5083超塑性的差温拉深,就是保持板料突缘部分在超塑性变
形温度下而凸模通水冷却的条件下,并且在一定的应变速率下对板料进行
拉深,使板料拉深性能显著提高。变形温度范围在350℃—535℃之间,超
塑性应变速率范围在10-5—10-2之间,通过对铝合金AA5083超塑性单向拉
伸实验来研究AA5083的力学特性。实验表明:AA5083的最佳变形温度是
525℃,最佳应变速率为2×10-4/s,最大延伸铝为470%。分别用等应变速率
,并且得到不同变形温
度下的本构关系。
超塑性差温拉深主要是通过控制拉深件突缘与凸模底部之间的温度
差来实现板料拉深性能的提高。本文主要通过建立板料与凸模接触时的温
度分布情况,定义不同温度下的材料属性,然后进行超塑性差温拉深模拟。
模拟结果表明:超塑性差温度拉深比超塑性拉深的厚度分布更均匀,并且
变形温度,拉深速度和摩擦都会对结果产生影响。
超塑性差温拉深试验除了突缘与筒壁之间的温度差之外,变形温度和
凸模的拉深速度也是影响试验结果的重要因素。在最佳变形温度下,计算
出凸模的最佳拉深速度。最后用超塑性差温拉深的工艺方法成形了空客的
支架零件。成形零件厚度均匀,试验结果和模拟结果基本一致。
关键词: 超塑性,变形温度,延伸率,应变速率敏感指数,超塑性差温
拉深,有限元模拟,厚度分布
南京航空航天大学硕士学位论文
ABSTRACT
Having medium mechanical behavior, high strength, good corrosion resistance, and
very good welding property, AA5083 of superplastic aluminium alloy is widely used in
the department of Aeronautics, Astronautics and ship.
In this paper, the superplastic differential temperature drawing of AA5083aluminum
alloy is performed. Deep drawing of sheet is made by the superplastic temperature, the
certain strain rate of the flange zone of a blank was kept, and the wall of die was
cooled. The deep drawability of the sheet was improved markedly. Uniaxial tensile test
of AA5083 aluminum alloy were carried out to research mechanical behavior at
temperatures between 350℃ and 535℃ over the initial strain rate from 10-5s-1 to
10-2s-1. It was found that the best temperature is 525℃, the best strain rate is
×10-4s-1, and the maximum elongation is 470%. Both constant strain rate and
velocity jump test were carried out to measure the strain rate sensitivity biggest
m value is and , and we obtained an elastic-viscoplastic constitutive modeling
under different temperature.
The differential temperature superplastic drawing realized to impove deep
drawability of the sheet by controlling temperature at punch bottom and die flange.
With research on defo