日本Sky公司提供的SP5083铝合金板材,分析其化学成分为Al–4.6 Mg–0.67Mn–0.1Cr–0.02Cu–0.05Si–o0.05 Fe–o0.01Ti.合金坯料是在530℃经过8小时使之均匀化然后经热轧成厚度为6㎜之后经冷轧成厚度为2

日本Sky公司提供的SP5083铝合金板材,分析其化学成分为Al–4.6 Mg–0.67Mn–0.1Cr–0.02Cu–0.05Si–o0.05 Fe–o0.01Ti.合金坯料是在530℃经过8小时使之均匀化然后经热轧成厚度为6㎜之后经冷轧成厚度为2
日本Sky公司提供的SP5083铝合金板材,分析其化学成分为Al–4.6 Mg–0.67Mn–0.1Cr–0.02Cu–0.05Si–o0.05 Fe–o0.01Ti.合金坯料是在530℃经过8小时使之均匀化然后经热轧成厚度为6㎜之后经冷轧成厚度为2㎜.板片在400℃经过10分钟的再结晶处理后,对于超塑性变形所得的预先平均晶粒尺寸为8.m.
在这项研究中,在每项试验中使用浸蚀板片上直径d0(2.5mm)的小圆形网格来测量应变速率.在超塑性成形的过程中浸蚀的小圆会因变形而变成椭圆形或变成较大的圆形.分别测量变形后长轴及短轴直径d1,d2来确定主轴应变.主轴应变、等效应变、应变速率可表达为：
ε1=ln(d1+d0) (1)
ε2=ln(d2+d0) (2)
ε3=ln(h/h0) (3)
=
=
式中：h0:最初板片厚度
h:变形后板片厚度
ε1,2,3：1,2及3方向主轴应变
：等效应变
：实际应变速率
t:成形时间
2.2超塑性成形试验
压力吹气成形模腔形状包括矩形和圆柱形.标准圆柱形模腔为直径40㎜和深度20㎜.矩形模腔为120㎜（长）*40㎜（宽）*20㎜（深）.模具是由4340低中碳合金钢构成的,其表面粗糙度为Ra=0.84?m,Ra值为算术平均粗糙度.超塑性通过有无润滑作用下的氩气压缩变形成为模腔.通过计算机SUPFORM2程序来计算期望的应变速率中的压力分布.为了达到期望的应变速率也通过计算机程序进行试运行来修改预测的压力分布.压力吹气成形在525℃下并且在应变速率分别为

日本Sky公司提供的SP5083铝合金板材,分析其化学成分为Al–4.6 Mg–0.67Mn–0.1Cr–0.02Cu–0.05Si–o0.05 Fe–o0.01Ti.合金坯料是在530℃经过8小时使之均匀化然后经热轧成厚度为6㎜之后经冷轧成厚度为2
Japan Sky provided SP5083 alloy plates,to analyze its chemical composition for Al-4.6 Mg-0.67Mn-0.1Cr-0.02Cu-0.05Si-o0.05 Fe-o0.01Ti.Alloy billets are at 530 ℃ after 8 hours And so that homogenization by hot-rolled into a thickness of 6 mm followed by cold-rolled into a thickness of 2 mm.Plate at 400 ℃ after 10 minutes after the recrystallization treatment,the superplastic deformation proceeds in advance of the average grain size of 8.M.
In this study,at each trial on the use of etching plate diameter d0 (2.5mm) small circular grid to measure the strain rate.In the superplastic forming process of erosion of the small round will become deformed into a large oval or round.Were measured after deformation and short-axis diameter of the long axis of d1,d2 to determine the strain axis.Axis strain,equivalent strain,strain rate can be expressed as:
ε1 = ln (d1 + d0) (1)
ε2 = ln (d2 + d0) (2)
ε3 = ln (h/h0) (3)
=
=
Where:h0:initial slab thickness
h:plate thickness after deformation
ε1,2,3:1,2 and the direction of 3 axis strain
:Equivalent strain
:The actual strain rate
t:Forming time
2.2 Superplastic Forming Test
Stress inflatable cavity forming the shape,including rectangular and cylindrical.Standard cylindrical cavity diameter 40 mm and depth 20 mm.Rectangular cavity of 120 mm (L) * 40 mm (wide) * 20 mm (D).Die by the 4340 low carbon steel composition,its surface roughness Ra = 0.84?M,Ra value is the arithmetic average roughness.Superplasticity,through the availability of lubrication under argon deformation become a cavity.SUPFORM2 computer program to calculate the desired strain rate in stress distribution.In order to achieve the desired strain rate through a computer program to carry out trial run to modify the prediction of pressure distribution.Forming inflatable stress at 525 ℃ and strain rate under separately for