铝合金板材三向应力状态下的成形性能  

Experiment on formability of aluminum alloy sheet under three dimensional stress state

作　　者：郎利辉[1] 阚鹏[1] 王耀[1] 孙志莹[1] 张泉达 

机构地区：[1]北京航空航天大学机械工程及自动化学院,北京100191

出　　处：《吉林大学学报（工学版）》2017年第5期1527-1533,共7页Journal of Jilin University:Engineering and Technology Edition

基　　金：国家重大科技专项项目(2014ZX04002041)

摘　　要：基于覆层板椭圆液压胀形试验对铝合金2B06板材在三向应力作用下的成形性能进行了研究。通过不同椭圆长短轴比的椭圆胀形试验获取成形板材的等效应力-应变曲线,同时,改变包覆层板的材料和厚度,进而探究其对成形板材的流动性的影响。结果表明:在有包覆层板作用的情况下,发生颈缩时等效应力-应变曲线能够达到更大的应变量,并且随着凹模椭圆长短轴比的减小,流动应力曲线与圆(椭圆长短轴之比为1)胀形的曲线偏差也越来越大;当包覆层板的强度系数、加工硬化指数以及厚度越大时,成形板材受到包覆层板的厚度法向应力越大,试件壁厚分布也更加均匀。合适的包覆层板能够显著地改善成形板材的流动特性。An experiment study on the flow characteristics of aluminum alloy 2B06 sheet under normal stress is carried out on the basis of the elliptical hydraulic bulging.The equivalent stress-strain curves of the target sheet are obtained by the ellipse bulging experiment with different ratio of the length semi-major to semi minor,b/a;meanwhile,the material and the thickness of the overlapping sheet are varied.The results show that,when nicking occurs,the equivalent stress-strain curve of the target sheet can achieve greater strain under the action of overlapping sheet.With the decrease in b/a,the flow stress curves tend move away from the curve obtained by circular(b/a=1)bulging test.At the same time,the larger strength coefficient of overlapping sheet,larger hardening exponent and larger thickness of the overlapping sheet lead the thickness of the target sheet more uniform.Proper overlapping sheet can significantly improve the flow characteristics of the target sheet.

关 键 词：机械制造工艺与设备 流动特性 覆层板 椭圆胀形 厚度法向应力 

分 类 号：TG115.5[金属学及工艺—物理冶金]