AA6061铝合金冷轧过程中织构的演变与断裂机制  

Texture evolution and fracture mechanism of cold rolled AA6061 alloy

作　　者：黄元春[1,2,3] 颜徐宇[1,4,3] 肖政兵[1,2,3] 杜志勇[2] 黄雨田[3] 邱涛[3] 

机构地区：[1]中南大学材料科学与工程学院,长沙410083 [2]中南大学机电工程学院,长沙410083 [3]中南大学轻合金研究院,长沙410083 [4]中南大学高性能复杂制造国家重点实验室,长沙410083

出　　处：《粉末冶金材料科学与工程》2015年第6期822-828,共7页Materials Science and Engineering of Powder Metallurgy

基　　金：高性能复杂制造国家重点实验室自主研究课题(zzyjkt2013-07B)

摘　　要：对商业用21.5 mm厚度的AA6061铝合金板材进行520℃/3 h固溶处理后,热轧到10 mm厚度,然后冷轧,冷轧变形量分别为21%、59%、78%和90%。通过拉伸性能测试、取向分布函数(ODF)、扫描电镜(SEM)、背散射电子衍射(EBSD)及透射电镜(TEM)等对该合金在冷轧过程中的织构演变、以及冷轧变形量对合金力学性能与断裂机制的影响进行研究。结果表明:随冷轧变形量增加,AA6061铝合金的变形织构逐渐增强,再结晶织构逐渐减弱;合金的抗拉强度随变形量增大而增加,变形量为90%时抗拉强度从热轧态的220 MPa提高到320 MPa;材料的屈服强度与抗拉强度大致相等,两者的变化相仿;随变形量增加,合金的断裂机制由韧窝型断裂转变为韧窝型断裂与沿晶型断裂并存的混合型断裂;伸长率下降,变形量为90%时,伸长率从热轧态的19%左右下降到4.5%。Commercial AA6061 Al alloy sheet with 21.5 mm thickness was hot rolled to 10 mm thickness after 520 ℃/ 3 h solid solution treatment and then cold rolled. The cold rolling deformations were 21%, 59%, 78% and 90% respectively. The texture evolution, the effect of cold rolling deformation on mechanical properties and fracture mechanism of AA6061 alloy were investigated, respectively. The rolled alloys were analyzed by using tensile test, orientation distribution function （ODF）, electron back-scatter diffraction （EBSD）, transmission electron microscopy （TEM）, and so on. The results show that the rolling texture components of AA6061 alloy with the cold rolling treatment increased with the reduction of the sheet thickness, comparing to the recrystallization component. The AA6061 alloy is reinforced from 220 MPa to 320 MPa with the increase of the deformation. The values of the yield strength are similar to the tensile strength. In the beginning, the fracture mechanism of AA6061 alloy is the dimples fracture mechanism at low deformation. With the increase of the deformation, the mechanism is changed to intergranular fracture mechanism together with the dimples fracture mechanism.

关 键 词：AA6061铝合金 织构演变 力学性能 断裂机制 

分 类 号：TG146[一般工业技术—材料科学与工程]