超快速加热退火下保温时间对5083铝合金组织及力学性能的影响

Effect of annealing holding time on microstructure and mechanical properties of 5083 aluminum alloy under ultra-rapid heating annealing

利用Gleeble-3500热模拟系统和电子背散射衍射(EBSD)技术对5083铝合金超快速退火组织的演变规律进行了研究,探讨了5083铝合金经过80%冷轧变形后以500℃/s加热至450℃时,不同保温时间(1~60 s,冷却速度40℃/s)对退火组织及力学性能的影响。结果表明,随退火保温时间从1 s延长到60 s,5083铝合金的平均晶粒尺寸由4.94μm增大到6.44μm,合金中主要产生了再结晶立方退火织构{001}<100>、旋转立方织构{001}<110>,以及少量的高斯织构{011}<100>和黄铜型织构{011}<211>。当退火保温时间从1 s增加到60 s,整体上合金中的再结晶退火织构先增强再减弱。退火保温时间对5083铝合金的强度影响较小,5083铝合金的屈服强度、抗拉强度没有明显的变化,分别约为170 MPa、326 MPa,而其伸长率由25.63%逐渐增大至30.06%,最后又降低至25.20%。

Microstructure evolution of 5083 aluminum alloy during ultra-rapid annealing was studied by means of Gleeble-3500 thermal simulation system and electron backscatter diffraction(EBSD)technology.When the 5083 aluminum alloy with cold deformation of 80%was heated to 450℃with heating rate of 500℃/s,the effect of annealing holding time(1-60 s,cooling rate of 40℃/s)on microstructure and mechanical properties was discussed.The results show that with the increase of annealing holding time from 1 s to 60 s,the average grain size of 5083 aluminum alloy increases from 4.94μm to 6.44μm,and the recrystallization textures in 5083 aluminum alloy consist of cube annealed texture of{001}<100>,rotation cube texture of{001}<110>,Gauss texture of{011}<100>and brass texture of{011}<211>.When the annealing holding time increases from 1 s to 60 s,on the whole,recrystallization textures in the alloy present a trend of increasing first and then decreasing,also the annealing holding time has little effect on strength of 5083 aluminum alloy,the yield strength and tensile strength of the 5083 aluminum alloy are about 170 MPa and 326 MPa,respectively.But the elongation of the 5083 aluminum alloy first increases from 25.63%to 30.06%and then decreases to 25.20%.