晶粒尺寸对7A04铝合金热变形行为的影响研究  

Influence of Grain Sizes on Hot Deformation Behavior of 7A04 Aluminum Alloy

作　　者：秦清风[1] 谭迎新[1] 杨勇彪[2] 王强[2] 任刚 

机构地区：[1]中北大学化工与环境学院,山西太原030051 [2]中北大学材料科学与工程学院,山西太原030051 [3]山西省机电设计研究院,山西太原030009

出　　处：《热加工工艺》2016年第11期59-63,共5页Hot Working Technology

摘　　要：采用Gleeble-1500热模拟试验机对不同晶粒尺寸的7A04铝合金进行了热压缩试验,研究了变形温度为320~480℃、应变速率为0.001~1 s-1时的晶粒尺寸对热变形行为的影响。利用金相显微镜分析了合金的微观组织。结果表明：在相同变形条件下,粗晶铝合金流变应力明显高于细晶铝合金的流变应力。不同晶粒尺寸的塑性变形机制在320、480℃分别为动态回复和动态再结晶。粗晶与细晶7A04铝合金的本构方程存在明显的差异,其热激活能分别为143.4、125.6 k J/mol。Compression tests of 7A04 aluminum alloy with different grain sizes were carried out by using Gleeble-1500 thermal simulation machine. The influences of grain sizes on hot deformation behavior were studied during the deformation temperature of 320-480 ℃ and the strain rate of 0.001-1 s-1. The results show that the flow stress of the aluminum alloy with coarse grain is higher than that of the aluminum alloy with fine grain at the same hot deformation conditions. The plastic deformation mechanisms with different grain sizes are dynamic recovery and dynamic recrystallization at 320 ℃ and 480 ℃respectively. The constitutive equations of 7A04 aluminum alloy with coarse and fine grain have obviously different, and the thermal activation energy is 143.4 and 125.6 k J/mol respectively.

关 键 词：7A04铝合金 晶粒尺寸 本构方程 动态再结晶 

分 类 号：TG376[金属学及工艺—金属压力加工]