热轧压下率对车用大厚度比镁铝合金板组织和力学性能的影响  

Effects of hot rolling reduction rate on microstructure and mechanical properties of Mg/Al alloy plate with large thickness ratio used in automotive

作　　者：赵华瑞[1] 丁彦霞 Zhao Huarui;Ding Yanxia(Department of Automobile Technology,Xinxiang Vocational and Technical College,Xinxiang 453000,China;School of Physics and Material Science,Henan Normal University,Xinxiang 453000,China)

机构地区：[1]新乡职业技术学院汽车技术系,河南新乡453000 [2]河南师范大学物理与材料科学学院,河南新乡453000

出　　处：《锻压技术》2021年第10期99-105,共7页Forging & Stamping Technology

基　　金：国家自然科学金资助项目(51775172)。

摘　　要：选择厚度为0.2 mm的6063铝合金与厚度为5.0 mm的AZ80镁合金进行组坯,设定厚度比为20,分析各热轧压下率下、以热轧方式制得的大厚度比镁铝合金板的组织和力学性能。研究结果表明:当热轧压下率达到45%或更高时,镁铝合金板形成了结合性能优异的界面,镁基体内形成了均匀分布的细小晶粒;提高热轧压下率后,基体中的晶粒尺寸不断减小,此时形成了更小的晶粒尺寸离散系数,更多晶粒被压碎,晶粒分布状态也比较均匀;提高热轧压下率后,获得了更高屈服强度的大厚度比镁铝合金板,材料发生了更明显的加工硬化,而抗拉强度则先增大再下降,当热轧压下率达到55%时,获得了最大的抗拉强度;当热轧压下率达到65%时,韧窝数量明显增多,表明镁合金通过动态再结晶转变获得了更强的韧性。屈服应力呈现明显波动的状态,热轧压下率为35%时,获得了最高的屈服强度,65%热轧压下率下的屈服强度最低,逐渐提高热轧压下率后,屈服应力也不断减小。The billets of 6063 aluminum alloy with the thickness of 0.2 mm and AZ80 magnesium alloy with the thickness of 5.0 mm was selected to assembling and the thickness ratio was set as 20.The microstructure and mechanical properties of Al/Mg alloy plate with large thickness ratio were analyzed under various hot rolling reduction rates by hot rolling.The results show that when the hot rolling reduction rate reaches 45%or higher,Al/Mg alloy plate forms an interface with excellent bonding performance,and the fine grains are evenly distributed in the magnesium matrix.After increasing the hot rolling reduction rate,the grain size of matrix decreases continuously.At this time,the smaller grain size dispersion coefficient is formed,more grains are crushed,and the grain distribution is more uniform.After increasing the hot rolling reduction rate,the Al/Mg alloy plate with larger thickness ratio and higher yield strength is obtained,and the material undergoes more obvious work hardening.The tensile strength increases first and then decreases,and the maximum tensile strength is obtained when the hot rolling reduction rate reaches 55%.The number of dimples increases significantly when the hot rolling reduction rate reaches 65%,indicating that the magnesium alloy obtaines stronger toughness through dynamic recrystallization transformation.The yield stress fluctuates obviously.The highest yield strength is obtained when the hot rolling reduction rate is 35%,and the lowest yield strength is obtained when the hot rolling reduction rate is 65%.After increasing the hot rolling reduction rate gradually,the yield stress also decreases continuously.

关 键 词：热轧 压下率 大厚度比 镁铝合金板 微观组织 力学性能 

分 类 号：TG146[一般工业技术—材料科学与工程]