退火工艺对Mg-8Li-3Al-2Zn合金挤压板材显微组织与力学性能的影响  

Effects of Annealing Treatment on Microstructures and Mechanical Properties of Extruded Mg-8Li-3Al-2Zn Plates

作　　者：陈黎松 刘金学 解海涛 刘志鹏[1,4] 宋新宇 肖阳 关绍康 何季麟[1,2] CHEN Lisong;LIU Jinxue;XIE Haitao;LIU Zhipeng;SONG Xinyu;XIAO Yang;GUAN Shaokang;HE Jilin(School of Materials Science and Engineering,Zhengzhou University,Zhengzhou 450001,China;Zhongyuan Critical Metals Laboratory,Zhengzhou 450001,China;Zhengzhou Light Alloy Institute Co.,Ltd.,Zhengzhou 450041,China;Henan Aerospace New Materials Research Institute Co.,Ltd.,Zhengzhou 450100,China)

机构地区：[1]郑州大学材料科学与工程学院,郑州450001 [2]中原关键金属实验室,郑州450001 [3]郑州轻研合金科技有限公司,郑州450041 [4]河南空天新材料研究院有限公司,郑州450100

出　　处：《材料导报》2025年第7期190-194,共5页Materials Reports

基　　金：中央军委装备发展部共性技术项目(50922010302);“慧眼行动”项目(619672D6);中原关键金属实验室研究基金(GJJSGFZD202305);中原科技创业领军人才资助项目(224300510014);国家自然科学基金面上项目(51974281)

摘　　要：采用光学显微镜(OM)、X射线衍射(XRD)、电子背散射衍射(EBSD)等手段研究了Mg-8Li-3Al-2Zn(LAZ832)合金挤压板材在300~420℃内退火15 min后的显微组织与力学性能。结果表明,镁锂合金经挤压后α-Mg与β-Li相均发生动态再结晶,并弥散析出大量亚稳相MgLi_(2)Al。挤压板材经300℃退火后二次相MgLi_(2)Al相消失;340℃退火后,初生相AlLi相开始溶解;380℃退火后,MgLi_(2)Al相和AlLi相近乎完全溶解,同时合金发生静态再结晶与长大,α-Mg相织构类型发生变化,由柱面{1120}〈0001〉织构转变为柱面{1120}〈0001〉和{1120}〈1010〉织构;进一步升高退火温度至420℃,晶粒明显长大。相比挤压态合金,在固溶强化和再结晶软化的综合作用下,随着退火温度的升高,合金的强度出现先增加后降低的趋势。其中合金在380℃退火后性能最优,此时合金强塑性均得到提高,屈服强度提升18.8%,抗拉强度提升13.8%,伸长率提升7.5%。The microstructure and mechanical properties of as-extruded Mg-8Li-3Al-2Zn(LAZ832)alloy after annealing within the temperature range of 300—420℃for 15 minutes were investigated by means of optical microscope(OM),X-ray diffraction(XRD)and electron backscatter diffraction(EBSD).The results show that theα-Mg andβ-Li phases of the Mg-Li alloy undergo dynamic recrystallization after extrusion,and a large amount of metastable phase MgLi_(2)Al is dispersed.The secondary MgLi_(2)Al phase disappeared after the extruded sheets were annealed at 300℃;after annealing at 340℃,the primary AlLi phase began to dissolve;after annealing at 380℃,the MgLi_(2)Al and AlLi phases were basically redissolved,and at the same time,the alloy underwent static recrystallization with grain growth,and the texture type ofα-Mg phase changed from{1120}〈0001〉prismatic texture to{1120}〈0001〉and{1120}〈1010〉prismatic texture;further increasing the annealing temperature to 420℃,grain growth was obvious.The strength of the alloy increases and then decreases with increasing annealing temperature due to the combined effect of solid solution strengthening and recrystallization softening,as compared to the extruded alloy.The alloy achieves optimum performance after annealing at 380℃,with improved strength and plasticity.The yield strength increases by 18.8%,the tensile strength increases by 13.8%,and the elongation increases by 7.5%.

关 键 词：退火 镁锂合金 固溶强化 再结晶 织构 

分 类 号：TG15[金属学及工艺—热处理]