锤锻及时效对Mg-8.3Gd-2.6Y-0.4Zr合金组织和力学性能的影响  

Effect of hammer forging and ageing treatment on microstructure and mechanical properties of Mg-8.3Gd-2.6Y-0.4Zr alloy

作　　者：赵伟堃 黄艳灵 董国超 李蕴泽 吕玲芳 陆冬华 王必正 ZHAO Weikun;HUANG Yanling;DONG Guochao;LI Yunze;LÜLingfang;LU Donghua;WANG Bizheng(Geely Farizon New Energy Commercial Vehicles Group Limted Company,Hangzhou 310000,China)

机构地区：[1]浙江吉利远程新能源商用车集团有限公司,浙江杭州310000

出　　处：《兵器材料科学与工程》2023年第3期121-128,共8页Ordnance Material Science and Engineering

摘　　要：用OM、EBSD、TEM、拉伸测试等手段,研究15%变形量的单向锤锻及265℃时效对Mg-8.3Gd-2.6Y-0.4Zr(质量分数)合金显微组织和力学性能的影响,结果表明:经510℃锻造,合金中变形与再结晶晶粒数量各占一半且尺寸接近。经440℃锻造,合金以变形大晶粒为主,晶内位错相互缠结。经390℃锻造,合金只存在变形大晶粒,其内部产生孪晶和呈近似平行分布的位错。锤锻态样品力学性能接近。经265℃/6 h时效,再结晶晶粒及富含缠结位错的晶粒内部形成均匀对称分布的β’相,合金强度提升约45~49 MPa,但伸长率降低。含平行分布位错的晶粒内部形成相同取向的β’相和无沉淀析出带(PFZs),相同取向的β’相可提升合金强度约30~36 MPa,PFZs促进应力释放,提升了合金伸长率。The effect of unidirectional hammer forging with a deformation of 15% and aging at 265 ℃ on the microstructure and mechanical properties of Mg-8.3Gd-2.6Y-0.4Zr(mass percent)alloy was investigated by using OM、EBSD、TEM and tensile tests.Results show that when forged at 510 ℃,the deformed and DRXed grains exhibit a nearly same quantity and an approaching grain size.When forged at 440 ℃,the microstructure is mainly composed of coarse deformed grains with tangled dislocations.When forged at 390 ℃,the microstructure is comprised of coarse deformed grains with nearly parallel arranged adislocations.The as-forged alloys exhibit similar mechanical properties.When aged at 265 ℃ for 6 h,β' phases with homogeneous and symmetric distribution are formed within DRXed grains as well as deformed grains with tangle dislocations inside,resulting in an improvement of 45-49 MPa for strength but a decrease for elongation.β' phases with the same orientation and precipitate free zones(PFZs)are formed within grains with nearly parallel arranged a dislocations inside.The strength is increased by 30-36 MPa from β' phases with the same orientation.The elongation is improved due to the stress relaxation promoted by PFZs.

关 键 词：MG-GD-Y-ZR 锤锻 位错 β’相 PFZ 力学性能 

分 类 号：TG319[金属学及工艺—金属压力加工] TG146.22[一般工业技术—材料科学与工程] TG156.92[金属学及工艺—金属材料]