摘要
利用真空感应熔炼-反向热挤压法制备了Mg-16Gd-xZn(x=0,0.5,1.0,2.0,wt.%)4组合金,用X射线衍射,激光扫描共聚焦显微镜、扫描电镜、透射电镜、能谱分析仪及EBSD技术研究了Zn元素添加对挤压态Mg-16Gd-xZn合金微观组织的影响。研究结果表明:Zn元素添加可以有效地细化合金晶粒,平均晶粒尺寸由4.8±2.3μm细化至3.3±1.4μm。二元Mg-16Gd合金由α-Mg与Mg5Gd两相构成;当添加Zn至x=0.5、x=1.0时,两组合金均由α-Mg、Mg5Gd、(Mg,Zn)3Gd三相组成;而Zn添加至x=2.0时,合金由α-Mg与(Mg,Zn)3Gd两相构成。挤压态Mg-16Gd-2.0Zn合金内存在大量的片层状γ'强化相,沿着{0001}基面生长,与基体完全共格。
Mg-16Gd-xZn(x=0,0.5,1.0,2.0,wt.%) alloys were fabricated by vacuum induction melting-indirect hot extrusion,microstructure and texture were investigated by X-ray diffraction,laser scanning confocal microscope,scanning electron microscope,transmission electron microscope,energy dispersive spectrometer and electron back scattering diffraction.Results show that grains of these extruded alloys are considerably refined when the zinc addition,and the grain size decreases from 4.8 μm to 3.3 μm.Mg-16 Gd binary alloy consist of α-Mg solid solution and Mg5Gd phase;when adding zinc to x=0.5,x=1.0,the alloys all consist of α-Mg,Mg5Gd and(Mg,Zn)3Gd phase;and added Zn to x=2.0,the Mg-16 Gd-2.0 Zn alloy consist of α-Mg and(Mg,Zn)3Gd.There are a large number of lamellar γ' phase within the α-Mg matrix in the extruded Mg-16Gd-2.0Zn alloy,it formed as(0001)α plates and completely coherent with the α-Mg matrix.
引文
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