通过失重法和电化学测试研究了稀土元素Gd对Mg-6Zn-Zr合金耐腐蚀性能的影响,并通过光学显微镜、扫描电镜和能谱仪观察了合金的显微组织和腐蚀形貌特征。结果表明：稀土Gd的添加有效细化了合金的晶粒,同时形成了Mg2Gd相和Mg-Zn-Gd相。随...通过失重法和电化学测试研究了稀土元素Gd对Mg-6Zn-Zr合金耐腐蚀性能的影响,并通过光学显微镜、扫描电镜和能谱仪观察了合金的显微组织和腐蚀形貌特征。结果表明：稀土Gd的添加有效细化了合金的晶粒,同时形成了Mg2Gd相和Mg-Zn-Gd相。随稀土元素Gd的添加,合金的腐蚀速率先增后减。当稀土Gd含量达到1.5wt%时,较基体合金自腐蚀电位提升36 m V,腐蚀速率下降40%,即Mg-Zn-Zr-1.5Gd合金的耐腐蚀性较好。展开更多
The microstructures and mechanical properties of Mg-9Gd-4Y-0.6Zr alloy were investigated. The results show that the ultimate tensile strengths of the extrusion-T5 temper of this alloy at -196,25, 250, 300 and 350℃are...The microstructures and mechanical properties of Mg-9Gd-4Y-0.6Zr alloy were investigated. The results show that the ultimate tensile strengths of the extrusion-T5 temper of this alloy at -196,25, 250, 300 and 350℃are as high as 521, 370, 348,262 and 150 MPa, respectively. It is noteworthy that 8% plasticity occurs at -196℃and 180% superplasticity occurs at 400℃. In the peak hardness of Cast-T5, Cast-T6, Ext-T5 and Ext-T6, the highest is that of Ext-T5. The prismatic precipitates providing an effective barrier to dislocation gliding on the basal plane are the cause of strengthening of this alloy. The plate-shaped precipitates formed on the prismatic planes provide the most effective barriers to the gliding dislocations, and they are the cause of strengthening of this alloy.展开更多
In order to improve the corrosion and mechanical properties of AM50 magnesium alloy, 1 wt.% Gd was used to modify the AM50 magnesium alloy. The microstructure, corrosion and mechanical properties were evaluated by X-r...In order to improve the corrosion and mechanical properties of AM50 magnesium alloy, 1 wt.% Gd was used to modify the AM50 magnesium alloy. The microstructure, corrosion and mechanical properties were evaluated by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, energy dispersive spectroscopy （EDS）, electrochemical and mechanical stretch methods. The results indicated that β-Mg17Al12 phase decreased and Al2Gd3 and Al0.4GdMn1.6 phase existed after Gd addition. Because of the Gd addition, the grain of AM50 magnesium alloy was refined significantly, which improved the tensile strength of AM50 magnesium al-loy. The decreasing ofβ phase improved the corrosion resistance of the magnesium alloy. The fracture mechanism of the Gd modified AM50 magnesium alloy was quasi-cleavage fracture. The corrosion residual strength （CRS） of AM50 magnesium alloy was im-proved after 1 wt.% Gd addition.展开更多
稀土镁合金因其优异的室温及高温力学性能而具有广阔的发展前景,文中详细介绍了稀土镁合金中稀土元素在铸造性能、微观组织、力学性能和耐蚀性能方面的作用,以及Mg-Y和Mg-Gd两大主要稀土镁合金系的发展现状。重点分析了目前的研究热点之...稀土镁合金因其优异的室温及高温力学性能而具有广阔的发展前景,文中详细介绍了稀土镁合金中稀土元素在铸造性能、微观组织、力学性能和耐蚀性能方面的作用,以及Mg-Y和Mg-Gd两大主要稀土镁合金系的发展现状。重点分析了目前的研究热点之一:长周期有序结构LPSO(Long Period Stacking Ordered Structure),并针对Mg-Y(-RE)-Zn和Mg-Gd(-RE)-Zn两个合金系的研究现状进行了阐述;如何提高稀土镁合金的强度、韧性、高温性能和耐蚀性能等方面的同时,解决高成本制备和环境污染问题,建立健全一个绿色的稀土镁合金产业链仍需科研工作者的进一步努力研究。展开更多
文摘通过失重法和电化学测试研究了稀土元素Gd对Mg-6Zn-Zr合金耐腐蚀性能的影响,并通过光学显微镜、扫描电镜和能谱仪观察了合金的显微组织和腐蚀形貌特征。结果表明：稀土Gd的添加有效细化了合金的晶粒,同时形成了Mg2Gd相和Mg-Zn-Gd相。随稀土元素Gd的添加,合金的腐蚀速率先增后减。当稀土Gd含量达到1.5wt%时,较基体合金自腐蚀电位提升36 m V,腐蚀速率下降40%,即Mg-Zn-Zr-1.5Gd合金的耐腐蚀性较好。
基金Project(51330) supported by the National Fundamental Research Program of China
文摘The microstructures and mechanical properties of Mg-9Gd-4Y-0.6Zr alloy were investigated. The results show that the ultimate tensile strengths of the extrusion-T5 temper of this alloy at -196,25, 250, 300 and 350℃are as high as 521, 370, 348,262 and 150 MPa, respectively. It is noteworthy that 8% plasticity occurs at -196℃and 180% superplasticity occurs at 400℃. In the peak hardness of Cast-T5, Cast-T6, Ext-T5 and Ext-T6, the highest is that of Ext-T5. The prismatic precipitates providing an effective barrier to dislocation gliding on the basal plane are the cause of strengthening of this alloy. The plate-shaped precipitates formed on the prismatic planes provide the most effective barriers to the gliding dislocations, and they are the cause of strengthening of this alloy.
基金Project supported by National Natural Science Foundation of China(51201068)Science and Technology Development Projects of Jilin Province(201201032)Science and Technology Development of Changchun City(11KZ31)
文摘In order to improve the corrosion and mechanical properties of AM50 magnesium alloy, 1 wt.% Gd was used to modify the AM50 magnesium alloy. The microstructure, corrosion and mechanical properties were evaluated by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, energy dispersive spectroscopy （EDS）, electrochemical and mechanical stretch methods. The results indicated that β-Mg17Al12 phase decreased and Al2Gd3 and Al0.4GdMn1.6 phase existed after Gd addition. Because of the Gd addition, the grain of AM50 magnesium alloy was refined significantly, which improved the tensile strength of AM50 magnesium al-loy. The decreasing ofβ phase improved the corrosion resistance of the magnesium alloy. The fracture mechanism of the Gd modified AM50 magnesium alloy was quasi-cleavage fracture. The corrosion residual strength （CRS） of AM50 magnesium alloy was im-proved after 1 wt.% Gd addition.
文摘胶州湾在促进青岛市经济发展的同时,人为活动对胶州湾的污染也愈发严重。本文对胶州湾冬季稀土元素(Rare earth elements,REEs)的地球化学特征和人为镧(La)、钆(Gd)污染进行了研究。胶州湾溶解态和酸溶态REEs含量的变化范围分别为:3.5 pmol/L(铕Eu)~359.1 pmol/L(铈Ce)和6.9 pmol/L(铥Tm)~4861.8 pmol/L(Ce)。由于颗粒物对REEs的吸附,导致溶解态的浓度明显低于酸溶态,溶解态REEs的PAAS(Post-Archean Average Australian Shale,后太古代澳大利亚页岩)标准化配分曲线表现为重稀土富集;(Yb)PAAS/(Nd)PAAS比值平均为4.7±0.7(Yb和Nd为镱和钕,分别代表重稀土元素和轻稀土元素),说明胶州湾溶解态轻稀土和重稀土之间分馏程度较大。酸溶态REEs配分曲线表现为中稀土富集;酸溶态轻中重稀土元素之间分馏程度较低。胶州湾溶解态和酸溶态钇(Y)和钬(Ho)之间也发生了明显分馏。溶解态Ce/Ce*表现为负异常,处于世界上已报道海湾Ce/Ce*变化范围之内;酸溶态Ce/Ce*表现为弱正异常,接近地壳平均值,具有亲陆性特征。La_(anthr)和Gd_(anthr)分别为人为源La和Gd的浓度,胶州湾溶解态La_(anthr)的平均浓度为(113.8±39.3)pmol/L,%Laanthr平均占(63.7±7.9)%;内湾人为La污染(La_(anthr)平均为(121.3±43.1)pmol/L)比外湾(La_(anthr)平均为(98.0±22.6)pmol/L)严重。Gd_(anthr)平均为(5.8±3.1)pmol/L,%Gd_(anthr)平均为(22.3±4.5)%。胶州湾人为La污染比Gd污染严重。
文摘稀土镁合金因其优异的室温及高温力学性能而具有广阔的发展前景,文中详细介绍了稀土镁合金中稀土元素在铸造性能、微观组织、力学性能和耐蚀性能方面的作用,以及Mg-Y和Mg-Gd两大主要稀土镁合金系的发展现状。重点分析了目前的研究热点之一:长周期有序结构LPSO(Long Period Stacking Ordered Structure),并针对Mg-Y(-RE)-Zn和Mg-Gd(-RE)-Zn两个合金系的研究现状进行了阐述;如何提高稀土镁合金的强度、韧性、高温性能和耐蚀性能等方面的同时,解决高成本制备和环境污染问题,建立健全一个绿色的稀土镁合金产业链仍需科研工作者的进一步努力研究。
