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The effects of Ca and Mn on the microstructure,texture and mechanical properties of Mg-4 Zn alloy

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Journal of Magnesium and Alloys 2021年第3期9卷 1084-1097页

作者： chunquan liu Xianhua Chen Jiao Chen Andrej Atrens Fusheng Pan International Joint Laboratory for Light Alloys(MOE) College of Materials Science and EngineeringChongqing UniversityChongqing 400045China National Engineering Research Center for Magnesium Alloys Chongqing UniversityChongqing 400045China Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of ScihencesShenyang 110016China School of Mechanical and Mining Engineering The University of QueenslandSt Lucia Qld 4072Australia

The microstructural evolution,texture and mechanical properties of nine Mg-4Zn-xCa-yMn alloys(x=0.3,0.6,1.0;y=0.2,0.3,0.7 wt.%)were investigated *** with Ca and Mn refined the grains of the extruded sheets and increased the unDRX *** could be the heterogeneous nucleation site of Ca2Mg6Zn3 phase because of a good atom matching at the orientation relationship of(211)_(Mn)//(1211)_(Ca2Mg6Zn3),(251)_(Mn)//〈1103〉_(Ca2Mg6Zn3).The traditional texture weakening effect of Ca was strongly decreased for the simultaneously addition of *** increasing Ca and Mn concentration,the strength increased and ductility ***-4Zn-0.6Ca-0.7Mn exhibited a good combination of ultimate tensile strength(320 MPa),yield strength(286 MPa)and elongation(16%).A model of strengthening indicated that grain boundary strengthening and precipitate strengthening made a large contribution to the strength of *** addition,the dynamic recrystallization,texture modification and the strengthening effect from different parts also have been analyzed in detail.

关键词： Mg-Zn-Ca-Mn alloy Texture Dynamic recrystallization Particle-stimulated nucleation Mechanical properties

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超高速激光熔覆制备耐腐蚀涂层研究进展

中国腐蚀与防护学报 2024年第4期44卷 847-862页

作者：杨海云刘春泉熊芬陈敏纳谢岳林彭龙生孙胜刘海洲湖南工学院材料科学与工程学院衡阳421002 湖南力方轧辊有限公司(湖南省高耐磨合金材料先进制造工程技术研究中心) 衡阳421681 新余华峰特钢有限公司新余338099

首先总结了涂层材料元素组成对耐腐蚀性能的影响;其次,从钝化膜、显微组织、位错、低角度晶界、热腐蚀动力学等几个方面总结了其与耐腐蚀性的联系;第三,综述了EHLA与场外辅助技术结合对所制备涂层耐腐蚀性的影响;最后,总结和展望了超高... 详细信息

首先总结了涂层材料元素组成对耐腐蚀性能的影响;其次,从钝化膜、显微组织、位错、低角度晶界、热腐蚀动力学等几个方面总结了其与耐腐蚀性的联系;第三,综述了EHLA与场外辅助技术结合对所制备涂层耐腐蚀性的影响;最后,总结和展望了超高速激光熔覆所制备涂层耐腐蚀性能的强化方法。

关键词：超高速激光熔覆腐蚀行为涂层

Altered age-hardening behavior in the ultrafine-grained surface layer of Mg-Zn-Y-Ce-Zr alloy processed by sliding friction treatment

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Journal of Materials Science & Technology 2021年第19期78卷 20-29页

作者： chunquan liu Xianhua Chen Yuan Yuan Wei Zhang Yusheng Zhang Fusheng Pan International Joint Laboratory for Light Alloys(MOE) College of Materials Science and EngineeringChongqing UniversityChongqing400045China National Engineering Research Center for Magnesium Alloys Chongqing UniversityChongqing400045China Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang110016China Northwest Institute for Nonferrous Metal Research Xi'an710016China

To gain insight into the ageing behavior of ultrafine grain(UFG)structure,the precipitation phenomena and microstructural evolutions of Mg-6 Zn-1 Y-0.4 Ce-0.5 Zr(wt.%)alloy processed by sliding friction treatment(SFT)were systematically studied using hardness texting,transmission electron microscopy(TEM)equipped with high-angle annular dark-field scanning(HADDF-STEM),X-ray diffraction(XRD)and XRD line broadening *** microhardness of the SFT-processed(SFTed)sample initially decreases from 109.6 HV to 104.8 HV at ageing for 8 h,and then increases to the peak-ageing point of 115.4 HV at16 ***,it enters the over-aged *** un-SFTed sample,as the counterpart,follows a regular ageing behavior that increases from 89.9 HV to 99.6 HV when ageing for 12 h,and then drops.A multi-mechanistic model is established to describe the strengthening due to grain refinement,dislocation accumulation,precipitation *** analysis reveals that the temperature sensitive UFG structure has an obvious grain coarsening effect,which arouses the soft phenomenon in the early ageing *** precipitation hardening provides an excellent hardness enhancement for overcoming the negative influence and helping to reach the peak-aged *** our microstructural observations,a lot of equilibrium ultrafine Mg Zn2 precipitates precipitate along dislocations because defects can provide the favorable conditions for the migration and segregation of solute atoms.

关键词： Ageing behavior Ultrafine-crystalline grain Nano precipitates Sliding friction treatment

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超声预处理对荠菜微波干燥品质的影响

农业工程学报 2024年第6期40卷 155-167页

作者：仇徐亮冯蕾聂梅梅刘春泉李大婧张钟元李建林邱晓峰唐冬妹南京师范大学食品与制药工程学院南京210097 江苏省农业科学院农产品加工研究所南京210014 江苏中宝食品有限公司南通226144 苏州优尔食品有限公司苏州215105

为提高荠菜的微波干燥品质,采用不同超声功率(4、6、8和10 W/g)对荠菜进行预处理,研究荠菜的传质特性、微观结构、水分分布、酶活性、微波干燥特性、色泽、复水性、营养成分和风味特性。结果表明:(1)相较于未超声对照组,超声预处理显著... 详细信息

为提高荠菜的微波干燥品质,采用不同超声功率(4、6、8和10 W/g)对荠菜进行预处理,研究荠菜的传质特性、微观结构、水分分布、酶活性、微波干燥特性、色泽、复水性、营养成分和风味特性。结果表明:(1)相较于未超声对照组,超声预处理显著降低了荠菜中过氧化物酶(peroxidase,POD)和多酚氧化酶(polyphenol oxidase,PPO)活性(P<0.05),提高了干物质损失率;(2)超声预处理后,荠菜内部细胞间隙及直径增大,荠菜的水分自由度增大,当超声预处理功率为6 W/g时,细胞结构较为完整;(3)超声预处理促使荠菜微波干燥速率提高,超声预处理功率为6 W/g时,荠菜干燥速率较高,有效水分扩散系数为2.1531×10^(−6) m^(2)/s;(4)荠菜微波干燥动力学模型拟合结果显示,Page模型决定系数R^(2)(0.9891~0.9950)较高,均方根误差RMSE(0.0242~0.0351)及卡方值χ^(2)(0.0006~0.0012)较低,拟合效果最佳;(5)超声预处理功率为6 w/g时,微波干制荠菜的复水比较高,叶绿素、总黄酮和总酚含量分别为39.29、24.66、7.70 mg/g,这3种营养成分含量均显著高于未超声对照组(P<0.05);(6)相较于新鲜荠菜,超声预处理提高了微波荠菜干制品中的氮氧化合物、含硫化合物和芳香成分响应值及丰富度、咸味和酸味强度。综合分析,以6 W/g超声功率对荠菜进行预处理,荠菜微波干制品品质最佳。该研究可为荠菜精深加工提供一定的理论依据和技术参考。

关键词：超声微波干燥荠菜微观结构水分分布

Effect of micro-alloying Ca on microstructure,texture and mechanical properties of Mg-Zn-Y-Ce alloys

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Progress in Natural Science:Materials International 2020年第2期30卷 213-220页

作者： Xiaofang liu Xianhua Chen Jianbo Li chunquan liu Di Zhao Renju Cheng Fusheng Pan International Joint Laboratory for Light Alloys(MOE) College of Materials Science and EngineeringChongqing University National Engineering Research Center for Magnesium Alloys Chongqing University Chongqing Academy of Science and Technology Shenyang Notional Laboratory for Materials Science Chongqing University

Microstructure,texture and mechanical properties of Mg-5 Zn-0.3 Y-0.2 Ce alloys with the addition of trace xCa(x=0,0.3,0.6 wt%) were systematically investigated in this *** results revealed that more secondary eutectic phases and smaller grain size of as-cast microstructure could be found with increasing Ca *** hot extrusion,the Ca-free alloy showed a uniformly recrystallized grain structure,while the Ca-containing alloys possessed a bimodal grain structure composed of fine dynamic recrystallized(DRXed) grains with a size of several microns and un-recrystallized coarse *** analysis showed that the three extruded alloys had a fiber texture of(0001) basal plane aligned with the extrusion *** intensity of the DRXed region was weaker than the deformed *** extruded alloy with the addition of 0.6 wt% Ca exhibited the highest yield strength of 321 MPa due to the smallest DRXed grain size,the deformed region with strong basal texture and dense nanosized precipitates.

关键词： Ca micro-alloying Extrusion Microstructure Texture Mechanical properties Mg–Zn–Y–Ce alloy

Annealing hardening effect aroused by solute segregation in gradient ultrafine-grained Mg-Gd-Zr alloy

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Journal of Materials Science & Technology 2023年第13期144卷 70-80页

作者： chunquan liu Xianhua Chen Domonkos Tolnai Yaobo Hu Wei Zhang Yusheng Zhang Fusheng Pan College of Materials Science and Engineering Chongqing UniversityChongqing 400045China National Engineering Research Centre for Magnesium Alloys Chongqing UniversityChongqing 400045China Institute of Metallic Biomaterials Helmholtz-Zentrum HereonMax-Planck Street 1Geesthacht 21502Germany Northwest Institute for Nonferrous Metal Research Xi’an 710016China

In this study,a remarkable annealing hardening effect was detected in gradient ultrafine-grained(UFG)Mg-0.32Gd-0.11Zr(at.%)alloy sheet fabricated by sliding friction treatment(SFT).Under the precipitation-free condition,the annealed UFG structure shows an obvious hardness increment from 1.40 GPa to 1.89 GPa after 200℃ heating for 12 h,which exhibits a much higher hardening response than the annealed coarse-grained(CG)*** high-angle annular dark-field scanning transmission elec-tron microscopy(HAADF-STEM)and elemental mapping reveal prominent segregation of solute Gd atoms along grain boundaries,which endows the UFG structure with excellent grain boundary ***-over,Gd segregation is also found around the extrinsic stacking fault(E-SFs)and the low-angle grain boundaries composed of edge *** large-scale solute partitioning provides a significant seg-regation hardening effect,which completely resists the softening effect aroused by the grain coarsening and dislocation *** work realizes a good combination of surface mechanical processing for fabricating UFGs and subsequent heat treatment,which earns desirable segregation hardening effects.

关键词： Ultrafine grains Segregation Annealing hardening

中低温退火对MoS_(2)纳米薄膜形貌、结构及电性能的影响

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金属热处理 2024年第7期49卷 186-194页

作者：刘春泉熊芬马佳仪周锦添梁泽巽黄建平湖南工学院材料科学与工程学院湖南衡阳421002 湖南工学院计算机科学与工程学院湖南衡阳421002

采用射频(RF)磁控溅射室温沉积制备了不同厚度的MoS_(2)薄膜,然后在95%Ar+5%H_(2)混合气氛中进行不同退火处理,采用原子力显微镜(AFM)、拉曼光谱、四探针和霍尔测试仪系统地研究了不同退火条件对MoS_(2)薄膜结构、表面形貌和电学性能的... 详细信息

采用射频(RF)磁控溅射室温沉积制备了不同厚度的MoS_(2)薄膜,然后在95%Ar+5%H_(2)混合气氛中进行不同退火处理,采用原子力显微镜(AFM)、拉曼光谱、四探针和霍尔测试仪系统地研究了不同退火条件对MoS_(2)薄膜结构、表面形貌和电学性能的影响。结果表明:在硅基片生长的MoS_(2)薄膜均匀连续,退火能有效去除MoS_(2)中的杂质氧进而改善其结晶性、稳定性和结构完整性。溅射沉积40 min(厚度约为300 nm)时MoS_(2)薄膜的综合性能较好,经500℃退火60 min时,MoS_(2)薄膜的结晶性和电学性能均较好。

关键词： MoS_(2)薄膜中低温退火结晶性

Changes in the sugars,amino acids and organic acids of postharvest sperminetreated immature vegetable soybean(Glycine max ***.)as determined by^(1)H NMR spectroscopy

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食物生产加工与营养(英文) 2020年第1期2卷 62-71页

作者： Jiangfeng Song Gang Wu Tao Li chunquan liu Dajing Li Institute of Farm Product Processing Jiangsu Academy of Agricultural SciencesNanjing 210014P.R.China Jiangsu Gian Food Co. Ltd.Nantong 226363P.R.China Dongtai Lvjiayuan Food Co.Ltd. Yancheng 224005P.R.China

^(1)H NMR spectroscopy was adopted to determine compositional changes(mainly sugars,organic acids and amino acids)involved in cold-stored immature soybean grains after exogenous spermine *** changes of sugars,including sucrose,galactose,myo-inositol,glucose and fructose were detected in soybean after spermine *** for the organic acids related to tricarboxylic acid cycle,the levels of malic and fumaric acids decreased but the level of citric acid ***,no significant changes were observed for amino acids in spermine-treated *** using metabolic profile analysis,a difference was observed between the aging of soybean grains as such and those treated with *** study provides an insight into the accumulation of metabolites in postharvest immature soybeans after exogenous spermine-treatment.

关键词： Exogenous spermine Vegetable soybean Sugars Amino acids Organic acids Cold storage

Improved Corrosion Resistance of Ultrafine-Grained Mg-Gd-Zr Alloy Fabricated by Surface Friction Treatment

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金属学报:英文版 2023年第8期36卷 1281-1291页

作者： chunquan liu Xianhua Chen Yulong Wu Yaobo Hu Wei Zhang Yusheng Zhang Jingying Bai Fusheng Pan International Joint Laboratory for Light Alloys(MOE) College of Materials Science and EngineeringChongqing UniversityChongqing400045China National Engineering Research Centre for Magnesium Alloys Chongqing UniversityChongqing400045China Institute of Surface Science Helmholtz-Zentrum HereonMax-Planck Street 121502GeesthachtGermany Northwest Institute for Nonferrous Metal Research Xi’an710016China Beijing Spacecraft China Academy of Space TechnologyBeijing100194China

Gradient ultrafine-grained (UFG) Mg-2Gd-0.4Zr (wt%) alloy sheet, with a UFG layer of about 118 nm on the topmost treated surface, was fabricated by sliding friction treatment (SFT). The corrosion resistance of the SFT-processed UFG surface layer was greatly improved compared to the original coarse-grained (CG) structure, representing as a higher impedance and a lower corrosion rate (CG: 4.11 mm y^(−1), UFG: 2.71 mm y^(−1)). The UFG layer with high density of grain boundaries exhibits an excellent impeditive effect on the cracking of corrosion product films. Compared to the CG sample, the stable corrosion product film inhibits the formation of pitting so providing a better protective effect. In addition, the Gd-rich clusters are randomly distributed after SFT processing, which decreases the tendency of galvanic corrosion on the UFG surface.

关键词： Ultrafine grains Mg-Gd-Zr alloy Corrosion resistance