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Unveiling annealing texture formation and static recrystallization kinetics of hot-rolled Mg-Al-Zn-Mn-Ca alloy

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Journal of Materials Science & Technology 2020年第8期36卷 104-118页

作者： Qinghang Wang Bin jiang Aitao Tang Jie Fu Zhongtao Jiang Haoran Sheng Dingfei Zhang Guangsheng Huang Fusheng Pan State Key Laboratory of Mechanical Transmissions College of Materials Science and EngineeringChongqing UniversityChongqing 400044China Chongqing Academy of Science and Technology Chongqing 401123China Research Institute for New Materials Technology Chongqing University of Arts and SciencesChongqing 402160China Shanghai Aerospace Equipment Manufactory Shanghai 200245China

The development of Mg-Al-Zn-Mn-Ca series alloys provides a potential prospect to achieve high strength and formability at room temperature(RT).The formation of elliptical annular texture is treated as a crucial factor for the enhanced RT formability.However,the origin of such an elliptical annular texture formation has been rarely reported.Herein,we unveiled the formation and evolution of elliptical annular texture in the hot-rolled Mg-1.6 Al-0.8 Zn-0.4 Mn-0.5 Ca(AZMX1100,wt.%)alloy after annealing at different temperatures for 1 h,and its static recrystallization(SRX)kinetics in given annealing temperature for different time.The results revealed that the formation of elliptical annular texture in the hot-rolled AZMX1100 alloy after annealing was derived from nucleation-oriented SRX mechanism,which took place in 200-300°C,induced by cracked chain-shaped Al2 Ca phases,contraction twins,intersections of double twins,intersections of double twins and grain boundaries and non-basal slips.On further annealing from300-450°C,the grains with 45°–70°transverse direction(TD)preferentially grew,which made elliptical annular texture extended along the TD.Based on the Johnson-Mehl-Avrami-Kolmogorov(JMAK)model,Avrami exponent n value was estimated to be 0.68–1.02,attributed to non-random SRX nucleation,giving rise to the lower activation energy QRof nucleation of^74.24 k J/mol.Since the co-segregation of Al,Zn and Ca atoms in grain boundaries created a strong interaction of solutes and grain boundaries,the hot-rolled AZMX1100 alloy exhibited the higher activation energy Qg(~115.48 k J/mol)of grain growth.

关键词： Mg-Al-Zn-Mn-Ca alloy Elliptical annular texture Nucleation Grain growth Static recrystallization kinetics

Influence of minor Ce additions on the microstructure and mechanical properties of Mg-1.0Sn-0.6Ca alloy

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Journal of Materials Science & Technology 2020年第2期37卷 26-37页

作者： Yanfu Chai Chao He Bin jiang Jie Fu Zhongtao Jiang Qingshan Yang Haoran Sheng Guangsheng Huang Dingfei Zhang Fusheng Pan State Key Laboratory of Mechanical Transmissions College of Materials Science and EngineeringChongqing UniversityChongqing400044China Chongqing Academy of Science and Technology Chongqing401123China Research Institute for New Materials Technology Chongqing University of Arts and SciencesChongqing402160China School of Metallurgy and Material Engineering Chongqing University of Science and TechnologyChongqing401331China Shanghai Aerospace Equipment Manufactory Shanghai200245China

The microstructure and mechanical properties of Mg-Sn-Ca-Ce alloys with different Ce contents(0.0,0.2,0.5,1.0 wt%)were studied at room temperature.Ce additions to ternary Mg-Sn-Ca alloy resulted in grain refinement as well as a change in the category of second phase from CaMgSn to(Ca,Ce)Mg Sn and Mg12Ce.The volume fraction of second phase increased with rising Ce content,which aggravated the restriction of DRXed grain growth during the extrusion process and eventually led to texture weakening of as-extruded Mg-Sn-Ca based alloys.In terms of plasticity,owing to vigorously activated basal slip and homogeneous distributed tensile strain in tension,the tensile ductility of as-extruded alloys reached the maximum value of 27.6%after adding 0.2 wt%Ce,which enhanced by about 26%than that of ternary MgSn-Ca alloy.However,further Ce additions(0.5 and 1.0 wt%)would coarsen the second phase particles and then impair ductility.The tension-compression yield asymmetry of as-extruded Mg-Sn-Ca ternary alloy was alleviated greatly via Ce additions,due to the joint effects of grain refinement,increased amount of strip distributed second phase particles and texture weakening.

关键词： Mg-Sn-Ca alloy Ce content Microstructure Texture Mechanical properties

Diffusion behavior and reactions between Al and Ca in Mg alloys by diffusion couples

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Journal of Materials Science & Technology 2018年第2期34卷 291-298页

作者： Jiahong Dai Hong Xiao Bin jiang Hongmei Xie Cheng Peng Zhongtao Jiang Qin Zou Qingshan Yang Fusheng Pan College of Mechanical and Electrical Engineering Yangtze Normal University Chongqing 408100 China State Key Laboratory of Mechanical Transmissions College of Materials Science and Engineering Chongqing University Chongqing 400044. China Chongqing Academy of Science and Technology Chongqing 401123. China Research Institute for New Materials Technology Chongqing University of Arts and Sciences Chongqing 402160 China School of Metallurgy and Materials Engineering Chongqing University of Science and Technology Chongqing 401331 China

The diffusion behavior and reactions between AI and Ca in Mg alloys by diffusion couple method were investigated. Results demonstrate that Al2Ca is the only phase existing in the diffusion reaction layers. The volume fraction of Al2Ca in diffusion reaction layers increases linearly with temperature. The standard enthalpy of formation for intermetallic compounds was rationalized on the basis of the Miedema model. Al-Ca intermetallic compounds were preferable to form in the Mg-Al-Ca ternary system under the same conditions. Over the range of 350-400℃, the structure of Al2Ca is more stable than that of Al4Ca, Al14Ca13and Al3Ca8, The growth constants of the layer I, layer II and entire diffusion reaction layers were determined. The activation energies for the growth of the layer I, layer II and entire diffusion reaction layers were （80.74 ± 3.01 ） kJ/mol, （93.45 ±2.12） kJ/mol and （83.52 ±1.50） kJ/mot, respectively. In layer I and II, AI has higher integrated interdiffusion coefficients D^i^Int,layer layer than Ca. The average effective interdiffusion coefficients D^Al^eff values are higher than D^Ca^eff in the layer I and II.

关键词： Magnesium alloys Diffusion behavior Interface lntermetallic compounds

Comparison of microstructures and mechanical properties of composite extruded AZ31 sheets

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Journal of Magnesium and Alloys 2019年第4期7卷 547-554页

作者： Yanfu Chai Yan Song Bin jiang Jie Fu Zhongtao Jiang Qingshan Yang Haoran Sheng Guangsheng Huang Dingfei Zhang Fusheng Pan State Key Laboratory of Mechanical Transmissions College of Materials Science and EngineeringChongqing UniversityChongqing 400044China Chongqing Academy of Science and Technology Chongqing 401123China Research Institute for New Materials Technology Chongqing University of Arts and SciencesChongqing 402160China Shanghai Aerospace Equipment Manufactory Shanghai 200245China

The microstructures and mechanical properties of the composite extruded AZ31/AZ31 and AZ31/4047 Al sheets were investigated and made a comparison to the conventional extruded AZ31 sheet.Owing to the introduced intense shear deformation at the interface during the composite extrusion,grain refinement and tilted texture were detected in AZ31 layers of the AZ31/AZ31 and AZ31/4047 Al sheets,while the conventional extruded AZ31 sheet exhibited a relative coarse,inhomogeneous microstructure and strong basal texture.The compressiontension yield ratio was increased gradually from the AZ31 to the AZ31/AZ31 and AZ31/4047 Al sheets.Besides,the AZ31/4047 Al sheet could successfully accomplish the whole bending forming process at room temperature,while the AZ31 and AZ31/AZ31 sheets were both bend-formed to failure with significant cracks in the outer tensile region under the identical bending parameters.Moreover,under the same bending strain,both the outward offset degree of strain neutral layer and the sheet thickening were more serious in the AZ31/4047 Al composite sheet than those of the AZ31 and AZ31/AZ31 sheets.The foremost reason was the quite wide gap of material properties between Mg alloy AZ31 layer(tensile loading in the outer region)and Al 4047 layer(compressive loading in the inner region).

关键词： Mg alloy sheet Composite extrusion Tension-compression yield asymmetry Bendability

Influence of different extrusion processes on mechanical properties of magnesium alloy

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Journal of Magnesium and Alloys 2014年第3期2卷 220-224页

作者： Qingshan Yang Bin jiang Hucheng Pan Bo Song Zhongtao Jiang Jiahong Dai Lifei Wang Fusheng Pan Chongqing Academy of Science and Technology Chongqing 401123China National Engineering Research Center for Magnesium Alloys Chongqing UniversityChongqing 400044China Key Laboratory for Anisotropy and Texture of Materials(Ministry of Education) Northeastern UniversityShenyang 110004Liaoning ProvinceChina Faculty of Materials and Energy Southwest UniversityChongqing 400715China

AZ31 Mg alloy sheets were processed by the conventional symmetrical extrusion(CSE)and the asymmetric extrusion(ASE).Progressive-asymmetric extrusion(PASE)and severe strain-asymmetric extrusion(SASE)were employed for ASE processes.The texture at near-surface and mid-layer zones of ASE sheets was diverse penetrating the normal direction(ND).This was attributed to an additional asymmetric shear strain deformation during the ASE process.(0002)basal planes of PASE sheets tilt to the shear deformation direction.Meanwhile,the basal texture intensity of PASE sheets has been weakened compared with one in CSE sheets.Grain refinement and tilted weak basal texture obtained by SASE process dramatically enhances the room temperature strength and plasticity of the extruded AZ31 magnesium alloy sheets.The microstructure and mechanical responses were examined and discussed.

关键词： Mg alloys Texture Microstructure Extrusion Shear

Stable Boron-Containing Blue-Photoluminescent Radicals

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Chinese Journal of Chemistry 2021年第5期39卷 1297-1302页

作者： zhongtao Feng Yuanyuan Chong Shuxuan Tang Huapeng Ruan Yong Fang Yue Zhao Jun jiang Xinping Wang State Key Laboratory of Coordination Chemistry School of Chemistry and Chemical EngineeringCollaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjingJiangsu 210093China Hefei National Laboratory for Physical Sciences at the Microscale CAS Center for Excellence in NanoscienceSchool of Chemistry and Materials ScienceUniversity of Science and Technology of ChinaHefeiAnhui 230026China

It is highly urgent to develop synthetic strategies to make new category of stable luminescent radicals with desired emission wavelength.In this study,we have isolated two dioxoborocyclic radicals(3 and 4)by a direct synthetic route.They were characterized by UV,EPR spectroscopy and SQUID measurements.Their structures were obtained by single-crystal X-ray diffraction.Both radicals produce blue-photoluminescence(458 nm for 3 and 478 nm for 4)by radiative decay from higher excited states(D_(2)/D_(3))to the ground state(D_(0))based on theoretical calculation,breaking Kasha rule.The work records a new kind of radical emitters and the first stable radicals with blue emission bands.

关键词： Boron Borocyclic radical Radical emitter Blue-photoluminescence X-Ray structure

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《上海市农药管理规定》新规解读

世界农药 2023年第4期45卷 22-26页

作者：姜忠涛上海市农业技术推广服务中心上海201103

《上海市农药管理规定》已自2020年12月1日起正式施行,是2017年新《农药管理条例》发布实施后我国出台的第一个农药管理方面的省级地方法规,是上海市结合自身情况在国家层面相关上位农药管理法规的基础上,对该市农药管理举措的细化、补... 详细信息

《上海市农药管理规定》已自2020年12月1日起正式施行,是2017年新《农药管理条例》发布实施后我国出台的第一个农药管理方面的省级地方法规,是上海市结合自身情况在国家层面相关上位农药管理法规的基础上,对该市农药管理举措的细化、补充和完善。也是政府管理部门针对新时期我国农药管理领域所面临的新形势和涌现的新问题而做出的积极探索和有益实践。

关键词：上海市农药管理规定政策解读

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稀土元素对钛合金组织与性能的影响研究进展

粉末冶金工业 2021年第5期31卷 81-86页

作者：蒋焓鸿姜中涛成都大学机械工程学院四川成都610106 重庆文理学院材料科学与工程学院材料表界面科学重庆市重点实验室重庆402160

本文介绍了稀土元素在钛合金领域的应用研究概况。主要概述了稀土元素Nd、Y、Gd、Er、La对钛合金的微观组织、力学性能及蠕变性能、抗氧化性能和热稳定性能的影响,就稀土元素在钛合金中的存在形式、添加量、添加方式进行分析,并为实现... 详细信息

本文介绍了稀土元素在钛合金领域的应用研究概况。主要概述了稀土元素Nd、Y、Gd、Er、La对钛合金的微观组织、力学性能及蠕变性能、抗氧化性能和热稳定性能的影响,就稀土元素在钛合金中的存在形式、添加量、添加方式进行分析,并为实现合金性能最优化提出了改进措施。本文立足于含稀土元素钛合金的研究现状,指出其实现工业化应用的限制因素,分析其应用前景及未来发展方向,并提出相关建议以期为进一步提高钛合金性能提供参考依据。

关键词：钛合金稀土元素微观组织力学性能前景展望

热处理对Mg-3.4Al-2Ca合金组织与力学性能的影响

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热加工工艺 2022年第8期51卷 132-134,138页

作者：代芳芳姜中涛西南铝业(集团)有限责任公司重庆401326 重庆文理学院材料表界面科学重庆市重点实验室重庆402160

对铸态Mg-3.4Al-2Ca合金进行先固溶热处理,再进行热挤压变形处理,研究了固溶热处理对铸态和挤压态合金组织以及挤压态合金力学性能的影响。结果表明,与未固溶处理相比,高温固溶处理可使镁合金中亚稳(Mg,Al)2Ca相转变为稳定的Al_(2)Ca相... 详细信息

对铸态Mg-3.4Al-2Ca合金进行先固溶热处理,再进行热挤压变形处理,研究了固溶热处理对铸态和挤压态合金组织以及挤压态合金力学性能的影响。结果表明,与未固溶处理相比,高温固溶处理可使镁合金中亚稳(Mg,Al)2Ca相转变为稳定的Al_(2)Ca相。挤压后合金发生完全再结晶,晶粒细小均匀,Al_(2)Ca第二相破碎成颗粒状,且有大量亚微米级Al_(2)Ca分布于合金中。固溶处理再挤压合金比仅固溶处理合金的屈服强度、抗拉强度和伸长率分别提高了25.0%、9.5%和15.1%。

关键词： Mg-Al-Ca合金固溶处理挤压变形 Al_(2)Ca