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ECAP制备超细晶生物医用钛及钛合金的研究进展

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稀有金属材料与工程 2023年第5期52卷 1673-1682页

作者：强萌杨西荣刘晓燕罗雷西安建筑科技大学冶金工程学院陕西西安710055

钛及钛合金由于质轻、弹性模量低、生物相容性佳和骨整合性优异,已成为应用最广泛的生物医学金属材料之一。然而,较低的塑性、耐腐蚀性能和耐磨损性能限制了其发展和应用。剧烈塑性变形被认为是对金属材料最有效的晶粒细化方法之一,其中... 详细信息

钛及钛合金由于质轻、弹性模量低、生物相容性佳和骨整合性优异,已成为应用最广泛的生物医学金属材料之一。然而,较低的塑性、耐腐蚀性能和耐磨损性能限制了其发展和应用。剧烈塑性变形被认为是对金属材料最有效的晶粒细化方法之一,其中,等通道转角挤压(ECAP)是制备块状超细晶(UFG)/纳米晶金属材料的常用技术。通过ECAP变形,可以制备具有优异综合性能的UFG钛及钛合金。本文综述了生物医用UFG钛及钛合金的ECAP制备方式,着重讨论了ECAP变形对钛及钛合金的组织、力学性能、耐腐蚀性能和耐磨损性能的影响,分析了钛及钛合金的ECAP变形机制和晶粒细化机制,提出了通过ECAP变形结合传统塑性加工和变形后热处理来进一步优化钛及钛合金综合性能的想法。

关键词：钛合金 ECAP UFG 耐腐蚀性能耐磨损性能

原始晶粒尺寸对ECAP变形纯钛组织性能的影响

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稀有金属材料与工程 2022年第6期51卷 1949-1956页

作者：强萌杨西荣刘晓燕罗雷西安建筑科技大学冶金工程学院陕西西安710055

室温下,对923及1023 K退火1 h所得的不同原始晶粒尺寸的工业纯钛进行ECAP变形。通过TEM、EBSD、室温拉伸和显微硬度测试研究原始晶粒尺寸对ECAP变形纯钛组织性能的影响。探讨纯钛ECAP变形孪生行为和变形机制。结果表明,退火温度越高,原... 详细信息

室温下,对923及1023 K退火1 h所得的不同原始晶粒尺寸的工业纯钛进行ECAP变形。通过TEM、EBSD、室温拉伸和显微硬度测试研究原始晶粒尺寸对ECAP变形纯钛组织性能的影响。探讨纯钛ECAP变形孪生行为和变形机制。结果表明,退火温度越高,原始晶粒尺寸越大。1道次变形后,1023 K退火纯钛的晶粒细化效果更显著。4道次变形后,923 K退火纯钛的组织更细小均匀。随着变形道次的增加,屈服强度不断增大,1道次变形后增幅最大,约为100%,且原始晶粒尺寸越大,强度增幅越大。纯钛ECAP变形机制包括位错滑移和孪生,原始晶粒尺寸越大,孪晶数量越多。

关键词：纯钛 ECAP 晶粒尺寸孪晶显微组织力学性能

A detailed mechanism of degradation behaviour of biodegradable as-ECAPed Zn-0.8Mg-0.2Sr with emphasis on localized corrosion attack

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Bioactive Materials 2023年第9期27卷 447-460页

作者： Jan Pinc Andrea Skolakova Vojtech Hybasek Sarka Msallamova Petr Vertat Petr Ashcheulov Martin Vondracek Jan Duchon Ingrid McCarroll Matej Hývl Swarnendu Banerjee Jan Drahokoupil Jirí Kubasek Dalibor Vojtech Jaroslav Capek Institute of Physics of the Czech Academy of Sciences Na Slovance 1999/2Prague 818221Czech Republic University of Chemistry and Technology Faculty of Chemical TechnologyDepartment of Metals and Corrosion EngineeringTechnicka 516628Praha 6-DejviceCzech Republic Max-Planck-Institut Für Eisenforschung Max-Planck-Straße 140237DüsseldorfGermany

In this study, advanced techniques such as atom probe tomography, atomic force microscopy, X-ray photoelectron spectroscopy, and electrochemical impedance spectroscopy were used to determine the corrosion mechanism of the as-ECAPed Zn-0.8Mg-0.2Sr alloy. The influence of microstructural and surface features on the corrosion mechanism was investigated. Despite its significance, the surface composition before exposure is often neglected by the scientific community. The analyses revealed the formation of thin ZnO, MgO, and MgCO3 layers on the surface of the material before exposure. These layers participated in the formation of corrosion products, leading to the predominant occurrence of hydrozincite. In addition, the layers possessed different resistance to the environment, resulting in localized corrosion attacks. The segregation of Mg on the Zn grain boundaries with lower potential compared with the Zn-matrix was revealed by atom probe tomography and atomic force microscopy. The degradation process was initiated by the activity of micro-galvanic cells, specifically Zn - Mg2Zn11/SrZn13. This process led to the activity of the crevice corrosion mechanism and subsequent attack to a depth of 250 μm. The corrosion rate of the alloy determined by the weight loss method was 0.36 mm⋅a􀀀 1. Based on this detailed study, the degradation mechanism of the Zn-0.8Mg-0.2Sr alloy is proposed.

关键词： Biodegradable metals Zinc-based alloy Characterization Mechanism ECAP

ECAP对Mg-9Al-1.5Bi-0.5In合金组织及电化学性能的影响

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中国有色金属学报 2022年第6期32卷 1695-1707页

作者：郭绘芬李子岩李秋睿汪英芝管仲徐姜泽王红霞太原理工大学材料科学与工程学院太原030024 太原理工大学新材料界面科学与工程教育部重点实验室太原030024

镁合金因放电稳定、成本低、标准电位较负非常适合作为电池阳极材料,而目前常用的正挤压态阳极镁合金往往会由于晶粒尺寸差异大、第二相分布不均匀而导致较差的放电性能。为提高挤压态合金的放电性能,采用等通道挤压(ECAP)技术对挤压态M... 详细信息

镁合金因放电稳定、成本低、标准电位较负非常适合作为电池阳极材料,而目前常用的正挤压态阳极镁合金往往会由于晶粒尺寸差异大、第二相分布不均匀而导致较差的放电性能。为提高挤压态合金的放电性能,采用等通道挤压(ECAP)技术对挤压态Mg-9Al-1.5Bi-0.5In合金进行变形处理,并对其进行组织观察及电化学测试。研究结果表明:ECAP后合金发生了完全动态再结晶,晶粒细化,第二相分布均匀;随着ECAP道次的增加,晶粒尺寸、第二相尺寸均先减小后增大,而第二相的体积分数先增大后减小,在2道次时达到最值;此外,2道次合金具有较好的电化学活性,腐蚀电流密度和腐蚀电位分别为126.63μA/cm^(2)、−1.48713 V,在较小电流密度下,2道次合金具有最大的利用率(53.74%)、功率密度(43.181 mW/cm^(2))和比容量(1412.574 mA·h/g)。因此,在小电流状态下,ECAP 2道次的Mg-9Al-1.5Bi-0.5In合金具有广阔的应用前景。

关键词：镁合金正挤压 ECAP 显微组织电化学性能

Arabidopsis ECAP Is a New Adaptor Protein that Connects JAZ Repressors with the TPR2 Co-repressor to Suppress Jasmonate-Responsive Anthocyanin Accumulation

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Molecular Plant 2020年第2期13卷 246-265页

作者： Changjiang Li Lei Shi Yanan Wang Wei Li Binqing Chen Lei Zhu Ying Fu State Key Laboratory of Plant Physiology and Biochemistry College of Biological SciencesChina Agricultural UniversityBeijing 100193China

Suppression mechanisms mediated by transcriptional repressors commonly exist in diverse phytohormone signaling pathways.In Arabidopsis thaliana,JASMONATE-ZIM DOMAIN(JAZ)proteins are transcriptional repressors that function as negative regulators of diverse JA responses.Novel Interactor of JAZ(NINJA)is an adaptor protein connecting JAZs with the co-repressor,TOPLESS(TPL),to mediate gene repression in JA-dependent root growth inhibition and defense pathways.However,whether NINJA or other adaptor proteins are employed in other JA-responsive biological processes remains to be elucidated.In the present study,we demonstrate that a previously uncharacterized protein,ECAP(EAR motif-Containing Adaptor Protein),directly interacts with JAZ6 and JAZ8 and enhances their transcriptional repression activities.We provide evidence that ECAP is a novel adaptor protein for JAZ6/8 recruitment of the transcriptional co-repressor,TOPLESS-RELATED 2(TPR2),into a transcriptional repressor complex that represses the WD-repeat/bHLH/MYB complex,an important transcriptional activator in the JA-dependent anthocyanin biosynthesis pathway.Our findings,together with previous reports,reveal that specific adaptor proteins play a critical role in distinct JA responses by pairing different JAZs(which possess overlapping but also specific functions)with the general co-repressors,TPL and TPRs.

关键词： jasmonate signaling anthocyanin adaptor proteins ECAP JAZ proteins TPL/TPRs

Precipitation behaviors and mechanical properties of a solution-treated Mg-Gd-Nd-Zn-Zr alloy during equal-channel angular pressing process

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Journal of Magnesium and Alloys 2022年第1期10卷 257-266页

作者： Zhenzhen Gui Fen Wang Junyi Zhang Dexin Chen Zhixin Kang School of Mechanical and Electrical Engineering Guangzhou University230 Wai Huan Xi RoadGuangzhou Higher Education Mega CenterGuangzhou 510006China Guangdong Key Laboratory for Advanced Metallic Materials Processing School of Mechanical and Automotive EngineeringSouth China University of TechnologyGuangzhou 510640China Institute of Advanced Wear&Corrosion Resistant and Functional Materials Jinan University601 Hmmgpu Avenue WestGuangzhou 510632China

A magnesium alloy processed by equal-channel angular pressing (ECAP) exhibited excellent microstructure refinement and improved strength and hardness.The comprehensive mechanical properties of magnesium alloys have supported the expansion of their applications in the automotive,aerospace,and biomedical industries.Herein,pre-treatment of a solution-treated Mg-2.9Gd-1.5Nd-0.3Zn-0.3Zr alloy was conducted to investigate the precipitate behavior and microstructure evolution during the ECAP process.β;phase grains quickly precipitated from the solution-treated alloy,which accelerated grain refinement and enhanced the ductility after the ECAP process,as compared to the as-cast alloy reported in our previous study.Moreover,spherical precipitates (~200 nm) and fine phases (~100 nm) precipitated along the stripe-like Zn;Zr;phase,which formed a kabap-like structure dispersing homogeneously in the solution-treated alloy during the ECAP process.Owing to grain refinement,dislocations,sphericalβ;precipitates,and texture evolution,the solution-treated alloy after eight passes of ECAP exhibited good comprehensive mechanical properties,with the ultimate tensile strength,yield strength,and elongation values reaching210.9 MPa,263.9 MPa,and 27.9%,respectively.

关键词： Mg-Gd-Nd-Zn-Zr alloy Precipitations Solid solution ECAP Mechanical properties

Role of bimodal-grained structure with random texture on mechanical and corrosion properties of a Mg-Zn-Nd alloy

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Journal of Magnesium and Alloys 2022年第8期10卷 2147-2157页

作者： Ming Gao Ke Yang Lili Tan Zheng Ma School of Materials Science and Engineering University of Science and Technology of ChinaShenyang110016China Shi-changxu Innovation Center for advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang110016China

Fine grained ZN20 alloy was obtained by combining equal-channel angular pressing(ECAP)with extrusion.Microstructural observation showed an obvious grain refinement with an average grain size of 10μm after ECAP.The original bimodal-grained structure composed of coarse grains with strong basal texture and fine grains with random texture was substituted by a new kind of bimodal-grained structure with finer grains and more random texture after 4 passes ECAP at 300℃.The combination of grain refinement and texture weakening caused the ductility can be increased by 40%compared with the as-extruded alloy.Immersion test in simulated intestinal fluid revealed an improvement of corrosion resistance after ECAP.Grain refinement can stable the corrosion product layer and basal texture is more beneficial for the corrosion resistance than the non-basal texture.

关键词： Magnesium ECAP Bimodal-grained structure Corrosion resistance Mechanical property

纯钛室温ECAP和旋锻复合变形过程中的织构演变

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塑性工程学报 2022年第3期29卷 117-123页

作者：高飞龙刘晓燕杨西荣罗雷张琪西安建筑科技大学冶金工程学院陕西西安710055

采用等径弯曲通道挤压(ECAP)和旋锻(RS)复合工艺在室温下对纯钛进行大塑性变形,利用X射线衍射技术分析了纯钛室温ECAP和ECAP+RS复合变形过程中的织构演变规律。结果表明,随着室温ECAP变形道次的增加,原始基面织构逐渐向锥面织构和柱面... 详细信息

采用等径弯曲通道挤压(ECAP)和旋锻(RS)复合工艺在室温下对纯钛进行大塑性变形,利用X射线衍射技术分析了纯钛室温ECAP和ECAP+RS复合变形过程中的织构演变规律。结果表明,随着室温ECAP变形道次的增加,原始基面织构逐渐向锥面织构和柱面织构转变,且织构强度减弱。室温ECAP变形过程中晶粒取向的变化主要以晶向绕TD轴的旋转为主,晶面旋转幅度较小。RS变形使得ECAP形变织构发生根本改变,柱面织构基本消失,形成以锥面织构和基面织构为主的形变织构,且织构强度显著增加。纯钛室温ECAP+RS复合变形过程中ODF图的演变是连续的,说明其塑性变形机制以位错滑移为主。

关键词： ECAP 旋锻纯钛织构

基于Bai-Wierzbicki准则的ECAP塑性损伤研究

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塑性工程学报 2021年第2期28卷 52-62页

作者：高建烨何涛霍元明宋淼姚婷婷杨万博上海工程技术大学机械与汽车工程学院上海201620 密歇根大学核工程与辐射科学学院密歇根州48109

通过韧性断裂试验建立了6063铝合金的Swift硬化准则和Bai-Wierzbicki韧性断裂准则,利用Abaqus/Explicit对ECAP过程中的韧性断裂进行了有限元模拟。模拟与试验结果表明:Bai-Wierzbicki韧性断裂准则能准确预测试件的韧性断裂。ECAP过程中... 详细信息

通过韧性断裂试验建立了6063铝合金的Swift硬化准则和Bai-Wierzbicki韧性断裂准则,利用Abaqus/Explicit对ECAP过程中的韧性断裂进行了有限元模拟。模拟与试验结果表明:Bai-Wierzbicki韧性断裂准则能准确预测试件的韧性断裂。ECAP过程中试件的塑性损伤主要发生在主变形区和试件头部翘曲处,其形成机制是通道拐角处压剪变形造成的剪切类塑性损伤。试件主变形区塑性损伤主要受模具内角和内角半径的影响,其大小随着内角和内角半径的增大而减小;而模具外角对试件头部的塑性损伤影响则较为显著,损伤大小随外角增大而减小。

关键词： ECAP 韧性断裂准则应力状态塑性损伤