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Bioactive Materials 2018年第4期3卷 385-388页

作者： Nathalie Annonay Fatiha Challali Marie-Noelle Labour Valerie Bockelee A.Garcia-Sanchez Florent Tetard Marie-Paule Besland Philippe Djemia Frederic Chaubet Laboratoire de Science des Materiaux et des Procedes UPR CNRS 3407Universite Paris 13Sorbonne-Paris-CiteInstitut Galilee99 av J.B.Clement93430VilletaneuseFrance Laboratory for Vascular Translational Science Inserm U1148Universite Paris 13Universite Paris-DiderotSorbonne-Paris-CiteInstitut Galilee99 av J.B.Clement93430VilletaneuseFrance Institut des Materiaux Jean Rouxel(IMN)UMR CNRS 6502 Universite de Nantes2rue de la HoussiniereB.P.3222944322Nantes Cedex 3France

1.Introduction Vascular stents are endo-prostheses that allow the restoration of blood flow in case of obstruction of a vessel.A stent usually consists of a corrosion-resistant metal such as Nitinol,316L steel or a CoCr alloy[1].Many studies have been undertaken for the production of polymer degradable stents[2,3]or metallic stents[4,5]and,among these,devices made of pure zinc or crystallized alloy based on zinc obtained by molding and extrusion are promising in terms of biodegradability,biocompatibility and mechanical properties[6],but also concerning the degradation rate of the stent which should to be effective until arterial remodeling and tissue healing are complete[5].The objective of this preliminary study is the comparison of the degradation in simulated biological medium and the endothelial cytotoxicity of amorphous and crystallized thin ZnZr films according to their composition and structure.In this work,the thin layers were deposited on silicon substrates by magnetron co-sputtering.This technology is already used to make metal stents[7,8].

关键词： alloy alloys corrosion

Mechanical, tribological and anti-corrosive properties of polyaniline/graphene coated Mg-9Li-7Al-1Sn and Mg-9Li-5Al-3Sn-1Zn alloys

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Journal of Materials Science & Technology 2019年第8期35卷 1767-1778页

作者： Rita Maurya Abdul Rahim Siddiqui Prvan Kumar Katiyar Kantesh Balani Materials Science and Engineering Indian Institute of Technology Kanpur Kanpur 208016 India Centre for Material Science & Engineering National Institute of Technology Hamirpur Hamirpur 177005 India China-Canada Institute for Advanced Surface & Interface Science and Engineering Jiangsu University of Technology Changzhou 213001 China

The mechanical,tribological and corrosion protection offered to Mg-9Li-7Al-1Sn and Mg-9Li-5Al-3Sn-1Zn alloys by the epoxy coating containing polyaniline/graphene(PANI/Gr)pigments is undertaken in the current work.PANI/Gr containing coatings were observed to be strongly adherent with a higher scratch hardness(Hs)and plowing hardness(Hp),i.e.Hsof 0.43 GPa,and Hpof 0.61 GPa,respectively when compared to that of neat epoxy coating(Hsof 0.17 GPa,and Hpof 0.40 GPa,respectively).Due to their higher Hsand Hpvalues,PANI/Gr based coatings displayed an enhanced wear resistance(Wear volume,Wv=4.53×10^-3 m^3)than that of neat epoxy coating(Wv=5.15×10^-3 m^3).The corrosion protection efficiency in corrosive environment of 3.5 wt%NaCl solution was obtained to be>99% for PANI/Gr containing coatings when compared to that of neat epoxy coating.The charge-transfer resistance(R(ct))of the PANI/Gr containing coatings were estimated to be>10^6 cm^2,which indicates their highly protective nature when compared to that of neat epoxy coating(R(ct)10^5 Ω cm^2).Hence,PANI/Gr containing coatings can be potentially used for wear resistance and corrosion protection applications in marine environments.

关键词： Mg-Li alloys Scratch hardness Plowing hardness Wear resistance Corrosion protection efficiency Charge transfer resistance

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Journal of Materials Science & Technology 2019年第8期35卷 1712-1718页

作者： Shude Ji Shiyu Niu Jianguang Liu School of Aerospace Engineering Shenyang Aerospace University Shenyang 110136 China Beijing Key Laboratory of Civil Aircraft Structures and Composite Materials Beijing Aeronautical Science & Technology Research Institute of COMAC Beijing 102211 China

The Zn-added ultrasonic assisted friction stir lap welding(UaFSLW) was carried out to improve the quality of dissimilar Al/Mg alloys joint. The effects of ultrasonic power on the joint quality were also investigated.The results indicated that the larger effective lap width and mixing region between Mg and Al(Mg/Al MR) were attained by Zn foil addition and external ultrasonic assistance. Compared with the conventional joint, the finer and better-distributed Mg-Zn IMCs placing the continuous Al-Mg IMCs were formed in the Mg/Al MR of the Zn-added UaFSLW joint. The Zn foil addition and external ultrasonic assistance significantly improved the tensile shear load of the joint, and the load was increased with the increase of the ultrasonic power. The maximum tensile shear load of 7.95 kN was attained, which was 52.6% larger than that of the conventional joint.

关键词： Dissimilar Al/Mg alloys Friction stir lap welding Zn foil Ultrasonic power Microstructures Tensile shear load

Resolution of a discrepancy of magnetic mechanism for Elinvar anomaly in Fe-Ni based alloys

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Journal of Materials Science & Technology 2019年第3期35卷 396-401页

作者： Fangyu Qin Wenlong Xiao Fengshuang Lu Yuanchao Ji Xinqing Zhao Xiaobing Ren School of Materials Science and Engineering Beihang University Functional Materials Research Institute Central Iron and Steel Research Institute Multi-Disciplinary Materials Research Center Frontier Institute of Science and Technology Xi'an Jiaotong University

Fe-Ni based Elinvar alloys performing temperature-independent elastic modulus over a wide temperature range have found wide and significant applications. Although numerous models involved with magnetism have been proposed to explain the Elinvar anomaly, some of the puzzles concerning the anomaly have not been fully understood. In this work, a remarkable discrepancy between the inflection temperature of modulus and the Curie temperature in a typical Fe-Ni-Cr Elinvar alloy was found,challenging the magnetic mechanism for Elinvar anomaly. Microstructural characterization and dynamic mechanical analysis demonstrate the occurrence of a strain glass transition with continuous formation of nanodomains. Accompanying such a transition, the gradual softening in the elastic modulus of austenite offsets the modulus hardening due to the vibrational anharmonicity of nanodomains upon cooling, leading to the Elinvar effect. As a result, the inflection temperature of modulus corresponds to the initiation of nanodomains' formation instead of magnetic transition. Our findings specify the association of Elinvar anomaly with structural aspects, and provide new insights into the mechanism of Elinvar anomaly in Fe-Ni based alloy.

关键词： Fe-Ni based alloys Elastic modulus Magnetism Strain glass transition Nanodomains

Understanding formation of Mg-depletion zones in Al-Mg alloys under high pressure torsion

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Journal of Materials Science & Technology 2019年第5期35卷 858-864页

作者： Jing Xue Shenbao Jin Xianghai An Xiaozhou Liao Jiehua Li Gang Sha Herbert Gleiter Institute of Nanoscience School of Materials Science and Engineering Nanjing University of Science and Technology Nanjing 210094 China School of Aerospace Mechanical and Mechatronic Engineering The University of Sydney Sydney NSW 2006 Australia Institute of Casting Research Montanuniversitat Leoben A-8700 Leoben Austria

Redistribution of elements may take place in alloys during severe plastic deformation, which significantly alters the mechanical properties of the alloys. Therefore, comprehensive knowledge about deformationinduced redistribution of elements has to be established. In the present paper, the distribution of Mg in an Al-Mg alloy processed by high pressure torsion was examined using atom probe tomography(APT).With crystallographic information extracted by APT data analysis, this research reveals that the movement of dislocations plays an important role in the formation of Mg-depletion zones in the deformed microstructure.

关键词： High-pressure torsion Atom probe tomography Aluminum alloys Grain boundary diffusion Dislocation

A general strategy for the reliable joining of Al/Ti dissimilar alloys via ultrasonic assisted friction stir welding

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Journal of Materials Science & Technology 2019年第1期35卷 94-99页

作者： Zhongwei Ma Yanye Jin Shude Ji Xiangchen Meng Lin Ma Qinghua Li School of Aerospace Engineering Shenyang Aerospace University

Ultrasonic assisted friction stir welding(UaFSW) was used to join 6061-T6 aluminum and Ti6Al4 V alloys.A small plunge depth endowed with the low heat input was used and the sound joints without obvious thickness reduction were achieved. A diffusion-type bonding without the intermetallic compounds layer was observed at the joint interface. The ultrasonic improved the diffusion thickness and decreased the average size of grains and titanium alloy fragments. A hook-like structure was formed at the bottom interface of the UaFSW joint, which improved the bonding length and the mechanical interlocking. The microhardness of the stir zone was increased because of the further grain refinement induced by ultrasonic. The maximum tensile strength of the UaFSW joint was 236 MPa, which reached 85% of the base6061-T6 alloy.

关键词： Friction stir welding Ultrasonic Aluminum/titanium alloys Microstructure Mechanical properties

Phase diagrams of permanent magnet alloys: Binary rare earth alloy systems

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Journal of Rare Earths 2019年第10期37卷 1040-1046页

作者： Kaicheng Yang Jiang Wang Qingrong Yao Zhao Lu Maohua Rong Huaiying Zhou Guanghui Rao School of Materials Science and Engineering & Guangxi Key Laboratory of Information Materials Guilin University of Electronic Technology

Thermodynamic optimization of the binary rare earth alloy(Cee La, Cee Pr, Cee Nd and Lae Nd) systems was performed in this work through the CALPHAD method based on the critical evaluation of all available phase diagram and thermodynamic data reported in the literature. During the thermodynamic modeling, the solution phases including liquid, bcc, fcc and dhcp, were treated as the substitutional solution model. Thermodynamic parameters of the stable phases in the Cee La, Cee Pr, Cee Nd and Lae Nd binary systems are obtained finally and would be used directly to develop the thermodynamic database of the multi-component Nde Fee B-based alloys, which is indispensable for designing alloy compositions and processes of Nde Fee B permanent magnets with highly abundant rare earth metals.

关键词： Permanent magnets Rare earth alloys Phase diagrams CALPHAD

Nuclear radiation shielding effectiveness and corrosion behavior of some steel alloys for nuclear reactor systems

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Defence Technology（防务技术） 2019年第4期15卷 621-628页

作者： M.M. Sadawy R.M. El Shazly Mining and Petroleum Engineering Department Al-Azhar University Nasr City Cairo 11371 Egypt Physics Department Faculty of Science Al-Azhar University Nasr City Cairo 11884 Egypt

Different types of nuclear parameters and corrosion behavior were deduced for carbon steel(AISI 1018),austenitic(304 SS),and duplex(2507 SS)stainless steel alloys.Three types of neutron energies as well as nine gamma ray energy lines(121.78-1407.92 keV)were used to evaluate the macroscopic neutron cross-sections(∑,cm^-1)and mass attenuation coefficients[σ,cm^2·g^-1)of gamma ray respectively.The corrosion behavior was investigated using different electrochemical techniques.The results showed that the stainless-steel alloys had a good attitude than that of carbon steel alloy for neutron and gamma ray parameters,especially the duplex stainless steel.The calculated values of mass attenuation coefficient using WinXcom computer program(Version 3.1),exhibited a very good agreement with the experimental values of that parameters.Moreover,the results indicated that duplex stainless-steel exhibited corrosion resistance higher than 304 SS and AISI 1018 steel alloys.

关键词： Steel alloys Macroscopic cross-section Mass attenuation coefficient Passive film Pitting

Optimization of annealing treatment and comprehensive properties of Cu-containing Ti6Al4V-xCu alloys

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Journal of Materials Science & Technology 2019年第10期35卷 2121-2131页

作者： Cong Peng Yang Liu Hui Liu Shuyuan Zhang Chunguang Bai Yizao Wan Ling Ren Ke Yang School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Institute of Metal Research Chinese Academy of SciencesShenyang 110016China Institute of advanced materials East China Jiaotong UniversityNanchang 330013China

The Ti6Al4V-Cu alloy was reported to show good antibacterial properties, which was promising to reduce the hazard of the bacterial infection problem. For the purpose of preparing Ti6Al4V-Cu alloy with satisfied comprehensive properties, it’s important to study the heat treatment and the appropriate Cu content of the alloy. In this study, high Cu content Ti6Al4V-x Cu(x = 4.5, 6, 7.5 wt%) alloys were prepared, and firstly the annealing heat treatments were optimized in the α+β+Ti2Cu triple phase region to obtain satisfied tensile mechanical properties. Then the effect of Cu content on the tribological property, corrosion resistance, antibacterial activity and cytotoxicity of the Ti6Al4 V-x Cu alloys were systematically studied to obtain the appropriate Cu content. The results showed that the optimal annealing temperatures for Ti6Al4 V-x Cu(x = 4.5, 6, 7.5 wt%) alloys were 720, 740 and 760℃, respectively, which was resulted from the proper volume fractions of α,β and Ti2Cu phases in the microstructure. The additions of 4.5 wt% and 6 wt% Cu into the medical Ti6Al4 V alloy could enhance the wear resistance and corrosion resistance of the alloy, but the addition of 7.5 wt% Cu showed an opposite effect. With the increase of the Cu content, the antibacterial property was enhanced due to the increased volume fraction of Ti2Cu phase in the microstructure, but when the Cu content was increased to 7.5 wt%, cytotoxicity was presented. A medium Cu content of 6 wt%, with annealing temperature of 740℃ make the alloy possesses the best comprehensive properties of tensile properties, wear resistance, corrosion resistance, antibacterial property and biocompatibility, which is promising for future medical applications.

关键词： Cu-containing Ti6Al4V-xCu alloys Annealing treatment High Cu content Comprehensive properties

Fundamental electronic structure and multiatomic bonding in 13 biocompatible high-entropy alloys

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npj Computational Materials 2020年第1期6卷 1296-1305页

作者： Wai-Yim Ching Saro San Jamieson Brechtl Ridwan Sakidja Miqin Zhang Peter K.Liaw Department of Physics and Astronomy University of Missouri Kansas CityKansas CityMO 64110USA The Bredesen Center for Interdisciplinary Research and Graduate Education The University of TennesseeKnoxvilleTN 37996-3394USA Department of Physics Astronomy and Materials ScienceMissouri State UniversitySpringfieldMO 65897USA Department of Materials Science and Engineering The University of WashingtonSeattleWA 98195USA Department of Materials Science and Engineering The University of TennesseeKnoxvilleTN 37996-2100USA

High-entropy alloys(HEAs)have attracted great attention due to their many unique properties and potential applications.The nature of interatomic interactions in this unique class of complex multicomponent alloys is not fully developed or understood.We report a theoretical modeling technique to enable in-depth analysis of their electronic structures and interatomic bonding,and predict HEA properties based on the use of the quantum mechanical metrics,the total bond order density(TBOD)and the partial bond order density(PBOD).Application to 13 biocompatible multicomponent HEAs yields many new and insightful results,including the inadequacy of using the valence electron count,quantification of large lattice distortion,validation of mechanical properties with experiment data,modeling porosity to reduce Young’s modulus.This work outlines a road map for the rational design of HEAs for biomedical applications.

关键词： alloys bonding entropy