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Martensitic transformation and magnetic properties of Ti-doped NiCoMnSn shape memory alloy

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Rare Metals 2014年第5期33卷 511-515页

作者： feng Chen yun-Xiang Tong Bing Tian Li Li yu-feng zheng Center for Biomedical Materials and Engineering Harbin Engineering University Department of Materials Science and Engineering College of Engineering Peking University

Martensitic transformation, microstructure, and magnetic properties of Ti-doped Ni43-xTixCo7Mn43Sn7（at%）（x = 0, 0.5, 1.0, 2.0, and 4.0） shape memory alloys were investigated. The results show that transformation temperatures of Ni43Co7Mn43Sn7 can be efficiently adjusted by the substitution of Ti for Ni. For example, the martensitic transformation starting temperature（Ms） is reduced by about 278 K with 4 at% addition of Ti. Room temperature microstructure evolves from single tetragonal martensite for the Ti-free alloy to dual phases（tetragonal martensite ＋ second phase） with 0.5 at%, 1.0 at%, and2.0 at% addition of Ti to dual phases（cubic austenite ＋ second phase） for 4.0 at% Ti-doped alloy. The mechanical properties can be obviously improved by adding an appropriate amount of Ti. A noteworthy point is that magnetic-field-induced reverse transformation is observed in Ni39Ti4Co7Mn43Sn7 alloy.

关键词： NiCoMnSn Shape memory alloy Martensitic transformation Magnetic property

New Formulas of Shear Strain during Equal-channel Angular Pressing Process with Consideration of Influences of Velocity and Motion Trajectory

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Journal of Iron and Steel Research International 2016年第10期23卷 1020-1027页

作者： Dian-tao ZHANG Zhen LI yun-xiang TONG yu-feng zheng Li LI Key Laboratory of Superlight Material and Surface Technology(Ministry of Education) Harbin Engineering University Center for Biomedical Materials and Engineering Harbin Engineering University Department of Materials Science and Engineering College of EngineeringPeking University

The influences of die parameters on shear strain were investigated by using two-dimensional finite element *** formulas of shear strain were *** to the results of formulas,the shear strain showed a linear dependence on the difference between internal and external fillet radius and the slope was determined by the intersection *** simulation results indicated that the velocities of the points from different zones were different in the specimen and the motion trajectories of different points did not follow geometrical *** influences of the average velocity and the motion trajectory on shear strain were incorporated in the formula to calculate the shear strain produced during equalchannel angular pressing *** reliability of simulation results has been partially validated by experiments.

关键词： equal channel angular pressing finite element method shear strain velocity motion trajectory

A review on biodegradable materials for cardiovascular stent application

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Frontiers of Materials Science 2016年第3期10卷 238-259页

作者： Li-Da HOU Zhen LI yu PAN Muhammadlqbal SABIR yu-feng zheng Li LI Center for Biomedical Materials and Engineering Harbin Engineering University Harbin 150001 China Institute of Materials Processing and Intelligent Manufacturing Harbin Engineering University Harbin 150001 China Department of Materials Science and Engineering College of Engineering Peking University Beijing 100871 China

A stent is a medical device designed to serve as a temporary or permanent internal scaffold to maintain or increase the lumen of a body conduit. The researcher;~ and engineers diverted to investigate biodegradable materials due to the limitation of metallic materials in stent application such as stent restenosis which requires prolonged anti platelet therapy, often result in smaller lumen after implantation and obstruct re-stenting treatments. Biomedical implants with temporary function for the vascular intervention are extensively studied in recent years. The rationale for biodegradable stent is to provide the support for the vessel in predicted period of time and then degrading into biocompatible constituent. The degradation of stent makes the re-stenting possible after several months and also ameliorates the vessel wall quality. The present article focuses on the biodegradable materials for the cardiovascular stent. The objective of this review is to describe the possible biodegradable materials for stent and their properties such as design criteria, degradation behavior, drawbacks and advantages with their recent clinical and preclinical trials.

关键词： biodegradable materials magnesium alloy polymers biodegradablestent cardiovascular stent

Achieving High Strength and High Electrical Conductivity in a CuCrZr Alloy Using Equal-Channel Angular Pressing

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Acta Metallurgica Sinica(English Letters) 2018年第10期31卷 1084-1088页

作者： yun-Xiang Tong yu Wang Zhi-Min Qian Dian-Tao Zhang Li Li yu-feng zheng Institute of Materials Processing and Intelligent Manufacturing College of Materials Science and Chemical Engineering Harbin Engineering University Department of Materials Science and Engineering College of Engineering Peking University

In the present work, a CuCrZr alloy characterized by ultrafine grains and nanoscale particles was prepared by equalchannel angular pressing （ECAP） at 450℃. A desired combination of a tensile strength （580 MPa） and an electrical conductivity （81% International Annealed Copper Standard） is simultaneously obtained in the as-ECAP-processed CuCrZr alloy without additional aging treatment. The improved properties can be mainly attributed to the ultrafine grains and nanoscale precipitates. This processing may pave a way to develop the CuCrZr alloys having high strength and high electrical conductivity for engineering applications.

关键词： Microstructure CuCrZr Equal-channel angular pressing Strengthening

Construction of TiO2/silane nanofilm on AZ31 magnesium alloy for controlled degradability and enhanced biocompatibility

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Rare Metals 2019年第6期38卷 588-600页

作者： Lei Huang Kun Su yu-feng zheng Kelvin Wai-Kwok Yeung Xiang-Mei Liu School of Materials Science and Engineering Hubei UniversityWuhan 430062China State Key Laboratory for Turbulence and Complex System Department of Materials Science and EngineeringCollege of EngineeringPeking UniversityBeijing 100871China Department of Orthopaedics and Traumatology Li Ka Shing Faculty of MedicineThe University of Hong KongPokfulam 999077Hong KongChina

A TiO2 nanofilm was prepared on the surface of AZ31 magnesium alloy with controllable thickness through atomic layer deposition(ALD) technique, which can adjust the corrosion behaviors of AZ31 Mg *** with the untreated Mg alloys, corrosion current densities(icorr)can decline by 58% in the 200-cycles TiO2-covered Mg alloy and further decline by up to 74% with the thickness of nanofilm up to 63 nm(400 cycles).The subsequent modification with a cross-linked conversion layer of 3-aminopropyltriethoxysilane(APTES) by a dipping method can produce a compact silane coating on TiO2 nanofilm, which can seal pinholes of TiO2 nanofilm and serve as a barrier to further adjust the corrosion behavior of the *** icorrcan decline about two orders of magnitude in the TiO2/silane composite *** the adjustable corrosion rate come true, which can be attributed to the precise control on the thickness of metal oxide nanofilm and additional protection from the compact silane *** vitro study discloses that the TiO2/silane hybrid coating shows higher expression of alkaline phosphatase(ALP)and can promote cellular adhesion and proliferation with better cytocompatibility than untreated Mg alloy.

关键词： Magnesium alloy TiO2 Biodegradability Atomic layer deposition Hybrid coating Biocompatibility

Advances in coatings on biodegradable magnesium alloys

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Journal of Magnesium and Alloys 2020年第1期8卷 42-65页

作者： zheng-zheng Yin Wei-Chen Qi Rong-Chang Zeng Xiao-Bo Chen Chang-Dong Gu Shao-Kang Guan yu-feng zheng Corrosion Laboratory for Light Metals College of Materials Science and EngineeringShandong University of Science and TechnologyQingdao 266590China Department of Orthopaedics and Traumatology Li KaShing Faculty of MedicineThe University of Hong KongHong Kong 999077China School of Engineering RMIT UniversityCarltonVIC 3053Australia School of Materials Science and Engineering State Key Laboratory of Silicon MaterialsZhejiang UniversityHangzhou 310027China School of Materials Science and Engineering Zhengzhou UniversityZhengzhou 450002China State Key Laboratory for Turbulence and Complex Systems and Department of Materials Science and Engineering College of EngineeringPeking UniversityBeijing 100871China

The clinic applications of bioabsorbable magnesium(Mg)and its alloys have been significantly restricted owing to their poor corrosion *** elemental alloying,surface modification and functionality is a major approach to increasing corrosion resistance for magnesium *** article reviews the cutting-edge advances and progress of biodegradable surface coatings upon Mg alloys over the last decades,aims to build up a knowledge framework of surface modification on biodegradable Mg alloys.A considerable number of conversion,deposition,mechanical and functional coatings and their preparation methods are *** emphasis has been placed on the composition of chemical conversion and deposited coatings to overcome the disadvantages of adhesion,corrosion resistance and biocompatibility of a single coating for biomedical *** issues have been addressed on the integration of the structural and functional factors of the composite coatings.

关键词： Magnesium alloy Biomaterial Corrosion resistance Coating Biodegradability

Advance in Antibacterial Magnesium Alloys and Surface Coatings on Magnesium Alloys:A Review

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Acta Metallurgica Sinica(English Letters) 2020年第5期33卷 615-629页

作者： Yang Shao Rong-Chang Zeng Shuo-Qi Li Lan-yue Cui yu-Hong Zou Shao-Kang Guan yu-feng zheng Corrosion Laboratory for Light Metals College of Materials Science and EngineeringShandong University of Science and TechnologyQingdao 266590China School of Materials Science and Engineering Zhengzhou UniversityZhengzhou 450002China College of Chemical and Environmental Engineering Shandong University of Science and TechnologyQingdao 266590China Department of Materials Science and Engineering College of EngineeringPeking UniversityBeijing 100871China

Magnesium(Mg)alloys as a bioabsorbable light metal have shown great clinical potential as bone replacement *** this review,the categories,progress in cutting-edge preparation technologies and antibacterial mechanisms of Mg alloys and considerable numbers of corrosion-resistant and functional coatings are *** relationship among the microstructure(grain size,intermetallic compounds),biocorrosion resistance and biocompatibility for antibacterial Mg alloys is *** challenge and outlooks of biomedical Mg alloys and coatings are proposed from an antibacterial perspective.

关键词： Magnesium alloys Antibacterial properties Coatings Degradation Biomaterial

New nitinol endovascular stent-graft system for abdominal aortic aneurysm with finite element analysis and experimental verification

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Rare Metals 2019年第6期38卷 495-502页

作者： Xiao-Chen Zhou Fan Yang Xiao-Yan Gong Ming Zhao yu-feng zheng Zhi-Li Sun Department of Materials Science and Engineering College of EngineeringPeking UniversityBeijing 100871China Beijing Percutek Therapeutics Co. Ltd.Beijing 102600China Suzhou Innomed Medical Device Co. Ltd.Suzhou 215123China Schlumberger Technology Corporation HoustonTX 77054USA State Key Laboratory for Turbulence and Complex System College of EngineeringPeking UniversityBeijing 100871China

Abdominal aortic aneurysm(AAA) is one of the most common and catastrophic manifestations of the acute aortic syndrome that can be treated with endovascular aneurysm repair(EVAR) which requires a specially designed stent-graft *** this work, a self-expanding nickel–titanium(nitinol) stent-graft system is aiming at AAA using finite element analysis(FEA) methods to analyze both fatigue behaviors and radial *** on the systematic analysis of the parametric variations, a final stent-graft system was developed by the selection and arrangement of the individual stent components, targeting an optimal performance for the treatment of *** tests, animal tests and clinical trials were carried out to confirm the *** animal trials and clinical trials showed comparable curative effects with Medtronic Endurant stent-graft(SG) systems.

关键词： Nitinol Stent-graft system Abdominal aortic aneurysm Fatigue safety factor Radial force Finite element analysis

Long-term efficacy,safety and biocompatibility of a novel sirolimus eluting iron bioresorbable scaffold in a porcine model

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Bioactive Materials 2024年第9期39卷 135-146页

作者： Ya-Nan Gao Hong-Tao Yang Zi-feng Qiu feng Qi Qian-Hong Lu Jian-feng zheng Zi-Wei Xi Xin Wang Li Li Gui Zhang De-yuan Zhang yu-Die Lu Hai-Ping Qi Hong Qiu Run-Lin Gao yu-feng zheng Department of Cardio-Metabolic Medicine Center Fuwai HospitalNational Center for Cardiovascular DiseasesChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina Department of Cardiology Coronary Artery Disease CenterFuwai HospitalNational Center for Cardiovascular DiseasesChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina Beijing Key Laboratory of Pre-clinical Research and Evaluation for Cardiovascular Implant Materials Animal Experimental CenterFuwai HospitalNational Center for Cardiovascular DiseasesChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina Department of Pathology Fuwai HospitalNational Center for Cardiovascular DiseasesChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina School of Engineering Medicine Beihang UniversityBeijingChina R&D Center Biotyx Medical(Shenzhen)Co.Ltd.ShenzhenChina Department of Cardiology Fuwai Yunnan HospitalChinese Academy of Medical SciencesAffiliated Cardiovascular Hospital of Kunming Medical UniversityKunmingChina Peking University Health Science Center BeijingChina Department of Cardiology Beijing Tsinghua Changgung HospitalBeijingChina Department of Cardiology Beijing Anzhen HospitalCapital Medical UniversityBeijing Institute of Heart Lung and Blood Vessel DiseasesBeijingChina School of Materials Science and Engineering Peking UniversityBeijingChina

Iron is considered as an attractive alternative material for bioresorbable scaffolds(BRS).The sirolimus eluting iron bioresorbable scaffold(IBS),developed by Biotyx Medical(Shenzhen,China),is the only iron-based BRS with an ultrathin-wall *** study aims to investigate the long-term efficacy,safety,biocompatibility,and lumen changes during the biodegradation process of the IBS in a porcine model.A total of 90 IBSs and 70 cobaltchromium everolimus eluting stents(EES)were randomly implanted into nonatherosclerotic coronary artery of healthy mini *** multimodality assessments including coronary angiography,optical coherence tomography,micro-computed tomography,magnetic resonance imaging,real-time polymerase chain reaction(PCR),and histopathological evaluations,were performed at different time *** was no statistical difference in area stenosis between IBS group and EES group at 6 months,1year,2 years and 5 *** the scaffolded vessels narrowed at 9 months,expansive remodeling with increased mean lumen area was found at 3 and 5 *** IBS struts remained intact at 6 months,and the corrosion was detectable at 9 *** 5 years,the iron struts were completely degraded and absorbed in situ,without in-scaffold restenosis or thrombosis,lumen collapse,aneurysm formation,and chronic *** local or systemic toxicity and abnormal histopathologic manifestation were found in all *** from real-time PCR indicated that no sign of iron overload was reported in scaffolded ***,the IBS shows comparable efficacy,safety,and biocompatibility with EES,and late lumen enlargement is considered as a unique feature in the IBS-implanted vessels.

关键词： Bioresorbable scaffold Sirolimus eluting iron bioresorbable scaffold Preclinical study Completely bioresorbable Late lumen enlargement