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Engineered Functional Surfaces by Laser Microprocessing for Biomedical Applications

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Engineering 2018年第6期4卷 822-830页

作者： Guoqing Hu kai guan Libin Lu Jiaru Zhang Nie Lu Yingchun guan School of Mechanical Engineering and Automation Beihang UniversityBeijing 100083China Hefei Innovation Research Institute Beihang UniversityHefei 230013China Department of Oncology Center of ExcellenceBOE Hefei Digital Hospital Co.Ltd.Hefei 230013China Beijing Long March Space Vehicle Research Institute First Academy of the China Aerospace CorporationBeijing 100076China National Engineering Laboratory of Additive Manufacturing for Large Metallic Components Beihang UniversityBeijing 100083China

Metallic biomaterials are increasingly being used in various medical applications due to their high strength,fracture resistance,good electrical conductivity,and ***,their practical applications have been largely limited due to poor surface *** microprocessing is an advanced method of enhancing the surface-related properties of *** work demonstrates the capability of laser microprocessing for biomedical metallic materials including magnesium and titanium alloys,with potential applications in cell adhesion and liquid *** investigate laser-material interaction,microstructural evolution,and surface performance,and analyze cell behavior and the surface-enhanced Raman scattering(SERS)***,we explore a theoretical study on the laser microprocessing of metallic alloys that shows interesting results with potential *** results show that cells exhibit good adhesion behavior at the surface of the laser-treated surface,with a preferential direction based on the textured structure.A significant SERS enhancement of 6×10^3 can be obtained at the laser-textured surface during Raman measurement.

关键词： Laser microprocessing Functional surface Metallic alloy Niocompatibility SERS

Effect of Y on Oxidation Behavior of Directionally Solidified Ni-Based Single-Crystal Superalloy

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CHINESE JOURNAL OF MECHANICAL ENGINEERING 2024年第1期37卷 1-13页

作者： Zhao, Zihan guan, kai Cui, Renjie Qin, Jianchao Huang, Zhaohui Beijing Inst Aeronaut Mat Sci & Technol Adv High Temp Struct Mat Lab Beijing 100095 Peoples R China

The effect of yttrium (Y) addition on the oxidation behavior of a Ni-based directionally solidified single-crystal superalloy is investigated in this study. Isothermal oxidation tests for samples with different levels of Y addition are conducted at 1100 degrees C in air. The Y content of the samples is determined by the actual pickup amount obtained from an Inductively Coupled Plasma-Atomic Emission Spectrometry test. It is discovered that the addition of Y increases the oxide resistance by the scale of an adhesive double-layer oxide, which is composed of Al2O3 and spinel Ni(Cr,Al)2O4. With 70 ppm of Y addition, the oxidation mass gain decreases from 12.6 g/m2 for the alloy without Y addition to 5.3 g/m2, and the oxidation rate decreases significantly. In addition, the internal nitride disappears after Y doping because of an increase in oxidation scale adherence and a decrease in oxidation products. In this study, the alloy with 660 ppm Y addition demonstrates the best oxidation resistance.

关键词： Isothermal oxidation Element Y Single-crystal superalloy Oxide scale

Microstructural evolution and aging behavior of Mg-4.5Y-2.5Nd-1.0Gd-0.5Zr alloys with different Zn additions

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Rare Metals 2021年第8期40卷 2188-2196页

作者： Zheng Tian Qiang Yang kai guan Zhan-Yi Cao Jian Meng Key Laboratory of Automobile Materials of Ministry of Education Department of Materials Science and EngineeringJilin UniversityChangchun130025China State Key Laboratory of Rare Earth Resources Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun130022China

Microstructures and mechanical properties of Mg-4.5 Y-2.5 Nd-1.0 Gd-0.5 Zr-xZn(x=0,0.5,1.0,and 1.5;wt%)alloys under as-cast and peak-aged states were investigated in this *** results indicate that the intermetallic phase components are closely dependent on Zn *** as-cast state,the dominant eutectic phase is Mg5 RE in the alloys with 0 wt%and 0.5 wt%Zn additions while Mg5 RE,18 R-and 14 H-LPSO(long period stacking ordered)phases in the alloys with 1.0 wt%and1.5 wt%Zn *** solution and peak-aging,the highest strength and hardness were obtained on the alloy with 0.5 wt%Zn *** electron microscopy(TEM)characterizations revealed that there are denser and finer precipitates on basal(β’)and prismatic(γ’)planes,***,the excellent mechanical performance of the alloy with 0.5 wt%Zn addition is mainly due to precipitation strengthening and grain boundary strengthening.

关键词： Magnesium alloy Intermetallic phase Precipitates Mechanical property

Modifying microstructures and tensile properties of Mg-Sm based alloy via extrusion ratio

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Journal of Magnesium and Alloys 2021年第3期9卷 1098-1109页

作者： kai guan Rui Ma Jinghuai Zhang Ruizhi Wu Qiang Yang Jian Meng Key Laboratory of Superlight Material and Surface Technology Ministry of EducationCollege of Material Science and Chemical EngineeringHarbin Engineering UniversityHarbin 150001PR China Department of Materials Engineering The University of TokyoTokyo 113-8656Japan State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022PR China

Microstructure and tensile properties of a Mg-Sm-Zn-Zr alloy with various extrusion ratios(ERs)of 6.9,10.4 and 17.6 were systematically *** was identified that,greater ER increased dynamic recrystallization(DRX)fraction and coarsened DRX grains,which further suggests weakened basal fiber texture for the studied *** is mainly due to the rising temperature from massive deformation heat when *** a result,greater ER corresponds to a decreased strength but improved ***,transmission electron microscopy(TEM)observations reveal that the dominant intermetallic phase,Mg_(3)Sm,is metastable,and it will transform into Mg_(41)Sm_(5)during extrusion with *** transformation leads to the accumulation of surplus Sm and Zn atoms,which induces the precipitation of Sm Zn_(3)phase at the surface of Mg_(41)Sm_(5)matrix.

关键词： Magnesium alloys Extrusion ratio Microstructure Phase transition Transmission electron microscopy Tensile properties

Hardening effect and precipitation evolution of an isothermal aged Mg-Sm based alloy

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Journal of Magnesium and Alloys 2023年第12期11卷 4619-4627页

作者： kai guan Chuang Li Zhizheng Yang Yongsen Yu Qiang Yang Wenwen Zhang Zhiping guan Cheng Wang Min Zha Huiyuan Wang Key Laboratory of Automobile Materials of Ministry of Education&School of Materials Science and Engineering Jilin UniversityChangchun 130022China State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China Department of Energy and Hydrocarbon Chemistry Graduate School of EngineeringKyoto UniversityNishikyo-kuKyoto 615-8510Japan

The age-hardening behavior and precipitation evolution of an isothermal aged Mg-5Sm-0.6Zn-0.5Zr(wt.%) alloy have been systematically investigated by means of transmission electron microscopy(TEM) and atomic-resolution high-angle annular dark field scanning transmission electron microscopy(HAADF-STEM). The Vickers hardness of the present alloy increases first and then decreases with ageing time. The sample aged at 200 ℃ for 10 h exhibits a peak-hardness of 90.5 HV. In addition to the dominant β_(0)’ precipitate(orthorhombic,a = 0.642 nm, b = 3.336 nm and c = 0.521 nm) formed on {11-20}α planes, a certain number of γ’’ precipitate(hexagonal, a = 0.556 nm and c = 0.431 nm) formed on basal planes are also observed in the peak-aged alloy. Significantly, the basal γ’’ precipitate is more thermostable than prismatic β_(0)’ precipitate in the present alloy. β_(0)’ precipitates gradually coarsened and were even likely to transform into β_(1) phase(face centered cubic, a = 0.73 nm) with the increase of ageing time, which accordingly led to a gradual decrease in number density of precipitates and finally resulted in the decreased hardness and mechanical property in the over-aged alloys.

关键词： Magnesium alloys Ageing treatment Microstructure characterization Age-hardening effect Precipitates

Achieving high ductility and low in-plane anisotropy in magnesium alloy through a novel texture design strategy

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Journal of Magnesium and Alloys 2024年第7期12卷 2863-2873页

作者： Shi Liu Cheng Wang Hong Ning Zhao-Yuan Meng kai guan Hui-Yuan Wang State Key Laboratory of Automotive Simulation and Control Jilin UniversityPR China Key Laboratory of Automobile Materials of Ministry of Education&School of Materials Science and Engineering Nanling CampusJilin UniversityNo.5988 Renmin StreetChangchun130025 PR China State Key Laboratory of Reliability and Intelligence of Electrical Equipment School of Material Science and EngineeringHebei University of TechnologyTianjin300130 PR China

Texture regulation is a prominent method to modify the mechanical properties and anisotropy of magnesium *** this work,the Mg-1Al-0.3Ca-0.5Mn-0.2Gd(wt.%)alloy sheet with TD-tilted and circular texture was fabricated by unidirectional rolling(UR)and multidirectional rolling(MR)method,*** generating a strong in-plane mechanical anisotropy in conventional TD-tilted texture,the novel circular texture sample possessed a weak in-plane yield *** can be rationalized by the similar proportion of soft grains with favorable orientation for basalslip and{10.12}tensile twinning during the uniaxial tension of circular-texture sample along different ***,compared with the TD-tilted texture,the circular texture improved the elongation to failure both along the rolling direction(RD)and transverse direction(TD).By quasi-in-situ EBSD-assisted slip trace analysis,higher activation of basal slip was observed in the circular-texture sample during RD tension,contributing to its excellent *** loading along the TD,the TD-tilted texture promoted the activation of{10.12}tensile twins significantly,thus providing nucleation sites for cracks and deteriorating the *** research may shed new insights into the development of formable and ductile Mg alloy sheets by texture modification.

关键词： Magnesium alloy TD-tilted texture Circular texture In-plane yield anisotropy Ductility

Microstructures and mechanical properties of as-cast Mg-Sm-Zn-Zr alloys with varying Gd contents

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Journal of Magnesium and Alloys 2022年第5期10卷 1220-1234页

作者： kai guan Daisuke Egusa Eiji Abe Jinghuai Zhang Xin Qiu Qiang Yang Jian Meng Department of Materials Science&Engineering The University of TokyoTokyo 113-8656Japan Key Laboratory of Superlight Material and Surface Technology Ministry of EducationCollege of Material Science and Chemical EngineeringHarbin Engineering UniversityHarbin 150001PR China State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022PR China Research Center for Structural Materials National Institute for Materials ScienceTsukuba 305-0047Japan

The effect of Gd content on the microstructure and tensile properties of as-cast Mg-Sm-Zn-Zr alloy has been systematically *** the Mg-3Sm-0.5Zn-0.5Zr alloy, the intermetallic compounds with multiple morphologies are identified as Mg_(3)Sm phase. In addition to Mg_(3)RE phase, Mg_(5)RE phase originated from Gd addition is observed in Gd-modified alloys. It should be noted that the lattice parameters of all the observed intermetallic compounds are significantly reduced by Zn segregation. The segregation behavior of Zn in Mg_(3)Sm phase is inhibited to some extent by Gd addition due to the electronegativity difference between Sm/Gd and Zn elements. In addition, the increased Gd content effectively leads to much more accumulation of solute atoms in front of the liquid-solid interface during solidification, which can prominently promote nucleation in liquid region and then refine grains. The tensile yield stress of the present alloys is thus improved with increasing Gd addition. Finally, Gd-modified alloys exhibit significantly age-hardening effect, which can be mainly attributed to the high-volume fraction and high density nano-scale precipitates.

关键词： Magnesium alloys Microstructure characterization Mechanical properties Transmission electron microscopy(TEM)

In-line Plasma-induced Graft-copolymerization of Pentaerythritol Triacrylate onto Polypropylene

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Chinese Journal of Polymer Science 2018年第8期36卷 979-983页

作者： Gui-Qiu Ma guan-kai Sun Zhe Ma Jing-Qing Li Jing Sheng Department of Polymer Material Science and Engineering Institute of Advanced Polymer MaterialsSchool of Material Science and EngineeringTianjin Key Laboratory of Composite and Functional MaterialsTianjin University

Pentaerythritol triacrylate （PETA） was successfully grafted onto the plasma-treated isotactic polypropylene （iPP） via the in situ melt processing. The X-ray photoelectron spectroscopy （XPS） results showed that the hydroxyl and carbonyl groups, and peroxides could be generated via plasma treatment. The content of free radical in plasma-treated iPP （PiPP） was measured by 2,2-diphenyl-1- picrylhydrazyl （DPPH）. It was found that the resulting peroxides induced the grafting copolymerization of PETA onto iPP, and the grafted PETA promoted the formation of β-crystal in PiPP, which was evidenced by Fourier transform infrared spectroscopy （FTIR）, differential scanning calorimetry （DSC） and wide-angle X-ray diffraction （WAXD） measurements, respectively.

关键词： Plasma treatment Melt processing Graft copolymerization Pentaerythritol triacrylate

Effects of substitution of Nd in a sand-cast Mg-2.5Nd-0.6Zn-0.5Zr alloy with x wt.% Sm(x=2.5, 4, and 6)

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Journal of Rare Earths 2017年第12期35卷 1261-1267页

作者： Deping Zhang Qiang Yang Dongdong Zhang kai guan Fanqiang Bu Hong Zhou Jian Meng The Key Lab of Automobile Materials The Ministry of Education Jilin University State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied Chemistry Chinese Academy of Sciences College of Material Science and Chemical Engineering Harbin Engineering University

The microstructures and mechanical properties of a series of sand-cast Mg-Sm-Zn-Zr alloys under ascast, solution-treated and peak-aged states were thoroughly investigated. The OM, XRD, SEM and HRTEM were employed to characterize the microstructural evolution. The results indicate that substitution Nd in the conventional Mg-2.5 Nd-0.6 Zn-0.5 Zr alloy with different contents of Sm has comparative grain refinement effect and will fully change the dominant intermetallic phase. In addition, the substituted alloys perform clearly higher strength with comparative ductility at both as-cast and peakaged conditions and much greater aging hardening response than the referential alloy. It is obvious that the strength increments of this alloy are attributed to the changes of the eutectic intermetallic particles on grain boundaries.

关键词： Mg-Sm-Zn-Zr Sand-cast Heat treatment Microstructure Mechanical property