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One-step PDA coating strategy on pure Zn for blood-contacting engineering

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Journal of Materials Science & Technology 2022年第28期123卷 78-91页

作者： Xiaoyun Qi Shicheng Zhou Hui Fang Shuhan Yang chunjin hang Yanhong Tian Chenxi Wang State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin 150001China

The mechanical performance degradation caused by pitting corrosion and the insufficient biocompatibility induced with ion release inhibit the application of Zn as the new biodegradable metallic materials for blood-contacting intervention *** work successfully coats a uniform polydopamine(PDA)layer on pure Zn via a one-step deposition process without introducing heavy metal elements or detrimental *** corrosion resistance and uniform corrosion have been performed on PDA coated Zn with corrosion products and pits reduced significantly than pure Zn during in vitro *** could be prohibited by anticoagulation performance with prothrombin time and activated partial thromboplastin time prolonged after co-incubation,and an almost 40%decrease of platelets adhesion,indicating the improved blood compatibility of coated ***,the poly(lactic-co-glycolic acid)(PLGA)is filmed on PDA coated Zn to realize a smooth double-coated structure with superior mechanical performance under stress loading to stably serve the multifunctional application,such as drug *** strategy not only represents a facile and biological friendly method for Zn surface modification but also puts forward new ideas on preparing PDA-based coatings on active biodegradable alloys,which are beneficial for better blood-contacting engineering.

关键词： Biodegradable Pure Zn Uniform corrosion Blood compatibility Doubled-coated structure

Fracture Statistics Dominated by Hot-Cutting Defect and Deviation from Weibull Distribution

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Journal of Harbin Institute of Technology(New Series) 2015年第2期22卷 41-48页

作者： Chao Zeng Chunqing Wang Yanhong Tian chunjin hang Wei Liu Rong An State Key Lab of Advanced Welding and Joining Harbin Institute of Technology

This paper characterizes the rarely noticeable hot-cutting defect and statistically models the fracture governed by this new type defect. The morphology of the defect on fired ceramic is examined and quantitatively featured through comparing the fracture strength governed by intrinsic defect and hot-cutting defect. Weibull distribution is utilized to fit the observed strength data and chi-square goodness-of-fit test is conducted to analyze the deviation. Kernel density estimation is introduced to explore the underlying strength distribution dominated by hot-cutting defect. Based on the shape information from kernel density estimating,gamma and lognormal distribution are compared and the hot-cutting defect governing fracture statistics is finally confirmed by chisquare test. Results show that the newly-defined hot-cutting defect is more dangerous than the intrinsic defect and the priori Weibull distribution fails to describe the fracture statistic governed by the edge defect while the lognormal with a slightly right skewed shape fits it very well.

关键词： hot-cutting defect deviation from Weibull Kernel density estimation lognormal distribution

Fabrication of Ag@Ag_(2)O-MnO_(x) composite nanowires for high-efficient room-temperature removal of formaldehyde

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Journal of Materials Science & Technology 2021年第32期91卷 5-16页

作者： Hui Fang Chenxi Wang Daoyuan Li Shicheng Zhou Yu Du He Zhang chunjin hang Yanhong Tian Tadatomo Suga State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin 150001China Collaborative Research Center Meisei UniversityTokyo 191-8506Japan

Efficient removal of pollutant formaldehyde(HCHO) at room temperature using transition-metal oxides remains a huge challenge to date. Manganese oxide can oxidize formaldehyde, however, how to control the valence states of manganese is the key to further improve the removal efficiency. We have successfully prepared porous manganese oxide nanowires(Mn OxNWs) with large surface area and multiple valence states of manganese using simple electrospinning followed by thermal calcination and potassium permanganate solution post-treatment(C/S process). The contents of trivalent and tetravalent manganese increased significantly after C/S process. Moreover, the composition of silver oxide coated silver nanowires(Ag@Ag_(2) O NWs) is realized by assistance with oxygen plasma, which further enhanced high valence manganese. The formaldehyde removal efficiency by Ag@Ag_(2) O–Mn Oxcomposite nanowires can reach 93.7%. The high-efficient catalytic activity is confirmed to attribute to the higher surface area of composite nanowires, the high-valence manganese and the silver oxide for oxidation of formaldehyde.

关键词： Electrospinning O_(2)plasma Manganese oxides Silver nanowires Formaldehyde

Femtosecond laser irradiation induced heterojunctions between carbon nanofibers and silver nanowires for a flexible strain sensor

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Journal of Materials Science & Technology 2021年第25期84卷 139-146页

作者： Jiayun Feng Yanhong Tian Sumei Wang Ming Xiao Zhuang Hui chunjin hang Walter W.Duley Y.Norman Zhou State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin150001China Centre for Advanced Materials Joining University of WaterlooWaterlooOntarioN2L 3G1Canada Laser Micro/Nano-Fabrication Laboratory School of Mechanical EngineeringBeijing Institute of TechnologyBeijing100081China Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes National Laboratory of Mineral MaterialsSchool of Materials Science and TechnologyChina University of GeosciencesBeijing100083China Department of Physics and Astronomy University of WaterlooWaterlooOntarioN2L 3G1Canada

We report the direct joining of carbon nanofibers(CNFs)to silver nanowire(Ag NWs)by controlled irradiation with femtosecond(fs)laser *** separate types of nano-junction dependent on joint geometry,laser fluence and irradiation time are identified in irradiated *** one type of junction,the tip of an Ag NW is melted and flows to form a bond with an adjacent *** second type of junction occurs without significant heating of the Ag NW and involves the softening and flow of carbon in the CNF in response to the transfer of plasmonic energy from the Ag NW into the *** in a T-type joint configuration can be of either kind depending on the relative orientation of the incident optical field and the long axis of the Ag *** simulations were used to explore this effect for different joint geometries and laser *** electrical properties of a heterojunction involving a single Ag NW-CNF structure have been measured,and it is found that the junction resistance can be reduced by six orders of magnitude after laser ***,we have investigated the properties of a strain sensor based on an Ag NW-CNF hybrid nanowire network and find that this device can exhibit high *** sensitivity occurs as nano-junctions induced by fs laser irradiation greatly reduces the initial *** laser-based technique for direct nanojoining of CNF and Ag NWs may enable the design of robust nanowire structures for application in a variety of new devices.

关键词： Nanojoining Carbon nanofiber Silver nanowire Femtosecond laser Strain sensor

High-efficiency extraction synthesis for high-purity copper nanowires and their applications in flexible transparent electrodes

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Nano Materials Science 2020年第2期2卷 164-171页

作者： He Zhang Shang Wang Yanhong Tian Jiayue Wen chunjin hang Zhen Zheng Yilong Huang Su Ding Chenxi Wang State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin150001China College of Materials and Environmental Engineering Hangzhou Dianzi UniversityHangzhou310036China

Copper nanowires(Cu NWs)are considered an excellent alternative to indium tin oxide(ITO)in flexible transparency electrodes(FTEs).However,the mixed particles and surface oxidation of Cu NWs degrade the transmittance and conductivity of the ***,highly purified Cu NWs without oxidation are vital for high-performance ***,a facile and effective purification process is introduced to purify Cu NWs in a water and n-hexane system,which takes advantage of the differences in hydrophilicity between Cu NWs and Cu NPs caused by their different adsorption affinities to octadecylamine(ODA).At the same sheet resistance,the transmittance of the purified Cu NW-based FTEs improved approximately 2%compared to that of non-purified Cu NW-based *** of the electrode in glacial acetic acid removed the surface organics and *** only 40 s of treatment,the sheet resistance dramatically decreased from 10^5 Ohm/sq to 31 Ohm/sq with a transmittance of 85%.In addition,the Cu NW-based FTE conductors showed excellent flexibility(remaining stable after 1000 bending cycles).The Cu NW-based FTEs were further applied to fabricate a flexible transparent *** a voltage of 10 V,the temperature of the heater reached 73℃,demonstrating the potential applications of this material in various fields.

关键词： Copper nanowires Purification Transparent electrode Flexible electronics

老化过程中Cu/Al合金键合界面金属间化合物的生长行为

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金属学报 2007年第2期43卷 125-130页

作者：徐慧王春青杭春进哈尔滨工业大学材料科学与工程学院哈尔滨150001

采用热压超声丝球键合方法,将直径50μm Cu引线键合到Al-1%Si-0．5%Cu金属化焊盘．对焊点在不同温度下进行老化,通过SEM,EDX和Micro-XRD分析了金属间化合物(IMC)生长情况．结果表明：老化后Cu-Al IMC主要为CuAl_2和Cu_9Al_4．在老化温... 详细信息

采用热压超声丝球键合方法,将直径50μm Cu引线键合到Al-1%Si-0．5%Cu金属化焊盘．对焊点在不同温度下进行老化,通过SEM,EDX和Micro-XRD分析了金属间化合物(IMC)生长情况．结果表明：老化后Cu-Al IMC主要为CuAl_2和Cu_9Al_4．在老化温度一定时,Cu-Al IMC层的生长厚度与老化时间的关系符合抛物线法则；由实验数据计算得到Cu-Al IMC生长的激活能为97．1 kJ/mol．

关键词： Cu丝球键合金属间化合物老化 Micro-XRD

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残余应力对混合组装BGA热循环可靠性影响

机械工程学报 2014年第2期50卷 86-91页

作者：田艳红贺晓斌杭春进哈尔滨工业大学先进焊接与连接国家重点实验室哈尔滨150001 哈尔滨工业大学微系统与微结构制造教育部重点实验室哈尔滨150080

研究混装球栅阵列（Ballgridarray，BGA）回流焊后产生的残余应力对热循环寿命产生影响。根据Sn63Pb37／***0．5Cu均匀混装BGA封装实体，建立有铅和混装BGA封装体ANSYS有限元模型。通过加载不同峰值温度（220～265℃）和不同降温速度（1... 详细信息

研究混装球栅阵列（Ballgridarray，BGA）回流焊后产生的残余应力对热循环寿命产生影响。根据Sn63Pb37／***0．5Cu均匀混装BGA封装实体，建立有铅和混装BGA封装体ANSYS有限元模型。通过加载不同峰值温度（220～265℃）和不同降温速度（1～6℃／s）的回流温度曲线后，得到BGA封装体焊点残余应力、应变。随后选取峰值温度243℃、降温速度3℃／s条件下的回流焊后BGA封装体模型施加热循环载荷，根据修正Coffin-Manson方程预测焊点寿命。研究结果表明：回流焊中降温速度对焊后应力占主导因素，应力降温速度的增加逐渐由27．9MPa增加到32．5MPa，而峰值温度对焊后应变影响明显；热循环分析中BGA焊球左上角区域始终处于高应力应变状态，均匀混装BGA寿命稍低于SnPb焊点BGA：回流焊工艺后进行热循环加载结果表明残余应力对Sn63Pb37／Sn3．0Ag0．5C均匀混装BGA寿命影响不大。

关键词：混装球栅阵列 ANSYS 可靠性残余应力热疲劳寿命

Recent advances in metal nanowire-based transparent conductive films:Fabrication and applications

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Science Foundation in China 2020年第2期28卷 85-103页

作者： TIAN YanHong Zhang He hang chunjin WANG Shang FENG JiaYun DING Su HUANG YiLong State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin 150001China

Transparent conductive films(TCFs)have attracted intense attention in many electronic products,such as flexible devices,organic light-emitting diodes and stretchable *** tin oxide(ITO)is the most commonly used transparent conductive ***,the instinct brittleness,low reserves and high manufacturing costs associated with ITO prompted searching for a suitable *** alternatives are expected to have a comparable optoelectrical performance with ITO,excellent flexibility and low *** present,metal nanowires(NWs)are the only alternative to ITO that satisfy these requirements ***,practical applications of metal NWs are still limited by several drawbacks,including the poor quality of synthesized NWs,the loose wire to wire junctions,and the low resistance against oxidation or *** review summarizes the recent developments of TCFs to address these challenging issues and highlights some most important fabrication methods to improve the conductivity and stability of *** last,the applications of TCFs in a variety of devices,such as transparent heaters,organic light-emitting diodes and electrochromic devices,are also discussed.

关键词： transparent corrosion conductive

纳米铜银核壳焊膏脉冲电流快速烧结连接铜基板研究

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机械工程学报 2019年第24期55卷 51-56页

作者：黄圆杭春进田艳红王晨曦张贺哈尔滨工业大学先进焊接与连接国家重点实验室哈尔滨150001 中国电子科技集团公司第五十五研究所南京210016

一种温和的两步液相法制备的纳米铜银核壳颗粒,实现了均径为6.9 nm的小尺寸纳米银颗粒包覆在均径为57.5 nm的纳米铜颗粒的表面,采用扫描电子显微镜、透射电子显微镜和高分辨率射像对其结构进行了表征。采用模板印刷法制备铜基板/纳米铜... 详细信息

一种温和的两步液相法制备的纳米铜银核壳颗粒,实现了均径为6.9 nm的小尺寸纳米银颗粒包覆在均径为57.5 nm的纳米铜颗粒的表面,采用扫描电子显微镜、透射电子显微镜和高分辨率射像对其结构进行了表征。采用模板印刷法制备铜基板/纳米铜银核壳焊膏/铜基板三明治结构,研究了脉冲电流对三明治结构的剪切强度大小和微结构特征的影响。试验结果表明脉冲电流烧结纳米铜银核壳焊膏连接Cu-Cu基板可在短时间(小于200 ms)内快速获得高致密度且实现冶金连接的高强度焊点结构。三明治结构的剪切强度随脉冲电流的增加而增大,在1.0 kA的脉冲电流下,可获得高达80 MPa的剪切强度。经研究脉冲电流烧结后的纳米铜银核壳焊膏内部显微组织结构,提出双脉冲电流下纳米铜银核壳焊膏烧结连接的机理。

关键词：纳米铜银核壳颗粒纳米焊膏脉冲电流烧结快速连接功率器件