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Laser Direct Metal Deposition Technology and Microstructure and Composition Segregation of Inconel 718 Superalloy

Journal of Iron and Steel Research International 2011年第4期18卷 73-78页

作者： ZHANG Qun-li yao jian-hua Jyoti Mazurnder Key Laboratory of E and M of Ministry of Education and Zhejiang Province Hangzhou 310014 Zhejiang China Research Center of Laser Processing Technology and Engineering Zhejiang University of Technology Hangzhou 310014 Zhejiang China Center for Laser Aided Intelligent Manufacturing University of Michigan Ann Arbor 48109 Michigan USA

Multilayer of laser direct metal deposition（DMD）was prepared by depositing a gas atomized pre-alloyed powder with a composition close to Inconel 718 alloy on Inconel 718 high temperature alloy *** effects of the DMD parameters on the build-up rate and the structure of the deposited layer were *** laser DMD sample was further processed by a solution *** microstructure and property of the laser DMD zone before and after heat treatment were investigated as *** results show that the laser parameters of actual laser power of 650 W,scanning speed of 5.8 mm/s,beam diameter of 1 mm,powder feed rate of 6.45 g/min,with a corresponding specific energy of 90-130 J/mm2,can be recommended as optimum parameters for high build-up rate of Inconel 718 *** the condition of optimized parameters,a directional solidification microstructure was obtained and the average distance between the columnar crystals was 5-10 μ*** microcomposition segregation was found between the columnar crystal trunk and columnar *** elements of Nb,Mo,Ti concentrated in the columnar crystal *** the heat treatment,the segregation was greatly minimized,and the segregation ratios were close to *** hardness of the laser deposited layer did not show obvious difference along the height of the layer either for the as-deposited layer or for the heat treated ***,the microhardness of the laser DMD zone after heat treatment was obviously higher than that after the as-deposited *** the heat treatment process,some Nb-and Mo-rich phases precipitated and strengthened DMD layer.

关键词： laser DMD Inconel 718 alloy composition segregation microstructure hardness

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Deposition Behavior at Different Substrate Temperatures by Using Supersonic Laser Deposition

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Journal of Iron and Steel Research International 2013年第10期20卷 87-93页

作者： YUAN Lin-jiang LUO fang yao jian-hua Key Laboratory of Special Purpose Equipment and Advanced Processing Technology of Ministry of Education Zhejiang University of Technology College of Zhijiang Zhejiang University of Technology

The supersonic laser deposition （SLD） is a new fabrication process which combines the supersonic powder stream found in cold spray with laser heating of the deposition zone. Because of the instantaneity of particles impact, the deformation behaviors and the adhesion behaviors of particles impacted on the substrate by SI.D cannot be well investigated through experiments. Therefore, a finite elemen! model was developed to solve the problems above. Meanwhile, the heat effect of the substrate heated by laser was discussed. The effective plastic strain and the effec- tive stress between the particle and substrate at different laser preheal temperatures were studied. The results show that laser depositing temperatures of 1 000 and 1 100 ℃ on substrate would be the optimized for the bonding of parti- cles and substrate. In addition, the simulation results conformed to experimental results.

关键词： supersonic laser deposition deformation behavior adhesion behavior finite element model

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Effect of Laser Power on the Cladding Temperature Field and the Heat Affected Zone

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Journal of Iron and Steel Research International 2011年第1期18卷 73-78页

作者： LUO Fang yao jian hua HU Xia xia CHAI Guo-zhong College of Zhijiang Zhejiang University of Technology Hangzhou 310024 Zhejiang China Key Laboratory of Special Purpose Equipment and Advanced Processing Technology of Ministry of Education Zhejiang University of Technology Hangzhou 310012 Zhejiang China

H13 powder is cladded on steel P20 （base） by continuous COe laser, and the influence of technological pa rameters such as the laser power is analyzed. The 3-D model of synchronous powder feeding is built under Gauss heat source. The simulative results in the heat affected zone are compared with the experimental ones, and the average er rors of width and depth are 15% and 4.5%, respectively. It is found that the simulative results provide basic data for investigating of laser cladding further.

关键词： laser power laser cladding temperature field heat affected zone

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Characteristics of Stellite 6 Deposited by Supersonic Laser Deposition Under Optimized Parameters

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Journal of Iron and Steel Research International 2013年第2期20卷 52-57页

作者： LUO Fang Lupoi Rocco Cockburn Andrew Sparkes Martin O'neill William yao jian-hua College of Zhijiang Zhejiang University of Technology College of Mechanical Engineering Zhejiang University of Technology Department of Mechanical and Manufacturing Engineering Trinity College Dublin Institute for Manufacturing Department of EngineeringUniversity of Cambridge

Stellite 6 powders were deposited on low carbon steel using SLD （supersonic laser deposition） under optimized parameters. The structure, line scan of elements and porosity of coating were examined and analyzed using SEM （scanning electron microscope）, OM （optical microscope） and XRD （X-ray diffraction）. The adhesion strength between coating and substrate was tested by PAT-ADHESION/TENSILE and E900STM adhesive. The results showed the deposition characteristics of optimized coating with N2 at a pressure of 3.0 MPa, a temperature of 450 ℃ and a laser power of 1.5 kW were compared with those of Stellite 6 coating deposited by the HVOF （high velocity oxygen fuel）.

关键词： Stellite 6 supersonic laser deposition deposition characteristic HVOF

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Laser Surface Remelting of Medium Ni-Cr Infinite Chilling Cast Iron Roll

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材料热处理学报 2004年第05B期25卷 1009-1012页

作者： yaojian-hua ZHANGQun-li XIESong-jing ZhefiangUniversityofTechnology HangzhouChina

Laser surface remelting of medium Ni-Cr infinite chilling cast iron was performed with a continuous wave COa laser beam with the power of 7 KW under the argon shielding. The microstructural analysis of the laser remelted layer by optical microscope shows that the laser remelted layer consists of three zones, which is the melting zone, the transition zone and the heat affected zone. The size of the dendrite of the melting zone is only in the 1/10 to 1/30 range of that of the substrate. The distribution of the hardness of the laser remelted layer was detected, and the carrying capacity of rolling steel was also field-tested. The results show that both the hardness of the remelted layer and the carrying capacity all increase, especially, the carrying capacity was 50% increased compared with the substrate.

关键词：激光重熔铸铁轧辊显微结构晶粒细化硬度承载能力 Ni-Cr激冷

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40Cr钢表面激光合金化及其在螺杆强化中的应用

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金属热处理 2007年第11期32卷 59-61页

作者：张伟姚建华浙江工业大学机械制造及自动化教育部重点实验室激光加工技术工程研究中心浙江杭州310014

在40Cr钢表面进行Co/W合金、超细WC(2～3μm)两种材料激光合金化的试验,检验了合金化层的组织和性能,通过与气体渗氮层的比较,表明激光合金化可以得到晶粒细化,稀释率低,与基体结合牢固的表面强化层。合金层的显微硬度、耐磨损等性能比... 详细信息

在40Cr钢表面进行Co/W合金、超细WC(2～3μm)两种材料激光合金化的试验,检验了合金化层的组织和性能,通过与气体渗氮层的比较,表明激光合金化可以得到晶粒细化,稀释率低,与基体结合牢固的表面强化层。合金层的显微硬度、耐磨损等性能比气体渗氮有不同程度的提高。40Cr钢的注塑机螺杆经激光合金化强化后使用寿命比气体渗氮提高了两倍,显示了良好的应用前景。

关键词： 40Cr钢激光合金化渗氮组织与性能

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激光熔覆镍包纳米氧化铝

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中国激光 2006年第5期33卷 705-708页

作者：姚建华张伟浙江工业大学机械制造及自动化教育部重点实验室浙江杭州310014

进行了2Cr13不锈钢表面激光熔覆镍包纳米氧化铝的实验。使用扫描电子显微镜(SEM)、X射线衍射仪(XRD)、X射线能量色散谱仪(EDAX)、显微硬度仪等设备检测了涂层表面、横截面的显微组织和涂层的硬度、耐磨损等性能,分析了加入纳米氧化铝粒... 详细信息

进行了2Cr13不锈钢表面激光熔覆镍包纳米氧化铝的实验。使用扫描电子显微镜(SEM)、X射线衍射仪(XRD)、X射线能量色散谱仪(EDAX)、显微硬度仪等设备检测了涂层表面、横截面的显微组织和涂层的硬度、耐磨损等性能,分析了加入纳米氧化铝粒子后对涂层组织和性能的影响。研究结果表明,激光熔覆可获得致密的Fe-Ni(Cr)合金和Al2O3粒子复合涂层。其中,纳米氧化铝粒子弥散分布在微细合金晶粒之间,并与合金晶粒一起形成了胞状树枝晶结构。纳米氧化铝粒子的加入增加了基质金属的成核率,起到了细晶强化以及弥散强化的作用,使得复合涂层的机械性能大幅度提高。复合涂层的平均硬度为700HV0.2,比基体提高了1.5倍,耐磨损性能比淬火态基体提高了1.25倍。

关键词：激光技术纳米复合涂层显微组织和性能激光熔覆镍包纳米氧化铝

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Inhibitory effects of 1-methyl-4-phenylpyridinium on glutamate uptake into cultured C6 glioma cells

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Acta Pharmacologica Sinica 2004年第7期 9-14页

作者： Hong-hong yao, jian-hua DING, Hai-rong HE, Gang HU2 Department of Pharmacologyand Neurobiology, Nanjing Medical University, Nanjing 210029, China

AIM: To investigate the effect of 1-methyl-4-phenylpyridinium (MPP+) on the glutamate uptake into cultured C6 glioma cells. METHODS: The glutamate uptake into C6 glioma cells was measured by radio-ligand binding assay method. The effect of MPP+ on the morphology of C6 glioma cells was observed under phase contrast microscopy; apoptosis of C6 glioma cells were measured by FITC-labeled Annexin V staining and flow cytometry. Cell viability was measured by MTT method. RESULTS: MPP+inhibited glutamate uptake into C6 glioma cells. However, MPP+ failed to induce any morphological changes of C6 glioma cells, and exposure to MPP+ had no effect on the viability and the apoptotic percentage of C6 glioma cells. Incubation with 12-O-tetradecanoylphorbol -13-acetate (TPA), a protein kinase C activator, caused a significant increase in glutamate uptake and completely reversed MPP+-induced inhibitory effect on glutamate uptake. CONCLUSION: The present results indicate that glutamate transporters mayhave important pathogeneticimplications in Parkinson disease. MPP+-inducedinhibition ofglutamate uptake was due to the dysfunction of glutamate transporters; TPA enhanced glutamate uptake and completely reversed the inhibitory effect of MPP+.

关键词： methyl-4-phenylpyridinium glutamate acid glioma apoptosis 4-O-methyl-12-O-tetradecanoyl- phorbol-13-acetate

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基于邻域算法的瑞利面波垂直-水平振幅比及频散曲线联合反演及应用

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地球物理学报 2016年第3期59卷 959-971页

作者：袁艺姚华建秦岩中国科学技术大学地球和空间科学学院地震与地球内部物理实验室合肥230026 蒙城地球物理国家野外科学观测研究站安徽亳州233527

瑞利面波垂直-水平振幅比(或ZH振幅比)是一个随频率变化的函数,对于台站下方浅层地壳结构非常敏感,且具有和频散资料不同的深度敏感核,是传统频散反演方法的一个很好的补充,从而可以将基阶瑞利面波的ZH振幅比和面波频散数据联合起来更... 详细信息

瑞利面波垂直-水平振幅比(或ZH振幅比)是一个随频率变化的函数,对于台站下方浅层地壳结构非常敏感,且具有和频散资料不同的深度敏感核,是传统频散反演方法的一个很好的补充,从而可以将基阶瑞利面波的ZH振幅比和面波频散数据联合起来更好地反演获得观测台站下方的速度结构.本文提出了基于邻域算法的面波频散曲线与ZH振幅比联合反演方法,我们进行了基于理论模型的模拟测试,证明了联合反演是一种更为可靠的反演方法,且能更好地约束浅层地壳结构.相比于频散曲线单独反演,联合反演不仅可以精确反演获得地壳的Vs结构,对分层地壳的Vp/Vs也能很好地约束.然后我们将联合反演算法应用于实际测量数据,获得了中国西南昆明台(KMI)下方更为准确的地壳横波速度结构及Vp/Vs模型.

关键词：联合反演邻域算法瑞利面波相速度频散 ZH振幅比地壳结构

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CdS_xSe_(1-x)/ZnS(核/壳)量子点的光谱截面及其掺杂光纤的传光特性

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光子学报 2017年第9期46卷 1-8页

作者：程成黄媛姚建华浙江工业大学光电子智能化技术研究所杭州310023 浙江省高端激光制造装备协同创新中心杭州310014

测量了不同组份比例x的CdS_xSe_(1-x)/ZnS(核/壳)量子点的吸收谱和发射谱,确定了量子点的吸收系数、吸收截面和发射截面.量子点吸收截面随粒径的增大而增大、随x的增大而减小.采用紫外固化胶,制备了掺杂浓度为0.1~5mg/mL的CdS_(0.4)Se_(... 详细信息

测量了不同组份比例x的CdS_xSe_(1-x)/ZnS(核/壳)量子点的吸收谱和发射谱,确定了量子点的吸收系数、吸收截面和发射截面.量子点吸收截面随粒径的增大而增大、随x的增大而减小.采用紫外固化胶,制备了掺杂浓度为0.1~5mg/mL的CdS_(0.4)Se_(0.6)/ZnS量子点光纤,测量了不同掺杂浓度量子点光纤中473nm泵浦功率的吸收衰减速率.吸收衰减速率和吸收截面弱关联于掺杂浓度.测量了光致荧光光谱强度随光纤长度和量子点浓度的变化.量子点光纤的光致荧光峰值强度随掺杂浓度和光纤长度变化而变化,且存在一个与最大峰值强度对应的饱和掺杂浓度和光纤长度.本文的实验结果有助于进一步构建新型的CdS_xSe_(1-x)/ZnS量子点增益型光电子器件.

关键词： CdSxSe1-x/ZnS量子点吸收截面光致荧光光谱量子点掺杂光纤量子点光纤传光特性

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