新型工具钢GDL-4的TiAIN涂层的制备及性能的研究

采用非平衡磁控溅射离子镀在GDL-4型合金工具钢表面进行TiAIN涂层，并与M2钢表面TiAIN涂层做对比性分析。用压入法测量涂层的结合强度、用显微硬度计以不同的载荷测量涂层硬度。结果表明，该钢经PVDTiAIN涂层后，结合强度达到HF1，膜厚为4．5—5．0μm，显微硬度为HV2360—2576，与M2钢为基体相比，在相同条件下进行表面TiAIN涂层，其结合强度、膜厚、显微硬度测量，结果都很相近。以廉价合金为主加元素的GDL～4型合金工具钢，可以替代价格昂贵的传统高速钢以降低工具钢成本。并采用维氏压头测量断裂韧性KIC和通过扫描电子显微镜观察压痕形貌来评定涂层的韧性。     

新型合金工具钢TiAlN涂层结构和结合结强度的研究

应用非平衡磁控溅射离子镀在一种新型合金工具钢表面进行TiAlN涂层,采用电子显微镜下观察涂层结构形貌,用压入法和划痕法测量涂层的结合强度.结果表明,涂层的表面组织均匀,当粗糙度0.02相似文献   

加钛高碳低合金工具钢磨损性能的研究

在无钛GDL-4工具钢的基础上,初步研究了添加钛元素对GDL-4材料耐磨性能的影响.并从材料硬度、摩擦系数、显微组织等方面分析了磨损性能变化的原因.摩擦磨损试验结果表明,加钛后材料的耐磨性能得到改善,在300 N和400 N载荷下,含钛GDL-4工具钢耐磨性能优于高速工具钢M2,在500 N的高载荷下两者耐磨性能接近.     

TiAlN/AlON纳米多层涂层组织及性能研究

研究AlON层厚度对TiAlN/AlON纳米多层涂层显微组织和性能影响.使用磁控溅射技术在高速工具钢（W6Mo5Gr4V2）上制备TiAlN/AlON纳米多层涂层,使用X射线衍射仪（XRD）、显微硬度计、通用表面测试仪表征和分析纳米多层涂层的组织和性能.结果表明:在TiAlN模板的作用下,非晶体的AlON转变为晶态,与TiAlN形成共格外延生长,使纳米多层涂层出现了超硬现象.当AlON层厚度为0.81 nm时涂层硬度最高,达到3 769.6 HV,比TiAlN单层涂层显微硬度提高了60.37%;之后随着AlON层厚度增加,硬度下降.当AlON层厚度为0.81 nm时,涂层抗刮性和摩擦磨损性能也达到最好.      

基体偏压对磁控溅射TiAlN薄膜性能的影响

采用中频孪生磁控溅射技术,以Q235碳钢为基体,通过调整薄膜沉积过程中基体负偏压大小,制备TiAlN薄膜.采用原子力显微镜(AFM)观察薄膜表面形貌,采用动电位极化试验研究薄膜的电化学腐蚀行为,用台阶仪和显微硬度计测量薄膜的厚度和硬度,用X-射线光电子能谱仪测试薄膜的组织成分.结果表明,TiAlN薄膜表面平整,粗糙度低.随偏压的增大,膜厚、显微硬度和耐腐蚀性都呈现也先增大,后减小的趋势.当负偏压增大到60 V时,薄膜的腐蚀电位和腐蚀电流密度分别为-256.2 mV和7.81×10-6A/cm2,抗腐蚀能力最强.X射线光电子能谱(XPS)检测结果表明,随负偏压幅的增大,Al/Ti原子比降低.     

钢表面激光熔覆铁/镍基合金熔覆层的组织与性能研究

针对提高20Cr13不锈钢的表面性能,采用激光熔覆技术在基体表面制备M2铁基和Ni60A镍基合金熔覆层;通过使用光学显微镜、显微硬度计以及电化学工作站对两种熔覆层进行金相组织、显微硬度和电化学腐蚀性能差异性研究;结果表明:铁基、镍基熔覆层与基体结合界面均有明显的白亮带,无气孔、裂纹等缺陷;铁基涂层微观组织主要由等轴晶和胞状晶组成,镍基涂层微观组织主要由和树枝晶组成;铁基涂层的显微硬度为5417 HV,镍基涂层的显微硬度为5923 HV,约为基体显微硬度（2207 HV）的2~3倍;铁基、镍基涂层均与20Cr13钢基体表面形成了较好的冶金结合,二者表面硬度均有了有显著提升,在熔覆区采用Ni60A镍基材料时的显微硬度要比采用M2铁基材料时的显微硬度高,而在热影响区部位两者显微硬度相差不大;铁基涂层的自腐蚀电位（-021 V）略高于镍基涂层的自腐蚀电位（-023 V）,铁基涂层的耐腐蚀性优于镍基涂层。     

碳氮强化电弧喷涂涂层合金组织与耐磨性能

研制一种新型的碳氮合金化喷涂丝材,通过高速电弧喷涂设备在Q235低碳钢板表面制备耐磨合金。用扫描电镜观察合金涂层形貌,用EDS分析涂层化学成分,并用显微硬度仪检测涂层显微硬度及磨粒磨损试验机测量涂层磨损失重。研究涂层的成形、耐磨损性能及其机制。结果表明:使用添加N替代部分C进行碳氮强化的喷涂丝材所制备的涂层合金成形良好,涂层组织均匀,结构致密;涂层显微硬度平均值为568HV0.1,最高值达593HV0.1;涂层结合强度达到45.8MPa; 细小的碳氮化物硬质相颗粒使涂层具有良好的耐磨损性能,其耐磨性是4Cr13不锈钢涂层的1.58倍。     

20Cr13钢表面激光熔覆铁/镍基合金熔覆层的组织与性能研究

针对提高20Cr13不锈钢的表面性能,采用激光熔覆技术在基体表面制备M2铁基和Ni60A镍基合金熔覆层;通过使用光学显微镜、显微硬度计以及电化学工作站对两种熔覆层进行金相组织、显微硬度和电化学腐蚀性能差异性研究;结果表明:铁基、镍基熔覆层与基体结合界面均有明显的白亮带,无气孔、裂纹等缺陷;铁基涂层微观组织主要由等轴晶和胞状晶组成,镍基涂层微观组织主要由和树枝晶组成;铁基涂层的显微硬度为541.7 HV,镍基涂层的显微硬度为592.3 HV,约为基体显微硬度(220.7 HV)的2～3倍;铁基、镍基涂层均与20Cr13钢基体表面形成了较好的冶金结合,二者表面硬度均有了有显著提升,在熔覆区采用Ni60A镍基材料时的显微硬度要比采用M2铁基材料时的显微硬度高,而在热影响区部位两者显微硬度相差不大;铁基涂层的自腐蚀电位(-0.21 V)略高于镍基涂层的自腐蚀电位(-0.23 V),铁基涂层的耐腐蚀性优于镍基涂层。     

螺杆表面超音速喷涂WC-Co耐磨涂层的研究

采用超音速喷涂技术在45#钢螺杆表面制备了钴基碳化钨型合金涂层,利用SEM、XRD和金相等手段分析了涂层的组织和性能.结果表明: 在45#钢基体和涂层的界面区域, WC-Co涂层主要由细小的WC相、块状含铁相和分布均匀的钴相组成;在WC-Co/45#钢界面层中,块状含铁相是α-Fe和马氏体组织;涂层的拉伸结合强度达到65 MPa, 显微硬度达到1200 HV.     

工艺参数对烧结法制备高铝青铜涂层的影响

利用真空热压烧结技术,在45#钢基体上制备高铝青铜合金涂层.采用SEM、EDS、XRD、显微硬度计和万能力学试验机对涂层和界面的微观组织、涂层相结构、元素分布、显微硬度以及界面结合强度进行表征,研究涂层制备工艺参数对制备的涂层组织和力学性能的影响.结果表明:合金涂层的适合烧结温度为900℃,合适的粉体粒度为-300目的细粉,该参数下烧结时涂层显微硬度可达392.6HV,抗压强度以及抗弯强度分别为1 225.8MPa和791.3MPa;烧结时加入钎焊剂后使涂层致密化程度提高、均匀细化程度增加,显微硬度可达383.5~409.4HV,涂层与基体形成结合带,结合强度为38.2MPa,能谱分析表明,界面结合处发生元素扩散,同时生成新相AlB2和Fe3B.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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