低温等离子体辅助脉冲直流磁控溅射制备TiN薄膜

采用一种新型的等离子体辅助脉冲直流磁控溅射溅射沉积方法,在低温状态(100℃)下制备了氮化钛薄膜,利用X射线衍射仪、轮廓仪、分光光度计、原子力显微镜对氮化钛薄膜进行了表征,研究了等离子体源在薄膜制备过程中的作用。结果表明采用该方法可在低温环境下制备高温抗氧化性能良好的氮化钛薄膜。当离子源功率为500 W时,制备的氮化钛薄膜表现良好氮化钛(111)择优取向,薄膜表面粗糙度为1.43 nm,红外反射率可达到90%。     

钛合金表面非平衡磁控溅射制备氮化钛薄膜性能研究

本文利用非平衡磁控溅射技术，通过改变薄膜沉积时氮气和氩气分压比（PN／PAr）和靶基距，在Si（100）和钛合金（Ti6A14V）基体上制备了氮化钛薄膜。利用X射线衍射（XRD）、扫描电子显微镜（SEM）、HXD-1000显微硬度仪和（CSEM）销盘摩擦磨损实验机对氮化钛薄膜的晶体结构、断面形貌、显微硬度和耐磨性进行了表征。研究发现，利用非平衡磁控溅射制备出致密的氮化钛薄膜，PN／PAr较小时，氮化钛薄膜中存在Ti2N相，Ti2N能够提高薄膜的硬度与耐磨性，随着N2／Ar的提高，薄膜硬度、耐磨性提高，当PN／PAr达到0．1时，随着N2／Ar的提高，薄膜硬度、耐磨性降低。结果表明，在钛合金表面制备氮化钛薄膜可以显著提高钛合金表面硬度与耐磨性，在改善用于人工心脏瓣膜的力学性能，提高人工心脏瓣膜的瓣架耐磨性，提高人工心脏瓣膜的寿命方面有较广阔的应用前景。     

反应磁控溅射离子镀氮化钛薄膜质量与工艺参数的关系

本文总结了影响反应磁控溅射离子镀氮化钛膜层质量的主要工艺参数。测得了靶极电压与氮气流量、靶极电流与氮气流量、溅射室内压强与氮气流量、氮化钛膜的颜色与氮分压、氮化钛膜的颜色与基板温度、靶极功率与氩气分压的关系以及薄膜层中氮、钛含量沿薄膜表面的分布。上述结果对提高溅射速率和薄膜质量有很大的实际意义。     

氮气流量对热丝增强等离子体磁控溅射制备CrN_x薄膜组织结构与性能的影响

采用热丝增强等离子体磁控溅射技术在SKD61钢基体上制备了CrN_x薄膜,并分析研究了不同氮气流量对薄膜相结构、组织形貌、粗糙度、厚度、耐磨性、膜基结合力以及纳米硬度和弹性模量的影响。结果表明:在较宽的氮气流量变化范围内可制备出厚度均匀、结构致密、高硬度及高耐磨性的CrN_x薄膜。随氮气流量增加,薄膜由Cr2N及CrN双相组成转变为CrN单相。由于复杂相及相取向的存在,氮气流量为90 mL/min的CrN_x薄膜内应力最大,膜基结合力最低。CrN_x薄膜使SKD61钢的纳米硬度、弹性模量及耐磨性能均大幅提高,最高纳米硬度及弹性模量分别达36 GPa,477 GPa。通过对材料韧性的综合评价,氮气流量为75 mL/min条件下所制得的以Cr_2N相为主的薄膜的韧性最佳。     

非平衡磁控溅射氮化钛薄膜及其性能研究

采用非平衡磁控溅射技术,在钛合金(Ti6Al4V)表面沉积氮化钛薄膜。通过改变氮气和氩气分压比(PN/PAr)和基体偏压,制备出不同结构、性能的氮化钛薄膜。采用X射线衍射技术、原子力显微镜、PS-168型电化学测量系统、CSEM球盘摩擦磨损实验机、HXD-1000 knoop显微硬度仪等研究了薄膜的结构、表面形貌、耐腐蚀性能与机械性能。结果表明,采用非平衡磁控溅射技术制备出了致密的氮化钛薄膜。当PN/PAr较小时,氮化钛薄膜中存在Ti2N时,Ti2N相可以有效提高薄膜的硬度和耐磨损性能;当PN/PAr增加到0.1时,薄膜硬度达到最大,耐磨损性能最优;随着PN/PAr的继续增大,氮化钛薄膜中主要存在TiN相,氮化钛薄膜的复合硬度和耐磨损性能降低。在钛合金(Ti6Al4V)表面沉积氮化钛薄膜可以显著提高其在Hanks类体液中的耐腐蚀性能。     

TiN薄膜光学性质与色散分析的第一性原理研究

为研究氮气流量对TiN薄膜光学性能的影响,本文利用反应磁控溅射技术,在不同氮气分压下制备了氮化钛薄膜.采用第一性原理方法计算了氮化钛的态密度和光学常数,详细分析了氮化钛的电子态密度以及介电函数的色散关系,得出了适合氮化钛的Drude-3Lorentz色散模型;采用此模型拟合了椭圆偏振光谱仪测试出的薄膜介电函数谱.结果表明:随着氮分压的降低,薄膜的等离子体共振频率向高能方向移动,金属性增强,薄膜中的晶格缺陷增多,晶界散射和缺陷吸收作用增强,可见光区的透射率下降.     

氮气流量对UBMS制备TiN薄膜结构和力学性能的影响

利用非平衡磁控溅射离子镀技术研究了不同氮气流量对TiN薄膜结构、摩擦性能、附着力及显微硬度的影响.研究结果表明:N2流量对TiN薄膜的择优取向有很大影响,N2流量较小时,TiN薄膜显示出{111}择优取向生长趋势,在N2流量为15sccm条件下沉积的TiN薄膜的(111)衍射峰强度最强,与之对应的薄膜硬度和膜基结合强度最高,耐磨性能也最好;N2流量的大小对TiN薄膜的沉积速率和摩擦系数影响显著,并随N2流量增加都有较明显的下降趋势.     

中频孪生靶非平衡磁控溅射制备氮化硅薄膜及其性能(英文)

本文采用中频孪生靶非平衡磁控溅射技术在不同氮气流量比例的条件下制备出氮化硅薄膜。利用傅里叶变换红外光谱仪(FTIR)、X射线衍射仪(XRD)、原子力显微镜(AFM)、椭偏仪等研究了氮气流量比率对氮化硅薄膜的微观结构、表面形貌、沉积速率、折射率的影响。结果表明:中频孪生非平衡磁控溅射技术制备的薄膜为非晶态氮化硅。随着氮气流量比率的增加,Si-N键红外光谱吸收带向低波数漂移,薄膜的沉积速率降低,表面结构更为光滑致密,氮化硅薄膜的折射率降低。薄膜的硬度和杨氏模量分别达到22和220GPa左右。     

离子源对磁控溅射制备TiNC膜基结合力的影响

由于膜基附着力不好,膜层脱落问题是工业生产中磁控溅射镀制黑膜最常见的问题.本实验采用 阳极线性离子源和霍尔点源辅助磁控溅射复合技术制备了TiNC薄膜,探讨解决TiNC膜基附着力不好的问题.初步实验结果表明,离子束辅助沉积对于改善膜基附着力的作用并不明显,本文还比较了脉冲偏压清洗对膜基附着力的影响,探讨了其可能影响因素.     

基底温度对直流磁控溅射制备氮化铜薄膜的影响研究

采用反应直流磁控溅射镀膜法,在氮气分压为0.9Pa、不同基底温度下、玻璃基底上制备了纳米多晶Cu3N薄膜,并研究了基底温度对薄膜结构和性能的影响。结果表明,当基底温度为100℃及以下时,薄膜以[111]方向择优生长为主;在150℃及200℃时,薄膜以[100]方向择优生长为主;250℃时开始出现Cu的[111]方向生长,300℃时已完全不能形成Cu3N晶体,只有明显的Cu晶体。随基底温度的升高,薄膜的沉积速率在13～28nm/min呈U型变化,低温和高温时较高,150℃时最低;薄膜的电阻率显著降低;薄膜的显微硬度先升后降,100℃时显微硬度最大。     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

From Industry 4.0 to Research 4.0. Development of High Performance Fibers in the Light of Digitization

We associate a variety of innovations with the term ＂Industry 4.0＂. The pioneer of many 4.0 modifications forms the basisfor the trend towards the integrated di...     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

Roman iron and steel: A review

ABSTRACT

The production of ferrous metal increased during the Roman Late Republican period, Principate and Empire. The direct bloomery process was used to extract the metal from its ores using slag-tapping and slag-pit furnaces. The fuel was charcoal and an air blast was introduced by bellows-operated tuyères. Iron formed as a bloom, often as a spongy mass of metal, which contained impurities from the smelting process, including unreacted ore, fuel, slag and fragments from the furnace walls, while the metal was often inhomogeneous with varied carbon contents. Blooms were either smithed directly into bars or ingots or they were broken up, which also allowed the removal of gross impurities and a selection of pieces with similar properties to be made. These could then be forge-welded together and formed into characteristically shaped ingots. Making steel in the furnace seems to have been achieved: it depended on the ore and the furnace and conditions within it. Surface carburization was also carried out. Iron and steel were used extensively in construction and for tools and weapons. Fire welding was often used to add pieces of steel to make the edges of tools and weapons, which could be heat-treated by quenching to harden them.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Synthesis of Alumina-Zirconia Nanocomposites by Solgel Process

Al₂O₃-ZrO₂ nanocomposites were developed starting with the solgel process. Composite alumina-zirconia nanopowders were synthesized from metallorganic precursors (Aluminium secondary butoxide and zirconium Iso propoxide) using the solgel process. The parameters affecting the synthesis—solvent, concentration of precursor, R/H ratio (i.e., dilution of water in solvent)—were varied as also the temperature and pH. BET and TEM were used to measure nanosize. Diffuse reflectance spectroscopy and also qualitative optical absorption led to identical particle size estimate. The variation of process parameters was used to study the effect and interdependence of process parameters. Artificial Neural Networks was used to rigorously analyze the process. Although this led to confirmation of interdependence of parameters, the presence of a single overwhelming solvent variable was also established. Then the optimal process was used to synthesize more nanopowder. To produce bulk nanocomposite the nanopowders were sintered by varying the temperature and time period. The sintered lithoids were probed with a vickers hardness tester to measure elastic modulus, hardness, and fracture toughness. The results showed high elastic modulus, modest hardness, and very high fracture toughness.     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.