Hemocompatibility of DLC coatings synthesized by ion beam assisted deposition

Ion beam-assisted diamond-like carbon (DLC) coatings have been used for growing the human platelet, fibrinogen, and albumin in the control environment in order to assess their hemocom-patibility. The hard carbon films were prepared on polymethylmethacrylate (PMMA) at room temperature using ion beam assisted deposition (IBAD). Raman spectroscopic analysis proved that the carbon films on PMMA are diamond-like with a higher fraction of sp3 bonds in the structure of mixed sp2 + sp3 bonding. The blood protein adsorption tests showed that DLC coatings can adsorb more albumin and are slightly more fibrinogen than the PMMA chosen as a control sample. The platelets adhered on DLC coatings were reduced significantly in number. These results indicate good hemocompatibility of DLC coatings.     

ZrN／TiN复合涂层刀具的制备及切削性能

采用中频磁控溅射和电弧离子镀2种方法组合，在YG6硬质合金基体上沉积ZrN／TiN复合涂层．研究了复合涂层刀具的制备工艺，并对复合涂层刀具的性能参数进行了测试．通过切削试验研究了ZrN／TiN涂层对硬质舍金刀具切削性能的影响，并与未涂层刀具的切削效果做了对比．结果表明：ZrN／TiN涂层提高了硬质合金刀具的硬度，降低了涂层刀具的切削力，提高了涂层刀具的耐磨损能力．     

Impact fatigue behavior of ZrN/Zr-N/Zr coatings on H13 steel by CFUBMSIP

ZrN/Zr-N/Zr coatings were deposited on H13 steel by close field unbalanced magnetron sputtering ion plating （CFUBMSIP） technique. The effect of two main parameters such as OEM and bias voltage for the CFUBMSIP process on the microstructure, mechanical properties and impact fatigue behavior of the coatings was investigated. The results indicate that with OEM increasing from 55% to 65% the surface particles size of the coatings increases while it remains almost similar when the bias voltage changes from 60 to 75 V. An aggregation of the particles occurs on the coatings surface, with further increasing the OEM and bias voltage to 75% and 90 V, respectively. The coatings show a columnar grain structure and are mainly composed of two phases of ZrN and Zr. The coating hardness decreases with OEM value increasing and both the coating hardness and modulus go up with bias voltage. The coating deposited under OEM of 65% and bias voltage of 75 V shows the best impact fatigue property.     

ZrN/TiN复合涂层刀具的制备及切削性能

采用中频磁控溅射和电弧离子镀2种方法组合,在YG6硬质合金基体上沉积ZrN/TiN复合涂层.研究了复合涂层刀具的制备工艺,并对复合涂层刀具的性能参数进行了测试.通过切削试验研究了ZrN/TiN涂层对硬质合金刀具切削性能的影响,并与未涂层刀具的切削效果做了对比.结果表明：ZrN/TiN涂层提高了硬质合金刀具的硬度,降低了涂层刀具的切削力,提高了涂层刀具的耐磨损能力.     

Microstructure and mechanical properties of TiAlSiN nano-composite coatings deposited by ion beam assisted deposition

TiAlSiN nano-composite coatings with Silicon contents from 4.1 to 23.9 at.% were deposited on Silicon wafers. The nanohardness, microstructure, and adhesion force of the coatings were deeply affected by Silicon contents. The TiAlSiN with 9.0 at.% Silicon has a maximum hardness of 40.9 GPa, a highest adhesion force of 67 N and a lowest friction coefficient of 0.5. Microstructures show that Silicon doping increases the hardness of coating due to solid solution hardening effect and grain boundary enhancement effect. The amorphous Si3N4 matrix, which contains(Ti,Al)N nano-crystals, is formed as the Silicon content is increased. The matrix contributes to the nano-hardness and helps to resist surface oxidization. Especially, the matrix induces low surface roughness and decreases the friction coefficient.     

Catalytic dechlorination of chlorinated methanes by nanoscale Pd/Fe bimetallic particles

This paper examined the potential of using laboratory-synthesized nanoscale Pd/Fe bimetallic particles to dechlorinate chlorinated methanes, including dichloromethane (DCM), trichloromethane (CF) and tetrachloromethane (CT). Nanoscale Pd/Fe bimetallic particles were characterized in terms of surface area, morphology, size and structure. The parameters affecting the dechlorination efficiency were studied through batch experiments. Effects of Pd content, Pd/Fe addition, and the initial pH value of reaction system on the dechlorination efficiency of chlorinated methanes were determined systematically. Results show that nanoscale Pd/Fe bimetallic particles play a prominent role in the dechlorination of chlorinated methanes. The change of pH value and ferrous ion concentration during dechlorination reaction were also investigated in this study. It is found that the dechlorination efficiency of chlorinated methanes is in the order of CT>CF>DCM.     

Synthesis of MnZn Ferrite Nanoscale Particles by Hydrothermal Method

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Preparation of β-Sialon/ZrN bonded corundum composites from zircon by nitridation reaction sintering process

β-Sialon/ZrN bonded corundum composites were synthesized using fused white corundum, alumina micro powder, zircon and carbon black by nitridation reaction sintering process. Phase composition and microstructure of the synthesized composites were investigated by X-ray powder diffraction and scanning electronic microscope, and the formation process of the composites was discussed. The results show that the composites with different compositions can be obtained by controlling the heating temperature and contents of zircon and carbon black. The proper temperature to synthesize the composites is 1 773 K.     

Tribological Properties of DLC Film Prepared by C ^＋ Ion Beam-assisted Deposition （IBAD）

C ^＋ ion beam-assisted deposition was utilized to prepare deposit diamond-like carbon （ DLC ） film. With the help of a series of experiments such as Raman spectroscopy, FT-IR spectroscopy, AFM and nanoindentation , the DLC film has been recognized as hydrogenated DLC film and its tribologicul properties have been evaluated. The bull-on-disc testing results show that the hardness and the tribologicul properties of the DLC film produced by C^ ＋ ion beam- assisted deposition are improved significantly. DLC film produced by C ^＋ ion beam- assisted deposition is positive to have a prosperous tribologicul application in the near future.     

含柠檬酸配体的钨氧配合物的合成、光谱及电子结构

报道了W／O柠檬酸配合物的合成及结构,并用元素分析、红外光谱、紫外-可见光谱、光电子能谱、核磁、热重-差热分析等手段进行了表征．而且还用EHMO方法研究了配合物的电子结构．解释了该类配合物的羧基红外振动峰是一宽峰且有劈裂的特点．     

Application of micro/nanoscale thermal radiation to thermophotovoltaic system

Thermophotovoltaic (TPV) system has been regarded as one promising means to alleviate current energy demand because it can directly generate electricity from radiation heat via photons. However, the presently available TPV systems suffer from low conversion efficiency and low throughput. A viable solution to increase their efficiency is to apply micro/nanoscale radiation principles in the design of different components to utilize the characteristics of thermal radiation at small distances and in microstructures. Several critical issues are reviewed, such as photovoltaic effect, quantum efficiency and efficiency of TPV system. Emphasis is given to the development of wavelength-selective emitters and filters and the aspects of micro/nanoscale heat transfer. Recent progress, along with the challenges and opportunities for future development of TPV systems are also outlined.     

化学沉积法制备Ni-P-SiC复合镀层的研究

研究了在碳钢基材表面进行化学沉积Ni-P-SiC复合镀层的工艺和条件,对镀层的成分进行了扫描分析,对镀层的金相组织进行了观察分析;结果表明SiC硬质纳米粒子嵌入,使Ni-P合金基质产生沉淀强化,使镀层硬度增加.通过对磨实验和腐蚀实验证明,复合镀层可使碳钢零件耐磨性能提高3倍,可使碳钢零件耐蚀性能提高4倍,有效地延长了钢铁零件的使用寿命.     

Fabrication of W/Cu and Mo/Cu FGM as Plasma-facing Materials

W/Cu Functionally Graded Materials (FGM) was designed not only for reducing the thermal stress caused by the mismatch of thermal expansion coefficients, but also for combining the features of W, Mo - high plasma-erosion resistance and the advantages of Cu - high heat conductivity and ductility. Four different fabrication processes for W/Cu or Mo/Cu, including hot-pressing, Cu infiltration of sintered porosity-graded W skeleton, spark plasma sintering and plasma spraying, were investigated and compared. It was foundthat the hot-pressing process is difficult to keep the designed composition gradient, while the other three processes are successful in making W/Cu or Mo/Cu FGM. Meanwhile, microstructures and composition gradients are analyzed with SEM and EDAX.     

反胶团微乳液制备纳米粒子的研究进展

反胶团微乳液制备纳米粒子已经引起人们的广泛关注,介绍了该微粒液的特点以及反胶团微乳液法制备纳米粒子的原理、实验室制备过程并讨论了影响粒径及其分布的有关因素。     

TiN／CrN multilayered hard coatings with TiCrN interlayer deposited by a filtered cathodic vacuum arc technique

TiN/CrN multilayered hard coatings with TiCrN interlayer were deposited on high speed steel substrates by using a filtered cathodic vacuum arc technique. The structure and composition of the coatings were characterized by scanning electron microscopy (SEM) and Auger electron spectroscopy (AES). A high adhesion of up to 80 N was demonstrated by scratching tests for the multilayered coatings. Nanoindentation tests were performed to determine the hardness and elastic modulus of the coatings as a function of the multiplayer modulation period. It was observed that the hardness of the multilayered coatings is higher than those of either TiN or CrN single coatings, and it increases with decreasing modulation periods, which is consistent with predictions from the Hall-Petch type strengthening mechanism, though at small modulation periods, deviation from the Hall-Petch relation has been observed for the multilayered coatings. The life-span of drills coated with TiN/CrN multilayered is triple as long as that coated with TiN layer.     

W／O微乳液中制备MgO超细粒子

研究了十六烷基三甲基溴化铵／环己烷／水／正己醇体系微乳液的组成和性质以及电解质、温度对此体系的影响．结果表明：当十六烷基三甲基溴化钱与正己醇的摩尔比为1：3时，该体系有较宽且稳定的相区；在该体系中制得的Mg（OH）2沉淀，其平均粒径为150nm左右；在马弗炉中500℃下煅烧2h制得的MgO，在电镜下观察粒子没有团聚现象，且MgO粒子粒径分布均匀，平均粒径为30nm。     

Effects of La^3＋ doping on MnZn ferrite nanoscale particles synthesized by hydrothermal method

MnZn ferrite nanoscale particles were synthesized by hydrothermal method. The effects of amount of addition La³⁺ on the products were discussed. The product was characterized by X-ray diffraction (XRD) and transmission electron microscope (TEM). The results show that the sample with 0.2% La³⁺ (mass fraction) or without La³⁺ has only spinel phase, but the sample with mass fraction of La³⁺ exceeding 0.4% posses second phase besides the spinel one; and the nano-MnZn ferrites change from cube to hexagon when the mass fractions of La³⁺ is up to 1.2%. TEM image of the sample with 1.2% La³⁺ indicates that the homogeneous hexagonal crystal is obtained and the particles are larger than those of undoped; the addition of La³⁺ has great influence on the crystallization of hydrothermal process and can change the shape of particles and improve their growth. The saturation magnetization of the sample with 1.2% La³⁺ (2.64 A · m² · kg⁻¹) is lower than that of undoped (17.54 A · m² · kg⁻¹) and it behaves superparamagnetically. Foundation item: Project (2001BA90A09) supported by the Tenth Five-Plan of China     

W丝／Zr基非晶复合材料的压缩变形行为

研究80％W丝／Zr基非晶复合材料在室温下的压缩断裂行为．在准静态压缩条件下,该非晶复合材料以弹性-塑性方式变形,断裂强度和塑性分别达到了2750MPa和35％．w丝对非晶单一剪切带的阻碍,促进多重剪切带的产生和扩展,使复合材料产生大量塑性变形．裂纹在w丝中不同的点同时萌生,随着载荷的增加,在同一直线上的小裂纹最终会逐渐扩展连成一条平行于V~-丝／非晶界面的大裂纹,试样的破坏方式主要是纵向劈裂．     

High temperature cyclic oxidation behavior of Y2O3-ZrO2 thermal barrier coatings irradiated by high-intensity pulsed ion beam

The high-temperature oxidation resistance behavior of 7% (mass fraction) Y₂O₃-ZrO₂ thermal barrier coatings (TBCs) irradiated by high-intensity pulsed ion beam (HIPIB) was investigated under the cyclic oxidation condition of 1 050 °C and 1 h. The columnar grains in the TBCs disappear after the HIPIB irradiation at ion current densities of 100–200 A/cm² and the irradiated surface becomes smooth and densified after remelting and ablation due to the HIPIB irradiation. The thermally grown oxide (TGO) layer thickness of the irradiated TBCs is smaller than that of the original TBCs. After 15 cycles, the mass gains of the original TBCs and those irradiated by ion current densities of 100 and 200 A/cm² due to the oxidation are found to be 0.8–0.9, 0.6–0.7, and 0.3–0.4 mg/cm², respectively. The inward diffusion of oxygen through the irradiated TBCs is significantly impeded by the densified top layer formed due to irradiation, which is the main reason for the improved overall oxidation resistance of the irradiated TBCs. Foundation item: Projects supported by The 2nd Stage of Brain Korea and Korea Research Foundation