TiB2与BN复相陶瓷的渗流模型

试验结果证实,TiB₂与BN复相陶瓷的导电性能符合渗流理论,原料粉粒度配比下,其渗流阀值为V_c%=22.9%;原料粉粒度比的改变将改变渗流阀值,从而改变各配比下的电阻率值;TiB₂与BN在SPS系统中快速烧结,晶粒的尺度比与原料粉的粒度比基本保持一致。     

WC对铜基和镍基喷焊覆层材料耐气蚀性能的影响

在CuNiSiB,NiCrSiB自熔合金粉末中添加WC陶瓷颗粒，利用氧乙炔焰粉末喷焊工艺制备覆层材料，用超声波振动气蚀仪对覆层材料进行耐气蚀性能研究，用扫描电子显微镜对覆层材料表面气蚀破坏形貌进行观察，结果表明：复合覆层材料的耐气蚀能力比基体强；提高CuNiSiB覆层材料耐气蚀能力的途径是强化晶界，还探讨了覆层材料的气蚀破坏机理。     

电子封装用金属基复合材料的制备

分析了电子封装用金属基复合材料的性能特点及其对制备工艺的要求，在此基础上论述了该种材料的各种制备工艺的特点及发展现状。     

镀镍云母导电复合材料的研究

对云母粒子化学镀镍及以LDPE为基材,镀镍云母粒子为填料制备的导电复合材料进行研究。认为此种导电复合材料只有质量轻、强度大及良好的导电等性能。     

Resilient metal spring network silicone-matrix composite for separable interconnections

Resilient metal spring silicone-matrix conducting composites for separable interconnections in electronics were fabricated by the impregnation of silicone into a preform comprising randomly oriented C-shaped Cu-Be springs and a small proportion of Sn-Pb solder, which served to connect the springs at some of their intersections. Composites containing 6.1-9.8 vol.% total filler exhibited volume electrical resistivity 0.5-1.0 mΩ.cm and contact resistivity (with copper) 11-17 mΩ.cm². A compressive stress of about 30 kPa was needed for the low contact resistivity to be reached. The volume 17-26% and the contact resistivity increased by 5% after heating in air at 130-150°C for seven days. Composites containing <9 vol.% total filler showed no stress relaxation for seven days at 6.0% strain.     

T8钢—聚有机硅氧烷仿生减粘降阻复合涂层的特性

研究了Ｔ８钢－聚有机硅氧烷仿生减粘降阻复合涂层的表面润湿性，磨料磨损性及土壤的减粘降组性能，与金属材料相比，仿生复合涂层的表面憎水性显著提高，水在其表面上的接触角达９２°；与４５钢相比，其磨料磨损的体积相对耐磨系数为６３％，降阻率达１５．２２％－－２２．２７％。     

粉末布法制备SiC/Ti基复合材料

用粉末布法制备了低成本SiC/Ti基复合材料.结果表明,采用合适的轧制参数即可容易地获得厚度合适、均匀的粉末布;热失重分析和热解残余物分析指出用来制备粉末布的有机粘结剂的去除过程分成两个阶段,合理除气后,基本没有残余物.使用真空热压工艺制备的SiC/Ti基复合材料,纤维分布基本均匀,纤维与基体的界面结合良好.     

Effects of temperature, ammonium and glucose concentrations on yeast growth in a model wine system

In enology, alcoholic fermentation is a complex process involving several mechanisms. Slow and incomplete alcoholic fermentation is a chronic problem for the wine industry and factors leading to sluggish and stuck fermentations have been extensively studied and reviewed. The most studied cause of sluggish and stuck fermentation is the nitrogen content limitation. Nevertheless, other factors, such as temperature of fermentation and sugar concentration can affect the growth of yeasts. In this study we modelled the yeast growth‐cycle in wine model system as a function of temperature, sugar and ammonium concentrations; the individual effects and the interaction of these factors were analysed by means of a quadratic response surface methodology. Cell concentrations and weight loss were monitored in the whole wine fermentation process. The results of central composite design show that lower is the availability of nitrogen, higher is the cell growth rate; moreover, initial nitrogen concentration also influences survival time of Saccharomyces cerevisiae.     

Ermüdungsverhalten und Dauerfestigkeit von Graphit und Aluminium – infiltriertem Graphit

Fatigue behaviour and endurance limit of graphite and of aluminium‐infiltrated graphite Fatigue properties of polycrystalline, isotropic graphite FU2590 and of FU2590 infiltrated with AlSi7Mg (FU2590/AlSi7Mg) were investigated in reversed bending tests at 25 Hz at numbers of cycles below 10⁷ and in tension‐compression tests at 20 kHz below 10⁹ cycles. The open porosity of Graphite (10‐11 Vol.‐%) was infiltrated with the aluminium alloy using the squeeze casting infiltration method, which led to an increase of the bending strength by 50 %, increase of tensile strength by 30 % and increase of stiffness by 15 %. Fully reversed tension‐compression loading of FU2590 delivers a mean endurance limit at 10⁹ cycles at the normalized maximum stresses (i.e. maximum tension stress of a cycle divided by the static strength) of 0,65±0,03. Mean numbers of cycles to failure of 10⁴ were found in fully reversed bending tests at the normalized maximum stress of 0,78. The infiltrated material shows approximately 30 % higher cyclic strength in reversed bending tests, and the mean endurance limit under tension compression loading increases by 15 %. The increased endurance limit of the infiltrated material is caused by the increased stiffness. The increased toughness of graphite due to the infiltration with aluminium is of additional beneficial influence at the higher cyclic stresses investigated in reversed bending tests and in static tests.     

Neutron Stress Measurement of W‐Fiber Reinforced Cu Composite

Stress measurement methods using neutron and X‐ray diffraction were examined by comparing the surface stresses with internal stresses in the continuous tungsten‐fiber reinforced copper‐matrix composite. Surface stresses were measured by X‐ray stress measurement with the sin²ψ method. Furthermore, the sin²ψ method and the most common triaxal measurement method using Hooke's equation were employed for internal stress measurement by neutron diffraction. On the other hand, microstress distributions developed by the difference in the thermal expansion coefficients between these two phases were calculated by FEM. The weighted average strains and stresses were compared with the experimental results. The FEM results agreed with the experimental results qualitatively and confirmed the importance of the triaxial stress analysis in the neutron stress measurement.