精轧油膜轴承密封失效机理的初步分析

对油膜轴承密封出现的进水、漏油现象作了大量的调查、测量和统计分析，找出了产生质量事故的根本原因，提出了解决措施。     

Measurement of the thermal diffusivity of thin films on substrate by the photoacoustic method

Measurements of the thermal diffusivity of thin films on substrate have been performed by the photoacoustic method. In order to examine the method we have built a new apparatus and proposed (1) a system calibration procedure using optically and thermally thick reference samples and (2) a data analysis procedure based on the RG (Rosencwaig and Gersho) theory. As a result of using a transparent photoacoustic cell, the systematic errors which are caused by stray light have been reduced. With this apparatus, measurements have been performed on platinum, titanium, and stainless steel (SUS304) thin foils (thickness form 50 to 100 µm) with three different liquid backing materials (water, glycerol, and ethyl alcohol). The reproducibility was within ±7% regardless of film thickness and substrate materials.     

磁控溅射WO3薄膜特性研究

用磁控溅射法制成WO3薄膜,通过改变成膜的溅射参数来改变WO3薄膜的性能.利用XRD分析了样品的粒径大小,研究了成膜工艺参数对气敏元件性能的影响.结果表明,薄膜中WO3晶粒的平均尺寸为17 nm,该传感器对NOx气体有非常好的灵敏度和选择性,对体积分数为1×10-5的NOx气体灵敏度高于50倍,而对其他干扰气体的灵敏度小于2倍.     

薄膜磁头磁轭制备工艺研究

本文重点讨论了用不同的工艺方法来制备薄膜磁头中的关键元件-磁轭。采用多次光刻的方法克服湿法工艺中磁性膜NiFe层的侧向钻蚀问题，从而实现对磁轭几何尺寸的精确控制，并对几种工艺方法的优缺点作了比较详细的分析。     

用于多种组装技术的厚膜导体复合结构

厚膜导体Ｐｄ－Ａｇ／Ａｕ、Ｐｔ－Ｐｄ－Ａｕ／Ａｕ平面复合结构，Ｐｄ－Ａｇ／Ａｕ立体复合结构可使多种组装技术相互兼容。立体复合结构还可有效地降低导体线电阻，减少线损耗。而且，其超声键合性尤佳     

Photo-reversible Reaction in Polymer Langmuir-Blodgett Films

Preparation of photoreactive Langmuir-Blodgett (LB) films was carried out using polymers/oligomers prepared from long-chain dialkyl esters of di-and tetra-olefins and having cyclobutane rings in the main chain. These polymers/oligomers formed stable monolayers on a water surface when mixed with arachidic acid. These monolayers could be deposited onto a substrate successfully forming Y-type films. The oligomer LB films were polymerized on irradiation. The polymer LB films showed a photo-reversible process between polymers and oligomers, depending on wavelength of the irradiating light. On the basis of spectral data and molecular weight change, this behaviour was found to be caused by cleavage and formation of cyclobutane rings.     

Modification of poly(N-vinyl-carbazole) thin films by bromine doping

Poly(N-vinyl-carbazole) (PVK) thin films doped with bromine has been studied by scanning electron microscopy, X-ray diffraction, infrared absorption, X-ray photoelectron spectroscopy (XPS), electron spin resonance (ESR), optical transmission (visible, near ultra violet) and conductivity measurements. The polymer has been doped at room temperature and at 373 K. It is shown by ESR, XPS and optical measurements that a charge transfer complex (CT-complex) is formed between PVK and Br. However, if some bromine acts as dopant of the polymer there is another bromine contribution, which corresponds to bromine covalently bonded to PVK and some only adsorbed. It is also shown by ESR that there is not only polymer doping by bromine but also some partial polymer degradation. Therefore, it can be said that the optimum doping condition of PVK thin films with bromine has been shown to be room temperature post-doping.     

Growth rate and surface microstructure in α(6H)–SiC thin films grown by chemical vapor deposition

Monocrystalline 6H-SiC thin films have been epitaxially grown on off-axis 6H-SiC {0001} substrates in the temperature range of 1623–1873 K via chemical vapor deposition. The growth rate was a strong function of the growth temperature and the reactant gas concentration. The activation energies for growth were 64 kJ/mole and 55 kJ/mole for the (0001) Si face and the (0001) C face, respectively. The concentration of growth pits in the films increased as a function of decreasing deposition temperature, increasing concentration of reactant gases and increasing off-axis orientation. Beta-SiC islands were also observed in the epilayers when the (SiH₄ + C₂H₄)/H₂ ratio was ≥2.5:3000.     

Off-Optimum Cure of Aerospace Epoxy Adhesives

Four epoxy film adhesives used in aircraft manufacture and repair have been examined to establish the effect of deviation from the cure cycle specified by the manufacturer. In addition to the variation of the cure cycle, two surface preparations of the aluminium adherends (chromic acid etch or grit blast followed by silane treatment) were evaluated. Thermal analysis was used to examine the cure envelope of the adhesive, and its extent of cure and glass transition temperature. The adhesive properties were assessed by shear strength (in both single lap joints and in Iosipescu configuration), durability (Boeing wedge test) and chemical resistance to selected aggressive fluids. The sensitivity of the performance of a particular adhesive to offoptimum cure conditions depends on its composition and needs to be determined, not predicted.     

Optical measurements of thermal diffusivity of a material

The measurement of thermal diffusivity of a material (in particular, a thin film) is important for various reasons, e.g., to predict the heat transfer in the solid subjected to a thermal process, to monitor surface composition or morphology, or to detect invisible subsurface defects like delaminations. This measurement can be done in a noncontact manner using various photothermal methods. Such methods typically involve pulsed heating of the surface by small amounts using a laser source; the decay of the surface temperature after this pulsed photothermal heating is then probed to provide the thermal diffusivity. Various probing methods have been developed in the literature, including the probing of reflection, refraction, and diffraction from the pulsed heated area, infrared thermal radiometry, and surface deformation. This paper provides an overview of such techniques and some examples of their applications.