Evaluation of Slow Crack Growth Resistance in Ceramics for High-Temperature Applications

The slow (subcritical) crack growth (SCG) resistance of Si₃N₄ and SiC ceramics has been evaluated by a stepwise loading test on bending bars precracked by Vickers indentation. Three highly refractory materials were selected for the evaluation: i.e., (1) high-purity Si₃N₄ sintered by hot isostatic pressing (HIP) without additives and (2,3) α - and β - SiC pressureless sintered with B and C addition. Under the hypothesis of linear elastic behavior at high temperature, which was found satisfied in the present materials, the SCG resistance was expressed in terms of initial stress intensity factor critical for SCG failure within a predetermined lifetime. The present method was found useful in shortening the testing time and consistent with other traditional fatigue tests (e.g., static-fatigue test): It is recommended as a screening test for materials under research and development. Among the materials tested in the present study, the highest SCG resistance up to 1440°C was found in the high-purity Si₃N₄ without additives.     

Micromachined silicon bolometers as detectors of soft X-ray, ultraviolet, visible and infrared radiation

This paper presents the development of micromachined thin-film silicon microbolometers which can be used for detection of soft X-ray, UV, visible and infrared radiation. The detector structure is a 1 μm thick polysilicon/Si₃N₄ membrane suspended over a cavity. This structure has been obtained by anisotropic etching of silicon with a previously deposited polysilicon/Si₃N₄ sandwich. Alternatively, porous silicon has been used as the sacrificial layer. Devices have been characterized. Good values of the voltage responsivity and detectivity have been obtained.     

激光法合成SiC超细粉末物理化学过程的研究——Ⅰ.实验规律及粉末特性

用50W连续波CO_2激光器为热源,诱发SiH_4和C_2H_4反应,合成SiC超细粉末。实验确定了反应腔体内压力p、气源中的C/Si原子比、喷嘴内径2r以及激光功率密度与粉末特性之间的关系,并对合成的产物进行物理、化学表征。     

锻热淬火工艺对工具钢碳化物粒度的影响

研究了锻热淬火工艺对Ｔ１０钢和ＧＣｒ１５钢碳化物技度的影响。结果表明，碳化物粒度随变形量的增大而细化；终锻温度在高于碳化物析出的温度范围内变化，其碳化物粒度都同样细小；终锻温度不宜过低，否则将使碳化物变粗。     

Study on Factors Affecting the Structure of High SpeedSteel Ingot Produced by ESR

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高温过热器12Cr2MoWVTib（102）钢管的显微组织和相结构分析

本文对原始状态和在火力发电厂使用不同时间的高这热器１０２钢管进行了显微组织和相结构变化规律的探讨和研究。显微组织研究表明，１０２钢管在高温高压下长期运行过程中，使用温度对显微组织和碳化物相有明显影响，而使用时间对其影响不如温度影响强烈。碳化物颗粒图象分析表明，碳化物随着使用时间缓慢长大，而新的碳化物不沉淀，使颗粒总数不断增加，颗粒，间距逐渐缩小。Ｘ射线衍射数据证明，钢管在高温长期使用过程中，ＭＣ相     

Comparison between normal and reverse thin crystalline silicon solar cells

The newly developed ingot growing techniques, as the three-grain and the columnar multigrain ingot processes, are now offering the possibility of slicing thinner wafers (≤ 100 μm). In this paper we present the results obtained on p type large area (≥ 100 cm²) and 100 μm thick wafers by using both conventional and reverse cell manufacturing technologies.The conventional cells are provided with aluminium or boron BSF plus screen-printed silver mirror or a silver-aluminium net; the reverse cells have a FSF and the deep back junction completely covered by a screen-printed or CVD silver layer.The constructing parameters have been chosen on the base of one and two dimensions modeling and both raw material and devices have been completely characterized.This work shows that very thin wafers do not introduce serious problems for the conventional manufacturing of solar cells. The efficiencies of the normal and of the reverse cells are found to be comparable and are of the same order than those of thicker cells, however at a significant lower cost. The main obtained result has to be related to the demonstration of a cell manufacturing feasibility starting from very thin wafers.     

MOSFET亚阈特性分析与低温按比例缩小理论的研究

器件尺寸按比例缩小是实现超大规模集成电路的有效途径，但寄生和二级效应却将器件限在一定的水平，本文在对比分析常温与低温下小尺寸器件效应的基础上，重点研究了ＭＯＳ器件亚阈特性对器件性能及按比例缩小的影响，并根据低温工作的特点，提出了ＭＯＳ器件一种低温按比例缩小规则，该原则对低温器的优化设计，从而更大程度在提高电路与系统性能具有重要的指导意义。     

直读光度法测定钼铁中的硅

试样经草酸、双氧水分解后，以盐酸羟胺破坏掉多余双氧水。以标准样品作参比，在硫酸－柠檬酸介质中，用钼酸铵显色，抗坏血酸还原，生成稳定的硅钼蓝。此方法可测定１．０％以下的硅，具有快速、准确、灵敏度高等优点。