SSRF储存环预研制铝合金真空室的机械加工

上海同步辐射装置（SSRF）储存环铝合金超高真空室已研制成功，该机加真空室的尺寸大、尺寸精度、形位公差及粗糙度要求极高，不同于常规的大型超高真空室。在预研件加工中，成功地解决了一系列问题，如光洁度提高困难，加工成型后变形大；加工尺寸和精度受环境温度影响较大等。本文详细阐述了储存环真空室材料和热处理状态的选择依据，为了保证尺寸精度和形位公差所采取的工艺措施，分析了粗糙度的形成机理和影响因素，从刀具材料、几何角度、切削参数、冷却液选型等多方面提出了解决办法。     

高强铝合金断裂韧性的研究现状及展望

通过对三种裂纹模式的概述，引出了铝合金断裂韧性的概念及断裂判据，重点评述了影响高强铝合金断裂韧性的内在与外在因素，以及断裂韧性与其它力学性能间的关系，最后提出了几个在今后的研究及应用中需要重点解决的问题。     

铝电解槽磁流体稳定性有限元分析

本文采用有限元法求解分层磁流体小扰动方程系统特征值，研究铝电解槽稳定性。研究结果表明，在没有电磁力时，铝液表面波动（内波）是稳定的。存在电磁力时，它会激发铝液表面波动的某些低频长波分量不稳定性，高频短波不受影响。被激发的不稳定波动频率和扰动增长率与电流密度，磁感应强度垂直分量，铝电解槽长宽比，电解质和铝液的密度差，厚度等因素密切相关。减少电流密度，磁感应强度，增加电极距离和铝液厚度可以提高铝电解槽的稳定性。这对铝电解槽优化设计和在线控制有重要意义。     

Oxidation of porous nanocrystalline titanium nitride. II. Scale structure and composition

We have used x-ray phase analysis to study the composition of the products of reaction between oxygen and nanocrystalline powders with particle sizes 15, 40, 55, and 80 nm, and also specimens pressed (and sintered) from them. The powders were oxidized in air at 100°C (400 h) to 500°C (5 min), while the sintered specimens were oxidized at 600–900°C for 15, 120, and 240 min. In all cases, in the initial oxidation step the oxynitride Ti(O_xN_y) is formed, which over time is oxidized to TiO, Ti₂O₃, Ti₃O₅, TiO₂ (anatase) and TiO₂ (rutile). In the range 600–800°C, formation of a continuous oxide layer and conversion of anatase to rutile slows down diffusion of oxygen in the scale. We have established that at 900°C, the growth rate of the scale thickness increases and so the reflections from the oxynitride are barely noticeable on the diffraction patterns taken from the surface of the oxidized specimen. In these diffraction patterns, along with strong reflections from the rutile, we also observed weak reflections from lower oxides and anatase, which may be due to reaction between oxygen and the titanium ions diffused to the scale surface. We have concluded that at T > 850°C, the mechanism for oxidation of TiN changes. This is due to superposition of counterdiffusion of titanium ions on the diffusion of oxygen. __________ Translated from Poroshkovaya Metallurgiya, Nos. 3–4(448), pp. 72–78, March–April, 2006.     

Pressure infiltration of boron nitride preforms with molten aluminum

The infiltration of compacted cubic BN (cBN) with molten aluminum has been investigated as a potential route for a cheap and easy method of manufacturing cBN/metal composites. CBN compacts have been infiltrated with molten Al at a temperature between 670 and 800 °C and pressure of 15 MPa in vacuum. At these temperatures no pronounced interactions between hexagonal and cubic BN with Al was observed, allowing the complete infiltration of cBN with 12 μm mean grain size. After infiltration at 800 °C, the temperature was increased without pressure to convert aluminum into borides and AlN. The hardness of the resulting materials depends on the content of hexagonal, cubic BN and the rate of conversion of Al into borides and AlN. The infiltration height of less than 1 mm obtained from infiltrating the 3 μm cBN powder green compacts gave a hardness of 22.0 ± 0.6 GPa after heat treatment.     

复合聚全氟乙丙烯材料的介电及高频击穿性能研究

在聚全氟乙丙烯(FEP)中添加 TiO_2和 Al_2O_3,通过热压成型的方法制备了 FEP/TiO_2复合材料和 FEP/Al_2O_3复合材料,研究了氧化物添加量对复合材料介电常数、介电损耗和高频击穿性能的影响。结果表明,随氧化物含量的增加,复合材料的介电常数和介电损耗均增加;在同一添加量下,TiO_2对复合体系的介电性能影响较大。FEP/TiO_2复合材料的高频击穿性能随 TiO_2含量的增加而下降,在 TiO_2含量为4.0%(质量分数,下同)时,复合材料的损伤阈值已降为 FEP 材料损伤阈值的48.9 %。而 FEP/Al_2O_3复合材料的高频击穿性能随 Al_2O_3含量的增加而升高,当 Al_2O_3含量为1.2%时,复合材料的损伤阈值已增大到 FEP 材料损伤阈值的2倍,达到313 J/m~2。     

M8011H16铝合金防盗盖板生产工艺研究

研究了元素含量变化对8011铝合金防盗盖板综合性能的影响，在8011合金中改变Cu、Mn元素含量后可提高防盗盖板的强度，同时研究了烘烤处理后的强度变化问题。本文研究出了8011铝合金防盗盖板新的生产工艺制度。     

混联法氧化铝生产中熟料窑节能降耗的研究

通过对熟料窑的热工综合测试，分析了熟料窑的能耗组成和影响能耗的关键因素，总结了技术改造带来的经济效益和生产中存在的问题，提出了进一步挖潜降耗的措施。