GRAIN BOUNDARY CHARACTER DISTRIBUTION, TEXTURE AND SUPERPLASTIC DEFORMATION BEHAVIOR OF AN AI-Li ALLOY

The grain boundary character distribution and thetexture of 2091 Al-Li alloy recrystallized at different temperatures were measured by TEM and X-ray techniques respectively. The occurrence frequency of low-energy boundaries decreases with increasing recrystallization temperature, while the frequency of highenergy boundaries increases. The strongest component of recrystallization texture in the test temperature range is {011} <111>. The relative intensity of the texture tends to decrease with increasing recrystallization temperature. The material which contains a high frequency of low-energy boundaries exhibits lower deforming stress and high elongation.     

实用组合机床CAD系统的研制

根据组合机床设计制造的特点,从方案设计选型和成本估算入手,采用ＶＣ＋＋谐和语言。集数据管理系统Ａｃｃｅｓｓ和ＣＡＤ系统 Ｓｏｌｉｄ Ｅｄｇｅ于一体,借助于屏幕交互技术,研制了实用组合机床ＣＡＤ系统。经试用表明,该系统在方案设计阶段即可较为准确地确定制造成本和制造周期,有利于开拓设计人员的视野,取得较好的效益。     

Effect of AIN Particulate Size on Superplasticity of AINp/6061 Al Composites

In recede years, superplasticity has been demonstrated in many discontinuously reinforcedcomposites [l--16]. These stUdies proved thatsuperplasticity is observed at very high strainrate (10--z--10 s--'). Although high strain ratesuperplasticity has been observed in variousaltuninum alloy composites, it has not been understood how particulate size of reinforcementhas an effect on HSRS behavior of Al-Manixcomposites. It is necessary, therefore, to investigate superplastic characteristics of A…     

消失模模具CAD/CAM集成系统的研究

以进气管为例,通过对引进系统的改进和二次开发,在对铸件工艺和结构特征分析的基础上,建立了消失模模具ＣＡＤ／ＣＡＭ系统。经实际验证,模具符合铸件产品要求。     

Extraction of Metal(Ti,V,Mo)-oxyl Cations by Monoacidic Phosphates and Phosphonates

The extraction of TiO~(2+),VO~(2+),VO_2~+ and MoO_2~(2+)by HDEHP,HEHEHP and HDTMPP was studiedrespectively.The orders of extraction ability for the three extractant systems are as follows:for TiO~(2+),VO~(2+):HDEHP>HEHEHP>HDTMPP;for VO_2~+, MoO_2~(2+):HDEHP< HEHEHP< HDTMPP.The experimental results were discussed from the point of view of extractant structures.     

凹凸棒石/聚丙烯酸钾包膜材料的制备与性能研究

以凹凸棒石与丙烯酸为主要原料,采用溶液聚合法制备凹凸棒石/聚丙烯酸钾复合膜材料,探讨了丙烯酸中和度、引发剂、交联剂和凹凸棒石添加量对膜材料吸水倍率和NH+4渗透速率的影响.结果表明:在丙烯酸单体浓度20％、中和度70％、引发剂用量0.1％、交联剂用量0.5％、凹凸棒石用量20％的条件下,合成的复合膜材料吸水倍率最高,达...     

RTM用苯并(恶)嗪树脂基碳纤维复合材料的性能研究

针对RTM成型工艺对基体树脂的特殊要求,结合MA型苯并(噁)嗪树脂耐烧蚀、高性能的特点,对制造高强度苯并(噁)嗪树脂基碳纤维复合材料进行了研究.系统考察了基体树脂体系的工艺性能、固化反应行为以及力学性能.结果表明:该树脂体系在95～115℃温度区间内至少有350min的低黏度(≤500mPa·s)时间作为工艺开放期,符合RTM成型工艺要求;树脂体系的玻璃化转变温度在223℃;RTM苯并(噁)嗪树脂基碳纤维复合材料的空隙含量仅为0.23％,树脂浇铸体和碳纤维复合材料的常规力学性能优异.MA型苯并(噁)嗪树脂完全可以采用RTM工艺成型高性能复合材料.     

4种萘酰亚胺类荧光增白剂的合成及性能研究

以4-溴-1,8-萘二甲酸酐为原料,与端基含有氨基的伯胺(如苯胺)和自制1.0G PAMAM发生酰胺化反应得到4-溴-1,8-萘酰亚胺,将其C4-位的溴被甲氧基和乙氧基取代进而得到4种具有强烈荧光性能的萘酰亚胺类荧光增白剂.经FT-IR表征其结构,用UV-vis、荧光光谱等手段研究了它们在水溶液中光物理化学性质.结果表...     

基于小波变换与反锐化掩模的图像对比度增强

针对传统空间域图像对比度增强算法存在灰度级空间分配不合理和噪声敏感的问题,基于图像的局部细节信息分析,提出了一种新的基于小波变换和反锐化掩模(UM)的图像对比度增强算法.该算法以小波变换作为工具,运用反锐化掩模的思想,计算出代表局部细节信息且同时考虑了图像中的噪声信息的统计量,然后将这一新的统计量作为重新分配灰度级空间...     

新型锂电池负极复合材料硅/无定形碳/碳纳米管的制备及性能研究

通过高温裂解蔗糖混合纳米硅和碳纳米管,得到硅/无定形碳/碳纳米管复合材料.实验结果表明,复合材料的首次放电容量高达1315.4mAh/g,首次充放电效率为72.4%,经过20次充放电循环后可逆容量仍高达830.5mAh/g.具有良好弹性的碳纳米管组成的网状结构使复合材料能保持较好的形貌,而碳纳米管优良的导电性可以使更多...