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采用电气控制铝合金阳极氧化工艺的方法,研究了磷酸溶液浓度、氧化时间、氧化温度、氧化电压对铝合金阳极氧化表面形貌的影响,并分析了碳纤维预浸渍前后对碳纤维金属层板力学性能的影响.结果表明,当采用电气控制,磷酸溶液浓度为30g/L、氧化时间为5min、氧化温度为15℃、氧化电压为120V时,铝合金材料表面可见尺寸均匀、孔径较... 相似文献
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以铝合金玻纤复合层板为研究对象.从金属层接缝界面端应力场分析出发,建立有限元模型,确定位移边界条件和载荷边界条件.利用有限元方法模拟出不同接缝宽度在常温下的热残余应力.通过实验得出常温和高温条件下的各个接缝宽度试样的破坏拉伸载荷.考察接缝大小对残余应力的影响和分布,从而研究其对铝合金玻纤复合层板拉伸性能的影响. 相似文献
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在煤炭产品检验工作中,要化验的物料常常是大量的,其组成很不均匀.化验时所称取的分析试样只是几克,几百毫克或更少,而分析结果必须能代表全部物料的平均组成,因此,正确地采取具有代表性的"平均试样",就具有极其重要的意义.
1 基本概念
商品煤样:代表商品煤平均性质的煤样.
子样:采集器具操作一次所采取的或截取一次煤流全断面所采取的一份样.
分样:由若干子样构成,代表整个采样单元的一部分煤样.
总样:从一个采样单元取出的全部子样合并成的煤样. 相似文献
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与一般金属材料不同,金属镀层金相试样制备的技术难度要大得多。对此,本文根据理论和实践,阐述了金属镀层金相试样的制备方法和显微分析技术。 相似文献
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文章将SiO2溶胶与聚酰胺酸溶液共混,得到的混合液均匀浸涂于玻璃纤维布,然后经干燥、脱溶分切、叠片、压制,得到了具有良好室温及高温力学及电性能的聚酰亚胺片材。研究表明,聚酰亚胺SiO2复合板具有良好的室温力学强度,而在300℃时片材的弯曲强度和弯曲模量可到120MPa和7.1GPa,体积电阻率保持在1011Ω·m水平,具有优异的力学和电性能保持率,能够作为高温承力结构件使用。 相似文献
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Some mechanical properties of particulate-filled polyethylene/epoxy and aramid/epoxy laminates are reported, following earlier work with particulate-filled glass/epoxy laminates. The behaviour of the organic fibre laminates was different from that of glass fibre ones, investigated and reported earlier. There was an increase in compression strength with increasing filler content, with both kinds of organic fibre reinforcement. The interlaminar shear strength values were significantly lower for the polyethylene laminates than the aramid ones at all filler concentrations, and they fell to little more than 10MPa at high filler levels. However, the impact damage zone in drop weight tests was generally smaller for the polyethylene laminates, and the visible crack damage was less apparent than in the aramid ones. The flexural strength and modulus values are also reported. © of SCI. 相似文献
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Epoxy (DGEBA)-glass fiber laminates were cured with different hardeners. Imide-amine hardeners were synthesized with different chemical groups in their backbone structure. Higher curing and postcuring temperatures were required for epoxy-glass fiber laminates cured with imide-amine hardeners. Compared to epoxy cured with aromatic amine (DADPM), tensile and flexural strength increased by 38.5% and 23.1%, respectively, in the laminates cured with imide-amine with sulfone groups in the backbone structure. Fracture surface of the laminates showed good bonding between the fiber and matrix. 相似文献
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以聚丙烯树脂为基体,聚丙烯纤维织物为增强体,采用层压成型工艺制备了聚丙烯自增强复合材料层压板。研究了成型温度、成型压力、成型时间和纤维含量等工艺参数对聚丙烯自增强复合材料层压板拉伸和弯曲性能的影响规律,并采用差示扫描量热(DSC)仪和扫描电子显微镜(SEM)对其进行了热分析和形态结构的表征。结果表明,当成型温度为175℃,成型压力为10 MPa,成型时间为15 min,纤维含量为60%时,聚丙烯自增强复合材料层压板的力学性能达到最大值,其拉伸强度为(125.76±0.77)MPa,弯曲强度和弯曲弹性模量分别为(30.77±0.70)MPa和(1 795.46±75.95)MPa;从DSC图和SEM图观察到成型温度为175℃时聚丙烯纤维表面发生了熔融,有利于纤维和树脂之间的界面粘结力的增强。 相似文献
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氢氧化铝是玛瑙人造板材的主要组成部分,氢氧化铝的结晶形态、粒度分布等对玛瑙板材的力学及其他性能有着重要影响,选择合适的氢氧化铝作填料将改善板材的性能。 相似文献
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《国际聚合物材料杂志》2012,61(3):259-270
Abstract Woven composites are getting acceptance in many engineering applications such as tranportation, construction and automotive, albeit in most instances are rather confined to those of thermoset matrices. In view of many favourable circumstances, thermoplastic based systems are slowly gaining recognition which can be easily attributed to their unique properties. For example, these include better damage tolerence, ease of handling, recyclability, etc. However, they are always referred to those derived from fabrics, either impregnated or otherwise. Here, an alternative system was realized by utilizing the impregnated towpreg or simply continuous fiber impregnated thermoplastic (COFIT). Results on composite testing, using tensile measurement as an example apart from type of towpregs, weave characteristics, etc., it clearly shows that the tensile properties of any woven structures are dependent on specimen cutting position coupled with gage length too. Generally, the woven system's properties are manifested by the presence of what is called weave characteristics such as interlaces, floats length, crimps, etc. 相似文献
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以稻壳为原料,研究稻壳在不同酸预处理条件和不同煅烧条件下制备得到的稻壳灰在表观性能、元素成分、反应活性、物相结构和微观结构等方面的特性差异及其对偏高岭土基地聚物力学性能的影响,确定稻壳灰最佳制备条件。结果表明,盐酸预处理会显著提高稻壳灰中无定形SiO2的纯度,高达98.354%(质量分数)。经酸预处理的稻壳在550 ℃下煅烧60 min即可煅烧完全,稻壳灰反应活性最高。酸处理后的稻壳灰使地聚物的孔隙结构更加致密,550 ℃稻壳灰地聚物(10%(质量分数)稻壳灰+90%(质量分数)偏高岭土)28 d抗压强度最高,达53.3 MPa。通过综合影响分析,得到稻壳灰的最佳制备条件为:经2.5%(质量分数)盐酸溶液浸泡1 h后,550 ℃煅烧1 h。 相似文献