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金属泡沫材料研究进展 总被引:14,自引:2,他引:12
综述了金属泡沫材料的各种制备方法。液相法制备金属泡沫材料包括气体吹入法、固体发泡剂法和固体—气体共晶凝固法、熔模铸造法、渗流铸造法、喷射沉积法以及粉末加压熔化法等制备方法。采用金属粉末烧结法、浆料发泡法等制备工艺可以从固相制备金属泡沫材料。电沉积法以及气相沉积法可用于制备高孔隙率的金属泡沫材料。最后简要总结了金属泡沫材料的应用。 相似文献
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真空渗流法制备的通孔泡沫铝的吸声性能 总被引:4,自引:1,他引:3
研究了真空渗流法制备的通孔泡沫铝的吸声性能、通孔泡沫铝的孔结构参数及厚度对通孔泡沫铝吸声性能的影响。试验结果表明 ,真空渗流法制备的通孔泡沫铝具有较大的吸声系数 ,而且随孔径减小或孔隙率、厚度增加 ,所制备通孔泡沫铝的吸声性能提高 相似文献
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新的多孔泡沫镍制备工艺 总被引:1,自引:0,他引:1
针对目前泡沫金属制备方法的缺点,提出了一种泡沫金属制备的新方法——电解液喷射沉积法。研究了喷射沉积制备泡沫镍的工艺,自行研制了试验装置,制备了具有不同孔隙率的泡沫镍试样,分析了相关工艺参数(电解液成分、电流密度、电解液喷射速度等)对泡沫镍微观结构的影响。结果表明:采用相对较低的镍离子浓度配方Bath A对制备均匀致密的枝晶多孔结构有利。随着电流密度的提高,泡沫镍的孔隙率逐渐降低;随着电解液喷射速度的提高,泡沫镍的孔隙率逐渐增加。总体上采用电解液喷射沉积法制备的泡沫镍的孔隙率在30~70%之间。 相似文献
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相变储能材料(PCM)具有储热密度大、储/放热过程几乎恒温性等优点,是解决电子器件狭小空间下高热流密度问题的理想方案,但相变材料本身的导热系数较低、传热效率差等特性却限制了其应用范围。针对上述难题,以石蜡作为相变材料,通过3D打印制备多孔铝骨架,再采用水浴灌注法将石蜡灌注到多孔铝骨架中,制备出多孔铝骨架/复合相变材料(AS-PCM)。通过实验探究了95%、85%、75%3种孔隙率的温控性能。实验结果表明,添加多孔铝骨架可增强PCM的热传递,从而降低热源温度。在较大的功率下,AS-PCM对传热的改善更为明显。熔化完成前,低孔隙率AS-PCM热沉的底部温度和温度梯度更低,使用多孔铝骨架代替泡沫金属,为提高PCMs的导热性能提供了了新的多孔金属基体。 相似文献
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为满足电动汽车锂离子电池热管理需求,具有优良温控效果的相变材料(PCM)冷却逐渐成为研究热点。本文从有机PCM物性不足出发,概括了目前复合有机PCM的制备及改进方向:添加多维高导热材料(如碳材料、纳米金属、泡沫金属等)强化导热;添加共聚物(如聚乙烯、热塑性弹性体等)提高材料柔韧性和添加阻燃剂(如红磷、聚磷酸铵等)提高阻燃效果以改善其实用性。分别指出膨胀石墨、苯乙烯-乙烯-丁二烯-苯乙烯和复合使用红磷与聚磷酸铵对导热、柔性和阻燃的显著提升。同时描述了有机PCM与热管、液冷、空冷等散热方式耦合后系统强化换热的效果,总结耦合热管时需要考虑不同热管排布;耦合液冷或空冷需要设计合适流道增强换热。随后介绍了通过模拟仿真分析有机PCM用于电池热管理系统影响因素及最佳使用工况的研究。最后总结有机PCM用于电池热管理的进展及不足,其难点仍在于其可燃和导电性的改善以及柔性有机PCM在室温下柔韧性不足,有机PCM耦合传统散热系统的车载可靠性和循环可行性也缺乏相应探讨,并为今后有机PCM用于电池热管理提出一定建议。 相似文献
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孔径可调的泡沫铝材料制备研究 总被引:3,自引:0,他引:3
利用传统熔体发泡法制备泡沫铝,产品的孔径大小很难精确控制.采用金属铝粉这种新型增粘剂,通过对铝粉的含量,发泡剂的含量以及控制发泡剂加入后熔体中的发泡温度,制备出孔结构均匀,不同密度和孔径大小的泡沫铝.整个工艺平稳、易控制和调整. 相似文献
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A new polythiophene containing a cholesteryl side chain in the -position was chemically polymerised in nitromethane/carbontetrachloride using FeCl3 as the oxidizing agent. Polymerisation was also achieved by constant current electrolysis in dichloromethane. Subsequently, conducting copolymers of thiophene-3-yl acetic acid cholesteryl ester (CM), PCM1 (obtained from chemical polymerisation method) and PCM4 (obtained from constant current electrolysis) with pyrrole were synthesized using p-toluene sulfonic acid and sodium dodecyl sulfate as the supporting electrolytes via constant potential electrolyses. Characterizations of the samples were performed by CV, FTIR, NMR, DSC, TGA and SEM analyses. Electrical conductivities were measured by the four-probe technique. 相似文献
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In this paper, a new combined method of sub-micron high aspect ratio structure fabrication is developed which can be used for production of nano imprint template. The process includes atomic force microscope (AFM) scratch nano-machining and reactive ion etching (RIE) fabrication. First, 40 nm aluminum film was deposited on the silicon substrate by magnetron sputtering, and then sub-micron grooves were fabricated on the aluminum film by nano scratch using AFM diamond tip. As aluminum film is a good mask for etching silicon, high aspect ratio structures were finally fabricated by RIE process. The fabricated structures were studied by SEM, which shows that the grooves are about 400 nm in width and 5 microm in depth. To obtain sub-micron scale groove structures on the aluminum film, experiments of nanomachining on aluminum films under various machining conditions were conducted. The depths of the grooves fabricated using different scratch loads were also studied by the AFM. The result shows that the material properties of the film/substrate are elastic-plastic following nearly a bilinear law with isotropic strain hardening. Combined AFM nanomachining and RIE process provides a relative lower cost nano fabrication technique than traditional e-beam lithography, and it has a good prospect in nano imprint template fabrication. 相似文献
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碳化硅增强铝基复合材料的力学性能和断裂机制 总被引:1,自引:0,他引:1
研究了碳化硅颗粒(SiCp)尺寸对用粉末冶金法制备体积分数为15%的SiCp/2009铝基复合材料力学性能和断裂机制的影响.结果表明,复合材料的强度随着SiCp尺寸的增大而减小,塑性则随着颗粒的增大而增大.当SiCp尺寸为1.5μm时,SiCp/2009A1复合材料的断裂主要以界面处撕裂和基体材料的开裂为主;当SiCp尺寸为20 μm时,复合材料的断裂主要以SiCp断裂为主;当SiCp尺寸处于两者之间时,SiCp/2009A1复合材料界面处撕裂和SiCp断裂的共同作用决定复合材料的断裂. 相似文献
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In this paper, honeycomb-like regular TiO2 nanoporous films deposited on different substrates including ITO glass and silicon wafer are fabricated by combining a nanoimprint technique with a sol-gel method. A novel soft polymer mold containing a thin layer of polymethylmethacrylate and a thicker layer of polydimethylsiloxane, which is obtained from an anodic aluminum oxide template, is carried out for the nanoimprint process. TiO2 precursor solution prepared by the sol-gel processing is used as the nanoimprinted material. After imprinting, the polydimethylsiloxane back layer is easily peeled off before the polymethylmethacrylate mold is chemically removed to avoid any demolding problem. The SEM images show that the honeycomb-like regular nanostructure of the initial anodic aluminum oxide template can be preserved completely on TiO2 via this method, and the XRD results indicate that there is a crystalline transition from amorphous to anatase of TiO2 after 450 degrees C heat treatment. 相似文献
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Yoon JM Shin DO Yin Y Seo HK Kim D Kim YI Jin JH Kim YT Bae BS Kim SO Lee JY 《Nanotechnology》2012,23(25):255301
Mushroom-shaped phase change memory (PCM) consisting of a Cr/In(3)Sb(1)Te(2) (IST)/TiN (bottom electrode) nanoarray was fabricated via block copolymer lithography and single-step dry etching with a gas mixture of Ar/Cl(2). The process was performed on a high performance transparent glass-fabric reinforced composite film (GFR Hybrimer) suitable for use as a novel substrate for flexible devices. The use of GFR Hybrimer with low thermal expansion and flat surfaces enabled successful nanoscale patterning of functional phase change materials on flexible substrates. Block copolymer lithography employing asymmetrical block copolymer blends with hexagonal cylindrical self-assembled morphologies resulted in the creation of hexagonal nanoscale PCM cell arrays with an areal density of approximately 176?Gb/in(2). 相似文献
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A highly ordered and hierarchical structural nanopore array is fabricated via anodizing a pre-patterned aluminum foil under an optimized voltage. A pre-patterned hexagonal nanoindentation array on an aluminum substrate is prepared via the nanosphere lithography method. This pattern leads to an elaborate nanochannel structure with seven nanopores in each nanoindentation after anodization treatment. The structure achieved in our study is new, interesting, and likely to be applied in photonic devices. 相似文献
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The focus of this paper aims at addressing the contemporary issues, i.e., agglomeration and nonuniform dispersion of reinforcement particles prevailing with stir casting method of fabricating metal matrix composites. Although it has been dealt with different approaches, viable optimal technique has not evolved so far. A novel encapsulate feeding technique aimed to accomplish uniform dispersion of ceramic reinforcement particles. In this research, we have chosen Aluminum Alloy 6061 (AA 6061) as a matrix material and cubic boron nitride (c-BN) as a reinforcement companion to form a unique combination of advanced aluminum composites to prove this innovative feeding technique. Two percent of Mg added in every casting as a wetting agent to improve binding nature between metals and ceramics. The Aluminum Boron Nitride (Al/BN) composites are fabricated through bottom type of pouring stir casting machine. Metallographic characterization ensures uniform particle dispersion. The composites are tested using pin-fin apparatus and Xe-flash laser setup and found enhanced (12%) thermal properties than pure AA 6061. 相似文献
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多孔铝合金的铸造工艺研究 总被引:6,自引:0,他引:6
采用加压铸造工艺,制备出了多孔铝合金。系统地研究了预制块的制备工艺过程及影响因素。利用所制备的预制块,研究了多孔铝合金的加压铸造工艺。研究表明,预制块孔隙大小及其初始温度、金属液浇注温度、外加压力等影响了金属液在预制块中的充型长度。采用合理的工艺,就可以获得大尺寸的多孔制品。 相似文献