共查询到20条相似文献,搜索用时 93 毫秒
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泡沫铝的孔隙率对压缩性能的影响 总被引:1,自引:0,他引:1
本文采用粉末冶金复合加热新方法,研究了泡沫铝制备工艺参数TiH2与Al2O3对孔隙率的影响、孔隙率及孔结构均匀性对泡沫侣屈服强度的影响以及泡沫铝压缩变形的基本特征。研究结果表明:该方法可以制备孔隙率与结构均匀性可控的泡沫铝;当WTiH2=1%,WAl2O3=1~2%可获得较高的孔隙率和均匀的孔结构;泡沫铝的屈服强度随孔隙率的增加而减小,塑性平台区的变形范围随之增加,应力变化范围减小,力学稳定性增加,能量吸收性能和抗冲击性能变好;泡孔结构均匀的泡沫铝,其应力-应变曲线的塑性平台区较不均匀的要平缓、稳定。 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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非常规孔结构Al-Si12泡沫芯消声器的吸声性能研究 总被引:1,自引:0,他引:1
以渗流法制备的宽孔径孔结构、周期孔结构及梯度孔结构三类非常规孔结构Al-Si12泡沫为芯材,制作了Al-Si12泡沫芯消声器,对其吸声性能进行了研究。结果表明,宽孔径孔结构Al-Si12泡沫芯消声器的吸声效果明显优于常规孔结构Al-Si12泡沫芯消声器;梯度孔结构Al-Si12泡沫芯消声器的吸声性能比宽孔径孔结构泡沫铝芯消声器优越;周期孔结构的泡沫铝芯消声器与宽孔径孔结构泡沫铝芯吸声性能相当;Al-Si12泡沫芯消声器的吸声性能与扩张室结构及流阻有关;与传统吸声材料芯消声器相比,宽孔径孔结构的Al-Si12泡沫芯消声器的吸声性能介于离心玻璃棉芯消声器及聚氨酯泡沫芯消声器之间。 相似文献
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开孔与闭孔泡沫铝的压缩力学行为 总被引:8,自引:0,他引:8
研究了开孔与闭孔两种胞孔结构不同、制备工艺不同的泡沫铝在准静态压缩载荷下的压缩响应曲线.结果表明:开孔与闭孔泡沫铝压缩应力-应变曲线均具有多孔泡沫材料明显的三阶段特征,即线弹性段、塑性屈服平台段及致密段;相对密度对泡沫材料的力学性能(如杨氏模量、屈服强度)有很大影响;在准静态下,开孔泡沫铝表现出明显的应变率效应,而闭孔泡沫不如开孔敏感;泡沫铝材料表现为弱的各向异性;胞孔结构影响两种泡沫材料的压缩响应曲线. 相似文献
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泡沫铝合金阻尼性能的研究 总被引:4,自引:0,他引:4
程和法 《材料科学与工程学报》2003,21(4):521-523
本文采用渗流工艺制备具有开孔结构的泡沫工业纯铝、泡沫铝—锌合金(Al—28wt%Zn)及泡沫铝—镁合金(Al—10wt%Mg),在多功能内耗仅上对这三种具有相同结构和相对密度的泡沫铝合金的阻尼性能进行了研究。实验结果表明,铸态下的泡沫铝—镁合金的阻尼性能高于泡沫纯铝,而泡沫铝—锌合金在室温下的阻尼性能比泡沫纯铝及泡沫铝—镁合金高3~4倍,分析认为泡沫铝—锌合金的高阻尼机制主要是由于在振动时其基体中较软的α相与较硬的富锌η相界面产生粘滞流动消耗能量的结果。 相似文献
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对熔体发泡法制备SiCp增强泡沫铝基复合材料的制备工艺进行了探索,通过正交试验研究了SiC的粒度、发泡剂TiH2的加入量、发泡温度、保温时间等工艺参数对泡沫铝孔隙率及孔结构的影响,确定了制备SiCp增强泡沫铝基复合材料的最佳工艺参数:掺入10%(质量分数)1000目的SiC颗粒增粘,在发泡剂TiH2加入量为2%(质量分数),搅拌时间2min,保温温度700℃以及保温时间3min的工艺条件下,制得的泡沫铝的孔隙率达到80%,平均密度达到了0.5g/cm^3,且基本没有无泡层。最后对泡沫铝的产业化生产的可行性作了讨论。 相似文献
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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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We describe a powder metallurgical space holder method to produce open-cell metallic foams. By changing the values of the main manufacturing parameters such as volume percentage and the particle size of the space holder agent, we produce different copper foam samples which cover a wide range of solid fraction, pore size and cell wall thickness. All the specimens were synthesized based on a series of designed experiments. We demonstrate how the foams’ density, cell size and specific surface area can be accurately controlled using two easily adjustable manufacturing parameters. The three-dimensional structure of these foams was investigated using X-ray micro tomography. The image quality is sufficient to measure local structure and connectivity of the foamed material, and the field of view large enough to calculate material properties. By combining the finite element method with the tomographic images, we calculate the mechanical response of the foams. We show that the foams’ bulk and shear moduli are strongly correlated to their cell size, cell wall thickness and specific surface area. These parameters can be easily controlled during manufacturing. 相似文献
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Tannin-based rigid foams and derived glasslike carbon foams are new, lightweight, cellular materials, prepared from 95% natural precursors. They are mainly based on bark extracts that are cross-linked with a little of formaldehyde, in the presence of furfuryl alcohol, blowing agent and acid catalyst. Their carbonaceous counterparts are obtained by pyrolysis in inert atmosphere. Various processing and composition parameters were varied, in order to observe the resultant effects on the pore structure, i.e., cell morphology, apparent density, homogeneity, and surface area. Especially, the amounts of foaming agent, strengthener and additives (nanoclay filler) were changed, and the influences of mould diameter and compression stress during foaming were investigated as well. The foams are found to be slightly orthotropic materials whose pore structure is mainly controlled by the amount of blowing agent, leading to an easily tuneable linear cell density that typically ranges from 50 to 250 pores per inch. All the other parameters have much lower influence. 相似文献
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Titanium foams have been of interest in dental and orthopedic implants over the past few decades on account of their excellent mechanical properties, chemical stability, and biocompatibility. A powerful tool, X-ray computed microtomography was used to measure quantitatively the effect of pore morphology on foam architecture. Mechanical properties of titanium foams with varying pore structure were investigated. Aspect ratio of the pores was quantitatively demonstrated to affect strength, degree of anisotropy and strain-rate sensitivity of the produced titanium foams. Needle-like pored foams showed 30-55% lower strength when compared to the foams having lower aspect ratio pores. Lower aspect ratio pored foams were 3-11%, higher aspect ratio pored foams were 17-34% weaker in the direction parallel to the compaction direction when compared to the perpendicular one. High aspect ratio pores also resulted in more pronounced strain-rate sensitivity. 相似文献
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A. Verdooren H.M. Chan J.L. Grenestedt M.P. Harmer H.S. Caram 《Advanced Engineering Materials》2004,6(6):397-399
A process has been developed for obtaining closed cell metallic foams using a ceramic foam precursor. In this approach, the major constituent of the ceramic foam precursor is iron oxide (Fe2O3), which is mixed with various foaming/setting additives. The mixture sets rapidly at room temperature to stabilize the foam generated by hydrogen release. The oxide foam is then reduced in a non‐flammable hydrogen/inert gas mixture to obtain a metallic foam with a cell diameter of 0.5–2 mm. Iron foams with a relative density of 0.23 were tested in compression and yielded an average compressive strength of ~ 34 MPa. The compressive stress‐strain curves obtained were typical of cellular metals. The normalized strengths of the metal foams obtained in the present study compare very favorably with that of steel foams produced by other techniques. 相似文献
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The replication process is used to produce open‐cell 99.99 % pure aluminium foams of controlled pore diameter and solid volume fraction; each parameter is varied respectively from 40 to 400 μm and 10 to 30 vol. pct. The foam tensile behaviour is consistent with the small‐strain compressive behaviour and shows a significant dependence on pore size. 相似文献
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Abd-Elmouneïm Belhadj Sid-Ali Kaoua Mohammed Azzaz Jean Dominique Bartout Yves Bienvenu 《Materials Science and Engineering: A》2008,494(1-2):425
This study is devoted to the fabrication of metallic foams based on tin–lead of various relative densities and pore sizes by means of the liquid alloy infiltration process and its characterization (mechanical behavior and microstructure). Room temperature uniaxial compression tests were carried out in order to study the influence of the size of cell and of the relative density on the behavior in compression and to interpret these relations within a framework. A characterization on a microscopic scale (metallography and hardness) is achieved in order to link the morphological and mechanical characteristics of the constitutive phases, the parameters of the process and the macroscopic mechanical behavior. 相似文献