Zr_(1-x)Ti_xCo合金的储氢性能及抗氢致歧化效应研究

采用真空电弧熔炼的方法制备Zr_(1-x)Ti_xCo合金,采用XRD表征所制备合金及其氢化物的相结构,采用Sievert-型吸放氢性能测试方法测试其放氢动力学性能及PCT曲线,获得放氢反应的熵变及焓变值,采用等容等温法测试所制备合金的歧化动力学,结果表明Ti掺杂含量增加可有效改善ZrCo合金抗氢致歧化性能,进一步TG-DSC研究Zr_(1-x)Ti_xCo合金氢化物放氢过程,结果表明Ti掺杂可实现对ZrCo合金的晶格调控,从而改善抗氢致歧化性能及热力学性能。     

改善ZrCo储氚合金抗歧化性能的研究综述:晶体结构、放氢热力学和歧化动力学

ZrCo合金由于优异的储氢性能以及安全特性,已被国际热核实验堆(ITER)研发团队选取为用于氢同位素快速储存与供给的重点备选材料。然而,由吸/放氢循环过程中发生的氢致歧化效应导致的储氢性能严重衰减,成为了ZrCo合金推广应用于氢同位素快速储存与供给的最大障碍。因此,改善ZrCo合金的抗氢致歧化性能对其广泛应用于氢同位素快速储存与供给领域具有重要意义。本文介绍了ZrCo合金的储氢性能和氢致歧化特性,综述了元素替代(掺杂元素部分替代Zr或Co)改善ZrCo合金抗歧化性能的研究进展,并指出进一步改善ZrCo合金抗歧化性能的必要性及可能的发展方向。     

第四组元对机械合金化MgNiCu合金贮氢性能的影响

采用机械合金化方法由Ｍｇ，Ｎｉ和Ｃｕ单质粉末以及添加第四组元粉末按选定比例合成ＭｇＮｉＣｕ和ＭｇＮｉＣｕ－Ｍ５％贮氢材料，着重研究了分别添加不同的第四组元Ａｌ，Ｍｎ，Ｔｉ元素对不同球磨时间后ＭｇＮｉＣｕ合金贮氢性能的影响。结果表明，添加第四组元都不同程度地改善了ＭｇＮｉＣｕ俣金的初始活化条件；添加Ｍｎ能降低ＭｇＮｉＣｕ合金的吸放氢平台，显著改善其吸放氢动力学性质；添加Ｔｉ提高了ＭｇＮｉＣｕ合金的最     

Ti-Mn系贮氢合金研究

Ti-Mn系贮氢合金与其它实用的合金系相比,具有高的吸放氢量,好的平台特征,良好的吸放氢动力学性能和较低的成本,是有发展前景的贮氢合金系统之一。本文综述了目前对Ti-Mn二元系,三元系及多元系贮氢合金的贮氢与工程应用特性研究情况,并讨论了置换元素对Ti-Mn系合金的影响。     

用工业V2O5直接制备钒基固溶体贮氢合金

研究了五氧化二钒直接制备钒基固溶体贮氢合金的方法.分析测试了合金的化学成分、组织结构和贮氢性能.结果表明,用工业五氧化二钒可以合成钒基固溶体贮氢合金V3TiN0.56Al0.2;PCT曲线表明该合金已具备平衡吸放氢的性能,吸放氢容量为1.8×10-4m3/g;合金中含有少量的氧化物夹杂,但通过真空感应精炼,可使夹杂含量降低.     

机械球磨制备La2Mg17/Ni复合材料的微观结构及气态吸放氢性能

为提高La2Mg17贮氢合金的吸放氢性能,以机械球磨La2Mg17+Ni+NbF5在氩气为保护气氛围下制备复合材料。采用XRD分析了球磨后复合材料的微观结构,用SEM观察了其形貌。通过自动控制的Sieverts设备测试了材料的吸放氢动力学性能。研究表明混合球磨后复合材料的吸放氢性能有了显著的提高,进一步说明Ni粉、NbF5促使了材料纳米晶/非晶结构的形成,而该结构的形成是材料吸放氢性能提高的主要原因。     

Pd含量对Mg-Ni合金相形成及贮氢性能的影响研究

采用机械合金化方法合成了Mg-54.7%Ni-x%Pd(x=0、3、10,质量百分比)贮氢材料.通过X射线衍射分析(XRD)和贮氢性能测试,研究了Pd含量对Mg-Ni合金相形成及贮氢性能的影响.XRD分析表明,在0.30MPa的氩气气氛下球磨30h后,粉末没有形成合金相;但在523K吸氢时,Mg-54.7%Ni-x%Pd(x=0,3)与氢气反应均生成了大量的Mg2NiH4,而Mg-54.7%Ni-10%Pd的氢化物中大部分为MgH2,只形成了少量的Mg2NiH4.贮氢性能测试结果表明,所制备的材料在473K无需活化即可吸氢;同Mg-54.7%Ni-x%Pd(x=0,10)相比,Mg-54.7%Ni-3%Pd吸放氢速度最快,可逆贮氢容量最大(2.82%,质量百分比).     

用工业V205直接制备钒基固溶体贮氢合金

研究了五氧化二钒直接制备钒基固溶体贮氢合金的方法.分析测试了合金的化学成分、组织结构和贮氢性能.结果表明,用工业五氧化二钒可以合成钒基固溶体贮氢合金V3TiN0.56Al0.2;PCT曲线表明该合金已具备平衡吸放氢的性能,吸放氢容量为1.8×10-4m3/g;合金中含有少量的氧化物夹杂,但通过真空感应精炼,可使夹杂含量降低.     

纳米晶稀土贮氢合金的研究

用双辊快淬工艺制备了纳米晶AB5型富镧稀土贮氢合金。对热处理后的合金进行X射线衍射和扫描电镜SEM分析，并测试合金的吸放氢等温平衡曲线PCT。结果表明，处理的合金晶粒尺寸〈50nm，该合金具有良好的吸放氢动力学性能。     

V3TiNi0．56Alx贮氢合金充放电性能和吸放氢性能研究

用自蔓延高温合成法制备了钒基贮氢合金V3TiNi0．56Alx（x=0．1、0．3），用EDXRF、XRD等方法分析了合金的组织成分，并对合金进行了充放电性能和吸放氢性能测试。结果表明：随Al含量增加，合金的最大放电容量和吸氢量均减小，但循环稳定性提高；合金的放氢平台均在0．5MPa附近，随Al含量增加，平台宽度变窄、平台倾斜度增加。     

Influence of filler selection on twin screw foam granulation

The influence of filler selection in wet granulation was studied for the novel case where the binder is delivered as an unstable, semi-rigid aqueous foam to an extrusion process. The work primarily examined the impact of differing concentrations of microcrystalline cellulose (Avicel PH® 101) in a formulation with spray-dried α-lactose monohydrate (Flowlac® 100) in regards to wetting and granule nucleation for this relatively new technique known as continuous foam granulation. Foam stability was varied within the work to change its drainage and coarsening behavior atop these powder excipients, by use of different foamable binding agents (METHOCEL? F4 PLV and METHOCEL? Premium VLV) as well as by adjusting the foam quality. A static bed penetration test was first used to study the foam behavior in wetting these powders without the processing constraints of an extruder which limit possible liquid-to-solids ratios as well as introduce shear which may complicate interpretation of the mechanism. The test found that the penetration time to saturate these powders decreased as their water absorption capacity increased which in turn decreased the size of the formed nuclei. Differences in the stability of the foamed binder had minimal influence on these attributes of wetting despite its high spread-to-soak behavior. The size of granules produced by extrusion similarly demonstrated sensitivity to the increasing water absorption capacity of the filler and little dependency on foam properties. The different liquid-to-solids ratios required to granulate these different formulations inside the extruder highlighted an evolving concept of powder lubricity for continuous foam granulation.     

Primary investigation on sound absorption performance of highly porous titanium foams

A novel sort of cellular titanium foam, whose total porosity was achieved as high as 86%–90% and main pores were spherically millimeter-scaled, was recently prepared successfully by an improved foaming method of melting the metallic powder. This titanium foam showed a good performance of sound absorption, and its sound absorption coefficient could be more than 0.6 in the sound-wave frequency range of 3150–6300 Hz and even exceed 0.9 at the resonance frequency. The main mechanism of sound absorption for this foam should be of interference silencing due to the surface reflection when the sound wave frequency is lower than about 4250 Hz, and the viscous dissipation when the frequency is higher than about 4250 Hz. A reticular product with millimeter-scaled pore size and about 90% porosity was also made by means of slurry-immersed sintering, and the resultant titanium foam might display an effect for sound absorption, but on the whole, its absorption was evidently inferior to that of the cellular product. The corresponding sound absorption coefficient could not be above 0.2 until sound-wave frequency is higher than 3150 Hz, keeping a relatively low value except for resonance occasion only, on which it could reach up to around 0.9 at about 4000 Hz.     

聚氯乙烯/杨木粉模压发泡材料的制备及性能研究

目的制备聚氯乙烯杨木粉发泡材料并研究其性能。方法采用模压法制备发泡材料,利用压缩试验表征其性能。结果随着杨木粉填充量的增加,聚氯乙烯杨木粉发泡材料的密度呈上升趋势。添加木粉后,压缩强度呈先升高后下降的趋势,当木粉填量为10份时,压缩强度达到最大。随着木粉粒度的增加,聚氯乙烯木粉发泡材料压缩强度也呈先上升后下降的趋势,在木粉粒度为100目时压缩强度达到最大。结论可采用模压法制备聚氯乙烯杨木粉发泡材料,发泡剂用量、木粉填量和粒度对发泡材料性能有一定影响。     

Study on microwave absorption properties of metal-containing foam glass

Materials with the properties of electromagnetic (EM) wave absorption are attractive topics. In this work, we report that EM wave absorption composites, consisting of foam glass, zinc and zinc oxide, were prepared by sintering mixture of foam glass raw material and zinc powder. Microwave reflection loss of composite was calculated based on the permittivity in the range of 8.2-12.4 GHz. The results show that zinc-containing foam glass absorbs efficiently microwaves. The sample with zinc filler to foam glass mass ratio of 3/18 had a reflection loss below −10 dB in the range of 11.3-12.4 GHz, and the minimum reflectivity was −15.6 dB at both 12.0 and 12.4 GHz. Microwave absorption performances of specimens can be controlled by changing the ratio between zinc powder and foam glass mass. The detailed mechanism of the control was investigated through X-ray diffraction (XRD) analysis and scanning electrical microscopy (SEM) observations.     

Refrigerant desorption and foaming in mixtures of HFC-134a and HFO-1234yf and a polyol ester lubricating oil

This paper presents a study of refrigerant desorption leading to foam formation in refrigerant-oil mixtures undergoing controlled depressurization. An experimental apparatus was designed and constructed to allow measurements of the depressurization rate, foam height and refrigerant gas mass flux resulting from expansion and desorption from a saturated liquid mixture. Quantitative data and high-speed video analyses were used to identify the main physical mechanisms in the foaming process, namely, bubble cavitation and growth, foam growth and foam decay. The experimental results for the maximum foam height, foam lifetime and liquid supersaturation during desorption were explored as a function of the overall initial refrigerant mass fraction and system temperature. A mathematical model based on integral mass balances was proposed and compared with the experimental data with deviations smaller than 20%.     

泡沫镁制备技术研究现状及其在航空航天领域的应用前景

泡沫镁作为一种新型功能材料,近年来逐渐受到了国内外的广泛关注,但由于镁过于活泼,易引起爆炸,难以在生产中被大量使用,故关于泡沫镁的研究较少。主要综述了泡沫镁阻尼性能、吸声性能、吸能性能、散热性能、生物医学性能和电磁屏蔽性能等几种主要的性能特点,进而综述了粉末冶金法、熔体发泡法、渗流铸造法等几种常见的泡沫镁材料制备工艺的研究进展,并结合笔者的研究理解对几种制备工艺进行了对比,分析了各种制备方法的优缺点。在此基础上对泡沫镁材料在航空航天领域上的应用进行了分析,表明了其在航空航天领域有着广阔的应用前景。     

A novel method for producing of steel tubes with Al foam core

In this study, the aluminum foam filling steel tube was produced by powder metallurgy and cold welding process. By this method, Al powder mixed with 0.6 wt.% TiH₂ powder and then pressed into the steel tube. This filled tube was treated in temperature above aluminum melting point for releasing the hydrogen gas by decomposition of TiH₂ particles for providing of foam production conditions. For the first time, the steel tube with Al foam core produced by this method, without using of binder or fitting. Main advantage of these filled tubes is high energy absorption. Energy absorption is very useful in automobile and railway industry. Lightweight is another advantage of these tubes for these applications. It is found that the Al foam filling steel tubes absorb higher energy with respect to the sum of the energy absorptions of the steel tube and aluminum foam alone.     

Titanium foam through powder metallurgy route using acicular urea particles as space holder

In the present work, Ti foam has been synthesized employing powder metallurgy route. Irregular titanium powder particles were used as the matrix and acicular urea particles as the space holder. The distribution of the urea particles in the matrix of the compacted mass was observed to be fairly uniform. Pore morphology and compressive behavior of the resulting foam have been studied. The processed foam consisted of acicular porous regions of size up to 500 μm. The porous regions contained a large number of micro-pores along with the occasional presence of coarse pores, the latter thought to be unhealed portions of the original acicular pores. The foam delineated a distinct plateau region with plateau stress of 275 MPa and energy absorption capacity of 55 MJ/m³.     

PSDC螯合树脂的合成及其对重金属离子的吸附性能研究

选用白色污染源泡沫作原料,通过氯甲基化反应得到氯甲基聚苯乙烯(交联度4%),并以氯甲基聚苯乙烯为母体合成聚苯乙烯二羧甲基二硫代氨基甲酸螯合树脂(PSDC),该树脂含有二硫化氨基甲酸(DTC)和亚氨基二乙酸(IDA)两种功能基团,将树脂应用于吸附废水中的铅、铜、镍、铬重金属离子,并对其吸附性能进行了考察。结果发现目标产物在高温下对铅、铜、镍、铬离子有更好的吸附,树脂吸附离子30min后可达到平衡,对不同金属离子的较佳吸附pH分别为6、5、5和4.5。