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Influence of twist extrusion process on consolidation of pure aluminum powder in tubes by equal channel angular pressing and torsion

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Transactions of Nonferrous Metals Society of China 2015年第7期25卷 2122-2129页

作者：王晓溪何敏朱珍薛克敏李萍徐州工程学院机电工程学院徐州221111 江苏省大型工程装备检测与控制重点建设实验室徐州221111 合肥工业大学材材料科学与工程学院合肥230009

In comparison with the conventional equal channel angular pressing（ECAP） process,a comprehensive study of influence of twist extrusion（TE） process on consolidating pure aluminum powder in tubes（PITs） by equal channel angular pressing and torsion（ECAPT） was conducted via three-dimensional（3D） finite element simulation,experimental investigation and theoretical *** results revealed that during the consolidation of aluminum powder particles by ECAPT,TE process played a significant role of back *** to the torsional shear and high hydrostatic pressure exerted by twist channel,both the magnitude and homogeneity of the effective strain were increased *** one pass of ECAPT process using a square channel with an inner angle of 90° and a twist slope angle of 36.5° at 200℃,commercial pure aluminum powder particles were successfully consolidated to nearly full *** and experimental results showed good *** the microstructure observations,grains were greatly *** the same time,porosities were effectively eliminated by shrinking in size and breaking into small *** test indicated that strain distribution of ECAPT-processed billet was more homogeneous with respect to the ECAP-processed *** these improvements may be attributed to the extreme intense shear strain induced during ECAPT and the increase in self-diffusion coefficient of aluminum due to the back pressure exerted by TE process.

关键词： aluminum powder equal channel angular pressing and torsion powder consolidation back pressure

Depositing of Amorphous Ferri-oxide Nanoparticles on Surfaces of Submicron aluminum powder

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Depositing of Amorphous Ferri-oxide Nanoparticles on Surface...

Synthesis of aluminum Titanate powder at Low Temperature via Nonhydrolytic Sol-gel Method by Using aluminum powder

2012 China Functional Materials Technology and Industry Forum

作者： Yi Wang Wei Jiang Xiao Lan Song Guo Dong Deng Feng Sheng Li National Special Superfine powder Engineering Research Center Nanjing University of Science and Technology School of Materials Science and Engineering North University of China School of Chemical Engineering and Environment North University of China

Nanoparticles with about 20nm diameter were densely coated on the surface of submicron Al via a sol-gel processing in ethanol,wherein 1,2-epoxypropane acted as a weak base to consume proton in *** the medium gelled,uniform network formed and aluminum particles imbedded in *** core-shell structure and the nanoparticles were observed in SEM *** EDS spectrum and the XRD pattern revealed that the cores consisted of amorphous ferri-oxide of which the mass ratio is closed to that of crystal *** analysis was performed and the results indicated that the DSC peak point of ferri-oxide/Al nanocomposite showed 53℃lower than that of[ferri-oxide+Al]simple mixture.

关键词： Nanocomposite Sol-gel Ferric oxide aluminum powder Thermite reaction

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Synthesis of Aluminum Titanate Powder at Low Temperature via...

Analysis of synthetic parameters for coating aluminum powders with phenyltriethoxysilane coupling agent and their effects on powder flow behavior

中国材料大会2012

作者： Weihui Jiang Zhifang Xu Jianmin Liu Qingxia Zhu Quan Zhang School of Material Science and Engineering Jingdezhen Ceramic Institute Jiangxi Key Laboratory of Advanced Ceramic Materials

ISBN: (纸本)9783037856079;3037856076

aluminum titanate （Al2TiO5 ） powder has been synthesized at low temperature via nonhydrolytic sol-gel method by using aluminum powder as aluminum source, titanium tetrachloride as titanium source, anhydrous ethanol as oxygen donor with different catalysts. The phase transformation of aluminum titanate xerogel powder during heat treatment and the influence of the mixing orders of raw materials, catalyst kinds on the synthesis of aluminum titanate were investigated by means of differential-thermal analysis （DTA-TG）, X-ray diffraction （XRD）, transmission electron microscope （TEM）. The results indicated that aluminum titanate powder was easily synthesized at 750 ℃ by using AlCl3 as catalyst with a mixing order of adding TiCl4 before AlCl3 into aluminum alcohol mixture. The catalytic order of the different catalysts in the preparation process of aluminum titanate is: FeCl3 ＞ AlCl3 ＞ MgCl2 . The catalyst promoted the activation of metal aluminum powder and played a major role in the synthesis of aluminum titanate powder at low temperature via nonhydrolytic sol-gel method.

关键词： aluminum powder Catalyst Nonhydrolytic sol-gel method aluminum titanate powder.

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Particuology 2024年第7期90卷 412-417页

作者： Lillian M.Mawby Bellamarie Ludwig Benjamin J.Lear Department of Chemistry The Pennsylvania State UniversityUniversity ParkPA16802USA Applied Research Laboratory The Pennsylvania State UniversityUniversity ParkPA16802USA

Though silanization of aluminum powder is currently used to improve its flow properties,for use as an alternative fuel source,there are a wide range of experimental parameters for the process and not all of them have been thoroughly *** this is complete,it is unknown if the process is optimized in terms of time,efficiency,and ***,we report on a study into the effects of changes in humidity,degree of agitation,reaction temperature,and curing time upon the deposition of phenyl triethoxysilane into 20μm(d50)aluminum *** confirm the deposition of the coating via diffuse reflectance infrared spectroscopy and x-ray photoelectron *** then characterize the coated particles using apparent density measurements and Carney flow *** analysis of variance,we find that,of the parameters explored,only changes in cure time and reaction temperature provide meaningful changes to the apparent density,while none of our parameters produced statistically significant changes in Carney flow ***,we conclude that,when optimizing silanization of aluminum particles,environmental control of humidity is unneeded and that the reaction can be run with minimal *** ability to largely ignore these parameters is a benefit to large-scale processing.

关键词： aluminum powder Silane Fluidization Apparent density Carney flow

aluminum and Activated Alumina powder Additions on Microwave Synthesis of Al_(4)SiC_(4)

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China's Refractories 2024年第1期33卷 44-48页

作者： WANG Li LIU Shijie WEI Haoyu MA Juanjuan DONG Binbin GENG Shangrui YAN Miaoxin QIN Feng GUO Yusen Henan Key Laboratory of Green Building Materials Manufacturing and Intelligent Equipemnt Luoyang Institute of Science and TechnologyLuoyang 471023China

Aiming at improving the properties of magnesia carbon materials,silicon aluminum carbide(Al_(4)SiC_(4))containing materials were prepared using industrial aluminum powder,silicon carbide powder,and graphite as raw materials,and activated alumina powder as an additive,mixing thoroughly,pressing into cylinders and then firing at 1200℃for 30 min in a carbon embedded atmosphere by the microwave *** effects of the aluminum powder addition(20%and 24%,by mass)and activated alumina powder addition(0,3%,5%and 7%,by mass)on the microwave synthesis of Al_(4)SiC_(4) as well as the effect of the obtained Al_(4)SiC_(4) containing material on the properties of magnesia carbon bricks were *** results show that:compared with the samples with 20%aluminum powder,those with 24%aluminum powder generate more Al_(4)SiC_(4).With the activated alumina powder addition increasing from 0 to 7%,the amount of Al_(4)SiC_(4) generated increases first and then *** with the sample without activated alumina powder,the samples with activated alumina powder show lower bulk density and higher apparent *** the activated alumina powder addition increasing from 3%to 7%,the bulk density of the samples increases first and then decreases,while the apparent porosity of the samples shows an opposite *** optimal additions are 24%aluminum powder and 5%activated alumina powder,and Al_(4)SiC_(4) synthesized in this sample has a hexagonal plate *** the synthesized Al_(4)SiC_(4) containing material added,the magnesia carbon brick has slightly increased cold modulus of rupture,basically the same modulus of elasticity and improved oxidation resistance.

关键词： aluminum powder activated alumina powder microwave synthesis Al_(4)SiC_(4) magnesia carbon bricks

Fabrication of phosphor bronze/Al two-phase material by recycling phosphor bronze chips using hot extrusion process and investigation of their microstructural and mechanical properties

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International Journal of Minerals,Metallurgy and Materials 2020年第6期27卷 809-817页

作者： Majid Hosseini Mohammad Hossein Paydar Department of Materials Science and Engineering School of EngineeringShiraz UniversityShiraz 71964-84334Iran

Despite the existence of conventional methods for recycling chips,solid-state techniques have become popular,whereby waste metals are directly recycled into consolidated products with the desired shapes and *** investigated the feasibility of recycling phosphor bronze chips through a hot extrusion process using aluminum powder as a metal binder for the fabrication of a metal-fiber-reinforced aluminum matrix *** do so,mixtures containing 20 vol%–50 vol%of chips were prepared,cold-compacted,and *** quality of the consolidated samples was evaluated by determining the density of the fabricated composites and studying their *** addition,we performed tensile and hardness tests to evaluate the mechanical properties of the fabricated *** also analyzed the fracture surfaces of the samples to study the fracture mechanism as a function of the volume fraction of phosphor bronze chips in the fabricated *** results indicated that the most effective consolidation occurred in the sample containing 20 vol%of chips extruded at 465℃in which the chips serve as ideal fibers for improving the mechanical properties,especially the ultimate tensile strength,in comparison with those of Al matrixes that contain no chips but are produced under the same conditions.

关键词： recycling hot extrusion metal–metal composite phosphor bronze chips aluminum powder

AP assembled on ultrafine aluminum particle and its application to NEPE propellant

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Defence Technology（防务技术） 2024年第6期36卷 20-29页

作者： Huixin Wang Qiang Li Hui Ren Liangjun Xie Tingting Liu Zhihong Chen State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China Inner Mongolia Institute of Synthetic Chemicals Hohhot 010010China

Coating modification is an important way to enhance the reactivity of aluminum *** this paper,ammonium perchlorate and aluminum powder were assembled into energetic microunits by liquid deposition *** particles with AP as shell and ultrafine aluminum powder as the core(Al@AP)were *** micromorphology results show that the coated particles are about 5μm,and the coating layer is evenly distributed on the outer surface of aluminum powder,indicating a complete *** energetic microunits were implanted into the nitrate ester plasticizing adhesive system(NEPE)as solid phase *** effect of filler on the rheological properties,safety,mechanical properties,thermal reaction and energy properties of the system was analyzed by comparing with the raw aluminum *** test results show that the rheological properties,mechanical properties and pressure index of NEPE containing system Al@AP meets the requirements of solid propellant *** with Al based propellant,the mechanical sensitivity and thermal sensitivity are decreased,the safety is better,and the explosion heat of the propellant is increased by 7.8%.The engine test shows that the specific impulse is increased by 1.2 ***@AP can improve the energy output and safety of NEPE propellant,and has potential application prospects in high-energy propellants.

关键词： aluminum powder Coating NEPE propellant Energy output Applied research

Effect of metal powders on explosion of fuel-air explosives with delayed secondary igniters

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Defence Technology（防务技术） 2021年第3期17卷 785-791页

作者： Yong-xu Wang Yi Liu Qi-ming Xu Bin Li Li-feng Xie School of Chemical Engineering Nanjing University of Science and TechnologyNanjingJiangsu210094PR China Xian Modern Chemistry Research Institute XianShaanxi710065PR China China Research and Development Academy of Machinery Equipment Beijing100089PR China

In order to improve the energy level of fuel air explosive(FAE) with delayed secondary igniters, high energetic metal powders were added to liquid fuels mainly composed of ether and isopropyl *** powders’ explosive properties and reaction mechanisms in FAE were studied by high-speed video,pressure test system, and infrared thermal imager. The results show that compared with pure liquid fuels, the shock wave overpressure, maximum surface fireball temperature and high temperature duration of the mixture were significantly increased after adding high energetic metal powder. The overpressure values of the liquid-solid mixture at all measuring points were higher than that of the pure liquid fuels. And the maximum temperature of the fireball was up to 1700C, which was higher than that of the pure liquid fuels. After replacing 30% of aluminum powder with boron or magnesium hydride, the shock wave pressure of the mixture was further increased. The high heat of combustion of boron and the hydrogen released by magnesium hydride could effectively increase the blast effect of the mixture. The improvement of the explosion performance of boron was better than magnesium hydride. It shows that adding high energetic metal powder to liquid fuels can effectively improve the explosion performance of FAE.

关键词： Fuel air explosive aluminum powder Boron Magnesium hydride Explosion performance

Effects of Parameters on Formation and Microstructure of Surface Composite Layer Prepared by Lost Foam Casting Technique

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Journal of Wuhan University of Technology(Materials Science) 2012年第1期27卷 82-87页

作者： CHEN Dongfeng DONG Xuanpu FAN Zitian State Key Laboratory of Material Processing and Die&Mold Technology Huazhong University of Science and Technology

Surface composite layer was fabricated on the AZ91D substrate using the lost foam casting （LFC） process. The pre-coating layer reacted with melt substrate and formed the composite layer, and the coating was mainly consist of alloying aluminum powder and low-temperature glass powder （PbO-ZnO-Na20）. The vacuum degree, pouring temperature, mold filling process of melt, and pre-coating thickness played an important role during the formation process of composite layer. The results show that surface morphology of composite layer can be divided into three categories： alloying effect of bad and good ceramic layer, alloying effect of good and bad ceramic layer, composite layer of good quality. The main reason for bad alloying layer is that alloying pre-coating thickness is so thin that it is scoured easily and involved in the melt, in addition, it is difficult for melt to infiltrate into the alloying coating owing to the surface tension of coating when the vacuum degree is excessively low. Bad ceramic layer is because of somewhat lower pouring temperature and the thicker alloying coating, due to the absorption of heat from the melt, making low temperature glass powder pre-coating layer fuse inadequate. Thus, to get good quality composite layer, the process conditions must be appropriate, the result shows that the optimum process parameters are as follows： at a pouring temperature of 800 ~C, vacuum degree of -0.06 MPa, alloying pre-coating thickness ofO.4 mm, and low glass powder pre-coating layer thickness ofl mm.

关键词： lost foam casting aluminum powder low temperature glass powder surface compositelayer pre-coating thickness