检索结果-南通市图书馆

Study on Multiple Electromagnetic Continuous Casting of Aluminum Alloy

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2006年第4期22卷 437-440页

作者： Zhifeng ZHANG Jun XUN likai shi National Engineering Research Center for Non-ferrous Metal Composites General Research Institute for Non-ferrous Metals Beijing 100088 China

To obtain semi-solid Al alloy billet with high quality, an investigation was carried out by imposing a multiple magnetic field from the outside of a copper mold in the continuous casting. AISi6Mg2 alloy designed for semi-solid metal （SSM） processing was continuously cast through a submerged entry nozzle under various conditions. Effects of multiple magnetic field on meniscus motion, temperature distribution and billet quality were examined. The experimental results showed that meniscus disturbance caused by electromagnetic stirring could be controlled effectively and the surface quality of semi-solid AI alloy billet was improved greatly, and an uniformly fine, globular microstructure across the transverse section of the billet was achieved by optimizing the distribution of multiple magnetic field.

关键词： Continuous casting Multiple magnetic field Aluminum alloy Semi-solid Microstructure

Research on development of in situ titanium matrix composites and in situ reaction thermodynamics of the reaction systems

在线全文

学校读者我要写书评

暂无评论

Journal of University of Science and Technology Beijing 2006年第6期13卷 551-557页

作者： Lifang Cai Yongzhong Zhang likai shi Haoqiang Yang Mingzhe Xi National Engineering Research Center for Nonferrous Metal Composites General Research Institute for Nonferrous Metals Beijing 100088 China

The in situ synthesis method for titanium matrix composites （TMCs） has obvious technical and economical advantages over other traditional methods. Ultrafine reinforcement particles were formed in situ by chemical reaction between elements or between elements and compounds. Using the approach, contamination at the composite matrix/reinforcement particle interface did not occur, interface bonding was good, and the reinforcement particle was thermodynamically stable. The stage of development of the preparation process for in situ TMCs as well as the thermodynamic analysis of the possible in situ reaction systems was described.

关键词： in situ titanium matrix composites reaction synthesis reaction system thermodynamic analysis

Annular electromagnetic stirring——a new method for the production of semi-solid A357 aluminum alloy slurry

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2009年第6期22卷 408-414页

作者： Guanglei ZHU Jun XU Zhifeng ZHANG Yuelong BAI likai shi National Engineering ＆ Technology Research Center for Non-ferrous Metal Matrix Composites General Research Institute for Non-ferrous Metals Beijing 100088 China

A new method for producing semisolid slurry, annular electromagnetic stirring （AEMS）, to refine and spheroidize grains was exploited. Experimental work was undertaken to investigate the effects of cooling rate, stirring power and stirring time on the solidification behavior of A357 alloy using A-EMS. It was found that increasing the cooling rate and stirring power gave rise to substantial grain refinement, which could be attributed to the increase of effective nucleation rate caused by the extremely uniform temperature and composition fields in the bulk liquid during the initial stage of solidification. Results showed that a fully grain refined spherical structure could be obtained using proper processing conditions within 10 s.

关键词： Semisolid Annular electromagnetic stirring A357

Microstructure and formation mechanism of titanium matrix composites coating on Ti-6Al-4V by laser cladding

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2007年第4期26卷 342-346页

作者： CAI Lifang ZHANG Yongzhong shi likai National Engineering Research Center for Nonferrous Metal Composites General Research Institute for Nonferrous Metals Beijing 100088 China

Laser cladding experiments were done on a 5-kW continuous wave CO2 laser to synthesize TiC and TiB rein- fowed titanium matrix composite coatings on Ti-6AI-4V alloy with a mixture of Ti and B4C precursor powder. The ther- modynamics of the reactions were calculated and analyzed. The microstructure and phase evolution of TiB and TiC com- posites were investigated. The results showed that the chemical reaction between Ti and B4C would release much heat, and these compounds, TiC, TiB, and small amount of TiB2, can be formed on the surface of Ti-6AI-4V alloy if the supplied en- ergy is sufficient to excite the reaction among the initial products. A good metallurgical bond between the coating and the substrate can be achieved. The microhardness of coating was irregular and the maximum value was approximately HV600.

关键词： coatings titanium matrix composites (TMCs) laser cladding, in situ formation

Break-up Process of Perturbed Molten Metal Jet and Preparation of Lead-Free Solder Balls

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2004年第z2期22卷 174-177页

作者： He Lijun Zhang Shuguang Zhang Shaoming Xu Jun shi likai National Engineering Research Center for Non-Ferrous Metals Composites General Research Institute for Non-Ferrous MetalsBeijing 100088China

Solder balls, which are used in advanced electronics packages such as BGA (Ball Grid Array) and CSP (Chip Scale Package) to substitute the leads and realize the electrical and mechanical connections between substrate and chip,have severe specifications in diameter tolerance, roundness and surface quality, and therefore challenge the traditional technologies for fabrication of metallic particles and powders. The present work made a survey of perturbed molten metal jet break-up process, observed the formation and growth of capillary wave of tin-lead melt jet by way of rapid solidification, and on the basis of the above research, successfully obtained tin-lead eutectic and Sn-4.0Ag-0.5Cu lead free solder balls with tight distribution and good sphericity of particles through optimization of processing parameters, forming a solid base for cost effectively producing solder balls.

关键词： solder balls jet break-up capillary wave perturbation

PREPARATION OF ROUND BILLETS BY SPRAY FORMING TECHNOLOGY

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

中国有色金属学会会刊：英文版 1999年第2期9卷 98-102页

作者： Xiong, Baiqing Zhang, Yong'an Lin, Yaojun Zhang, Shaoming shi, likai Beijing General Research Inst for Nonferrous Metals Beijing China

１ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｓｐｒａｙｆｏｒｍｉｎｇｔｅｃｈｎｏｌｏｇｙｉｓａｎｅｗｔｅｃｈｎｏｌｏｇｙｆｏｒｍａｋｉｎｇｍａｔｅｒｉａｌｓ．Ｉｔｈａｓｂｅｅｎｄｅｖｅｌｏｐｅｄｏｎｔｈｅｂａｓｉｓｏｆｔｈｅｃ... 详细信息

１ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｓｐｒａｙｆｏｒｍｉｎｇｔｅｃｈｎｏｌｏｇｙｉｓａｎｅｗｔｅｃｈｎｏｌｏｇｙｆｏｒｍａｋｉｎｇｍａｔｅｒｉａｌｓ．Ｉｔｈａｓｂｅｅｎｄｅｖｅｌｏｐｅｄｏｎｔｈｅｂａｓｉｓｏｆｔｈｅｃｏｎｖｅｎｔｉｏｎａｌｒａｐｉｄｓ...

关键词： spray forminground billetsnumerical methodratio of gas flux to melt flux

Preparation of tube blanks by atomization deposition process

在线全文

学校读者我要写书评

暂无评论

中国有色金属学会会刊：英文版 1999年第3期9卷 472-476页

作者： Xiong Baiqing(熊柏青) Zhang Yongan(张永安) Lin Yaojun(林耀军) Zhang Shaoming(张少明) shi likai(石力开) Gen Res Inst NonFerrous Met Beijing 100088 Peoples R China

By using the method of mathematical calculation combined with experiment, the technological conditions of atomization deposition process for making tube blanks with even thickness were studied. The results show that in the case of the substrate rotating and translating simultaneously, when the ratio of the rotation frequency to the translational velocity is very large, and the other deposition conditions are suitable, tube blanks with even thickness and high density can be produced, and the actual deposition efficiency will be highest.

关键词： atomization deposition process tube blanks rotation frequency translational velocity Document code:A

Effects of Processing Technologies on Mechanical Properties of SiC Particulate Reinforced Magnesium Matrix Composites

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2014年第4期29卷 769-772页

作者：樊建锋 ZHANG Hua DONG Hongbiao XU Bingshe ZHANG Zhifeng shi likai Key Laboratory of Interface Science and Engineering in Advanced Materials Taiyuan University of Technology Ministry of EducationTaiyuan University of Technology Shanxi Research Center of Advanced Materials Science and Technology College of Materials Science and Engineering Taiyuan University of Technology Beijing General Research Institute for Non-ferrous Metals

Mg matrix composites with SiC particles ranging from 5vol%-25vol% were prepared using stirring casting method. Die casting, squeezing casting, and extrusion were applied for inhibiting or eliminating the defects such as gas porosity and shrinkage void. Through die casting and squeezing casting, most of the defects in Mg matrix composites could be eliminated, but the mechanical properties were improved limitedly. On the other hand, after hot extrusion, not only most of the defects of as-cast composites ingots were eliminated, but also the mechanical properties were improved markedly. With the addition of SiC, the tensile strength, yield strength and elastic modulus of as extrusion SiCp/AZ61 composites increased remarkably, and the elongation decreased obviously.

关键词： Mg matrix composites stirring casting forming technology mechanical property

Effects of deformation parameters on microstructure and mechanical properties of magnesium alloy AZ31B

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2006年第z2期25卷 105-110页

作者： ZHANG Shaoming YANG Bicheng XU Jun shi likai CHEN Guoliang State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing Beijing 100083 China General Research Institute for Non-Ferrous Metals Beijing 100088 China General Research Institute for Non-Ferrous Metals Beijing 100088 China General Research Institute for Non-Ferrous Metals Beijing 100088 China General Research Institute for Non-Ferrous Metals Beijing 100088 China State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing Beijing 100083 China

Plastic deformation and dynamic recrystallization (DRX) behaviors of magnesium alloy AZ31B during thermal compression and extrusion processes were studied. In addition, effects of deformation temperature and rates on the microstructure and mechanical properties were investigated. The results show that the DRX grains nucleate initially at the primary grain boundaries and the twin boundaries, and the twinning plays an important role in the grain refinement. The DRX grain size depends on the deformation temperature and strain rate The average grain size is only 1 μm when the strain rate is 5 s-1 and temperature is 250 ℃. It is also found that the DRX grain can grow up quickly at the elevated temperature. The microstructure of extruded rods was consisted of tiny equal-axis DRX grains and some elongated grains. The rods extruded slowly have tiny grains and exhibit good mechanical properties.

关键词： magnesium alloy thermal simulation extrusion dynamic recystallization