最新刊期
卷 ， 期 1 ， 2006
- 摘要：The bulky ultra-fine 2A12 aluminum alloy with grain size about 200 nm and high angular boundary can be prepared by 8-turns pressing with ECAP die with the inner angle 90 and outer angle 30 at ambient temperature, and the microstructure and its evolution of the 2A12 aluminum alloy during pressing were observed by Hitachi S-800 TEM. The results show that grain size is significantly refined due to the sharply increases of dislocation density in grain resulting in dislocation tangle after one-turn pressing. Needle-like secondary phase Al2Cu is transformed into particle , dispersing in a-Al matrix, and Al2 CuMg particle is pressed into grain boundary due to the refinement of the grain size with shearing, where these compound particles are not changed in the following pressing process. The 2A12 aluminum alloy with ultra-fine structure can be prepared due to the dislocation gradually moving from grain towards grain boundary, and forming cell structure on grain boundary, finally gradually becoming clear small angular boundary or large angular boundary by continuously pressing.关键词：ECAP;Ultra-fine Materials;2A12 Aluminum Alloy;Structure;Dislocation
- 2
- |
- 469
- |
- 13
发布时间：2023-12-18 - 摘要：The force acting on the magnetic impurities in alternative magnetic field was analyzed , and the magnetic forces formed in alternative and steady magnetic field were compared. The results show that two kinds of magnetic forces can be united, and the moving rules of magnetism particles can be described with the same theory also. Both electromagnetic force and magnetic force can drive the paramagnetic iron-rich phase impurities in Al-Si alloy move. Electromagnetic separation experiment shows that the electromagnetic force is dominant in driving impurities particles to move to separator inner side with the magnetic induction intensity more than 145 mT while magnetic force is dominant in driving the impurities to move to the outer side of separator with the magnetic induction intensity less than 120 mT, which can guide the structure design of separator.关键词：Magnetic Impurity Particle;Magnetic Susceptibility;Electromagnetic Force;Magnetic Force;Electromagnetic Separation;Al-Si Alloy
- 2
- |
- 103
- |
- 1
发布时间：2023-12-18 - 摘要：Nd2Fe14B alloy thin film is prepared by means of direct current magnetization magnetron sputtering, in which substrate is preheated and continuous dynamic heating is conducted during sputtering. The effects of the method on magnetic property of the thin film are investigated. The results indicate that the thin film has excellent o-rientation, exhibiting obvious columnar growth tendency. The coercive force of the thin film is greatly increased and the H/H ration is improved. The optimum magnetic property can be obtained with heating from 200C to 500C gradually and holding time for 10 min.关键词：Nd2Fe14B Alloy Thin Film;Oriented Deposition;Dynamic Heating;Magnetic Recording Property
- 2
- |
- 87
- |
- 1
发布时间：2023-12-18 - 摘要：The effects of pouring temperature and cooling rate on the microstructure of Al-Cu alloy was investigated by SEM and OP observation. The observation indicates that eutectic structure occurs in Al-Cu alloy with the 5. 65 % Cu content, increasing volume fraction of the eutectic structure with increase of the pouring temperature. The reduction of Al atom cluster in Al-Cu melt is reduce with the increase in temperature of the atom cluster in Al melt. Meanwhile, the volume fraction of the eutectic structure with the same composition is reduced and the distribution of the lamellar space becomes dispersive at the same pouring temperature with the decrease in the cooling rate.关键词：Al-Cu Alloy;Pouring System;Volume Fraction;Lamellar Space
- 2
- |
- 148
- |
- 1
发布时间：2023-12-18 - 摘要：The reaction mechanism of Al-Ti-B system prepared with pure Ti particle was investigated, and the ther-mo-dynamics of melt reaction for three kinds of addition ways were approached. The experimental results show that Al-Ti-B master alloys prepared by three kinds of addition ways possess the same phase structure in case of complete reaction. Although the A1B2 phase occurs in the melt a-head of adding KBF4, it is finally converted into TiB2 phase through completely melt reaction with Ti soluted in aluminum melt. The forming of second phase （TiAl3, TiB2） is the fastest in the condition of mixing addition.关键词：AI-Ti-B Master Alloy;Melt;Thermo-dy-namics
- 2
- |
- 284
- |
- 3
发布时间：2023-12-18 - 摘要：Changes of solute content in grain and solidification structure of 7075 aluminum alloys under a stationary magnetic field were investigated. The experimental results show that Zn, Mg, Cu contents in grain of stationary magnetic field treated 7075 aluminum alloy can be increased compared with those of samples without magnetic field treatment. In addition, the macro-structure of the treated alloy samples can hardly change while the precipitated phase in grain transform from coarse needle-like structure without magnetic field treatment to fine and even structure. The operation mechanism of magnetic field is approached. It is concluded that electromagnetic field can make the relative motion between solute element and aluminum matrix, which increases the diffusion of solute elements in liquid Al, resulting in the increase of the solute content in grain.关键词：7075 Aluminum Alloy;Stationary Magnetic Field;Solute Content in Grain;Solidification Structure
- 2
- |
- 357
- |
- 1
发布时间：2023-12-18 - 摘要：A new way of 3D design for lost foam casting production line was proposed through applying the computer graphics techniques. A 3D design software suitable for lost foam casting were developed based on OpenGl and Vi-sualC + + software. The procedure and effects of the 3D design was verified through a lost foam casting actual production line with 1500 tons cast steel castings per year.关键词：Computer Graphics Techniques;3D Design;OpenGL;Lost Foam Casting
- 2
- |
- 124
- |
- 1
发布时间：2023-12-18 - 摘要：Analysis of hot spot resulting from core during casting process was conducted by ANSYS software aiming at the boss hot spot. The quantitative relation between hot pipe structure and cooling ability of partial die casting mould was approached. The results show that although it only slightly affects the heat change with the cooling length ratio of 1, the hot pipe diameter increasingly affects the heat change with the increase of length-diameter ratio.Meanwhile, hot pipe internal diameter has a critical value.The different length-diameter ratios were given.关键词：Boss Hot Spot;Numerical Analysis;Hot Pipe
- 2
- |
- 113
- |
- 1
发布时间：2023-12-18 -
- 摘要：Modification of Fe-rich impurity phases in the a-luminum sheet for easy-open can was performed by adding trace RE, and effects of modification were examined by means of SEM, X-ray diffusion and ED AX. The results show that RE gathered in matrix grain boundary improves the nucleation rate of Fe-rich phase and promotes the growth change, and it takes obvious modification effects through the following approaches including forming Fe-rich heterogeneous nuclei with Al melt, influencing the diffusion progress of solute atom and growth way of the impurity phase, substituting some composition in Fe-rich phase to reduce the Fe/Mn ratio. The coarse fish-skeleton Al（Fe,Mn,Si） compound phase is transformed into short-small skeleton or round Al （Fe, Mn, Mg, Si, RE） and Al （Fe, Mn. RE ） complex phase, which will improve the plasticity of the alloy remarkably.关键词：Aluminum Sheet for Easy-open Can;RE;Modification;Impurity Phase
- 2
- |
- 180
- |
- 4
发布时间：2023-12-18 - 摘要：The principle and development tendency of different directional technologies were expounded. It is a history of improved temperature gradient and promoted cooling rate from the aspect of directional solidification technology evolution, from traditional directional solidification to cold crucible directional solidification, and to soft contact ceramic mold directional solidification, and thereafter to e-lectromagnetic confined directional solidification. Constitutional undercooling, interface stability, and the phase selection and microstructure evolution of pertiectic, monotec-tic and eutectic binary alloy systems were reviewed briefly.关键词：Directional Solidification;Solidification Theory;Temperature Gradient;Solid-liquid Interface;Phase Selection
- 2
- |
- 4733
- |
- 22
发布时间：2023-12-18 - 摘要：The application of ultrasonic in metallurgy and preparation of MMCs in last years and the effects of ultrasonic on degassing and slag-removal in smelting as well as its mechanism were surveyed, and the problems and future tendency of the ultrasonic in the field were approached also. Meanwhile, ultrasonic separation and its application in MMCs were reviewed. Based on the mechanism above mentioned, a method to prepare the particle reinforced MMCs was proposed.关键词：Ultrasonic;Metallurigy;MMCs
- 2
- |
- 819
- |
- 16
发布时间：2023-12-18 - 摘要：Effects of cooling rate on primary Si in hypereutectic Al-Si alloy prepared by electromagnetic stirring were investigated. Experiment indicates that continuous cooling rate can refine primary Si in hypereutectic Al-Si alloy in e-lectromagnetic stirring. The primary Si can be increasingly refined due to the increase of the nucleation rate with the increase of the cooling rate in the range of 3 癈/min 10 癈/min under the condition of electromagnetic stirring current of 10 A while the grain size will become coarse due to the aggregation of nucleated primary Si with the increase of the cooling rate in range of 10C /min 24C/min.关键词：Electromagnetic Stirring;Hypereutectic Al-Si Alloy;Cooling Rate;Primary Si
- 2
- |
- 347
- |
- 1
发布时间：2023-12-18 - 摘要：The morphology of grain in semi-solid slurry and its forming mechanism as well as 3D geometry shape were approached by means of a new self-developed rotating barrel rheomolding equipment with different processing parameters. It is found that the grain morphology in semi-solid slurry under continuous cooling condition is superior to that under constant temperature condition with the same shearing rate, where the grain possesses higher spheroidization and smaller and more uniform size. Three-dimensional morphology of standard grain in semi-solid slurry prepared by mechanical stirring is approximately spheroidal from preliminary research.关键词：Semi-solid;Morphology;Grain;Mechanical Stirring;AZ91DTechnological Characteristics and Practice of the Low
- 2
- |
- 380
- |
- 13
发布时间：2023-12-18 -
- 摘要：The technological characteristics of Mg alloy in low pressure-expendable pattern casting were described. Following facts are shown: （ 1） the fluidity of molten metal in LP-EPC is affected by the flux and pressure of filling gas, casting temperature, coating thickness, foam density and vacuum level; （2） filling shape of molten metal in LP-EPC is presented in arch and layer forming from the in-gate on the condition of low filling velocity and low vacuum level, and filling shape would be more protuberant with high filling velocity, and attached wall effects are shown with high vacuum level. ; （3） the solidification of Mg alloy in LP-EPC advents the simultaneous solidification earlier compared with EPC; （4 ） mechanical properties of the Mg alloy in LP-EPC, such as tensile strength 180.8 MPa, yield strength 113.2 MPa, elongation 4.4%, are superior to those in EPC and in resin sand casting, and equivalent to that in metal mold casting, which can meet the performance requirements of die casting Mg alloy after heat treatment. Production verifies that Mg alloy in LP-EPC has the advantages of good anti-oxidation ability, excellent fillingperformance and mechanical properties, and can produce high precision and thin-walled complex components.关键词：Mg AUoy;Low Pressure Casting;Expendable Pattern Casting
- 2
- |
- 478
- |
- 4
发布时间：2023-12-18 - 摘要：As an important technological parameter in indirect squeezing casting, the casting temperature has some effects on the hot tearing trend and mechanical properties of Al-5Cu alloy. The hot tearing rate and hot tearing coefficient obtained through changing casting temperatures indicate that proper increase of the casting temperature can be helpful to reducing hot tearing trend and to gaining the casting with impact structure. The experimental results show that for the alloy in squeezing casting at 750C , as-cast tensile strength is 273. 8 MPa, and T6 treated tensile strength is 450. 0 MPa, and T4 treated elongation is 17.6%.关键词：Casting Temperature;Indirect Squeezing Casting;Al-Cu Alloy;Hot Tearing Trend;Mechanical Properties
- 2
- |
- 248
- |
- 8
发布时间：2023-12-18 - 摘要：Outwater base and engine bracket for Nissan car were manufactured by using double-directional convergent runner. It is found that the gas-pore defects present in the die castings,and the permeability rate is more than 90%. The easily presented position of the defects was observed by computer simulation. The above problems can be eliminated by thickening ingate, setting two overflow slots, increasing the diameters of stationary mould core and adjusting processing parameters.关键词：Simulation;Die Castings;Filling
- 2
- |
- 37
- |
- 1
发布时间：2023-12-18 - 摘要：Electrical equipment bracket in ship possesses features of many small holes and side-holes, thin-walled and large geometry shape as well as long-narrow rib and holes in outer-side, which can take the difficulty in bracket production and die design. In the design, slide camber and pin were used for side-face and side-hole forming, and a secondary pusher was used in lifter to avoid deformation in taking off a thin-walled castings. The quality of batches of bracket of electrical equipment in ship can be assured.关键词：Bracket of Electrical Equipment;Die Casting Die;Slide Camber;Lifter Structure
- 2
- |
- 134
- |
- 4
发布时间：2023-12-18 - 摘要：China’s investment industry see the tendency of energy-saving, consumption reduction and environmental-protection, and the industry has a larger scale with production volume more than 600 thousand tons and product value more than 10. 8 billion yuan per year with rapid development in last decade. Progress in computer application, e-quipment upgrade and new technologies as well as new material in investment enterprises were introduced.关键词：Investment Enterprise;Wax Materials;Shell Mold;Energy-Saving
- 2
- |
- 189
- |
- 1
发布时间：2023-12-18 -
- 摘要：The actual production from ring nozzle in investment castings indicates that for complex ring thin-walled parts, initial two layer of solidified shell use sol silicate and enhanced layer adopts sodium silicate. Centrifugal casting at the pouring velocity within 300 r/min, meeting the requirements of the customer, can produce the ring nozzle with complete blade and good surface quality.关键词：Investment Casting;Centrifugal Casting;Compound Mold Shell
- 2
- |
- 199
- |
- 1
发布时间：2023-12-18 -
- 摘要：In-situ MoSi2-Fe composites were prepared in MoO3-Al-Si-Fe reaction system by SHS-casting. The effects of reaction thermodynamics, formation of Mo-Si-Fe alloy melt and cooling rate during SHS on the microstructure of the composites are researched. The experiment indicates that in-situ MoSi2-Fe composites can be prepared successfully by SHS-casting. The composites are composed of Mo-Si2 and Fe,where Fe phase formed is distributed along the MoSi2 boundary. The grain size of MoSi2 can be reduced remarkably with the increase of the cooling rate of the melt.关键词：MoSi2-Fe Composites;SHS;Composites
- 2
- |
- 201
- |
- 4
发布时间：2023-12-18 - 摘要：Because Carbon-steel-structure water container for NH4-cleaning tower in synthesized NHL plant did not meetthe requirements of heat-exchange, 5454 aluminum water container was adopted to enhance the heat exchange effects and to improve the working condition in the tower. The application indicates that using 5454 aluminum water container can not only improve NH4 production volume and save cooling water volume but also extend the service life of the water container and reduce the frequency of the water-container-cleaning and replacement. The feasibility of the way was analyzed by relevant measurement and data calculation.关键词：Heat Exchange;NH4-cleaning Tower;5454 Aluminum Water Container
- 2
- |
- 35
- |
- 1
发布时间：2023-12-18 -
- 摘要：Rotating blowing nozzle for blowing nitrogen refining aluminum alloy melt was upgraded to negate the pin-hole and inclusion defects in gravity casting aluminum components. The degassing and slag-removal effects were improved to refine aluminum alloy melt and to improve the quality of the component by refining N2 gas-bubble size to increase the contact area between N2 and aluminum melt.关键词：Rotating Blowing Nitrogen;Aluminum Refinement;Gas Content
- 2
- |
- 198
- |
- 5
发布时间：2023-12-18 - 摘要：Effects of ageing treatment on microstructure and mechanical properties of cast Cu-15Ni-8Sn alloy were investigated. It is found that with ageing at 400 癈 , the supersaturated solid solution a is firstly decomposed spinodally, then the metastable ?’ precipitated phase appears after spi-nodal decomposition, and thereafter discontinuous precipitation ? phase occurs in grain boundary. The microstructure transformation process affects the mechanical properties of the alloy with ageing treatment. Tensile strength, yield strength and hardness of the alloy are gradually increased to a peak value （formation of meatstable ?’precipitated phase ） earlier, then is decreased with increasing the ageing time or temperature. Fracture toughness of the alloy is severely impaired due to the grain boundary precipitates.关键词：Cast Cu-15Ni-8Sn Alloy;Microstructure;Mechanical Properties;Ageing
- 2
- |
- 236
- |
- 8
发布时间：2023-12-18 -
-
- 摘要：<正>《特种铸造及有色合金》杂志创刊25周年座谈会于2005年12月30日在武汉华中科技大学举行。出席座谈会的有《特种铸造及有色合金》杂志在汉编委和相关领域的专家,学者、企业家。华中科技大学科学技术协会副主席彭世卿、材料科学与工程学院院长李德群、副院长陈立亮应邀出席了座谈会。 座谈会由《特种铸造及有色合金》杂志社社长张振斌主持,《特种铸造及有色合金》杂志主编袁振国作刊物工作汇报。与会人员纷纷发言,对《特种铸造及有色合金》杂志创刊25周年表示热烈祝贺,并对杂志今后的发展提出了意见和建议。 《特种铸造及有色合金》杂志主编袁振国在汇报中回顾了《特种铸造及有色合金》杂志从季刊、双月刊到月刊的发展历程,指出“特色”和“创新”是刊物的灵魂,表示要加倍努力,把为行业奉献一本精品期刊作为奋斗目标。 华中科技大学科学技术协会副主席彭世卿在讲话中指出,期刊发展的出路在改革,探索一条适合期刊发展的道路具有重要意义,相信华中科技大学在合作办刊中能发挥更大作用。 华中科技大学材料科学与工程学院院长李德群代表该院热烈祝贺《特种铸造及有色合金》杂志创刊25周年,并表示积极支持杂志在新的历程中取得新的发展和进步。 《特种铸造及有色合金》杂志编委会副主任、华中科技大学教授黄乃瑜是杂志几届编委会成员,亲眼目睹了杂志的发展壮大,他提出杂志应在已有成绩的基础上,更上一层楼,努力创办具有国际水平的期刊。 《特种铸造及有色合金》杂志编委、武汉理工大学前副校长张幼陵关心杂志的发展和进步,对杂志工作给予了大力支持,他殷切希望杂志在新的时期创造新的辉煌。 《特种铸造及有色合金》杂志编委、武汉理工大学教授罗继相参加过多次杂志与学术团体、行业组织合办的学术交流和技术交流会议,认为此举扩大了杂志的知名度和影响力,值得倡导。
- 2
- |
- 32
- |
- 0
发布时间：2023-12-18
- Technical support is provided by Beijing Founder electronics co., LTD 京ICP备09064830号-19
京公网安备11010802024621 - It is recommended to read the content of this site in Chrome&IE9+. Please switch to extreme mode in browser 360.
- Cookies We use cookies to help provide and enhance our service and tailor content. By continuing, you agree to the use of cookies.
0