最新刊期
卷 ， 期 1 ， 2003
-
-
-
- 摘要：Microstruetures and cooling velocity of Al-8Pb-3Si-2Sn-lCu monotectic alloy by rotating molten metal were investigated. Results indicated that great cooling velocity obtained in the centre and surface of the particle depended on the particle diameter and cooling medium.The non-equibrium solidifieation can prevented from Pb gravity segregation with the particle diameter less than 4.1 mm . With the decrease in the particle diameter the transformation hypermonoteetic non-equilibrium state into hypononoteetic equilibrium state during solidification of the alloy resulted in Pb more uniform micro-distribution .关键词：Al-Pb Alloy;Particle;Cooling Velocity;Mi-crostrucfure.
- 2
- |
- 137
- |
- 1
发布时间：2023-12-18 - 摘要：A high Si aluminum alloy powder was prepared by ultrasonic gas atomization process. The morphology and size distribution characteristics of the alloy powder were observed by means of SEM and mechanical vibration method systematically. The results showed that the powder prepared by ultrasonic gas atomization has relatively uniform size distribution ranging from 40 to 100 μm. The morphology characteristics is related to the powder size. With decrease in size the morphology became regular more and more.关键词：Rapid Solidification;Ultrasonic Gas Atomization;Aluminum Alloy;Morphology;Size Distribution
- 2
- |
- 306
- |
- 10
发布时间：2023-12-18 - 摘要：Preparation of Zr base bulk amorphous alloy rod up to 20mm diameter in electric arc furnace with graphite crucible was performed for replacement in arc furnace with water cooled crucible by suction pouring forming. The results showed that the temperature and composition are more homogenous in the molten alloy by smelting in graphite crucible, and the cooling conditions favorable to glass-forming are consequently improved.关键词：Graphite Crucible;Bulk Amorphous Alloy;Glass Forming Ability
- 2
- |
- 227
- |
- 2
发布时间：2023-12-18 - 摘要：It is reported in the literature that the formation of Al 4C 3 can affect the interface reaction of Gr-Al-Si composites. In this paper, however, the results showed that the presence of a small amount of Al 4C 3 phase in raw materials is beneficial to improve u-niform distribution of graphite without detriment to tensile strength of the materials at high temperature. An alternative available approach was presented for preparing qualified Gr-Al-Si composite in gravity casting. The proper Al 4C 3 phase formation temperature ranged from 550 to 600 ℃. Amount of Al4C3 can be measured by X-ray quantitative analysis.关键词：Al 4C 3;SiC;Graphite;Al-Si Alloy;Composites
- 2
- |
- 207
- |
- 1
发布时间：2023-12-18 - 摘要：The effects of Micro-alloying elements, in cluding Si, Ce, La, Ti, Zr, Ni,Mn on the quasi-solid mechanical properties of Al-4.5Cu alloy were investigated through examining contracted strain and hot crack resistance as well as quasi-solid mechanical behavior. The results showed that addition of Si, Ce, La, Ti, Zr can reduce the hot crack tendency of the alloy. Adding 2% Si into the base alloy, recalescence phenomenon of the alloy is so severe that the alloy has no longer higher strength resulting in rapid! fracture. Compared to other AlCu4.5Si alloy, AlCu4.5Si3 alloy exhibited very strong feeding ability and highest fracture stress value. Addition of La can reduce secondary dendrite arm spacing and improve significandy hot crack resistance of the alloy.关键词：Hot Crack;Cast A14.5Cu Alloy;Quasi-solid;Hot Crack Resistant Behavior
- 2
- |
- 207
- |
- 10
发布时间：2023-12-18 - 摘要：We have developed a experimental equipment to examine the compressive creep behavior of ZA27 alloy in sand mold and permanent mold. The results showed that primary compressive creep strain and steady creep rate of the alloy increased with the increase in applied temperature and stress. The primary creep strain of the alloy in permanent mold is lower than in sand casting at lower temperature. Compressive creep strain of the alloy conformed to the empirical equation of 1nt = C -nlnσ + Q/RT. The stress exponent n of the alloy for sand casting and for permanent mold casting are 3.88 and 3.49 respectively and the activation energies are 85.44 kJ/mol and 81.02 kJ/mol respectively. The compressive creep strain of the alloy is governed by the lattice diffusion and dislocation limb of zinc. The compressive creep resistance of the alloy at whole testing temperuture and all applied stress in sand mold is higher than in permanent mold.关键词：ZA27 Alloy;Casting in Sand Mold;Casting in Metal Mold;Compressive Creep
- 2
- |
- 82
- |
- 3
发布时间：2023-12-18 - 摘要：The effects of La-RE on the morphology and size of Si in P modified Al-18Si alloy were examined. The results showed that La-RE can enhance P modified effect. Addition of both La-RE and P can not only refine the primary Si but also modify eutectic Si. Moreover, the coarsening tendency of P-La RE modified primary Si in hypereutectic Al-Si alloy was weakened significantly and the modification fading can be extended for 6 h longer. The distribution of La-RE in the alloy was determined by SEM. The mechanism of La-RE effects on P modification was analyzed and approached.关键词：Hypereutectic Al-Si Alloy;RE;Modification;P
- 2
- |
- 251
- |
- 6
发布时间：2023-12-18 - 摘要：aluminum alloy gradient materials were prepared by semi-continuous casting with double-stream-pouring technique . The influence of throttle bore diameter and melt temperature in internal ladle on constituent distribution, marco-structure androckwell hardness of the casting was investigated. The results showed that the alloy volume fraction in the inner casting can be increased by enlarging throtte bore diameter and raising melting temperature in internal ladle under pertinent mold filling conditions. The corresponding relation among composition, macro-structure and mechanical properties of the alloy showed that it is feasible to prepare 2024/3003 multi-component aluminum alloy gradient materials by semi-continuous casting with double-stream-pouring technique.关键词：Aluminum Alloy;Gradient Materials;Semi-continuous Casting
- 2
- |
- 193
- |
- 5
发布时间：2023-12-18 - 摘要：Detailed procedure of Unigraphics software application to design and manufacture of die-casting die and its advantages were expounded. The application effects of UGH software were described briefly.
- 2
- |
- 59
- |
- 3
发布时间：2023-12-18 - 摘要：The specific heat and thermal conductivity coefficient for bulk amorphous Zr41Ti]4Ni10Cu12.5Be22.5 alloy have been measured. With increasing temperature from 15 CCC to 350℃, the specific heat and thermal conductivity change from 0. 386 to 0.485 kJ/kg℃ and from 4.8 to 7.74 W/m℃ respectively. In supercooled liquid region, its specific heat and thermal conductivity are 0.59 kJ/kg℃ and 9.55 W/m℃ respectively. The numerical simulation during cooling process was carried out for the bulk amorphous alloy based on the measurement and analysis of the thermo-physical properties obtained. A wedge casting for the bulk amorphous alloy was used to verify the numerical simulation results. Cooling rate obtained for bulk amorphous Zr 41Ti 41Ni 10Cu 12.5 Be 22.5 alloy in water cooled copper mold can be predicted by using numerical simulation and correlated with the amorphous characteristics. 4Ni10Cu12.5Be22.5 alloy have been measured. With increasing temperature from 15 CCC to 350℃, the specific heat and thermal conductivity change from 0. 386 to 0.485 kJ/kg℃ and from 4.8 to 7.74 W/m℃ respectively. In supercooled liquid region, its specific heat and thermal conductivity are 0.59 kJ/kg℃ and 9.55 W/m℃ respectively. The numerical simulation during cooling process was carried out for the bulk amorphous alloy based on the measurement and analysis of the thermo-physical properties obtained. A wedge casting for the bulk amorphous alloy was used to verify the numerical simulation results. Cooling rate obtained for bulk amorphous Zr 41Ti 41Ni 10Cu 12.5 Be 22.5 alloy in water cooled copper mold can be predicted by using numerical simulation and correlated with the amorphous characteristics.关键词：Bulk Amorphous Alloy;Thermo-physical Properties;Numerical Simulation
- 2
- |
- 370
- |
- 4
发布时间：2023-12-18 - 摘要：According to the characteristics of thermal exchange, various types of cooling interface in low pressure die-casting were approximately classified into 3 types. Aimed to the individual type, taking account of its parameters of the cooling medium and pipeline, the corrsponding calculating model was established. Simulation for actual casting was performed by developed calculating program.关键词：Low Pressure Die-casting;Temperature Field Simulation;Boundary Conditions
- 2
- |
- 142
- |
- 1
发布时间：2023-12-18 - 摘要：The development of infiltration technique with ceramic material preform was described. The various types of infiltration techniques and its influence on microstructure and properties of composites were emphatically discussed from the view point of infiltration mechanism and techniques.关键词：Ceramic Materials;Preform;Infiltration
- 2
- |
- 150
- |
- 3
发布时间：2023-12-18 - 摘要：A available divided coding system was provided on the basis of structural features of the workpiece and die in squeezing casting. The detailed code of the typical workpiece and its die was given and programmed through the computer. The results showed that the coding system has better effect with expected purpose in actual run and can provide a reference for coding of other type of die..关键词：Squeezing Casting;Coding;Die;CAD/CAE
- 2
- |
- 73
- |
- 4
发布时间：2023-12-18 - 摘要：Lubrication mechanism of emulsion coating for die-casting die can be as sumed that a large portion of the lubricants has been thermo-decomposed into gaseous state to form consistent and proper gas-gap between die and liquid metal during die-casting process. Because lubricant layer consists of released gas and residual lubricant, the evolved gas features and friction coefficient of the lubricant at high temperature are the key factors controlling emulsion die-coating. Friction coefficient at high temperature plays an important role for die-casting in the beginning of process, and then gaseous lubrication controls the whole die casting process. It is necessary to add high heat resistant component to the coating to ensure consistent and stable release of the gas in the whole process for large aluminum alloy and Mg alloy casting.关键词：Die-casting Die;Coating;Emulsion;Gaseous Lubricantion
- 2
- |
- 132
- |
- 3
发布时间：2023-12-18 - 摘要：Mold filling smoothly with low speed and large flow rate as well as instant pressurization in time conformed to the basic principles of squeezing casting.The lower specific pressure and delay pressurization in time during casting process were responsible for surface blister and cold shut of motor cycle wheel in squeezing casting. An available chamber design is presented to prevent squeezing casting from creation of shrinkage crack and shrinkage hole as well as to elevate specific pressure.关键词：Squeezing Casting;Pressurization;Surface Blister;Cold Shut;Shrinkage Crack
- 2
- |
- 719
- |
- 12
发布时间：2023-12-18 - 摘要：A die casting aluminum alloy with better machinabihty was developed by addition of （0.5～1.5）% Cu, （0.4～0.7）% Mg, （0.1～0.3）%Pb and （0.1～0.3）% Bi weight percent to conventional eutectic ZL102 alloy. There appeared CuAl2 and Mg2Si strengthening phase and granular eutectic silicon in the alloy performance tests were conducted for the developed die casting Al-al-loy and conventional eutectic ZL102 Al alloy. The results showed that the die casting aluminum alloy with better machinability not only met the requirements of die casting process but also exhibited excellent machinability. Also the tensile strength of the developed alloy was higher by 14.16% compared to Z1102 alloy.关键词：Machining;Die Casting;Aluminum Alloy
- 2
- |
- 300
- |
- 5
发布时间：2023-12-18 - 摘要：According to the symmetric structure reletive to the Al-Fan center, an intake of Al-melt was designed from the rotating center.Moreover,considering the direction of gas release consistent with the direction of Al-melt filling the casting technology in chill design and location were unproved for favorable gas release and feeding.
- 2
- |
- 96
- |
- 1
发布时间：2023-12-18 - 摘要：Constructive equation among running flow rate Q and static pressure head △p, outlet height of liquid aluminum /（ h） as well as dropped height of liquid aluminum in crucible g （h） was established by measuring process variables of imported electromagnetic pump in low pressure casting combined with Origin software for data handling and with mathematical analysis.The relative error between calculated results with the contractive equation for flow rate of electromagnetic pump and test results stood up to 7%关键词：Aluminum Alloy;Electromagnetic Pump in Low Pressure Casting;Calculation of the Flow Rate
- 2
- |
- 173
- |
- 5
发布时间：2023-12-18 -
- 摘要：Present status of dimensional accuracy of investment castings in China and gap of some related standards between China and foreign countries were introduced from objective point of view. Various factors influencing dimensional stability and key links influencing the assignment of the tooling allowance for the castings were expounded. It is emphasized to establish rational dimensional measuring system.关键词：Investment Castings;Dimensional Stability;Dimensional Accuracy;Tooling Allowance
- 2
- |
- 315
- |
- 6
发布时间：2023-12-18 - 摘要：Surface roughness and dimensional accuracy reach up to Ra 6.3～3.2 and CT6 ～ CT5 respectively for the casting obtained by compound casting process substitutive for conventional process based on analysis of wax pattern making and shell making process in investment casting. At present, the developed compound technology has been used for over 69 kinds of precision castings free from machining in investment casting. Developed compound technology contained the adjustment of wax-ethyl silicate pattern component, increase in the pressure for wax pressurization and use of silicate sol-sodium silicate compound technology for mold shell making.关键词：Investment Casting;Compound Mold Shell;Refractory;Binder
- 2
- |
- 266
- |
- 5
发布时间：2023-12-18 - 摘要：The dimensional measurement for long arm shaped symmetric part in EPC found that the contractive rate greatly depended on the pouring variance. The contractive rates on both sides in symmetric part were basically of the same for horizontal pouring while of extreme difference for vertical pouring. The reason for contractive nonuniformity was analyzed and scheme for the part of this type was performed.关键词：LFC;Long Arm Symmetric Shaped Casting;Contractive Nonuniformity
- 2
- |
- 72
- |
- 0
发布时间：2023-12-18 - 摘要：Calculation of heat distribution was conducted for hollow camshaft based on experimentally measuring temperature field during mold filling in EPC. The results showed that main loss of heat in mold filling was used to heat sand mold and steel pipe. Misrun in hollow camshaft can be avoided by adopting steel pipe with thin wall and increasing pouring temperature, which was identical with the experimental verification.关键词：EPC;Hollow Camshaft;Mold Filling
- 2
- |
- 44
- |
- 1
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