最新刊期
卷 ， 期 12 ， 2005
- 摘要：The rod Cu 50Zr 42Al8 bulk amorphous alloys with smooth surface and typical metal lightness were successfully prepared by copper-mold suction casting combining with magnetic-suspending melting method.The maximum diameter of prepared rod Cu 50Zr 42Al8 bulk amorphous alloys is less than 5 mm under the above experimental conditions.Cu 50Zr 42Al8 bulk amorphous alloys have excellent glass-forming ability with glass transition temperature （Tg） 723 K,crystallization temperature （Tx） 773 K,supercooled temperature 50 K and reduced glass transition temperature （T rg） 0.753.关键词：Cu-based Bulk Amorphous Alloys;Glass-Forming Ability;Cu Mold
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发布时间：2023-12-18 - 摘要：A coupled macro-microcosmic model （direct difference -cellular automaton model,namely CA-DD model） was built up to simulate the competitive growth process of crystal in heated mould continuous casting based on macro-microcosmic coupling method.The effects of processing parameters on the liquid-solid interface morphology and crystal competitive growth were investigated also.The results indicate that macro-microcosmic coupling method is efficient and feasible for simulating the microstructure evolution and effects of variables on microstructure formation.关键词：Heated Mould Continuous Casting;Microstructure;Cellular Automaton;Numerical Simulation
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发布时间：2023-12-18 - 摘要：The microstructure characteristic of Al-Ti-C master alloy prepared by liquid-solid reaction method were investigated by SEM,XRD,EPA.Combining with thermo-dynamics approached the nucleation and fading mechanism of TiC particle.The experimental results show that the nucleation mechanism of TiC is that Ti atoms diffuse in certain mechanism onto the surface of TiC particles to form rich Ti layer near to the chemical composition of TiAl3,meanwhile,α-Al phase is formed by the peritectic reaction of TiAl3 and adjacent liquid Al during solidification.The refinement effect fading is resulted from the diffusion of C from TiC to liquid Al leading to the decrease of stability and the transformation of TiC to Al4C3 to result in the mismatch of α-Al lattice.关键词：Al-Ti-C Master Alloy;α-Al Nucleation Mechanism;Fading Mechanism
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发布时间：2023-12-18 - 摘要：The influence of CeCl3 on the kinetic process,composition,structure and property of aluminizing on the surface of pure copper was investigated.The activation energy of aluminizing is calculated by determining the aluminum depth on pure copper at different temperatures and times by means of Akinwosi equation for the research of aluminizing layer formation mechanism.The Cu-Al2O3 composites was prepared by using residual oxygen in commercial N2 gas to conduct internal oxidation.Aluminizing agent with CeCl3 can not only possess obvious aluminizing effects but also improve the aluminizing speed.Dispersive nano-Al2O3 particle can be uniformly distributed in the internal oxidized Cu matrix.关键词：Pure Copper;Aluminizing;Internal Oxidation;Activation Energy
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发布时间：2023-12-18 - 摘要：The experiments from the Mg alloy with different Mg contents show that the microstructure of as-cast AE41 alloy is characterized by classical dendrite,composed of α-Mg matrix and some acicular compound Al 11RE3.A little Ca addition can refine the microstructure of the alloy and result in the formation of thermo-stable phase Al2Ca.Al2Ca phase has two morphologies:one is lamellar distributed along grain boundaries and another is granular existed within the matrix grain.The yield strength at ambient and high temperature and elevated instantaneous tensile strength of the alloys were improved while the plasticity was decreased with the Ca addition.关键词：Mg Alloy;Ca;Microstructure;Mechanical Strength
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发布时间：2023-12-18 - 摘要：The main techniques of die casting die CAD/CAE/CAM integrated technology and its implementing route were introduced.The practical application verify that integrated CAD/CAE/CAM can be effectively used to design die casting die and analyze manufacturing process,and improve the feasibility,actuality and machining precision of die structure,serving for the practical product.关键词：Die Casting Die;CAD/CAE/CAM;Integrated Technology
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发布时间：2023-12-18 - 摘要：The dendrite evolution and micro-segregation based on mechanism of solute diffusion controlling interfacial growth is simulated by cellular automaton.The simulated results show that using the method can not only reveal dendrite morphology and micro-segregation but also represent the recalescence phenomenon.It is found that although the simulated dendrite tip radius is well in agreement with the theoretical radius,there are some fluctuations.Through analyzing the simulated results,it is the rules of cellular automaton discreting the continuous process of dendrite into a discrete growth process,resulting in the appearing wave in simulated results.关键词：Numerical Simulation;Dendrite;Cellular Automaton;Micro-segregation
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发布时间：2023-12-18 - 摘要：It is very important for saving to realize sustainable development of foundry industry at home.The challenge and existing problems in developing economical and recycling economics for foundry industry were expounded.Some suggestions,including building up law safeguard,adopting energy-reduction technology means,for developing saving-recycling economics for foundry industry were given.关键词：Saving;Foundry Industry;Recycling Economics;Resource;Sustainable Development
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发布时间：2023-12-18 - 摘要：Development status of contact wire at home and abroad and requirement of modern high-speed electrical railways on contact wire as well as the interesting research field were reviewed.The future tendency on contact wire includes the development and preparation multi-micro-alloying and compound contact wire as well as innovative owned-processing technology.关键词：Copper Alloy;Contact Wire;High Strength;High Conductivity
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发布时间：2023-12-18 - 摘要：Rapid prototyping is a high-novel technology developed since 1 990 s,which can make the designed idea rapidly transform real product,especially it need not anything tools and equipments,significantly shortening trial time of samples and new product and increasingly becoming a key means for improving enterprise competitivity.93% in four hundreds of investment casting plants for the European has utilized the rapid prototyping pattern.All acknowledged that it is very important to promote the development of new product and improve the fast responsible ability to market by using the technology.KeyWords: Rapid Prototyping,Investment Casting,Wax Pattern关键词：Rapid Prototyping;Investment Casting;Wax Pattern
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发布时间：2023-12-18 - 摘要：Effects of trace alloying element RE,Ti and different heat treatment methodes on microstructure of high-strength bainite casting steel in investment casting were researched.The results show that although bainite casting steel in investment casting possesses coarse microstructure,the microstructure of the bainite casting steel can be effectively refined through adding 0.06% RE and trace Ti alloying and quenching as well as high temperature tempering before normalizing or normalizing treatment at austenitizing temperature 1 000 ℃.The mechanism of refining microstructure by trace-alloying and heat treatment was analyzed.关键词：Bainite Cast Steel;Investment Casting;Trace-alloying;Heat Treatment
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发布时间：2023-12-18 - 摘要：The semi-solid hypereutectic Al-20Si alloys have been prepared by electromagnetic stirring,modification and combination action,respectively.The effects of combination action of electromagnetic stirring and modification on growth and morphology of primary Si in hypereutectic Al-20Si alloy were observed.The results show that compared with that of by modification and electromagnetic stirring,the microstructure of primary Si in hypereutectic Al-20Si alloy prepared by combination means is finer and more roundness,decreased by 25.19 % in average grain size and increased by 8.40 % in average roundness,meanwhile,microstructure of eutectic Si can be spheroidized.The mechanism of combination refinement is revealed that applied rotating magnetic field after modification has promoted the diffusion of modifier to make the mutual destruct between more primary Si and eutectic Si structure,enhancing the effects of modification and electromagnetic stirring and refining microstructure.关键词：Hypereutectic Al-Si Alloy;Electromagnetic Stirring;Primary Si;Modification;Combination Action
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发布时间：2023-12-18 - 摘要：Using equal channel angular extrusion and semi-solid isothermal treatment,metalloscope and SEM,microstructure evolution of AZ91D Mg alloy extruded by ECAE was described during semi-solid isothermal treatment.Based on the results,new SIMA method is put forward to prepare AZ91D semi-solid billet.Microstructure of semi-solid billets prepared by new SIMA method is very homogeneous,in which fine and globular grain with the grain size in the range of 20～50 μm occurs.With increasing holding time,growing phenomenon occurs in the microstructure of the semi-solid billets,which can be described by Ostwald opening law.With the increase of isothermal treatment temperature,grain size firstly is increased then decreased,and its shape factor approached to one.With increasing in equivalent strain obtained by ECAE,grain size is decreased.关键词：AZ91D Mg Alloy;Semi-solid Billet;New SIMA;Microstructure
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发布时间：2023-12-18 - 摘要：The die with one mould and one cavity was designed based on the geometry size and structure of the components.Component end face is not used as the optimal parting face.Ring pouring channel was set for pouring position.Ladder-like horizontal gate was designed for horizontal gate.Section area of ingate was calculated by the equation.The die with oblique side of guide pillar to take out core and release link was designed to take off mould smoothly.The casting shape and surface quality can meet the requirement of the drawing using the die.关键词：Parting Face;Gating System;Die Casting Machine;Mould Structure
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发布时间：2023-12-18 - 摘要：The factors influencing the service life of punch for die casting and the countermeasures are described ,especially the material selection of the punch and the measures of improving the quality of the beryllium-copper products.The elongation of beryllium-copper can be obviously improved by vacuum smelting and adding 0.2RE Nd,increased by 9% from 2%～5% for high beryllium-copper containing 1.9%～2.0% beryllium and 19% from 8%～13% for low beryllium-copper containing 0.45%～0.55%.Compared with that of the nodular iron punch,the service life of the low beryllium-copper punch and high beryllium-copper punch is increased by 5 times and 10 times,respectively,showing excellent comprehensive benefit.关键词：Die Casting;Punch;Beryllium-copper;Toughness
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发布时间：2023-12-18 - 摘要：Origination of casting defects in aluminum alloy motorcycle damping cylinder in metal mould casting was analyzed.The blister and inclusion can be obviously reduced by strictly carrying out the smelting of melt liquid,removing the floating dregs and oxide film on liquid surface promptly,enhancing the gas elimination from permanent mold and controlling the pouring velocity.Proper decreasing the thickness of hot spot of casting or using local cooling method can eliminate the shrinkage porosity tendency.To eliminate the transverse crack in castings,it is necessary to strictly control the impurities in chemical composition and drawing core time as well as stayed time of castings in mould.Above mentioned counter-measures have been verified through practical production,showing good effects.关键词：Aluminum Alloy;Damping Cylinder;Casting Defects;Permanent Mold
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发布时间：2023-12-18 -
- 摘要：Effects of section-ratio of gating system on the quality of aluminum alloy castings in lost foam casting were investigated.The proper section-ratio of gating system can be determined.The experimental results show that the aluminum alloy castings in lost foam casting should adopt open-gating system.For gating system with two unites,its sectional ratio is ∑F sprue∶∑F ingate=1.00∶ （1.30～1.50）.关键词：Lost Foam Casting;Aluminum Alloy;Gating System;Castings
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发布时间：2023-12-18 - 摘要：MgO particle reinforced Cu matrix composites were prepared by stirring-casting method.The microstructure and mechanical properties of the composites were observed and measured by OM and SEM,meanwhile,the phase constituent of the composites was analyzed by X ray.The results show that the strength,hardness of the composites is greatly increased while the electric conductivity is decreased with increase the MgO addition,and strength of the composites is remarkably deteriorated with the MgO addition over a certain value.The strength,electric conductivity and soften temperature of composites is 520 MPa,53.5 MS/m and over 800 ℃,respectively with the 1% MgO addition,showing excellent comprehensive properties.关键词：MgO;Cu Matrix Composites;Electric Conductivity;Casting Method
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发布时间：2023-12-18 - 摘要：The effects of some micro-alloying elements,including Ag,Si,Ge,Cd,on ageing behavior of Al-Cu-Mg alloy were analyzed by examining the influence of micro-alloying elements on precipitated phase in conventional ageing treated Al-Cu-Mg alloy.The results show that the micro-alloying elements play roles on the alloy as follows: one is to fully change the structure of traditional precipitated phase to form a new precipitated phase; two is to partially change the precipitated phase structure to improve the enhancing effects of precipitated phase; three is to promote the precipitation of precipitated phase.The problems in improving thermo-strength of the Al-Cu-Mg alloy by micro-alloying,and the future tendency were proposed.关键词：Al-Cu-Mg Alloy;Ageing Strengthening;Mismatch;Thermo-stability;Co-clustering
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发布时间：2023-12-18 - 摘要：Primary silicon in the solidification structure of Al-18Si hypereutectic alloy concentrated on the edge of the sample,in which some appears to be coarse plates and strips,and the eutectic structure appeared in the center of the sample without the static magnetic field.The bulky uneven primary Si in size and distribution was distributed into the whole section of the sample with radius static magnetic field.Furthermore,imposing radius static magnetic field and adding P modifier can obtain bulky and finer primary Si with even size and distribution.关键词：Static Magnetic Field;Modification;Primary Si;Eutectic Structure
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发布时间：2023-12-18 - 摘要：BFe30-1-1 tubes with outer diameter 10 mm and thickness 2 mm have been cast by horizontal heated mold continuous casting.The tubes with smooth and straight surface and compact microstructure can be obtained with liquid surface height 30 mm,mould temperature 1 250 ℃ and cooling distance 6 mm,drawing velocity at 30 mm/min.The tubes possess column dendrite structure,whose tensile strength and elongation are 350 MPa and 65%,respectively.Meanwhile,the micro-segregation resulting from Ni,Fe,Mn can be greatly decreased.The corrosion resistance to sea water of the tubes in longitude direction is superior to the semi-continuous ones while in transverse direction,the corrosion resistance is inferior to the semi-continuous ones.关键词：Cupronickel Tube;Heated Mold Continuous Casting;Segregation;Sea Water Corrosion
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发布时间：2023-12-18 - 摘要：Although P can deoxidize the Cu materials in continuous casting,it can greatly affect the quality of continuous casting Cu billets.The effects of P-Cu addition on the deoxidization and microstructure behavior as well as surface quality of Cu billets in up-drawing continuous casting were investigated.The results show that a certain P addition take a better deoxidization,meanwhile deteriorate the as-cast grain structure.With the P addition at a certain extent,the mechanical properties of the Cu billets can be improved and the working plasticity can be slightly decreased.With P addition more than 0.15%,the surface roughness is increased.The mechanical properties and processing performance of the billets is decreased with increase in P-Cu addition.It is difficult to take up-drawing,more even resulting in the occurrence of the drawing-out with the P addition more than 0.45%.So,proper P addition can better deoxidize the Cu materials and improve mechanical properties and machining performance.关键词：P-Cu Alloy;Addition;Up-drawing Continuous Casting Cu Billets
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发布时间：2023-12-18 -
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