最新刊期
卷 ， 期 3 ， 2008
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- 摘要：Effects of temperature in range of 780 ℃ to 1 080 ℃ on the flow stress of the TC11 alloy have been tested by the Thermecmaster-Z thermo-analogue machine with strain rates of 10 s-1 and 70 s-1and on the microstructure have been observed.The results reveal that the steady flow characteristics can be observed during hot compressive deformation of TC11 alloy with the temperature in range of 990 ℃ to1 080 ℃,while the flow softening characteristics can be exhibited with the temperature in range of 780 ℃ to 960 ℃ at strain rates of 10 s-1 and 70 s-1.The microstructure observation shows that the TC11 alloy deformed in α+β phase zone exhibits adiabatic shearing or partial flow with temperature less than 900 ℃ at strain rates of 10 s-1 and 70 s-1.The microstructure of the alloy deformed in β phase zone consists of elongated β grain and minor dynamic recrystallization grain and show boundary deformation,which results in the mechanical instability of β phase.关键词：TC11 Alloy;Temperature;Flow Stress;Microstructures
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发布时间：2023-12-18 - 摘要：The effects of Ce and Sn addition on microstructure of AZ91 magnesium alloy have been described.It is found that the grain size in the microstructure can be obviously refined with Ce addition,and rod-like Al-Ce compound can be observed.The Al-Ce phase in the matrix gradually grows and is aggregated with the Ce addition more than 0.6%,resulting in the fading of reining effects.Long rod-like Al-Cu phase can be further refined and diespersively distributed into the AZ91-0.6Ce alloy with Sn addition.The refining effects of Ce and Sn mixed addition are superior to those of Ce addition only in T4 treated Alloy,in which the grain size is decreased from 150200μm to 6080μm with 0.6% Ce and 0.3%0.5%Sn mixed addition.关键词：Ce;Sn;AZ91 Alloy;Microstructure
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发布时间：2023-12-18 -
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- 摘要：Effects of rare earth element on growth of primary α phase in ZL101 alloy were described based on thermodynamics and kinetics.The results indicate that the Re can promote the spherodization of α phase due to affecting the interface condition between α phase and liquid phase during growth process,refining the grain size of α phase,and an optimal Re addition with 0.5% can be observed.关键词：Semi-solid;Al-Si Alloy;Solidification;RE
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发布时间：2023-12-18 - 摘要：The effects of different Ca contents including 0 and 0.3% on microstructure and mechanical properties of the wrought magnesium alloy sheets with 1 mm in thickness which was prepared from cast magnesium alloy ingots followed by homogenization and hotrolling were investigated by the OM（optical microscope）,SEM（scanning electron microscope）and standard universal testing machine.It is indicated that the anisotropy of mechanical properties of the alloy sheets can be obviously improved as a result of the increase of homogenization of microstructure with Ca addition,which decreases the difference of tensile strength and elongation of the alloy in different direction,especially increasing the strength and elongation of the alloy at 45°to the rolling direction.The tensile strength,yield strength and elongation of rolled alloy sheet are 292.7 MPa,200.1 MPa and 9.2%,respectively,compared with those of the alloy without Ca,increased by 25.25%,43.75% and 24.32%,respectively.In addition,the reduction of magnesium alloy with Ca（the rolling reduction was fixed as 50% per pass）reaches 33.8% at 350 ℃,increased by 10%.关键词：Ca;Magnesium Alloy;Rolling;Microstructure;Mechanical Properties
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发布时间：2023-12-18 - 摘要：Solidification structures of hypereutectic Pb-45Sn alloy and hypoeutectic Pb-64Sn in rotating magnetic field with different rotating velocity and magnetic flux density were observed based on a self-designed rotating magnetic field apparatus,and were compared with those of alloy in conventional condition.The results reveal that the rotating magnetic fileld can greatly refine grain size in the hypereutectic Pb-45Sn alloy due to broken dendrite while it can coarsen the eutectic structure in inter-dendrite with the creation of bulk structure due to suppressing the gravity-induced macro-segregation.In addition,with the increase of both magnetic flux density and rotating velocity,the numbers of equiaxed grain in solidification structure of both hypereutectic Pb-45Sn alloy and hypoeutectic Pb-64Sn alloy are increased.关键词：Rotating Magnetic Field;Pb-Sn Alloy;Flow;Dendrite Fragmentation
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发布时间：2023-12-18 - 摘要：The effects of Amper·coil,slit numbers,alloy and coil position on meniscus height in induction solidified shell melting was simulated by a numerical model.The results reveal that the meniscus height linearly increases with increasing in Amper·coil value,where the meniscus height is increased by 4.2 mm with increasing 1 000 A·coil.Meanwhile,the meniscus height is proportional to slit numbers in the mold with the silt numbers less than 40,in which the meniscus height is increased by 0.6 mm with increasing one slit number,while it is slowly increased with increasing slit numbers when the slit number is more than 40.In addition,the meniscus height increases with the decrease of relative magnetic induction density of the alloy,and it is decreased with the increase of the alloy density.So the meniscus height of Ti-48Al-2Cr alloy melt is the highest in the three alloys.关键词：Induction Solidified Shell Melting;Meniscus;Numerical Simulation
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发布时间：2023-12-18 - 摘要：When it is applied in the PLC-based control system for low pressure casting,the PID function in S7-200 PLC which was produced by the Siemens,not only has the advantages of good static performance,no steady-state error,but also has the disadvantages of poor dynamic response and being easy to overshoot.By fuzzification for error and error change during the control progress,the fuzzy-PID algorithm,which could adjust three parameters KP,KI and KD in PID algorithm online,was established.The new control algorithm was realized in PLC by indirect addressing.The production application shows that it exhibits desirable controlling effects.关键词：Low Pressure Casting;Fuzzy Control;PID;PLC
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- 466
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发布时间：2023-12-18 - 摘要：Effects of crucible with different sizes and straight pipe on microstructure of semi-solid feedstock prepared by straight pipe pouring have been observed at different temperatures.It is found that the cooling capacity of straight pipe has some effects on microstructure of feedstock.In addition,the straight pipe has different effects on the feedstock with different size,in which the effects on microstructure of the billet with large size are higher.The desirable microstructure can be prepared by straight pipe pouring with cooling at room or water cooling for the feedstock with 80 mm in diameters and 150 mm in length,however,the microstructure is deteriorated with the pouring temperature more than 200 ℃.Although the feedstock with sound microstructure can be prepared by straight pipe pouring with cooling at room or water cooling for the billets with 98 mm in diameters and 150 mm in length,the microstructure of the semi-solid billets at water cooling is obviously superior to that of ones at room.关键词：Semi-solid;Straight Pipe;!Microstructure;Crucible Size;Cooling Capacity
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- 153
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发布时间：2023-12-18 - 摘要：The microstructure of reheated semi-solid A357 alloy billets in die casting was systematically analyzed by the quantitative method to understand the evolution and filling behavior of primary α phase.The results indicate that the primary α phase is coalesced and grown and spheroidized during reheating process with the increase of temperature and time.Coarse primary α phase is aggregated at the corner and at pouring position during filling process,while fine primary α phase appeares in the place with much liquid phase.关键词：Primary Phase;Grain Coalesce;Reheating;Semi-solid Forming;A357 Alloy.
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发布时间：2023-12-18 - 摘要：Based on the practical experiences in squeezing casting aluminum alloy,some key factors in whole processing procedures were proposed according to equipment structure and parts features.The available suggestions were proposed.In squeezing casting,the pouring temperature should be higher than that in common die casting,and the elemental Si,Mg,Cu and Fe content in liquid aluminum alloy should be strictly controlled,and the wider section area of ingate and shorter sprue should be adopted.In addition,the shift position of injection velocity from filling sprue to fill cavity as well as to high velocity filling should be strictly set,and the exhausted and dross design with larger channel should be adopted.Some bottleneck problems in the squeezing casting industry at domestic were discussed,and the future development was suggested.关键词：Aluminum Alloy;Squeezing Casting;Casting;Die Casting
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- 387
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发布时间：2023-12-18 - 摘要：The design process and key procedure of die casting die for throttle were described based on its structure features and technical requirements.The processing of throttle,the determination of parting surface and ingate position and the selection of die casting machine were paid attention to.关键词：Throttle;Die Casting Die;Pro/E Software
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发布时间：2023-12-18 - 摘要：The Cu-Al2O3 composites were prepared by a simplified internal oxidation method combining with hot extrusion.Effects of hot extrusion on microstructure,hardness,tensile strength and electric conductivity of the composites have been examined.The results show that the microstructure of the hot extruded composites can be refined with more homogeneous.The pore defects in the composites are decreased,which leads to the densification of the composites with density of 8.82 g/cm3.The hardness,tensile strength and electric conductivity of the hot extruded composites reach up to 111HV,242 MPa,41.76 S/m,respectively.The fracture morphology observation reveals that the fractures of both sintered and hot extruded composites are characterized by dimple aggregation crack,in which the hot extrusion can improve the ductility of sintered composites.关键词：Cu-Al2O3 Composites;Internal Oxidation;Hot Extrusion;Sintering;Microstructure
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发布时间：2023-12-18 - 摘要：The wear resistance of specimens with smooth and non-smooth surface was compared by processing the striate and reticulate non-smooth surfaces in different distributing distance on the 3Cr2W8V tool steel with laser treatment.The results show that the wear resistance of processed non-smooth surfaces is obviously superior to that of un-treated smooth surface.In addition,the wear resistance of reticulate non-smooth surface of the specimens is superior to that of striate ones.Furthermore,the wear resistance is improved with the decrease of distributed distance of non-smooth unit.The practical production verifies that the wear resistance and service life of the die casting die for cover lid of engine are significantly improved.关键词：Die;Laser Treatment;Wear Resistance
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发布时间：2023-12-18 - 摘要：The quantitative relationship between porosity caused by en-trapped gas and mechanical properties of ADC12 alloy has been calculated.The ADC12 plate castings were produced with different injection velocity.The mechanical properties of the samples cut from different position in the plate castings were tested.The volumetric fractions and maximum size of porosities induced by entrapped gas were quantitatively measured by the Arkimeters and image quantitative system to understand the effects on the mechanical properties of the castings.The quantitative relationship between mechanical properties including tensile strength and elongation and porosity fraction as well as maximum size of ADC12 die castings was proposed by the multivarient linear regression method.It was found that the fraction and maximum size of porosities should be controlled less than 4.3% and 180μm in the ADC12 die castings,respectively.关键词：ADC12 Alloy;Plate Castings;Porosity;Mechanical Properties;Multivarient Linear Regression
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- 443
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发布时间：2023-12-18 - 摘要：Production of cast steel box by rapid prototpe PC was conducted.The processing procedure of prototype making by rapid prototype and the production process of cast steel box without wax pattern in investment casting were described.The RP can greatly shorten the design and production period as well as improving the first successful rate of design and production,decreasing the developing cost.The practical production verifies that it has a desirable effect.关键词：RP（Rapid Prototype）;Investment Casting;Pattern;Vacuum Pouring
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发布时间：2023-12-18 - 摘要：The processing design,processing parameters and technical control of heavy machine tool in full mold were described.The forming processing,pouring and some defects as well as countermeasures during production were paid attention to.关键词：Full Mold;Machine Tool;Design
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发布时间：2023-12-18 - 摘要：The filling process of molten metal in lost foam casting was simulated to analyze the effects of pattern density on filling behavior by establishing boundary of free surface heat-exchange and pressure boundary condition according to the difference of filling behavior in lost foam casting and in green sand casting.The simulated results reveal that the liquid metal is filled radially into the cavity from the ingate with smooth process,and the cascading tendency of molten metal in the mold is controlled by the relative values of the pressure of the vaporized pattern to the gravity.Furthermore,the potential defect in the casting was visualized,which provided a reference to optimize filling process of design to check up to re-design in CAD.关键词：Lost Foam Casting;Filling Behavior;Numerical Simulation;CAD for Casting Process
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发布时间：2023-12-18 - 摘要：Production of aluminum alloy housing by fine-hole casting was described,focusing on the production process,defects and countermeasures as well as the checking measures.关键词：Fine-hole Casting;Fine-hole Core;Core Bracket;Residual Copper
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- 146
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发布时间：2023-12-18 - 摘要：Hot compression testing of Mg-Y-Nd-Gd-Zr magnesium alloy RE-containing was performed on the Gleeble 1 500 at strain rate in range of 0.002 to 1 s-1 and temperature from 250 to 450 ℃ with the deformation degree of 50%.The steady flow stress during hot deformation was calculated by the exponential equation.Processing map of the alloy was established on the basis of dynamic material model.Microstructural observation indicate that the peak value of dissipation factor is 0.36 at 400 ℃ and 1s-1,which shows that the domain at the medium temperature and high strain rate is the desirable processing performance area.In addition,the working processing of more pass with small reduction rate is helpful to obtaining a larger region of desirable processing performance.关键词：Mg-Y-Nd-Gd-Zr Magnesium Alloy RE-containing;Flow Stress;Hot Deformation;Processing Map
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发布时间：2023-12-18 - 摘要：The effects of different Si content,including 1.0%,1.1%.1.3%.and 1.5%,on hot crack and mechanical properties as well as microstructure of 6082 alloy have been investigated,in which the microstructures of the alloys have been observed by OM（optical microscope）and SEM（scanning electron microscope）.The results reveal that the eutectic phase in grain boundary of the alloys with decreasing in hot crack tendency is increased with increasing in Si content.Meanwhile,the hardness and tensile strength of alloy with the reduction of elongation are increased.关键词：6082 Alloy;Hot Crack;Mechanical Properties
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发布时间：2023-12-18 - 摘要：Effects of Nd addition including 0,1%,2%,3%,on microstructure and ambient and elevated mechanical properties of the Mg-4Al-1S alloy have been investigated.It is found that the mechanical properties of the alloy with Nd addition can be significantly improved as a result of the refinement of grain size and creation of acicular high melting point Al11Nd3 phase.The ambient and elevated tensile strength of the alloy reaches 206 MPa and 138 MPa,respectively,with 2.0% Nd addition,compared with that of alloy without Nd addition,increased by 20% and 14%,respectively.With the further increase of Nd addition,the mechanical properties of the alloy are deteriorated due to the creation of bulk Al2Nd phase in the alloy.关键词：Magnesium Alloy;Nd;Microstructure;Mechanical Properties
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发布时间：2023-12-18 - 摘要：As-cast microstructure of AM60 magnesium alloy with different Ti content was observed by OM（optical microscope）,XRD（X-ray diffraction meter）and SEM（scanning electron microscope）and ambient tensile strength of the alloy was measured.The results reveal that the minor Ti addition can remarkably refine the as-cast microstructure of AM60 magnesium alloy.The desirable refinement effect with uniformly distributed fine second phase can be observed with 0.2% Ti addition,in which the semi-continuous β-Mg17Al12 distributed along grain boundary was converted into particle and dispersively distributed TiAl3 particle can be created in α-Mg phase,obtaining the highest tensile strength and elongation.When Ti addition is more than 0.2%,the tensile strength and elongation of the alloy are decreased with increasing in Ti addition as a result of the coarsenization of β-Mg17Al12 and α-Mg phase,and are superior to those of AM60 magnesium without Ti.The improvement of mechanical properties of AM60 magnesium alloy is attributed to Ti addition refining grain size and β-Mg17Al12 phase in the alloy as well as formed TiAl3 phase distributed into the matrix and secondary phase to strengthen the alloy.关键词：AM60 Magnesium Alloy;Ti Alloy;Microstructure;Mechanical Properties
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发布时间：2023-12-18 - 摘要：The effects of melt flow on the solidification behavior were investigated by measuring the flow velocity along pulling-direction based on the flow simulation of mercury in mold of horizontal continuous casting thin-slab with electromagnetic stirring.The horizontal continuous casting copper thin-slab was produced on the basis of the mentioned results.The results reveal that electromagnetic stirring can reduce and eliminate the gas hole in the copper thin-slab and decrease the average segregation degree with the refinement of columnar grain and the existence of equiaxed grain region in center of the thin-slab,realizing the columnar-equiaxed grain transition in the horizontal continuous casting copper thin-slab.关键词：Thin-slab;Horizontal Continuous Casting;Electromagnetic Stirring;Flow;Solidification
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发布时间：2023-12-18 - 摘要：Corrosion behavior of as-cast and spray formed ZA35 alloy containing 3.5% Mn was observed in 3.5% NaCl salt spray atmosphere.The results indicate that the corrosion dynamic curves of spray formed alloy are accordant with the parabola curves,and the corrosion rate is remarkably slower than that of as-cast alloy which is accordant with linear dynamics.The corrosion mechanism is attributed to the prefer dissolution of η phase.The existence of amounts of lamellar MnAl6 phase provides a rapid channel for η phase dissolution in as-cast ZA35 alloy,resulting in the acceleration of corrosion,while Mn in the spray formed is totally solved,which decreases the potential difference between η phase and α phase,relieving the corrosion behavior.关键词：Spray Forming;ZA35-3.5Mn Alloy;MnAl6;Salt Spray Corrosion Behavior
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发布时间：2023-12-18 - 摘要：The hot deformation behavior and microstructure of the Cu-Se-Bi alloy were investigated by thermal compression with Gleeble-1500 machine with the deformed temperature in range of 550 ℃ to 700 ℃ and strain rate at 0.0110 s-1,and the constitutive equation for the hot deformation behavior has been established based on the experimental data.The results reveal that the dynamic recrystallization at high temperature in Cu-Se-Bi alloy can remarkably decrease the flow stress which tends to a constant value with 15%80% deformation rate.The fluctuant of the flow stress can be observed with the strain rate in range of 2.5 s-1 to 10 s-1,in which the maximum fluctuant value of 12 MPa can be observed with strain rate of 10 s-1 and true strain of 0.010.15 at 700 ℃.The recrystallization is increased with the increase of the strain,and the grain size is decreased with the decrease of strain rate.The average grain size of 8.5 μm can be obtained with the strain of 60% and strain rate of 0.01 s-1 at 600 ℃.关键词：Cu-Se-Bi Alloy;Thermal Analogue;Constitutive Equation;Dynamic Recrystallization
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- 104
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发布时间：2023-12-18 - 摘要：The Mg2Si particulate reinforced Mg matrix composites was prepared by in-situ synthesized method with Si as reactive agent.The microstructure of the composites was observed by OM（optical microscope）,XRD（X-ray diffractionmeter）.It is found that microstructure of the composites is composed of α-Mg phase,β-Mg17Al12 phase and Mg2Si reinforcement.The mechanism of in-situ synthesized Mg2Si phase was expounded based on thermodynamics and kinetics,and the kinetic model was established.The results show that the reactive rate of in-situ synthesis is controlled by system temperature,Si particle size and the thickness of diffusion layer.关键词：In-situ Synthesis;Mg2Si;Mg Matrix Composites;Thermodynamics;Kinetics
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发布时间：2023-12-18 - 摘要：The Al-15Mg2Si and Al/15Mg2Si/Al2O3 gradient composites were prepared by introducing SiO2 particle into Al-15Mg2Si alloy in high frequency magnetic field.The effects of SiO2 particle on microstructure and mechanical properties of two kinds of composites were analyzed,and the hardness of the composites in radial was measured.The results indicate that the hardness of the composites in radial exhibits gradient distribution,meeting the demands of the composites with high intensity in outer layer and high flexibility in inner layer.关键词：High Frequency Magnetic Field;Electromagnetic Separation;Hypereutectic Al-15Mg2Si Alloy;Gradient Composites
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发布时间：2023-12-18 -
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