最新刊期
卷 36 ， 期 9 ， 2016
- 摘要：2dimension-continuous carbon fiber reinforced magnesium（2D-Cf/Mg）composites were fabricated by liquid-solid extrusion directly combining with vacuum infiltration technique.The effects of different cooling rate on the carbon fiber,hardness and ultimate tensile strength of Cf/Mg composites were analyzed.The experimental results reveal that a higher cooling rate can reduce the damage of carbon fiber,relief the interface reaction,and improve the ultimate tensile strength（UTS）and hardness of the composites prepared.The tensile strength of 2D-Cf/Mg composites with T700 carbon fiber can reach 450 MPa.关键词：Liquid-solid Extrusion with Vacuum Infiltration Technique;Cooling Rate;Cf/Mg Composites
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发布时间：2023-12-18 - 摘要：Using TLJ400 continuous extrusion machine,and based on Deform-3Dfinite element simulation software,the temperature field,effective stress field and torque of metal continuous extrusion forming process at different wheel angular velocities were analyzed through establishing the numerical simulation model of continuous extrusion for copper magnesium alloy.The results show that with the increase of wheel angular velocity,the deformation temperature of the metal is increased,and the effective strain and the extrusion wheel torque are decreased gradually.关键词：Continuous Extrusion;Copper Magnesium Alloy;Wheel Angular Velocity;Numerical Simulation
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发布时间：2023-12-18 - 摘要：Four design schemes of the head board for 20 000 kN die casting machine were modeled by UG software and simulated by the ANSYS software for the finite element analysis,stiffness verification and strength verification.Based on the results of the analysis and verification,the region of the head board was found,which was vulnerable to crack as the internal stress exceeded over the yield strength of the material.关键词：Die Casting Machine;Head Board;Finite Element Analysis;Stiffness;Strength
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发布时间：2023-12-18 - 摘要：Mg-5Li-3Al-2Zn-2.1Ce alloy was prepared by vacuum casting combined with extrusion deformation.The microstructure of the alloy was analyzed by OM（optical microscopy）,SEM（scanning electron microscopy）,XRD（X-ray diffraction）and EDS（energy dispersed spectrometer）,and the compressive behaviors were tested at 1.67×10-4、1×10-3、5×10-3 and 1×10-2 s-1 at room temperature.The results show that Mg-5Li-3Al-2Zn-2.1Ce alloy is composed ofα-Mg,Al2Ce and Al4Ce phase.The maximum compression strength and the maximum strain of the alloy reach 516.69 MPa and 19%,respectively.At different strain rates,the strain rate sensitivity of the alloy is negative,and there exists a large number of twins in the alloy with high strain rate.The deformation mechanism at low strain rate compression is characterized by the lattice slip coordinated with recrystallization,and the deformation mechanism at high strain rate is characterized by the lattice slip coordinated with twins.关键词：Mg-Li Alloy;Microstructure;Strain Rate Sensitivity;Deformation Mechanism
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发布时间：2023-12-18 - 摘要：The in-situ TiB2/A356 was synthesised successfully to understand effects of different TiB2 addition on the microstructure and mechanical properties of TiB2/A356 composites.The results indicate that with the reinforced TiB2 particles of 150560nm,grain size in the composites is refined obviously,meanwhile,dendrite growth is inhibited.The strength of the composites is increased while elongation is decreased with the increase of TiB2 addition.The yield strength,tensile strength and elongation of TiB2/A356 composites reach 242265 MPa,270297 MPa and 4.2%5.8%,respectively.关键词：In-situ;Composites;Particulate Reinforcements;TiB2 Particles;A356Alloy
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发布时间：2023-12-18 - 摘要：The casting process of sand casting diffuser as the key part of underwater device was simulated by the ProCAST software,and feasibility of casing process was verified.Through calculation of temperature field,the time before the casting solidification completion and a lot of brittleσphase precipitation was determined.Shakeout operation was implemented at this time from pouring completion to the casing cooling in the actual production,eliminating the stress caused by contraction of the blade.So the crack defects were eliminated,and quality of the casting was improved.关键词：Diffuser;Duplex Stainless Steel;Temperature Field;Crack
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发布时间：2023-12-18 - 摘要：Al-5Band Al-7Balloy melts were poured into different moulds（graphite mould,iron mould and sand mould）for solidification to understand influences of cooling rate and stirring on the microstructure evolution of Al-B alloys.The results demonstrate that the average size and width of the size distribution of the boride particles are decreased with the increase of cooling rate.At fixed cooling rate,a boride particle in Al-5Bmaster alloy exhibits serious segregation while it exhibits weak segregation in Al-7Bmaster alloy.Furthermore,effects of stirring on microstructural evolution of Al-B master alloy were described.It also indicates that stirring before casting can prevent effectively the coagulation between the boride particles and inhibit the formation of coarse boride particles,promoting the formation of dispersed microstructure.关键词：Al-B Alloy;Cooling Rate;Stirring;Microstructure
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发布时间：2023-12-18 - 摘要：Recent progress in eutectic silicon modification of Al-Si alloys was summarized,and application status of the main modifier and key factors affecting modification treatment were reviewed,focusing on influences of modifiers on the porosity in castings and the interaction between modifiers and grain refiners.Recently,the research on the widest used Na and Sr series modifiers is concentrated on the mechanism and solutions on porosity increase in castings caused by modification.The cooling rates and alloying elements are two important factors affecting the modification.The method to improving the modification level of eutectic silicon in multi-element Al-Si alloys at a lower cooling rate is still an important research direction.The nature of mutual poisoning effect between Sr andα-Al grain refiners is the reaction between Sr and refinement particles resulting in efficient content reduction of both modifier and grain refiner.By rational control of content of modifier and grain refiner in the melt and the addition technique,the well-modified eutectic silicon and fineα-Al grains can be achieved.In addition,development of novel Al-（Si）-Sr-（Ti）-B master alloy is also an efficient way to avoiding mutual poisoning.关键词：Eutectic Silicon;Modification;Porosity;Cooling Rate;Interaction
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发布时间：2023-12-18 - 摘要：The thin-walled castings of aluminum alloys with characteristic of light-weighting and good mechanical properties have good prospect in producing large complex structure such as vehicle body and automotive chassis.The development of the high pressure die casting thin-walled aluminum alloy parts was reviewed and analyzed,focusing on the applications of the high pressure die casting thin-walled aluminum alloys,aluminum alloy materials and numerical simulation of the HPDC for thin-walled aluminum alloys.关键词：Thin-walled Casting of Aluminum Alloys;High Pressure Die Casting;Integral Casting;Simulation
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发布时间：2023-12-18 - 摘要：Aluminum slag is an unavoidable by-product formed during aluminum scraps remelting process,which contains large quantities of metallic aluminum,aluminum oxide,aluminum nitride,saltflux mixture,and other impurities.Aluminum slag recycling is very attractive for aluminum producers from both the economic and the ecology standpoints.A review of metallic aluminium recycling from aluminum slag in high or normal temperature was presented.Utilization methods of aluminum dross,generated after treatments of aluminum slag,through chemical reaction or pyrolytic smelting were summarized.Furthermore,the current research conditions and its developing trends were discussed.关键词：Secondary Aluminum;Aluminum Slag;Aluminum Dross;Recycling
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发布时间：2023-12-18 - 摘要：According to the design principles of hot chamber die casting die and enterprise experiences,two different schemes of gating system for die casting zinc alloy cover plate were designed.Through comparing the simulated results of filling process,entrapped-gas and surface defect,the optimum gating system with conical structure was designed.The results reveal that the gating-overflow system can eliminate effectively casting defects,which are well in agreement with the simulated ones.Based on the selected ones,the over-flow system was set and verified by CAE simulation to prevent defect distribution.Finally,the surface roughness and the form accuracy reach 0.113 6μm and 2.916 9μm,respectively,by experiment test after polishing.关键词：Die Casting Zinc Alloy;Gating System;Numerical Simulation;Surface Measurement
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发布时间：2023-12-18 - 摘要：Based on JAVA WEB technology and SSH frame design,casting process aided design platform was developed with the help of C/S,which could realize casting process data query,calculation function,and data storage and maintenance features.The effective storage of large amounts of data-aided design and reasonable utilization was resolved.The product development cycles were shortened,meanwhile,product rapid development capabilities and product quality were improved with enhancing product design and manufacturing capabilities.关键词：Casting Process;Gating System;Feeding System
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发布时间：2023-12-18 - 摘要：SiCp/Al matrix composites for electronic packaging were prepared by thixoforming technique at different remelting temperatures.The results reveal that alloy matrix is connected each other to form net-like structure in the thixoformed Al matrix composites,and SiC particulates are well distributed in the aluminum matrix.With the increase of remelting temperature,the relative density,thermal conductivity（TC）,bending strength and hardness can be improved obviously while the coefficient of thermal expansion（CTE）is decreased,and the main fracture mode is characterized by the brittle fracture.The ultimate thermal conductivity（TC）,hardness and bending strength of the composites prepared reach117.54135.51 W·m-1·K-1,99.47113.52 HV,325.90346.91 MPa,respectively.Meanwhile,the mean linear coefficient of thermal expansion（CTE）of composites from room temperature to 300℃is less than 7×10-6℃-1.关键词：Thixoforming;Composites;Microstructure;Mechanical Properties
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发布时间：2023-12-18 - 摘要：A novel two-stage reheating process has been applied to investigate the microstructural evolution of semi-solid aluminum alloy 6061 at varied temperature,which was compared with that of ones in traditional reheating process.The results reveal that a desirable semi-solid microstructure with a higher roundness,smaller equivalent diameters can be obtained in the novel two-stage reheating process,significantly improving the thixoforming.The optimum microstructure with the equivalent diameter of 121.9μm and spheroidization value of 0.72 can be obtained with previously preheated to the stage-one temperature at 590 ℃for 5min,then heated to the scheme stage-two temperature at 640 ℃ within 10 min.关键词：Semi-solid;6061Aluminium Alloy;Two-stage Reheating Process;Microstructure
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发布时间：2023-12-18 - 摘要：The effects of T6 heat treatment on microstructure and mechanical properties of die casting Al-7Si-5.5Cu-0.4Mg alloy were investigated.The results demonstrate that the clusters of the skeleton Si particles are interrupted gradually to separate ones with the increase of solid solution treatment time as a result of the dissolution of the second phase Al2 Cu in the matrix.With solid solution treatment for 3h,the Si particles’ shape is transformed from irregular to spherical structure with a more uniform distribution.During aging times from 0to 6h,hardness of the alloy is increased dramatically and then reached gradually the peak value of 74.5 HRE at 3h.After that the hardness value keeps a dynamic balance,however fluctuates near slightly lower than the peak value after 4.5h.The fracture is characterized by brittle fracture in the macro-morphology.关键词：T6Heat Treatment;Microstructure;Fracture Morphology
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发布时间：2023-12-18 - 摘要：The AZ91 alloy was prepared by semi-solid rheological die-casting,and effects of the hand wheel opening angle,pouring temperature and filling time on casting forming,microstructure and mechanical properties of AZ91 alloy were analyzed.In addition,the formation mechanism was described.The results show that the suitable semi-solid die casting process of AZ91 alloy are presented as follows:hand wheel opening angle of 1 080°,pouring at 585℃and filling for 3s.The semi-solid die casting parts has the satisfied surface quality,and brinell hardness,tensile strength,yield strength and elongation of the die casting parts reach 83 HBW,285 MPa,172 MPa and 4.9%,respectively.关键词：AZ91 Alloy;Die Casting;Microstructure;Properties
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发布时间：2023-12-18 - 摘要：Effect of carbon fibers content in selective laser sintering sand mold on relative density and mechanical properties of vacuum counter-pressure casting ZL205 Aalloy were analyzed by testing the aluminum castings prepared by resin coated sand mold with five different carbon fibers contents.The results indicate that with increase of the carbon fibers content,relative density of the ZL205 Aalloy is increased,and tensile strength and elongation of the ZL205 Aalloy are increased firstly and then decreased.The relative density,tensile strength and elongation of the ZL205 Aalloy reach 0.9962,496.42 MPa and10.23%,respectively,with 3%carbide fibre content.When carbide fibre content is more than 3%,relative density of the alloy is decreased.关键词：Vacuum Counter-Pressure Casting;Carbon Fibers;ZL205A Alloy;Relative Density;Tensile Strength
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发布时间：2023-12-18 - 摘要：The investment casting of complex multi-hole thin-wall structure parts of 00Cr18Ni10 Nalloy was simulated by using ProCAST software.The possible defects in filling and solidification process were predicted.The optimized parameters of investment casting are presented as follows:shell preheating at800 ℃,pouring at 1 650 ℃,filling pressure of 0.4Pa and filling velocity of 0.8m/s.Optimized heat treatment parameters are presented as follows:solid solution at 1 020 ℃for 2.5hand air-cooled,and then annealing at 900 ℃for 1.5h+air-cooled.The results reveal that the investment castings exhibit desirable appearance with uniform chemical composition and absence of obvious defects such as porosity and shrinkage.Tensile strength,yield strength and elongation of the investment castings are increased technical requirements by 8.29%,3.86% and 80%,respectively.关键词：00Cr18Ni10NAlloy;Complex Multi-hole Thin-wall Structure Parts;Investment Casting;Numerical Simulation
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发布时间：2023-12-18 - 摘要：With the rapid development of aerospace industry,the defect detection and quality evaluation of castings become a very important part in the industrial production.Methods and equipment for the detection of casting defects have achieved a lot of achievements.The application of advanced testing equipment in the quality inspection of castings was reviewed briefly.关键词：Investment Casting;Optical 3D Measurement;Ti Alloy
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发布时间：2023-12-18 - 摘要：The medical stainless steel vortex tube has complex structure,uneven wall thickness and isolated spots,so shrinkage porosities always appear in the investment casting,which affects the normal use of the vortex tube.Also,the qualified rate of product is decreased.The pouring system was redesigned by using the ProCAST software after the analysis of initial system.The new pouring system successfully resolved the shrinkage defects in the vortex tube casting by providing metal feeding for the edge position of the castings,increasing the qualified rate of vortex tube.关键词：Vortex Tube;Investment Casting;ProCAST;Optimization
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发布时间：2023-12-18 - 摘要：Surface cracks on TP2 copper tube in horizontal continuous casting could reduce the final products rate.The formation mechanism of surface cracks on horizontal continuous casting TP2 copper tube and its countermeasures were presented by chemical composition analysis,microstructure observation and SEM,EDS.Based on formation mechanism of crack,through improving purity of furnace and mould design,casting process,surface crack on the copper tube can be eliminated obviously.关键词：Horizontal Continuous Casting;Surface Crack;TP2 Copper Tube;Formation Mechanism;Countermeasures
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发布时间：2023-12-18 - 摘要：4043aluminum alloy rod with 9.5mm in diameter was manufactured by continuous casting and rolling product line.The 4043 aluminum alloy rod has the stable mechanical properties and fine grain size.After annealing treatment,the plasticity of the aluminum alloy rod is increased greatly,and average elongation is increased by 13.8%.关键词：4043Aluminum Alloy;Continuous Casting and Rolling;Mechanical Properties;Grain Size
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发布时间：2023-12-18 - 摘要：In-situ A357 composites were synthesized in A357-Na2B4O7-K2ZrF6 system and A357-KBF4-K2ZrF6 system by direct melt reaction.The results show that as the volume fraction less than 1.5%,only Al3Zr reinforcement can be observed,while as volume fraction more than 2%,both ZrB2 and Al3Zr reinforcements can be fabricated in system A357-Na2B4O7-K2ZrF6.Only ZrB2 reinforcement can be synthesized in system A357-K2ZrF6-KBF4,and with volume fraction increase,the number of ZrB2 reinforcements is increased.The tensile strength of composites synthesized in A357-Na2B4O7-K2ZrF6 system is decreased firstly and then increased,where the highest value reaches 182 MPa,which is 1.17 times of the matrix,while the tensile strength of composites synthesized in A357-K2ZrF6-KBF4 system presents an increasing trend,where the highest value is 192 MPa,which is 1.24 times of the matrix.In addition,fracture mechanism of the composites from both systems is characterized by plastic fracture.关键词：In-situ Composites;Nano ZrB2 Particles;A357 Alloy;Mechanical Properties
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发布时间：2023-12-18 - 摘要：The influences of mechanical stirring on microstructure of primary silicon in hypereutectic Al-Si alloys were analyzed.The microstructure of modified and un-modified Al-30 Si alloys were observed by optical microscope and metallographic analysis software.The results show that the primary silicon particles can be refined and spheroidized obviously by controlling the stirring temperature and speed,where the refinement of grain is dependent on the higher speed and lower temperature,and spherodization of primary phase is controlled by the higher speed and higher temperature.With stirring at 900r/min and680 ℃,primary silicon particles exhibit the satisfied refinement in un-modified Al-Si alloy,while with at900r/min and 765 ℃,primary silicon particles have the acceptable spheroidization effects in modified Al-Si alloy.关键词：Hypereutectic Al-Si Alloys;Mechanical Stirring;Modification;Morphology of Primary Silicon
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发布时间：2023-12-18 - 摘要：The modification effects of sodium salt and rare earth lanthanum as well as compound modification of Na salt+La on microstructures and hardness of hypoeutectic Al-10 Si alloy were investigated.Meanwhile,the modification mechanism of sodium salt and rare earth lanthanum was analyzed.The results show that the grain exhibits fine equiaxed structure after Na-La compound modification,and the coarsensess of grain after annealing can be ignored.Eutectic silicon appears branch and finer to be fiberlike.The primary dendrite tends to fusing and presents equiaxed,and the interface between eutectic and primary phase exhibits clear and smooth.The effect of annealing on microstructure and morphology of alloy after sodium salt and rare earth lanthanum compound modification is slight.The hardness of the modified alloy is increased.The mechanism of sodium salt modification is that it can trigger twin crystal of eutectic silicon and continuously block the groove of twin crystal,while the mechanism of rare earth lanthanum modification dependent on its gathering in the front of the solid-liquid interface changing the growing characteristic of eutectic silicon.关键词：Al-10Si Alloy;Sodium Salt;Rare Earth Lanthanum;Microstructure;Hardness
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发布时间：2023-12-18 - 摘要：The homogenization annealing treatment of 6061 alloy was conducted at different temperatures.The microstructure of the alloy at as-cast and heat treatment state was analyzed comparatively by using optical microscope（OM）,scanning electron microscope（SEM）and energy dispersive spectrometer（EDS）.The electrical conductivity and mechanical properties of the alloy before and after heat treatment were also tested.The experimental results reveal that the microstructure of as-cast 6061 alloy are composed ofα-Al matrix,Mg2 Si,β-AlFeSi andα-Al12（FeMn）3Si2phase.With the homogenization annealing temperature more than 580 ℃,over-burning phenomenon occurs.With the increase of the homogenization annealing temperature,the yield strength,tensile strength,elongation and percentage reduction of area are increased firstly and then decreased.The maximum value can be observed when homogenizing annealing temperature is 575 ℃,so the suitable annealing temperature for 6061 alloy is 575 ℃.关键词：Heat Treatment;6061 Aluminium Alloy;Microstructure;Mechanical Properties
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发布时间：2023-12-18 - 摘要：Microstructure,surface roughness,hardness,tensile properties,electrical conductivity and other performance of the cold sprayed copper coatings on high-voltage electrical switches were investigated.The results show that copper coating and aluminum substrate exhibit the satisfied mechanical interlocking and partial metallurgical bonding,and physical and chemical properties of high-voltage switch can meet the technical requirements.关键词：Aluminum Alloy;Cold Spray;Copper Coatings
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发布时间：2023-12-18 - 摘要：The modification effects of rare earth Er content on primary Mg2Si in hypereutectic Mg-5Si alloy were investigated,and mechanical properties of the alloy containing different Er were tested.In addition,the modification mechanism of Er was described.The results reveal that the primary Mg2Si phase can be modified and refined effectively with adding 2.0% Mg-30 Er,where the average size of primary Mg2Si phase can be decreased from more than 150μm to less than 15μm,and the morphology of primary Mg2Si phase is transformed from the coarse dendrite into fine polyhedron particle with uniform distribution.The tensile strength and elongation of the alloy with 2.0% Mg-30 Er reach 135 MPa and 3.8%,respectively.However,with the Mg-30 Er content more than 3.0%,the primary Mg2Si phase in hypereutectic Mg-5Si alloy becomes coarse again,which is attributed to the enrichment of Er on the growth facets of the primary Mg2Si crystals to depress preferred growth manner of the primary Mg2Si crystals.关键词：Rare Earth Er;Hypereutectic Mg-5Si Alloy;Primary Mg2Si;Modification
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发布时间：2023-12-18 - 摘要：The effects of ultrasonic vibration on the microstructure and properties of ZL101 alloy were investigated.The results show that the fine equiaxed grain in ZL101 alloy can be generated by ultrasonic vibration.The grain size in ZL101 alloy is refined and homogenized increasingly with the decrease of pouring temperature.The application of ultrasonic vibration is helpful to refining the equiaxed grain and improving its properties such as strength and hardness.关键词：Ultrasonic Vibration;ZL101Alloy;Properties
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发布时间：2023-12-18
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