最新刊期
卷 37 ， 期 12 ， 2017
- 摘要：Effects of alloying elements Mg,Cu and heat treatment on microstructure and mechanical properties of AlSiMgMn alloys fabricated by squeeze casting were investigated by OM,SEM and EDS.For the AlSiMgMn alloys with trace Sr modification,the eutectic silicon modification levels are about grade 5 according to the American Foundry Society（AFS）standard chart for Al-Si alloys.The AlSiMgMn alloys with 0.3% Mg or 0.5% Mg show the same optimized heat treatment parameters:solution at 535 ℃for 4 and aging at 160 ℃ for 6.While the Mg content in AlSiMgMn alloys is increased from 0.3%to 0.5%,the tensile strength and yield strength of the alloy prepared are increased by 60 MPa and 70 MPa,respectively.Replaced Sr with Sb for modification of the AlSiMgMn alloy with 2.5%Cu addition,in consideration of the detrimental effect of Cu on Sr modification,the modification level of eutectic silicon is about grade 34.Although eutectic silicon particles could be spheroidized well in the subsequent heat treatment,the particle aggregation occurs obviously because of non-uniform modification effect in the casting process.It is found that strength of squeeze cast AlSiMgMn alloy is improved obviously by Cu addition,where tensile strength,yield strength and elongation of the alloy after T6 treatment reach 435 MPa,338 MPa and 7.0%,respectively.关键词：Squeeze Casting;Strengthening Phase;Heat Treatment;Strength;Toughness
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发布时间：2023-12-18 - 摘要：Hot compression tests of the homogenized Al-5.87 Zn-2.07 Mg-2.28 Cu alloy were performed on the Gleeble-3180 thermal simulation machine at the temperature range of 350450℃and the strain rate range of 0.0110 s-1.The results show that the power dissipation efficiency of the alloy is increased with increasing temperature and decreasing strain rate at each true strain.The flow instability region is enlarged and the optimum processing parameters of the alloy are changed with increasing strain.With increasing in deformation temperature and decreasing strain rate,the flow stress of the alloy is decreased,and the main softening mechanism is changed from dynamic recovery to dynamic recrystallization.When the temperature is 420 ℃,the dynamic recrystallization occurs at all strain rates.关键词：Al-Zn-Mg-Cu Alloy;Hot Deformation;Processing Map;Microstructure
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发布时间：2023-12-18 - 摘要：The high temperature mechanical properties of cast 42 CrMo steel that commonly used in bearings were investigated by high temperature tensile testing on Gleeble-3500 thermal simulator.The tensile strength model was established and the accuracy of the model was verified.Meanwhile,the hardening coefficient and strain rate sensitivity coefficient were calculated.The results reveal that the hardening coefficient of cast 42 CrMo steel is decreased with the increase of heating temperature,and increased with the increase of strain rate.The sensitivity coefficient of strain rate is increased with the increase of temperature and decreased with the increase of strain rate.关键词：42CrMo;High Temperature Tensile;Tensile Strength;Hardening Coefficient;Strain Rate Sensitivity Coefficient
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发布时间：2023-12-18 - 摘要：Through the special mold,the rheological squeeze casting of aluminum alloy wheel parts was carried out.The self-developed 3 000 kN vertical semi-solid squeeze casting machine was used to produce the parts,and microstructure and mechanical properties of the parts were analyzed.The results show that with mold temperature of about 200 ℃,the pouring temperature of 630636 ℃,and the specific pressure of 80 MPa,rheo-squeezing casting 7075 aluminum alloy wheel-shaped parts has the fine grain size with absence of dendrites,and the comprehensive mechanical properties meet the requirements,which are closed to the forging parts after T6 heat treatment.关键词：Aluminium Alloy 7075;Rheological;Wheel-Shaped Part;Squeeze Casting
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发布时间：2023-12-18 - 摘要：The Mg-Al-Li alloy hydrogen storage materials were synthesized by mechanical milling,and the mechanical milling effect on the hydrogen storage properties of Mg-Al-Li alloy were analyzed.The XRD analysis shows that although the mechanical milling can’t change the structure of Mg-Al-Li alloy,the appropriate time of mechanical milling can improve hydrogen storage properties.With mechanical milling of 60 h,the hydrogen absorption/desorption kinetic properties and thermodynamic performance for Mg-Al-Li alloy exhibit desirable.关键词：Mg-Al-Li Alloy;Mechanical Milling;Hydrogen Storage Performance
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发布时间：2023-12-18 - 摘要：In order to improve the brittleness of Fe-24 Al alloy,the alloying of C and Mn elements duplex was adopted,and the microstructure,phase structure and formation mechanism of the alloying Fe-24 Al alloy were investigated by the metallographic,SEM,XRD and confocal laser scanning microscopy.The results show that the phase structure is composed ofα-Fe、FeAl、Fe3Al and Fe3AlC phase,in which Alenrichment and C-enrichment phase can be observed.The hardness and strength of the alloys are increased from 280 HV,400 MPa to 330 HV,741 MPa,respectively,and the fracture modes are changed from brittle fracture to a fewer ductility fracture.The confocal laser scanning microscopy indicates that two kinds of white-enriched phases become cleaner,and the number of fine-enriched phases is increased.With the further increase of the temperature,the number of the white bulk and strip rich phases is decreased,and the ordered phases is dissolved into the matrix.When the temperature is the higher than1 100 ℃,the local oxidation phenomenon is presented in microstructure of the alloy.关键词：Fe-24Al-C-Mn Alloy;Ordered Phase;Formation Mechanism
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发布时间：2023-12-18 - 摘要：A compound treatment of conventional Mn modification and electric pulse modification（EPM）was carried out to optimize the size,morphologies and distributions ofβ-Fe phases in Al-Si alloys by OM and XRD.Additionally,the mechanical properties of Al-Si alloys were measured by tensile strength testing.The results show that after EPM,the length-needleβ-Fe phases are cracked into small pieces and present a trend to Chinese scriptα-Fe phases with increasing in Mn content.Meanwhile,as compared to the conventional Mn modification,the compound treatment can reduce the addition of Mn,and the tensile strength and elongation of Al-Si alloys are increase by 7.6% and 4.2%,respectively.关键词：Electric Pulse Modification;Al-Si Alloy;Fe Phase;Compound Treatment
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发布时间：2023-12-18 - 摘要：7000 series high strength aluminum alloys have been widely used in aerospace field.However,due to its poor casting properties,the forming method is mainly adopted plastic deformation,such as rolling and extrusion.Forming products include mainly plates and profiles,while it is difficult to prepare parts with complex shapes.Liquid extrusion casting and semi-solid squeeze casting technology can provide a feasible approach for the casting and forming of 7000 series aluminum alloys and their composites.It is expected to achieve "casting instead of forging",becoming an important direction of the development of high strength aluminum alloy forming technology in recent years.The research progress in squeeze casting 7000 series aluminum alloys and their composites was described,and the current problems were presented.Then the development direction was pointed out.关键词：7000Series Alloys;Aluminum Matrix Composites;Squeeze Casting;Semi-solid Squeeze Casting
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发布时间：2023-12-18 - 摘要：The research of melt purification methods presents importance for improving the quality of EC-aluminum alloy rods.The application status and prospect of three kinds of purification methods for EC-aluminum alloy melt,such as absorption purification,non-absorption purification and compound purification,were reviewed,respectively.Above mentioned methods,for example the blowing gas,flux,filtration,ultrasonic and electromagnetic purification method,have been widely used and a lot of achievements have been obtained.The high efficient and accessible combined purification methods are focused recently in this field.关键词：EC-aluminum Alloy;Melt Purification Method;Application Status and Prospect
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发布时间：2023-12-18 - 摘要：Aiming at the air porosity and gas-leakage defect in aluminum alloy camshaft bracket of engine in the trial-product state,origination of defects was analyzed by the Magma software to simulate filling and solidification process of liquid aluminum alloy.The results reveal that excessive thick wall-thickness can increase the solidification time,so the large hot spot can be formed in the castings,resulting in the shrinkage porosity.Through optimizing process,the defects in the die castings can be eliminated,and quality of the castings is improved with the decrease of developing period.关键词：Aluminum Alloy;Die Casting;Magma;Simulation
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发布时间：2023-12-18 - 摘要：The shrinkage hole was observed at the joint of nozzle and pipe hole of cylinder head of cape single cylinder engine.The simulation of filling and solidification process of the cylinder cover by AnyCasting was carried out,which indicated that there exsited a thermal center at the joint of nozzle and pipe hole of cylinder head in the solidification process after pouring,and then shrinkage and porosity occur.In order to keep the good technical and economic index of the original process,an improved scheme for adding internal chill at the hot spot was determined.The results show that the original shrinkage hole is solidified ahead of other parts of the cast,and shrinkage conditions are eliminated effectively.关键词：Cylinder Head;Simulation Calculation;AnyCasting
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发布时间：2023-12-18 - 摘要：The real-time monitoring system for castings was developed,which could really-time monitor the foundry enterprise basic data,production and sales accounting data the foundry raw material purchase data as well as casting sales data.Meanwhile,it could standardize the production and processing enterprises casting and processing behavior,and gradually implement the main responsibility for production and processing as well as improving regulatory efficiency.In addition,combined with two-dimensional code and printing technology,dealers and consumers can check real-time inspection of castings,and ultimately to achieve real-time monitoring of castings.关键词：Jeesite;MySQL;2DCode;Casting Traceability Real-Time Monitoring
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发布时间：2023-12-18 - 摘要：Based on inverse heat conduction,the anti-arithmetic program of heat transfer coefficient was developed.In the process of calculating the ITHC,the inverse analysis method is dependent on experiment temperature data.Unidirectional gravity casting experiment was designed.The interface heat transfer coefficient of GKMS60 copper and copper chill was obtained based on measured temperatures near the interface position.The results reveal that the IHTC is changed in the range of approximately1 000～2 700 W/（m2·K）in the liquid-solid phase zone.By applying the identified IHTC into low-pressure casting simulation,accuracy of the numerical simulation was improved effectively.关键词：GKMS60Copper;Interfacial Heat Transfer Coefficient;Inverse Heat Conduction;Low-pressure Casting
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发布时间：2023-12-18 - 摘要：The development and trend of automobile body structures were described.And the factors affecting the production quality were also discussed.And key points for the die design of high vacuum die casting Al-Mg alloy structure parts were introduced,such as gating system design,die temperature control and high vacuum structure design.关键词：Body Structure;High Vacuum HPDC;Sealing Design;Die Temperature Control Design
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发布时间：2023-12-18 - 摘要：According to the thermal-elasto-plastic theory,thermal stress model of cavity surface of die casting die during multiple die casting cycles was established,and the thermal stress to time curves of different depth points from cavity surface were analyzed.The results reveal that the point at the near distance from cavity surface exhibits a large thermal stress and thermal stress fluctuation.The die surface area within 3 mm is controlled mainly by low cycle thermal fatigue failure,while the area outside 5 mm is dominated by high cycle thermal fatigue failure,and the 35 mm region is between high cycle thermal fatigue failure and low cycle thermal fatigue failure.关键词：Die Casting Die;Thermal Stress;Model;Copper Alloy
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发布时间：2023-12-18 - 摘要：With the deeply understanding of the development of semi-solid metals（SSM）processing,the conception of"Generalized SSM"and"SSM +"were proposed.So called"Generalized SSM",indicating the melt on the liquidus temperature and the solid-liquid region via the high shearing of the melt and the forced uniform solidification to control nucleation and growth,is on the purpose of the structure refinement and the composition homogenization of the melt in nature,breaking the constraint of the composition of alloys.SSM +",based on the generalized SSM technology,is considered as a means of transforming the traditional processing technology."Generalized SSM"can be combined with liquid forming processes such as vertical semi-continuous casting,horizontal continuous casting,high pressure casting,extrusion casting,vacuum casting,etc.,and it also can be combined with deformation process such as forging,extrusion,rolling and so on.关键词：Generalized Semi-Solid;Forced Uniform Solidification;Semi-solid+
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发布时间：2023-12-18 - 摘要：Based on reverse solution of 3 Dimage and people photo,SLS and RP as well as SDP forming technology were analyzed.Wax pattern was printed based on 3 Dprototype with silicone mould.And then the copper people image was produced by investment casting.关键词：Reverse Solution Molding;3DPrinting;People Image Molding;Investment Casting
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发布时间：2023-12-18 - 摘要：A method for casting metal artware technique was proposed based on the profile failed laser three-dimensional printing and sand mold cast.By theoretical design and CAD data processing,the resin sand molding was manufactured by laser printing,and then the metal artware was produced successfully.关键词：Laser Three-dimensional Printing;Sand Mold Casting;Metal Artware
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发布时间：2023-12-18 - 摘要：Origination of the shrinkage porosities（holes）and other casting defects in stainless steel tube joint during casting process was analyzed,and optimization of gating system was carried out by the ProCAST software.Through optimizing the pouring position,exhausting position and processing parameters,the casting defects can be reduced greatly,improving casting surface quality and production efficiency.关键词：Cast Stainless Steel Multi-Pipe Joint;Investment Casting;Parameters Optimization
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发布时间：2023-12-18 - 摘要：Deformability of an investment casting shell affects directly forming quality of TiAl alloy castings.There exists absence of general standard for evaluation of shell deformability,which results in a slow development of process technology of TiAl alloy investment casting shell and can’t meet requirements of the formation of TiAl alloy castings.Room temperature bending strength and high temperature deflection are taken as evaluation method of the shell deformability for judging the differences of deformability of mold shells made by different types of binder.The results show that silica sol shell has a high room-temperature strength,poor plasticity and a higher high-temperature strength.The room-temperature strength of ethyl silicate shell is the lower than that of the silica sol shell,and the high temperature strength is much lower,while the plasticity is relatively excellent.It can be concluded that the deformability of ethyl silicate shell is the better than that of silica sol shell.The deformability of the TiAl alloy investment precision casting shell can be estimated effectively by using three point bending strength tests and high temperature deflection tests.关键词：TiAl Alloy;Investment Casting;Deformability of Shell;Three Point Bending Test;High Temperature Deflection Test
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发布时间：2023-12-18 - 摘要：Cu36Zr48Al8Ag8 amorphous alloy samples（BMGs）with diameter of 3 mm were prepared by copper mold suction casting method.Effects of pre-compression treatment time on plasticity of Zr-Cu based amorphous alloy were investigated by means of X-ray diffraction（XRD）,transmission electron microscope（TEM）,universal testing machine,differential scanning calorimeter（DSC）and scanning electron microscope（SEM）.Experimental results show that the samples prepared exhibit amorphous alloys.With the increase of pre-compression processing time,the free volume content and the room temperature plasticity of the sample are improved,and the treatment time is 100 min,they exhibit the desirable value.Further to increase pre-compression processing time,free volume content and room temperature plasticity of the amorphous are increased with slow tendency.关键词：Amorphous Alloy;Pre-compression Processing;Free Volume;Room Temperature Plasticity
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发布时间：2023-12-18 - 摘要：The research status and progress of bulk amorphous alloy casting forming,and the principle and advantages-disadvantages of the preparation technology of bulk amorphous alloys were reviewed briefly,focusing on the copper mold casting,vacuum casting method and phase-changed refrigeration casting method.Some problems needing to be solved in casting process of bulk amorphous alloys were put forward.关键词：Bulk Amorphous Alloy;Casting Forming;Fluidity;Solidification Behavior
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发布时间：2023-12-18 - 摘要：Aiming at the problems in preparation of the micro-fine Cu-Ag alloy wires,a method of horizontal directional solidification casting Cu-4.0 Ag alloy rod associated with continuously multi-pass cold drawing was proposed.The results reveal that the micro-fine Cu-4.0 Ag alloy wire with diameter of 0.05 mm can be prepared by continuously cold drawing of φ8 mm casting rod with continuous longitudinal columnar structures,and any intermedial annealing is canceled.The problems of requirement of several intermediate annealing process were avoided and the wire was prevented from oxidation and breakage.The strength of φ0.05 mm wire prepared is more than 1 GPa,and the conductivity reaches 44.78 MS/m.The strengthening mechanism is mainly attributed to the strengthening effects of silver fibers.
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发布时间：2023-12-18 - 摘要：Effects of scanning modes on welding surface forming,microstructure and mechanical properties of vacuum electron beam welding T2 copper sheet with 2 mm thick were investigated.The results reveal that at the fixed parameters,such as scanning distance of 300 mm,accelerating voltage of 60 kV,focusing current of 502 mA,welding speed of 800 mm/min and electron beam of 27 mA,the welding effects of welding joint with different scanning modes were analyzed comparatively.The results show that with adding triangle wave scanning,welded joints have the desirable forming quality,and hardness and tensile strength of the welding joint are improved,where the average tensile strength of welded joint reaches 178.8 MPa,and the maximum tensile strength can reach 85% of the base metal,meanwhile the elongation rate is 84.5% of the base metal.However,the strength and hardness of the welded fusion zone is the lowest.关键词：T2 Copper;Electron Beam Welding;Weld Formation;Mechanical Properties
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发布时间：2023-12-18 - 摘要：60%SiC particles（volume fraction）reinforced 6061 aluminum alloy composites were fabricated by direct electro thermal vacuum forming process.The effects of solid solution and aging treatment on flexural strength and hardness of the composite prepared were investigated,and the optimized heat treatment process parameters were presented.The influences of surface modification of SiC particles on the mechanical properties of the composites were analyzed.The result reveal that with the solid solution,the mechanical properties of the composites can be improved,where the maximum hardness and flexural strength can be obtained at 530℃for 1 hand aging at 175℃for 15 h.Due to high temperature oxidation and mixing pickling pretreatment,SiC particles are passivated,which can improve uniformity of particle distribution in the matrix and improve the interfacial bonding of SiC particles and aluminum matrix interface,so the porosity is decreased,and the flexural strength and coefficient of thermal expansion are increased.In addition,the performance of the composites with SiC particle after pickling is better than that of the corresponding oxidation state.关键词：6061Aluminum Alloy Composites;SiCp;Solid Solution and Aging Treatment;Surface Modification;Mechanical Properties
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发布时间：2023-12-18 - 摘要：Al-80Mg3Sb2composite coating was prepared on the surface of magnesium alloy AZ31Bby thermal spraying.XRD,electro-chemical experiment and SEM,electrochemical corrosion tribometer were employed to analyze the phase composition,microstructure,polarization curves and corrosion resistance under abrasion condition of the coating.The results reveal that the main phases are composed of Al and Mg3Sb2with uniform distribution in the coating.The free corrosion potential of the coating is-0.98V,and the free corrosion current density reaches 0.048×10-3A/cm2.In tribocorrosion test,the open circuit potential of AZ31B keeps always constant,however,the open circuit potential of coating is decreased with loading then increased with unloading.The open circuit potential of AZ31B and coating presents micro"W"shape in a reciprocating wear period（about 0.008s）.In addition,the average frictional coefficient of the AZ31B and coating reaches about 0.10and about 0.14,respectively.关键词：AZ31B Magnesium Alloy;Al-80Mg3Sb2 Coating;Polarization Curve;Tribocorrosion
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发布时间：2023-12-18 - 摘要：Al-Mg-Cu-Sn-Ga alloys were prepared by smelting-casting method.The effects of indium addition on microstructure,mechanical properties and corrosion properties of the based alloys were investigated by means of X-ray diffraction（XRD）,scanning electronic microscope（SEM）,Vickers hardness,compression testing and immersion test.The results show that the alloys mainly consist of Al matrix phase,long strip Al2MgCu phase and skeleton Mg2Sn phase.In addition,a small amount of line-like Ga5Mg2phases are distributed the Al2MgCu phases.The indium element is segregated at the grain boundaries of the alloy matrix.When the content of indium element reaches to 1%,the hardness,compressive strength and degradation rate of the alloy reach 142HV,582 MPa and 4.7g/h,respectively.关键词：Degradable Aluminum Alloy;Indium;Microstructure;Mechanical Properties;Corrosion Behavior
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发布时间：2023-12-18 - 摘要：In the process of solidification of 7 A04 aluminum alloy,the rectangular wave magnetic field was applied.The effects of different frequencies on the solidification structure,grain size and solidification cooling curve of 7 A04 aluminum alloy were analyzed.The results show that under the role of rectangular wave field,the solidification structure,grain size and cooling curve of 7 A04 aluminum alloy are changed obviously.When the frequency is 40 Hz,the grain refinement of ingot exhibits desirable.Compared with that without magnetic field treatment,it is not only increased undercooling,but also increased hardness.Meanwhile,the grain size is decreased by 37.1%.关键词：Rectangular Wave Magnetic Field;Grain Refinement;Solidification Structure
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发布时间：2023-12-18 - 摘要：Cu-P master alloy and Al-RE master alloy were added into Al-20 Si alloy to understand influence of modification treatment on microstructure of the alloy by SEM,X-ray diffractometer and optical metallographic microscope.The experimental results reveal that the AlP phase can be generated by reaction of P and Al as the heterogeneous nuclei of the primary silicon phase to effectively refine the primary silicon in the alloy.The rare earth elements are adsorbed and dissolved into the growth step of the Si phase,resulting in the increase of lattice constant of Si phase in the Al-20 Si alloy and the shift of X-ray diffraction pattern with a small angle.With the increase of modification time,the average grain size of primary silicon is decreased from 85.6μm to 13.2μm.The eutectic silicon phase is changed from long needle to short rod shape with uniform distribution in the matrix.The hardness（HB）is increased from68.5 to 80.8.关键词：Hypereutectic Al-Si Alloy;Phosphorus-Rare Earth Compound Modification;Primary Silicon
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发布时间：2023-12-18 - 摘要：A356 aluminum alloys with different amount of Sc and Y were prepared.Through metallographic analysis and tensile testing,influences of trace Sc and Y on the properties and microstructure of A356 aluminum alloy were investigated.The results indicate that after compound addition of trace Sc and Y,Al3 Y and Al3 Sc strengthening phase can be generated in the microstructure of A356 aluminum alloy,soα-Al matrix is refined apparently and morphologies of most of eutectoid silicon are transformed from lamellar structure into granulate,which are responsible for improvement of tensile properties and plasticity.With 0.2%Sc+0.2%Y addition,mechanical properties of the alloy exhibit desirable.With excessive Y and Sc addition,the comprehensive performance of the alloy is deteriorated as a result of composition segregation.关键词：Sc and Y;Grain Refinement;Microstructure;Mechanism;Mechanical Properties
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发布时间：2023-12-18 - 摘要：The effects of rare earth yttrium with different content on the degassing efficiency,corrosion resistance and hardness of the A356 alloy were investigated by rapid hydrogen gauge,intergranular corrosion,optical microscopy and hardness testing.The results show that the proper content of rare earth yttrium can purify effectively the alloy melt and reduce the hydrogen content in alloy melt and porosity.The proper amount of rare earth yttrium can improve the corrosion resistance and hardness of the alloy,however,the mechanical properties of the alloy are decreased with the excessive addition of Y.When rare earth yttrium addition is 0.3%,the hydrogen content in alloy melt is 0.16 mL/100 g Al,which is decreased by 56% compared with that of ones without Y addition,and the hardness is increased to 73 HB,increased by about 40%.Corrosion testing reveals that with 0.3%rare earth yttrium addition,the corrosion resistance of the A356 alloy is improved significantly,and absence of obvious corrosion pit on the surface layer can be observed,and the corrosion depth reaches approximately 145μm.Compared with that of ones without rare earth yttrium addition,the corrosion depth is decreased by 56%.关键词：Y;Degassing Efficiency;Corrosion Resistance;A356Alloy
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发布时间：2023-12-18 -
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