最新刊期
卷 38 ， 期 5 ， 2018
- 摘要：The isothermal compression bonding deformation of 705/706aluminum alloy laminated materials was carried out on Gleeble-3500hot-simulation machine at 573773Kand 0.0110s-1.The hot bonding behavior and hot workability of the materials were analyzed,and the constitutive equation and processing map were established.The results show that in the process of compression deformation of the705/706aluminum alloy laminated materials,the flow stress is decreased with the increase of deformation temperature and increased with the increase of strain rate,exhibiting steady rheological characteristics when the flow stress reaches the peak value,so it is characterized by positive strain rate sensitivity.The deformation activation energy of the laminated materials is about 147.2kJ/mol,which is lower than that of single Al-7.0Zn-2.9Mg alloy.The processing maps with different true strains show that safe deformation zone of 705and 706aluminum alloys bonding deformation is mainly attained at high cladding temperatures,moderate strains and low strain rates.The bonding strains range of 0.20.4,temperatures range of 723748Kand the strain rates range of 0.10.01s-1 are appropriate for bonding deformation of the 705/706aluminum alloy laminated materials.关键词：Al-Zn-Mg Aluminum Alloy;Laminated Material;Bonding Deformation;Constitutive Equa tion;Processing Map
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发布时间：2023-12-18 - 摘要：The low temperature superplastic deformation behavior of TC4alloy was investigated by the tensile tests for multi-pass warm rolled TC4alloy at 700870℃and 0.0010.01s-1.A maximum elongation of 1 550%can be obtained at 800℃and 0.001s-1.At 700℃,the elongation of the Ti alloy at0.001s-1 and 0.01s-1 reach 576%and 356%,respectively.The enhanced superplastic ductility can be attributed to the refined microstructure with fragmented and uniformly distributed fineβgrains as well as dynamic recrystallization.The coefficient of strain rate sensitivity is increased with the temperature increase.The activation energy of the alloy at 800℃and 870℃reach 226.8kJ/mol and 220.2kJ/mol,however,it is increased to 377.5kJ/mol at 700℃.The fracture of alloy is controlled by the interaction of internal cavity growth and external necking.关键词：Multi-pass Warm Rolled;TC4 Titanium Alloy;Superplasticity;Fracture Mechanism
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发布时间：2023-12-18 - 摘要：The orthogonal experiment was used to optimize the solution-aging（T6）and the solution+double stages aging treatment process parameters of original forged 6082 aluminum alloy,and the optimization scheme was verified.The results show that the optimization process of T6 and solution+double-stages aging treatment are 550 ℃×2 h+190 ℃×8 hand 550 ℃×6 h+120 ℃×10 min+190 ℃×8 h,respectively.The tensile strength,elongation and hardness of T6 treated alloy reach 305.7 MPa,7.1% and 109,respectively,which are 90.0% and 34.1% higher than that of original as-forged alloy in tensile strength and hardness,and decreased by 47.4%in elongation.Tensile strength,elongation and hardness of solution+double-stages aging treated alloy are 335.8 MPa、8.7%、129.3,respectively,which are 9.8%、22.5% and 18.6% higher than those of T6 treated alloy.关键词：6082 Al Alloy;T6 Heat Treatment;Double Stages Aging;Microstructure and Properties
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发布时间：2023-12-18 - 摘要：Fiber laser welding of Ti-15-3（Ti-15 V-3 Cr-3 Al-3 Sn）alloy was performed with different postwelded heat treatments comprising single and duplex aging with or without prior solution treating after welding.The effect of PWHTs on microstructure and mechanical properties of the welded joints was investigated by optical and electron microscopes,tensile and microhardness test.The results indicate that solution treating after welding can increase the tensile strength of the welded joint with the decrease of the ductility.The welded joints without solution treating presents a better combinations behavior of strength and ductility.Electron microscopy results demonstrate that basket-weave morphology and finer size ofαphase are responsible for higher ductility of welded joints without post-weld solution treatment.Precipitation of finerαphase in microstructure of the duplex aged welded joints can be observed compared with the single aged ones,so presenting the higher micro-hardness and tensile strength.关键词：Laser Welding;Ti-15-3;β-Ti Alloy;Post-welded Heat Treatment;Duplex Aging
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发布时间：2023-12-18 - 摘要：Aiming at one-piece inline four-cylinder water-cooling diesel engine cylinder head,quartz pebble was chosen as molding material.The casting mould is made of resin coated sand shell,shell core and hot corebox sand.Mold compaction has been processed in a single flask with straight wall and with the aid of clamping plate on the top of the opening flask.HT250 inoculated cast iron was poured in gravity casting with bottom and open gating system,which realized non-joint flash & non-fins in mold parting and non-air vent riser in mold cavity.The practical production reveals that roughness of casting surface feature reaches Sa=11.89μm,and tensile strength and hardness of the castings reach 265.2 MPa and209 HB,respectively.Graphite morphology and graphite size grade in the casting matrix structure belong to A type and 34 grade,respectively,and the content of pearlite and sorbate are more than 98%.In addition,product yield and overall yield reach 95%and 85%,respectively.Sand metal ratio may be 1∶1,and recycling ratio of quartz pebble and shell core precoated sand are more than 90%.关键词：Cylinder Head;Quartz Pebble;Shell Assembly Mold;Gating System;Non-Directional Solidifi cation
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发布时间：2023-12-18 - 摘要：The lateral extrusion process of semi-solid 7075 aluminum alloy prepared by recrystallization and partial remelting method was investigated by numerical simulation and microstructure analysis.The velocity field of lateral flow,stress field in extrusion sample and the load-stroke curve in the extrusion process were analyzed.Meanwhile,the microstructure at different position of sample after extrusion was also observed.The results show that the semi-solid metal preferentially fills into the cavity with the bigger cross section in the lateral extrusion process,and the maximum stress concentration zone is gradually extended from turning zones of flow direction forward surrounding region.The lateral extrusion and stress concentration lead to the serious elongated grains in the microstructure of turning zones of flow direction.关键词：7075 Aluminum Alloy;Semi-solid Extrusion;Lateral Flow;Numerical Simulation
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发布时间：2023-12-18 - 摘要：Aiming at the long development cycle of die casting die and the complicated design of the gating system,a high efficient development system for gating system of die cast die based on the Excel VBA was put forward.The system includes mold experience design formula,commonly used die casting material parameters,die casting machine parameters and p-Q2 diagram,common feeding design plan,common gate design and runner design parameters.Gating system of a PDA shell was designed by the developed system,in which the integrated parameters can be invoked efficiently to complete the development of the gating system,and finally avoid effectively the negative effects of traditional experience and trial and error method on the innovation of die design industry.关键词：Die Casting Die;Gating System;Gate Design;Feeding System
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发布时间：2023-12-18 - 摘要：A model of part scale was established to predict the deformation of SLM-formed AlSi10 Mg alloy cantilever beam by shrinkage volume method.The influence of geometry,scanning patterns and preheating temperatures on the residual distortion of the cantilever was analyzed.The results reveal that the warping direction and deformation trend of the simulated calculation are well in agreement with the experimental ones.The greater the thickness of the cantilever,the greater its rigidity and the stronger the ability to resist deformation.The increase of preheating temperature can reduce effectively the deformation of the parts.关键词：Numerical Simulation;Distortion Prediction;Selective Laser Melting;Shrinkage Volume Method
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发布时间：2023-12-18 - 摘要：The gravity filling process of the ZL205 Aframe casting was conducted by analyzing the structure and process characteristics,and the distribution of solidification temperature and shrinkage under two gravity filling process was simulated by the HUAZHU CAE software.The structure design optimization of the internal injection gating system was obtained through the process analysis of the origination of the shrinkage,and the shrinkage defects were eliminated effectively through adjusting the solidification sequence.The average tensile strength,yield strength,elongation and Brinell hardness of the castings reach 510 MPa,424 MPa,8.1% and 131 HBS,respectively,after the T5 heat treatment,which meets the HB962-2005Ⅱtechnical indicators.关键词：ZL205A Alloy;Process Design;Numerical Simulation;Gating System
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发布时间：2023-12-18 - 摘要：Segregation in the ZL205 Aalloy large axisymmetric-body is harmful greatly to the properties of the castings.By using ProCAST software,the effects of casting parameters on the filling process and temperature distribution of the castings were simulated.Moreover,the optimized processing parameters were also used in the manufacturing of the axisymmertric-body to verify the calculation results.The results show that,by using low pressure casting process,the rational casting parameters,such as d=80 mm,b=35 mm,δ=25 mm,can improve significantly the segregation defects of the casting by decreasing the temperature gradient to realize the sequential solidification.关键词：ZL205A;Axisymmetric-body Casting;Casting Technology;Segregation
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发布时间：2023-12-18 - 摘要：The flow field and solidification of aluminum alloy caliper under gravity and tilting pouring condition were analyzed by numerical simulation.And the change curve of the specified temperature under the color temperature of the casting temperature changes was observed during the solidification process for the selected temperature-measured points.Compared with gravity casting,the tilting casting process exhibits more stable with the lower temperature gradient,so the gas is easy to be exhausted,which takes the absence of shrinkage,porosity and shrinkage defects.Adopting tilting casting design with three parts in one mould,the experimental results indicate that the product quality presents desirable,and the caliper quality and the production yield are improved greatly.关键词：Numerical Simulation;Casting Method;Color Temperature Curve;Gravity Casting;Tilting Casting
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发布时间：2023-12-18 - 摘要：The large-scale water valve belongs to a small batch production of nodular cast iron parts.Through a comprehensive analysis of its structure and production technology,sand casting was determined to produce the valve body.The core box precision assembling core was adopted to mold,and double-step ladle gating system was selected to pour with "full riser design".Meanwhile,by adding cold iron,the internal defects in the water valve body was eliminated.By using Anycasting simulation and actual production verification,the correctness and feasibility of the designed scheme were confirmed.关键词：Large Water Valve;Sand Casting;Simulation Analysis
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发布时间：2023-12-18 - 摘要：The surface of magnesium alloy is easily corroded to form loose porous magnesium oxide due to extremely active chemical behavior,which limit the wide application of magnesium alloy.Therefore,in order to meet the different market demands and expand the application areas of magnesium alloys,the different surface treatment technologies for magnesium alloys were put forward to improve the corrosion resistance of magnesium alloys and make the parts with good appearance.关键词：Magnesium Alloy;Micro-arc Composite Ceramic;Seamless Plastic Coating;Composite Deposition
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发布时间：2023-12-18 - 摘要：The defects in die-casting transmission housing were investigated,and the internal porosity condition and mechanical properties of the transmission housing were improved by applying high vacuum die-casting technology.The results reveal that the gas leakage rate of the oil passages is reduced greatly after using high vacuum technology,and the yield rate is increased to 97%,decreasing greatly cost.Compared with those of conventional vacuum castings,the tensile strength and elongation of high vacuum castings are increased by 17.4% and 37.1%,respectively.关键词：Transmission Housing;High Vacuum Die Casting;Gas Hole;Mechanical Properties
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发布时间：2023-12-18 - 摘要：At a given solid solution time and aging time,effects of different solid solution temperature and aging temperature on performance of A356 low pressure cast aluminum alloy wheels were investigated.The results reveal that at solid solution temperature of 555℃,aging treatment can lead to the over burning of alloy wheel.At 545 ℃ solid solution and 150 ℃ aging or at 550 ℃ solid solution and 150 ℃aging,A356 alloy wheel exhibits the desirable performace.关键词：A356 Alloy Wheels;Solution;Aging
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发布时间：2023-12-18 - 摘要：3 D model of the aluminum alloy stair with gating system was established by Solid Edge software.Through selecting nine sets of parameters and applying the ProCAST software to enmesh grids of the 3 D model of the stair,the filling and solidification process of the stair were simulated,and the defects in the stair were predicted and analyzed.Finally,the appropriate processing parameters were determined as follows:preheating mould at 190℃and pouring liquid alloy at 620℃ with injecting velocity of5 m/s.关键词：Aluminum Alloy;Stair;Numerical Simulation;ProCAST Software
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发布时间：2023-12-18 - 摘要：The properties of silica-based ceramic cores impregnated by the hydrolysate with different Si/Al ratio were analyzed comparatively for those of ethyl silicate hydrolysate（TOES）and Si-sol.The results reveal that the density,porosity,high temperature strength and the resistance of high temperature deformation of the ceramic cores impregnated by the composite hydrolysate with Si/Al ratio of 1∶3 are improved to some extent,and the values are between those of TOES and Si-sol.After impregnated by SA13,the cores present an optimal size stability and better high temperature chemical stability with DD6 superalloy.关键词：Silica-based Ceramic Cores;Impregnation;Hydrolysate with Different Si/Al Ratio
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发布时间：2023-12-18 - 摘要：Using vacuum induction melting combined with inert gas protection,the occurrence and formation Law of the interfacial reaction between DZ22Bsuperalloy and Al2O3ceramic shell for investment casting were investigated with considering different melting temperature and contacted time.Moreover,the resultant surface sanding defect caused by interfacial reaction was also discussed.The results show that the Hf element in superalloys exhibits highly active,which is prone to react with Al2O3and the reaction product of HfO2is formed on the casting surface.With the contacted time of 15min,the interfacial reaction is enhanced with the increase of melting temperature.It is found that absence of interfacial reaction occurs at 1 400℃,and weak interfacial reaction is formed at 1 500℃,and then serious reaction can be expected at 1 600℃,accompanied with the sand sticking phenomenon.Due to the formation of physical permeability layer and the presence of stress concentration,the surface layer of ceramic shell is inclined to fall out.Most serious reaction can be observed with the contacted time of 30min and melting temperature of 1 600℃,where the reaction zone with the size of 1mm is formed on the casting surface.关键词：Interfacial Reaction;Active Element;Sanding Sticking;Superalloy;Investment Casting
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发布时间：2023-12-18 - 摘要：The process of investment casting trapezoidal arm was designed by Pro/E software.The filling process was simulated by ProCAST software,and the pouring scheme was optimized by adding air outlet.The bending stress of trapezoidal arm was analyzed by ANSYS.The results reveal that with the initial process design,shrinkage porosities（holes）is easily generated,which are concentrated in the sprue and bending surface of the arm castings.The ingate is modified to the bottom with adding air outlet at the top,and casting defects can be reduced greatly.ANSYS analysis shows that the maximum bending stress and the maximum deformation reach 105.86 MPa and 6.981 6 mm,respectirely,meeting the design requirement.关键词：Trapezoidal Arm;Numerical Simulation;ProCAST;ANSYS
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发布时间：2023-12-18 - 摘要：The effects of pattern density and pouring temperature on the filling and solidification of gray cast iron in lost foam casting process were understood using numerical simulation method,which were compared with the practical casting.The simulated results show that the filling speed of molten metal is increased with the increase of the pouring temperature and the decrease of the pattern density.At the same time,the high pouring temperature will also increase the pressure of the gas film between the pattern and the molten metal,which will make the rate of return and molten metal forward speed to achieve dynamic balance.The higher pouring temperatures and lower pattern densities tend to reduce the formation of shrinkage porosity.关键词：Lost Foam Casting;Numerical Simulation;Pattern Density;Pouring Temperature;Pressure in Gas Gap
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发布时间：2023-12-18 - 摘要：A356/Zn bimetal composite plate was prepared by double liquid composite casting.The interfacial microstructure and interface cross sectional height of the composite plate were adjusted by changing the pouring sequence of the two alloys and the pouring temperature of A356 aluminum alloy.The microstructure and mechanism of composite layer formation at the A356/Zn interface were evaluated by scanning electron microscope（SEM）and energy dispersive spectrometer（EDS）.The results reveal that the interface of A356/Zn bimetal composite plate presents desirable metallurgical bonding with A356 melt at660 ℃,where a well-developed dendrite can be formed with interface cross sectional height of about 2 mm.The interface can be divided into three regions based on the generation phase.When the pouring temperature of A356 aluminum alloy is 620℃,the dendrites in the composite interface are reduced obviously or even absent with the width of composite interface decreased to about 1 mm.关键词：A356/Zn Bimetal Composite Plate;Interfacial Microstructure;Element Diffusion;Formation Mechansim
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发布时间：2023-12-18 - 摘要：Multi-walled carbon nanotubes（MWCNTs）/poly（Dicyclohexyl Vinyltere-phthalate）composites containing 1%,3% and 5% MWCNTs were prepared through the solution blending method,and the effects of MWCNTs contents on the storage modulus,tensile properties,shape memory recovery speed and recovery stress of the composites were investigated by a series of experiments.The results show that the addition of MWCNTs can improve the storage modulus and tensile stress of poly（dicyclohexyl vinylterephthalate）sheets.When the content of MWCNTs is 3%,the MWCNTs/poly（dicyclohexyl vinylterephthalate）sheets have the maximum tensile stress and fracture tensile rate.Through DMA shape memory test,it is found that the shape memory recovery speed and stress of poly（dicyclohexyl vinylterephthalate）fibers are increased with the addition of MWCNTs.When the content of MWCNTs is 3%,MWCNTs/poly（dicyclohexyl vinylterephthalate）composites exhibit the desirable mechanical properties and shape memory behavior.关键词：Shape Memory Material;Poly Dicyclohexyl Vinyltere-phthalate;Multi-walled Carbon Nano tube;Shape Memory Behavior
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发布时间：2023-12-18 - 摘要：The influence of Zn interlayer on the microstructure and mechanical properties of FSLW 6061 aluminum alloy with 2 mm thick and T2 copper thin plate joints was investigated by adopting pure Zn with 30μm thick as pre-setting interlayer.The results reveal that Al and Cu dissimilar metals can be welded together with the addition of Zn interlayer.At a plunge depth of 0.1 mm,the joint exhibits the satisfied bonding quality with absence of welding defects,and the maximum tensile load reaches about2.8 kN.The joint load is decreased slightly with increasing in the plunge depth（0.2 mm）due to the increase of hook defects size resulting in decrease of effective plate thickness.As the plunge depth increased to 0.3 mm,the more welding defects can be formed in the joints.Zn interlayer can promote the alloying reaction between Al and Cu substrates in the hook zone to form an Al-Cu diffusion layer with a thickness of about 4μm,decreasing the detrimental effect of hook defects on the joint and increasing the effective bonding area,thus improving the joint quality.关键词：Dissimilar Metals;Friction Stirring Welding;Zn Interlayer;Hook Defects
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发布时间：2023-12-18 - 摘要：Effects of laser welding heat input on the formability,microstructure,mechanical properties and fracture morphology of Mg-3 Nd-0.2 Zn alloy welded joint were investigated,and the action mechanism of Nd element was expounded.The results reveal that when the welding heat input is less than 84 J/mm,weld joint is not penetrated,and with the increase of welding heat input,the welding penetration is increased gradually.In addition,when the welding heat input is increased to 84 J/mm and above,the welding joint is permeable,and with the increase of heat input,the welding width between the surface and the lower surface of the weld joint is increased.With the increase of welding heat input,the heat affected zone width and grain size of welded joints show a trend of gradual increase.When the welding heat input is less than 84 J/mm（unmelted）,the change of width of heat affected zone and grain size can be ignored.When the welding heat input is greater than or equal to 84 J/mm（penetration）,tensile strength and elongation welding joint reach more than 85% and 87% of the parent material under three kinds of welding heat input.Under the condition of full penetration,the increase of welding heat input will reduce the strength and plasticity of welded joint,and the desirable strength and plasticity can be obtained when the welding heat input is 84 J/mm.关键词：Welding Heat Input;Mg-3Nd-0.2Zn Alloy;Microstructure;Mechanical Properties
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发布时间：2023-12-18 - 摘要：Two sets of TiAl alloys,Ti-46 Al-9 Nb-0.5 Si and Ti-46 Al-2 Cr-0.5 Si-0.2 C,were synthesized and consolidated by spark plasma sintering from elemental powders as raw materials.The elemental diffusion and evolution of microstructure with various SPS conditions were investigated.The uniform diffusion of Ti,Al,Si and C can be realized at/above 1 300 ℃×5 min.The diffusion of Cr can almost completed with few enrichment regions.However,the diffusion of Nb can’t be realized.The two alloys exhibit typical duplex microstructure with lamellar colonies andγphase.The amount of lamellar colonies and grain size are increased with the increase of sintering temperature and holding time.The compressive strength is in range of 1 200 MPa to 1 350 MPa under the SPS conditions.More lamellar colonies lead to a higher strength,however,the coarsening of grains caused by higher temperature and longer duration can reduce the strength.The room temperature compressive properties are comparable to the previous values obtained from casting plus heat treatment and SPSed pre-alloyed powders.关键词：Ti Al Alloys;Sintering;Microstructure;Mechanical Properties
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发布时间：2023-12-18 - 摘要：Effects of pulsed magnetic field on solidification structure and compressive performance of AZ31 alloy were investigated.Morphology of primary phase and grain size in the alloy with different pulsed voltage,pulsed frequency and mould temperature under the conditions of designed temperature were expounded.The results show that solidification structure of AZ31 alloy can be improved significantly by pulsed magnetic field treatment.With the increase of pulsed voltage（0300 V）,or pulsed frequency（110 Hz）,primary phase in the alloy is degraded gradually from well-developed dendrites into fine equiaxed grains or rosette crystals.With mould temperature at 20600℃,primary grain size is refined firstly and then coarsened.At 200 ℃,grain size presents desirable.Pulsed magnetic field can improve greatly compression performance of AZ31 alloy.With the pulsed voltage of 300 V,pulsed frequency of 5 Hz and pouring temperature of 720 ℃ as well as mould temperature of 200 ℃,the compressive stress of the AZ31 alloy reach 340.87 MPa.Compared with conventional casting,compressive stress and compressibility of the alloy are increased by up to 71.40% and 75.14%,respectively.关键词：AZ31 Magnesium Alloy;Pulsed Magnetic Field;Solidification Structure;Compression Per formance
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发布时间：2023-12-18 - 摘要：The process of in-mold oxidation of cast aluminum alloy was analyzed.A kind of special coating contained the CrO3oxidant was coated on the surface of a sand core prepared by triethylamine cold box core-making technique.The sand core prepared was assembled in the mold after being dried,which was reacted with the aluminum alloy melt entried the mold to increase greatly the oxidized layer on the aluminum alloy surface.The results reveal that the processing results can be affected obviously by the content of oxidant,content of refractory aggregate and the particle size of refractory aggregate.With the200mesh SiO2 powder as refractory aggregate,an optimum effects can be obtained when the special coating is composed of 105portions SiO2,30portions oxidant,6portions bentonite clay,0.4portions CMC and 6portions mixed salts.The uniform oxidized layer with the thickness about 3!m can be observed.The corrosion resistance of samples in 3.5%NaCl solution was tested using electrochemical impedance method.It is found that the corrosion resistance of the samples after in-mold oxidization treatment is improved greatly.关键词：Cast Aluminum Alloy;In-mold Oxidation;Coating;Oxidant
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发布时间：2023-12-18 - 摘要：The development and progress of aluminum alloy preparation technology has driven the rapid development of aluminum industry,which plays a very important role in the national economy.Based on the international patent database of Derwent Innovations Index,the development and application progress of aluminium alloy technology patent were analyzed by TDA analysis tool.The results show that the patent and core patents of aluminum alloy are mainly concentrated in Japan,USA and China etc.The development direction of aluminium alloy patent technology mainly focuses on specific alloy type,alloy product structure,and the improvement of product performance through heat treatment.In recent years,the hot research and development directions are interested in aluminum alloy coatings,alloy components complication and alloy functional diversification etc.关键词：Aluminium Alloy;Patent Technology;Core Patent
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发布时间：2023-12-18 - 摘要：K2 ZrF6 was used as modifiers for the modification treatment of ZL114 Aalloy,and influences of varied modification temperature on the microstructures and tensile properties of ZL114 Aalloy were investigated.The results show that,with the increase of modification temperature,the modification effect is increased firstly and then decreased,and the optimized modification temperature of ZL114 Aalloy is 725 ℃.Under the conditions,theα-Al phase exhibits the euiaxed structure with small grain size,and eutectic silicon phase presents mainly thin fibrous or short-rod.Meanwhile,the yield strength,tensile strength and elongation of as-cast ZL114 Aalloy reach 151 MPa,176 MPa and 4.3%,which are increased to 251 MPa,300 MPa and 5.0% after T6 heat treatment,respectively.关键词：ZL114A Alloy;Modification Temperature;Microstructures;Tensile Properties
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发布时间：2023-12-18 - 摘要：The effects of LPSO（Long Period Stacking Order）phase on the microstructure and properties of Mg-Gd-Y-Zn-Zr alloys were investigated.Mg-6 Gd-2 xY-xZn-0.6 Zr（x=1、1.5、2、2.5,constant value of Y/Zn）alloy was analyzed by XRD、SEM-EDS、tensile test and damping test.The results show that,with the increase of Y and Zn content,the magnesium matrix phase is decreased while the second phase is increased,and the as-cast alloy phase consists Mg matrix and Mg10（Gd,Y）Zn phase.As a result,the microstructure and ultimate tensile strength of the alloy are improved,and the plasticity is increased slightly.Moreover,the fracture mechanism of the alloy is changed from brittle cleavage fracture to quasi-cleavage fracture.And damping properties of LPSO-containing magnesium alloys could not be explained by single G-L theory.关键词：Mg-Gd-Y-Zn-Zr Alloy;Long-period Stacking Ordered Structure;Mechanical Properties
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发布时间：2023-12-18 - 摘要：Cu-37.4 Pb monotectic alloys were prepared under different process conditions,and the structure,phase composition,friction and wear properties of the monotectic alloy prepared were analyzed.The results reveal that the Cu-37.4 Pb monotectic alloy prepared under normal conditions is mainly composed ofα-Cu,β-Pb and the segregation of Pb block,and grain size exhibits coarse with high un-even microstructure.In the monotectic alloy prepared under the strong pulse current field,the serious segregated Pb phases are transformed into short rods with dense distribution.In the microgravity field of the monotectic alloy,Pb block is converted into long strip with sparse distribution and even structures as well as coarse grain size.The compositions of the monotectic alloys prepared by the strong pulse current and microgravity composite field are mainly composed ofα-Cu andβ-Pb,and grain size exhibits equiaxed structure with uniform distribution.The friction and wear experiments show that the Cu-37.4 Pb monotectic alloy prepared by the compound field has the lower friction coefficient and wear volume,and the friction performance exhibits desirable.关键词：Strong Pulse Current Field;Microgravity Field;Cu-Pb Monotectic Alloy;Friction Performance
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发布时间：2023-12-18 - 摘要：Effects of different processing parameters,such as feeding ratio,the first induction and annealing temperature on grain size in the QSn7.0-2 alloy were analyzed by the single factor experimental table.The origination of difference on grain size was described.The results show that the average grain size in the microstructure is decreased firstly and then increased with the feed ratio increase.However,the increase of first induction can be ignored to effects on grain size change.With increasing in annealing temperature,the average grain size is increased slightly.关键词：Power Spinning;Process Parameters;QSn7-0.2 Alloy;Grain Size
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发布时间：2023-12-18
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