最新刊期
卷 29 ， 期 3 ， 2009
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- 摘要：As-cast microstructure of Mg-7Gd-5Y-1.2Nd-Zr magnesium alloy was observed,and the mechanical behavior of the alloy during hot deformation process was examined on the Gleeble-1500D hot simulator with reduction of 60% and strain rates of 0.002,0.01,0.1,1 s-1 at 573～723K.As-cast microstructure of the alloy is composed of α-Mg phase and net-like eutectic phase.At a given temperature,the peak stress is increased with increasing in strain rate;while with a given strain rate,it is decreased with increasing in deformation temperature.Softening of eutectic phase in microstructure of the alloy plays an important roles in decreasing in peaking stress at high temperatures.Discontinuous recrystallization in the alloy is more distinct at strain rate of 0.1 s-1,resulting in the failure of alloy.Average deformation activation energy and stress exponent are 243.5kJ/mol and 4.1972,respectively.The deformation activation energy is related directly to deformation temperature and related indirectly to strain rate.关键词：RE Magnesium Alloy;Hot Deformation;Microstructure;Flow Stress;Deformation Activation Energy
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发布时间：2023-12-18 - 摘要：Change size of film on LY12 aluminum alloy in process of micro-arc oxidation was examined by propeller micrometer and eddy current thickness meter.The ceramic coating with 30 μm in thickness was prepared in 100g/L Na2SiO3 solution for 75 min with voltage of 550V and current of 25A.The phase constituent,morphology and element distribution in the ceramic coating were analyzed by XRD（X-ray diffraction）,SEM（scanning electron microscope）and EDS,and formation mechanism of phase constituent in the coating was described.The results reveal that micro-arc oxidation can increase specimen size and decrease substrate size,and the coating thickness growing to outside is equal to the substrate lossing thickness.The coating which mainly contains O,Si and Al element is made of the substrate and amounts of cavities with about several microns in diameters.Phase constituent is composed of Al phase and Al2O3 as well as SiO2 amorphous phase.Micro-hardness of the coating makes HV 2200.关键词：LY12 Aluminum Alloy;Micro-arc Oxidation;Size;Amorphous Phase;Micro-Hardness
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发布时间：2023-12-18 - 摘要：Crystallization behavior of Zr65Ni10Cu17.5Al7.5 bulk amorphous alloy in the temperature range of glass transition to melt point was examined by DSC（differential scanning calorimeter）at different heating rates.The results reveal that there exist three stages in the whole crystallization process.Glass transition temperature,crystallization temperature and peak temperature corresponding to each stage move towards higher temperature with the increase of heating rates,which was described by Johnson-Mehl-Avrami（JMA）theory and thermal kinetics.The microstructure of the quenched bulk amorphous alloy was analyzed by XRD（X-ray diffraction）.It is found that with increasing in heating temperature,phase constituent of the alloy corresponding to the three stages is evolved from quasicrystal to isomorphous system Al2Zr3 and NiZr3 phase and then to isomorphous system CuZr2 phase,cubic system NiZr2 phase and orthothombic system Al3Zr2 phase.Meanwhile,crystallized product and grain size in every stage are slightly related to the heating rates.It is observed that crystallization behavior at the second stage can inhibit ones at first stage with high heating rates.关键词：Heating Rates;Zr-Ni-Cu-Al Bulk Amorphous Alloy;Crystallization;Nano-crystalline
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发布时间：2023-12-18 - 摘要：Over-critical infiltration behavior of mercury through Al2O3 fiber porous perform was observed by XRD（X-ray diffraction）and TEM（transmission electron microscope）at room temperature in centrifugal force field.The results reveal that during over-critical infiltration in the perform,mercury is advanced in such types as dribble flow,discrete column flow or intermittent laminar flow.Discrete infiltration is prior to appear in those porosities on the initial boundary where the infiltration condition is met,and it arrives at the end of the perform to accumulate then backward filling densely,which greatly decreases infiltration possibility in other porosities with the same diameters as a result of the decrease of centrifugal force on the initial boundary with increasing in mercury infiltration at a given rotary speed.XRD observation reveals that the Coriolis forces generated from the centrifugal forces field has the great effects on the discrete infiltration.关键词：Centrifugal Forces Field;Mercury;Over-critical Infiltration;Porous Perform
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发布时间：2023-12-18 - 摘要：Formula of mass transfer speed and diffusion flux was established during gas atom moving towards gas bubble by theoretically analyzing gas bubble growth in vertical centrifugal casting liquid metal.The results show that gas atom moving towards gas bubble can be divided into three stages.At the first stage,gas atoms diffuse from the inner of liquid metal towards the surface of gas bubble.Gas atoms transfer from solution to absorption and react into gas molecules in the absorptive layer at the second stages.Gas molecules diffuse into the gas bubble in the final stage.The mass transfer speed and diffusion flux of gas atoms diffusing into the gas bubble can be decreased with increasing in the centrifugal angular velocity and radius.In addition,a quantitative equation between the gas bubble radius and the centrifugal angular velocity as well as centrifugal radius is established for the gas bubble with the internal pressure equal to the external pressure.关键词：Centrifugal Casting;Liquid Metal;Gas Bubble;Growth
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发布时间：2023-12-18 -
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- 摘要：A porous reticulated TiAl intermetallics framework with excellent properties was prepared by sintering at low temperature and then high temperature,in which porous TiAl billet with high interconnected pore rate was formed by infiltrating a reticulated polymeric sponge with interconnected pores being used as primal framework into proportioned TiAl slurry.The reticulated TiAl intermetallics framework with desirable high interconnected pore rate and high compressive strength can be prepared by sintering at 1380℃.Compressibility and wear-friction behavior of porous reticulated TiAl intermetallics reinforced Al matrix composites were investigated.The results reveal that wear resistance and compressibility of the composites are obviously superior to those of Al matrix due to reinforcing effects of porous reticulated TiAl intermetallics.The wear mechanism of the composites is characterized by adhesive wear.关键词：TiAl Intermetallics;Porous Reticulated Structure;Compressive Strength;Porosity;Wear
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发布时间：2023-12-18 - 摘要：Isothermal tensile of cast-rolling and normal rolling AZ31 magnesium alloy sheet was tested on the Gleeble 1500D hot simulator with strain rate of 0.3～0.0003 s-1 at 150～400 ℃ to observe microstructural evolution.The results indicate that microstructure of AZ31 magnesium alloy mainly consists of elongated and broken grains and twins at the low temperature deformation.With increasing in temperature,recrystallization occurs and grain size is coarsened in the microstructure of cast-rolling and normal rolling AZ31 magnesium alloy sheets.Cavity size,volume fraction and density of cast-rolling sheet caused by grain boundary sliding under the deformation condition of high temperature and low strain are higher than those of normal rolling ones,while dynamic recrystallization grain sizes are less than that of normal rolling ones.Dynamic recrystallization grain size has a power law relation with Z parameters.关键词：AZ31 Magnesium Alloy;Cast Rolling;Isothermal Tensile Testing;Microstructure
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- 282
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发布时间：2023-12-18 - 摘要：Effects of different solution processes on microstructure and properties of rapidly solidified hypereutectic Al-Si alloy strips,which were prepared by single roller melt-spinning method,were investigated by scanning electron microscope（SEM）and transmission electron microscope（TEM）.The results indicate that compared with as-cast microstructure,micro-nanocrystal hypoeutectic phase in rapidly solidified hypereutectic Al-Si alloy can be observed and α-Al phase is prior to precipitate from the Al-Si alloy,which is attributed to rapid solidification restraining the nucleation and precipitation of Si phase in the alloy.Furthermore,in the process of solution treatment,Si element can be precipitated from the matrix and gradually aggregated to generate fine silicon particle,which was uniformly distributed into the matrix,with extending holding time.Desirable fine silicon particle with high spheroidization rate can be observed in the alloy with holding for 100 min at 480℃ followed by quenching in water and natural aging for 96 h,which makes maximum hardness of HV 241.67 for the alloy.关键词：Rapid Solidification;Hypereutectic Al-Si Alloy;Microstructure;Micro-Hardness;Solution Treatment
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- 523
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发布时间：2023-12-18 - 摘要：Solidification behavior and as-cast microstructure of permanent mould casting Mg-10Zn-2Al alloy were investigated by optical microscope（OM）,scanning electron microscope（SEM）,X-ray diffraction（XRD）and differential scanning calorimetry（DSC）.Meanwhile,phase transformation during solidification process was approached with the help of DSC analysis and Mg-Zn-Al ternary liquidus projection phase diagram.The results indicate that as-cast microstructure of the alloy is composed of primary α-Mg phase,Mg32（Al,Zn）49 and MgZn phase,in which continuous or semi-continuous skeleton Mg32（Al,Zn）49 phase is uniformly distributed in interdendrite and along grain boundaries.The liquidus temperature and solidus temperature are 609.4℃ and 300.0℃,respectively,which makes a wide solidification range of approximately 309.4℃.In addition,the second phase transformation starts at 332.2℃ and ends at 300.0℃.关键词：Magnesium Alloy;Mg-10Zn-2Al Alloy;Solidification Behavior;Microstructure
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发布时间：2023-12-18 - 摘要：Foamed magnesium was prepared with ZM5 alloy as matrix alloy and SiC as viscosity-increasing agent as wellas MgCO3 as foaming agent by direct molten foaming process.It is found that foamed magnesium with low density and high porosity rate can be successfully prepared.With increasing in MgCO3 or SiC content,density of the foamed magnesium is decreased.However,it is slightly increased with MgCO3 content more than 1.5% or SiC content more than 15%.Variation of average porous rate in foamed magnesium is opposite to that of density’s.关键词：Foamed Magnesium;Direct Molten Foaming Process;MgCO3
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- 485
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发布时间：2023-12-18 - 摘要：Effects of pouring temperature on non-dendrite structure in as-cast microstructure of semi-solid ZL101 alloy were observed,which was prepared by controlling pouring method.The results reveal that coarse dendritic structure is observed with pouring at 680℃,and partly dendritic structure exists in the microstructure of the alloy with pouring at 625℃,and uniformly spheroidized non-dendrite structure can be obtained in the microstructure of the semi-solid ZL101 alloy with pouring at 615℃,while non-dendrite structure with large grain size can be created in the microstructure at 605℃.In addition,formation mechanism of non-dendrite structure in the microstructure of the semi-solid ZL101 alloy was approached.关键词：Pouring Temperature;Semi-solid;ZL101 Alloy;Non-dendritic Microstructure
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发布时间：2023-12-18 - 摘要：The microstructural evolution and preparation as well as control of non-dendrite in the microstructure of the semi-solid Mg-20Al-0.8Zn magnesium alloy which was refined by Al-Ti-B master alloy were investigated during isothermal treatment process.The results indicate that grain size in as-cast microstructure of Mg-20Al-0.8Zn magnesium alloy can be greatly refined with Al-Ti-B addition.The more uniform and finer spheroidal particle phase in the Al-Ti-B refined semi-solid magnesium alloy can be observed after isothermal treatment,in which the spheroidized particle exhibits slowly coarsening tendency.The grain size with average diameters of 55～65 μm can be observed in the microstructure of the prepared magnesium.The semi-solid magnesium slurry more suitable for thixo-forming process can be obtained,and more uniformly distributed fine particles phase can be prepared with isothermal treatment at 450℃ for 90～120 min or at 465℃ for 90 min or 485℃ for 60～90 min.关键词：Magnesium Alloy;Semi-solid Isothermal Heat Treatment;Non-dendrite;Microstructural Evolution
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发布时间：2023-12-18 - 摘要：Microstructure,mechanical properties,fracture morphology and fracture mechanism of differential pressure casting Mg-10Gd-3Y-Zr alloy with solution treatment were investigated by optical microscope（OM）,scanning electron microscope（SEM）,X-ray diffraction（XRD）and tensile testing.The results show that grain size in the microstructure is increased from 73 μm to 90 μm,and hardness as wel as yield strength is firstly increased then decreased and then increased with solution temperature increasing from 500℃ to 535℃.Microstructure of T4 treated alloy is composed of α-Mg solid solution and cuboidal particles with rich（Gd+Y）phase,whose tensile strength,yield strength and elongation are 231MPa,149MPa and 4.8%,respectively,after solution treatment at 535℃ for 10 hours,exhibiting desirable comprehensive mechanical properties.The fracture morphology of the T4 treated alloy is characterized by intergranular and transgranular fracture combining with limited cleavage fracture.关键词：Mg-10Gd-3Y-Zr Alloy;Solution Treatment;Cuboidal Particles;Fracture Behavior
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发布时间：2023-12-18 - 摘要：The H13 hot working die steel for die casting was treated by quenching,tempering and secondary hardening to prevent the early-stage failure and improve the service life of mould;meanwhile,strength,plasticity,hardness and impact toughness of the H13 die steel were measured.The results indicate that the second hardening temperature of advanced H13 die steel is 50～70℃ higher than that of conventional one.The H13 die steel exhibits excellent strength-toughness properties and comprehensive service performance after quenching at 1100℃ and secondary tempering at 600℃,where the elongation,yield strength and tensile strength are 8.10%,1335MPa and 1534MPa,respectively.关键词：H13 Hot Working Die Steel;Die Casting;Mould;Quenching;Tempering
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发布时间：2023-12-18 - 摘要：An FEM model for magnesium alloy tailor-welded drawing was established on the basis of numerical analysis of weld seam movement by a commercial software,which was employed to simulate AZ31 and AZ81 magnesium alloy tailor welded drawing to understand role of bland holder force and deformation temperature on weld seam movement.The motion principle of weld seam at bottom of cup and at side wall and flange was obtained.The results indicate that weld seam moves towards AZ80 magnesium alloy at bottom of cup while it moves towards AZ31 magnesium alloy at side-wall and at flange.The simulated results are well in agreement with experimental ones.Weld seam movement of magnesium alloy tailor welded blanks drawing can be controlled by heterogeneous blank holder forces or heterogeneous temperature field.关键词：Magnesium Alloy;Tailor-welded Blanks;Drawing;Weld Seam Movement
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发布时间：2023-12-18 - 摘要：Interface reaction between TiNi alloy and BN based shell mold for investment casting Ti and its formation mechanism were described.The results show that thickness of reaction layer on castings surface makes only several micrometers even if pouring temperature of liquid TiNi alloy is 1600℃,exhibiting slight reaction between the BN based shell mold and TiNi alloy.So BN based shell mold can be substituted for Y2O3 or ZrO2 based shell mold to be used for shell-making of investment casting Ti alloy at a low pouring temperature.关键词：TiNi Alloy;BN;Investment Casting;Interface Reaction
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发布时间：2023-12-18 - 摘要：Burning-on defects often occurs in surface of investment casting pulley for port machinery when Al2O3 sand（powder）was used as surface layer coating of shell mold,which can result in the discard of the pulley due to not be able to clean.The surface burning-on defects in the investment casting pulley can be eliminated by using Cr2O3·FeO instead of Al2O3 sand（powder）as surface coating of mold shell,meanwhile,Cr2O3·FeO can decrease shrinkage porosity（hole）due to improving feeding effects on thick-large location in the investment casting pulley,increasing qualified product rate.Working mechanism of the Cr2O3·FeO sand was approached.关键词：Investment Casting;Refractory;Cr2O3·FeO Sand
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发布时间：2023-12-18 - 摘要：Hydraulic brake rotor for diesel locomotive,which has the features of distinct difference in wall thickness,requires the whole casting and high dimension precision,so it is very difficult to produce by investment casting.The technological process in investment casting hydraulic brake rotor was described including structure design,wax-pattern making,mold making and dewaxing,melting as well as pouring.The qualified hydraulic brake rotor was successfully produced by adopting combined supporter with the same materials for castings to prevent collapse and using low point wax as well as assembling welding wax-pattern,and so on.关键词：Brake Rotor;Wax Pattern;Investment Casting
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发布时间：2023-12-18 - 摘要：Microstructure and mechanical properties of in-situ sub-micron TiB2/7055 matrix composites have been investigated by OM（optical microscope）,SEM（scanning electron microscope）and XRD（X-ray diffraction）.The results indicate that uniform particle with 200～500 nm in size can be generated in 7055 aluminum matrix composites with 12% TiB2 content in volumetric fraction prepared by salt-mixture method.Appropriate Mg addition can greatly restrict the agglomeration of the TiB2 particles as a result of improving interface wettability between TiB2 particles and aluminum matrix,which can be responsible for the composites with the tensile strength of 718MPa,yield strength of 679MPa and elongation of 4.2% as well as elastic modulus of 86GPa.Fracture morphology of the composites is characterized by ductile mode,and failure of TiB2 particle with matrix interface is controlled by debonding mechanism.关键词：Aluminum Matrix Composites;TiB2 Particles;In-situ;Microstructure;Mechanical Properties
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发布时间：2023-12-18 - 摘要：TiC/Ni3Al composite coating on steel was fabricated by self-propagating high temperature synthesis in Ti-C-3Ni-Al system with addition of a little of magnesium element.The effects of Mg on self-propagating process,composition and microstructure of thermal explosive product as well as microstructure of coating were analyzed by DSC（differential scanning calorimetry）,XRD（X-ray diffraction）,SEM（scanning electron microscope）and EDS（energy dispersive spectrum）,and micro-hardness and wear resistance at room temperature and high temperature were measured on the composite coating.It is found that addition of 2% Mg can accelerate the formation of TiC/Ni3Al coating and the bonding with the steel by decreasing initial reactive temperature and shortening reactive time as a result of effectively cleaning the surface of TiC particles.TiC particles with size of less than 1μm are uniformly distributed in Ni3Al phase in prepared coating,and metallurgical bonding between coating and steel can be observed,exhibiting gradient distribution in hardness from coating to steel matrix.The wear resistance of the composites is obviously superior to that of H13 steel.关键词：Mg;TiC/Ni3Al;Composite Coating;Wear Resistance
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发布时间：2023-12-18 - 摘要：Effects of SiFe75 inoculation treatment on microstructure and properties of TiCp/Fe composites were investigated.The results indicate that graphite morphology in the microstructure is converted from coarse flake structure into fine flake and short rod structure with tending to uniformly distribute into the microstructure with SiFe75 inoculation treatment,which can greatly reduce the destroying effects of graphite on the matrix.Grain size in TiCp/Fe composites can be slightly refined with SiFe75 inoculation treatment,in which pearlite content is somewhat increased,leading to the increase of impaction toughness and tensile strength as well as improvement of comprehensive mechanical properties.关键词：TiCp/Fe Composites;Inoculation;Microstructure;Mechanical Properties
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发布时间：2023-12-18 - 摘要：Effects of different homogenized annealing temperatures and times on microstructure of as-cast AZ80 magnesium alloy were observed by OM（optical microscope）and SEM（scanning electron microscope）,XRD（X-ray diffraction）and EDS（energy dispersive spectrum）.The desirable grain size and constituent area distribution in microstructure can be obtained with homogenizing at 410℃ for 10 hours.Compressive behavior and microstructure evolution of the AZ80 magnesium alloy at high temperatures were investigated.The results show that desirable comprehensive properties of the alloy can be obtained at 300～400℃.关键词：AZ80 Magnesium Alloy;Homogenization Treatment;Microstructure;High Temperature Deformation
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- 415
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发布时间：2023-12-18 - 摘要：Dual-phase Mg alloy consisting of α-Mg and Mg12Pr was prepared by permanent mold casting.Effects of Pr content on microstructure and phase constituent of Mg-0.6Zr alloy were investigated by optical microscope（OM）,SEM（scanning electron microscope）and XRD（X-ray diffraction）.Meanwhile,the mechanical properties of the prepared alloy at room temperature were measured by tensile testing.The results show that grain size in the magnesium alloy can be refined as a result of creation of high strength intermetallic compound,which is responsible for the improvement of mechanical properties of the alloy.Compared with those of Mg-0.6Zr alloy,the tensile strength,yield strength and elongation of Mg-0.6Zr-0.6Pr alloy are increased by 9.8%,42% and 118%,respectively.关键词：Pr;Mg-0.6Zr Alloy;Microstructure;Mechanical Properties
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发布时间：2023-12-18 - 摘要：Heredity effects of fine-grained materials in ZAlSi7Mg1 alloy in sand casting were examined.Heredity of fine-grained structure was confirmed by comparatively analyzing microstructure and mechanical properties of re-molten ZAlSi7Mg1 alloy ingot in sand casting and in permanent mold casting.Heredity effects of 10% squeezing-forging fine-grained ZAlSi7Mg1 alloy on structure and mechanical properties of the alloy in sand casting were examined.The results show that the structure of ZAlSi7Mg1 alloy in sand casting can be evidently refined by adding 10% squeezing-forging fine-grained ZAlSi7Mg1 materials with holding for 20 min.关键词：Structure Heredity;Grain Refinement;Metastable Colloidal Structure;Al Alloy
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发布时间：2023-12-18 - 摘要：Microstructure and properties of Mg-xSn-2La（x=2.34～9.36）alloy were investigated by OM（optical microscope）,SEM（scanning electron microscope）,XRD（X-ray diffraction）and EDS（energy dispersive spectrum）.It is found that with 2.34% Sn content,the alloy is mainly composed of α-Mg phase and Mg-La-Sn phase.With increasing in Sn content,Mg2Sn phase in the alloy is increased greatly and Mg-La-Sn phase is gradually coarsened,meanwhile,fine granular phase is decreased as rod-like phase increases.Furthermore,more RE phase tends to distribute along the interdentritic boundaries not to along grain boundary.In addition,tensile strength and elongation of the alloy are improved greatly with Sn addition.Mg-7.02Sn-2La alloy exhibits the optimum tensile strength of 151MPa while the Mg-4.68Sn-2La alloy shows the desirable elongation of 12.7%.However,excessive Sn addition can be detrimental to the mechanical properties of the magnesium alloy.关键词：Mg-Sn-La Alloy;Microstructure;Properties
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发布时间：2023-12-18 - 摘要：After homogenized annealing at（390±10）℃ for 12 hours,AZ61 alloy was hot extruded at 360,370,385 and 400℃ with extrusion ratio of 32:1.Microstructure,mechanical properties and tensile fracture of annealed specimens and hot extruded specimens were investigated.A complete and finished product can be obtained by extruding AZ61 magnesium alloy at 370,385 and 400 ℃,however,it can not be produced by extruding at 360 ℃.With increasing in extrusion temperature,the numbers of recrystallization grain in the extruded AZ61 magnesium alloy are increased greatly,in which the uniformly fine equaixed grain are observed in the extruded specimens at 400 ℃.In addition,the specimens extruded at 370,385 and 400 ℃ are characterized by ductile fracture mechanism,and the specimens extruded at 400 ℃ exhibits excellent performance with tensile strength of 297.43MPa,yield strength of 221.42 MPa and elongation of 22.39%.关键词：AZ61 Magnesium Alloy;Hot Extrusion;Microstructure;Mechanical Properties
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发布时间：2023-12-18 - 摘要：Effects of RE erbium on microstructure and mechanical properties of permanent mold casting ZA73 alloy were investigated by OM（optical microscope）,SEM（scanning electron microscope）,EDS（energy dispersive spectrum）and tensile testing.The results indicate that semi-continuous distributed eutectic compound [τ（Mg32（Al,Zn）49）] is converted into discontinuous globular particle on boundary with minor erbium addition,meanwhile,fine Er-Al phase in the alloy can be identified.Tensile testing reveals that with increasing in erbium content,the tensile strength is improved and elongation reachs a peak value with 0.4% Er addition at 200℃.Elevated tensile strength is firstly increased and then decreased with increasing in temperature,in which the maximum value of tensile strength can be obtained at 150℃.关键词：Heat Resistant Magnesium Alloy;Erbium;ZA73 Magnesium Alloy;Microstructure;Mechanical Properties
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发布时间：2023-12-18 - 摘要：Numerical simulation of temperature field and grain structure in heated mould continuous casting Cu-10Al alloy was carried out by the Procast software based on established model on Pro/E platform.The results reveal that variation of temperature field and morphology evolution of solid-liquid interface can be accurately predicted by means of steady calculation in process of heated mould continuous casting.Meanwhile,transformation of equiaxed grain into columnar grain and competitive growth in columnar grain domain can be accurately visualized by the CAFE module.关键词：Heated Mould Continuous Casting;Numerical Simulation;Procast;Steady Calculation;CAFE Module
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- 325
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发布时间：2023-12-18 - 摘要：Microstructure of Cu-1.0Cr alloy in the non-steady directional solidification were observed in directional solidification at different growth rates to understand effects of the interface morphology in an initial transient zone on the steady solidified structure.The results reveal that the microstructure evolution of hypoeutectic Cu-1.0Cr alloy undergoes three stages:the planar primary α phase,the whole eutectic（α+β）to the dendrite α phase +eutectic（α+β）phase.With the increase of growth rates,the microstructure evolution in an initial transient zone is transferred from two stages,consisting of the planar primary α phase and the whole eutectic（α+β）,into one stage,being the single planar primary α phase,which shows that steady solidification structure can be controlled by interface morphology in an initial transient zone.The hypoeutectic Cu-Cr alloy with the whole eutectic structure can be obtained if structure evolution in non-steady unidirectional solidification process keeps in the form of planar interface for the binary Cu-Cr eutectic series alloy.关键词：Cu-Cr Alloy;Directional Solidification;Interface Morphology;Initial Transient Zone
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发布时间：2023-12-18 - 摘要：Flow stress behavior of Cu-Ni-Si-Cr alloy was examined on the Gleeble-1500D testing machine with strain rate of 0.01～10 s-1 at 600～800℃.It is found that dynamic recystallization in the alloy is closely related with strain rate and deformation temperature.With increasing in deformation temperature,dynamic recrystallization behavior is easier to be observed,in turn,with decreasing in strain rate,it is easier to be observed.Hot deformation activation energy of the Cu-Ni-Si-Cr alloy is 265.9kJ/mol.In addition,a formula for strain rate is proposed based on exponent-type equation from the Zener-Hollomon parameters.关键词：Cu-Ni-Si-Cr Alloy;Dynamic Recrystallization;Thermal Simulation
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发布时间：2023-12-18 - 摘要：Effects of rare earth element including La,Ce,Nd and Y on the electric conductivity,hardness and microstructure of pure copper were investigated.The results show that appropriate RE elements,such as La,Ce,Nd and Y can improve electric conductivity of pure copper as a result of purification and impurity removal.The desirable La,Ce,Nd and Y additions are 0.05%,0.06%,0.06% and 0.02%,respectively,in which Y element exhibits the optimum effects on improvement of electric conductivity of pure copper.Mechanical properties of pure copper can be improved with RE element addition as a result of refining grain size,especially Y element addition.关键词：Pure Copper;RE Element;Electric Conductivity;Hardness
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发布时间：2023-12-18 - 摘要：Difficulty in ellminating the defects in EPC aluminum alloy parts resuted from very complicated processing inhibited the development of EPC aluminum alloy at home.Origination of common defects in EPC aluminum alloy was described,including cold shut,inclusion,deformation,and so on,and countermeasures were proposed,such as controlling pouring temperature and melting quality,using rational filling velocity,and so on.关键词：Aluminum Alloy;EPC;Defects Analysis
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- 257
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发布时间：2023-12-18 - 摘要：We have developed a three-dimensional mechanical vibrating table to be used for LFC ZL101 alloy to understand effects of varied frequency and varied direction on microstructure and properties of ZL101 alloy.The results show that tensile strength and elongation of LFC ZL101 alloy can be improved as a result of greatly refining grain size and decreasing pinhole rate by mechanical vibration.In addition,the optimum microstructure and properties of the LFC alloy can be obtained with vibrating at 20～60 Hz in vertical direction.关键词：LFC;Aluminum Alloy;Vibration Solidification;Microstructure and Properties
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发布时间：2023-12-18 -
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