最新刊期
卷 29 ， 期 1 ， 2009
- 摘要：Semi-solid aluminum alloy slurry by ultrasonic vibration was prepared,and processing parameters, formation mechanism of non-dendrite and microstructure of semi-solid aluminum alloy were investigated. The results indicate that the semi-solid aluminum alloy slurry with fine spheroidal structure can be successfully prepared by directly vibrating liquid aluminum alloy using Ti alloy vibrator with ultrasonic power of 1.2kW at 20kHz as a result of cavitation effects and acoustic streaming effects. Grain size of primary Si in the prepared semi-solid A390 alloy slurry can be refined to approximately 20μm without P modification. Fine spheroidal primary α-Al phase with 80μm in diameters can be observed in semi-solid ZL101 alloy slurry prepred by ultrasonic vibratior.关键词：Ultrasonic Vibration;Semi-solid;Aluminum Alloy;Rheocasting
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发布时间：2023-12-18 - 摘要：Ignition point of ZM5 magnesium alloy with 0.1%MM addition can be increased by approximately 206℃. Microstructure of the ZM5 magnesium alloy with 0.1% MM addition was observed by SEM （scanning electron microscope）, EDS (energy dispersive spectrum and XRD （X-ray diffraction）. The results indicate that compact oxidation film composed of RE2O3, MgO, Al2O3 and Mg17Al12 phase is created on the surface of the ZM5 magnesium alloy, on which MM exhibits obvious enrichment. Thermodynamic analysis of the forming process of oxide film reveals that interaction between RE and MgO can increase the RE2O3 content in middle layer, resulting in the improvement of compactness of middle layer, which is responsible for the improvement of ignition-proof effects of ZM5 magnesium alloy.关键词：Ignition-Proof Magnesium Alloy;Mitschmetal;Oxidation Film;Thermodynamics
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发布时间：2023-12-18 - 摘要：Dynamic compressive behavior of Si3N4p/Al composites with 34.4%, 46.3% and 51.41% of Si3N4p ceramic content in volumetric fraction prepared by pressure-free infiltration technology was examined by the Split Hopkinson Pressure Bar apparatus with different strain rate and was compared with that of ones in quasi-static state to analyze effects of strain rate and ceramic content as well as microstructure. The results reveal that dynamic compressive strength of Si3N4p/Al composites is higher than quasi-static strength. Dynamic compressive response of the composites is characterized by the interaction of strain rate strengthening with hot softening, which is attributed to high strain rate loading resulting in high dislocation accumulation rate of aluminum matrix in the composites and high temperature-increment. Dynamic compressive strength of the composites is increased with increasing in the ceramic content, while hot softening is declined with increasing in the ceramic content and decreasing in the strain rate of aluminum matrix.关键词：Composites;Si3N4p/Al Composites;Dynamic Compressive Behavior;Strain Rate Strengthening;Hot Softening
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发布时间：2023-12-18 - 摘要：Aging characteristics of ZA35 alloy containing 3.5% Mn which was prepared by spray forming technique were examined with different holding temperature and holding time. Meanwhile, the microstructure of the alloy was observed by means of XRD （X-ray diffraction） and SEM （scanning electron microscope） and TEM （transmission electron microscope）, and mechanical properties were measured. The results indicate that mechanical properties of the spray formed ZA35 alloy containing 3.5% Mn are closely related to aging treatment. During aging treatment, two-peak hardness value of the alloy curves can be observed with increasing in aging time. Meanwhile, MnAl6 phase is preferentially precipitated from supersaturated α-Al. In addition, with increasing in aging temperature and aging time, the metastable phase of manganese, such as Al11Cu5Mn3 and CuMnZn phase, can be precipitated from the microstructure. Nano-whisker and MnAl6 particle precipitated from the alloy after aging treatment are responsible for the significant improvement of mechanical properties of the spraying formed alloy.关键词：Spray Forming;ZA35-3.5Mn Alloy;MnAl6 Phase;Aging Characteristics
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发布时间：2023-12-18 - 摘要：An estimation algorithm was proposed to calculate the displacement field of turbine blade profile during solidification based on reverse engineering in investment casting. Firstly, the turbine blade profile was reconstructed based on measured data from coordinate measuring machine （CMM）. Secondly, two-step match algorithm was employed to calculate the rotating and translating matrixes which were defined as the best space transformation of reconstructed profile to CAD model profile. Thirdly, the normal offset-distance of every node between the reconstructed profile and CAD model profile was calculated to be suggested as displacement of the node, which can be used for accurate modification of sequent mould. The practical validation shows that the method mentioned can achieve the accurate estimation for displacement of turbine blade profile in investment casting, providing a desirable basis for mould modification.关键词：Displacement Field Estimation;Turbine Blade;Reverse Engineering;Mould Modification
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发布时间：2023-12-18 -
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- 摘要：Response of the location of the liquid/solid interface to processing parameters （cooling distance and pulling velocity） in OCC （ohio continuous casting） was expounded. The physical and mathematical models were established based on heat transfer in OCC process to obtain response function of location of liquid/solid interface to different cooling distance and pulling speed. Response ability of the location with varying in cooling distance and in pulling speed was simulated by the model. The results reveal that adjustment of cooling distance is prioror in the closed-loop control of the OCC process.关键词：OCC Process;Numerical Simulation;Liquid/solid Interface Location;Response Function
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发布时间：2023-12-18 - 摘要：Microstructural evolution of Al-Cu alloy in semi-continuous casting was simulated by means of a multi-scale calculation method. A new method for semi-solid alloy design was proposed on the basis of microstructural simulation. Temperature field and phase transformation models were established to simutate continuous casting, in which solid fraction was used to couple the calculation of macro-scale and mesoscale. Non-physical boundary for outlet side of mold in continuous casting was established based on an extrapolation method, which exhibits high efficient accuracy for steady temperature field. Effects of chemical composition, pouring temperature and pouring velocity on microstructure and constituent distribution of Al-Cu alloy were simulated by the multi-scale model. The results reveal that grain is grown dendritically and form grain boundary with high alloy concentration due to the merging of adjacent grain with different orientations. The desirable semi-solid microstructure in the Al-Cu alloy can be observed with 8.0% Cu content, where microstructure of the alloy is slightly related to casting velocity and pouring temperature. The simulated results are well in agreement with experimental ones in ZL201 alloy, which shows that the multi-scale simulation is an effective method to simulate design of semi-solid alloy and to predict processing parameters.关键词：Multi-scale Simulation;Semi-solid Forming;Near-Liquidus Casting;Liquid/solid Phase Transformation
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发布时间：2023-12-18 - 摘要：Design of monitor and controller for die casting machine was proposed based on the DSP to improve control system performance of die casting machine and to relief labor intensity of worker as well as raising product quality and efficiency. Based on TMSS320F2812DSP core, the monitor and controller extend peripherally storage module, communication module, analogue input/output module and human-machine interface to fully utilize powerful computing capability, which exhibits the desirable availability of real time detecting die processing parameters and real-time controlling die casting process.关键词：Die-casting Machine;Monitor and Controller;Circuit Layout;Injection
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发布时间：2023-12-18 - 摘要：In process of low-pressure die-casting filling for aluminum alloy wheel, the pressure condition is the key influential factors for quality. A method of non-linear pressure load was put forward. Based on the simulation of linear pressure and non-linear pressure, feasibility of non-linear pressure was validated, and effects of pressure condition on filling process and defects in die casting were described. Steady filling process can be realized by applying non-linear pressure to wheel with complicated cavity. Pressure-applying velocity can be properly increased after front-flow fills the cavity. The pressure should be increased gently in the filling of wheel spoke and lower half-space of wheel rim, while in the rising filling process of wheel rim, the pressure-applying velocity can be increased once again. The results indicate that non-linear pressure condition can greatly reduce defects in filling process to improve the qualified product rate of complicated wheel. The rational non-linear pressure condition can be realized by numerical simulation and trial die-casting under the condition of keeping steady front-flow.关键词：Aluminum Alloy Wheel;Numerical Simulation;Low Pressure Die Casting Filling;Non-linear Pressure-applying;Pressure Condition
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发布时间：2023-12-18 - 摘要：Hard spots in die casting ZL111 aluminum alloy crankcase were observed by OM （optical microscope）, electronic prober and micro-hardness tester, and so on. The results reveal that serious segregation and exceeding-standard of chemical composition in the crankcase can be examined. There exists heterogeneous distribution of white block and gray inclusion as well as low-gray compound hard spots in the microstructure, which coresponding to quenching low hardness spots entrapped by turbulent flow injection, unsmelted Si phase and spinel, MgAl2O4, AlSiMnFe phase as well as compound hard spot of intermetallic compound, respectively.关键词：Aluminum Alloy;Die Casting Parts;Hard Spot;Defects
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发布时间：2023-12-18 - 摘要：In order to improve the performance operation for various aluminum castings, a multi-functional counter-gravity casting device for aluminum alloy was developed. Key structure of the device consists of two sealed-in jar, i. e. the upper jar and the nether one, in which fuzzy algorithm treated integral-separated PID is taken as control project of the control system, and combined valve controlled by digital signal is adopted as the executive unites of the pneumatic system. Three counter-gravity castings methods including low-pressure casting, differential-pressure casting and vacuum-assisted pressure casting can be accomplished by combining the control system with the main body of equipment, improving the practicability of the counter-gravity casting equipment.关键词：Counter-gravity Casting;Equipment;Aluminum Alloy;Multi-function
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发布时间：2023-12-18 - 摘要：Effects of processing parameters including pouring temperature, casting pressure, fast shot speed and fast shot shift point on porosity in aluminum alloy air-conditioning compressor cylinder were investigated by measuring density of as-cast and heat treated die casting cylinder. The results reveal that porosity rate in the cylinder is increased with increasing in pouring temperature and in fast shot speed while it is decreased with increasing in fast shot shift point, and it is firstly increased then decreased with rising in casting pressure. Minimum porosity in the cylinder can be obtained with pouring at 700720℃ and casting pressure of 104MPa, shot velocity of 1.49m/s as well as fast shot shift distance at 320 mm, exhibiting desirable properties.关键词：Die Casting Parameters;R14 Aluminum Alloy Air-conditioning Compressor Cylinder;Changing Rate of Density;Porosity
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发布时间：2023-12-18 - 摘要：Microstructure and properties of solution treated semi-solid AZ91 magnesium alloy slab which was forged with 60% reduction at 400℃ after extrusion were investigated. The results indicate that fine grain size in extruded AZ81 magnesium alloy can be observed, in which major broken Mg17Al12 phase is dispersedly distributed along grain boundary with minor streamline ones. Yield strength, tensile strength and elongation of the extruded alloy are increased by 69.9%, 63.2% and 164.6%, respectively, compared with those of semi-continuous alloy slab. Refiner grain size can be observed in extruded AZ81 magnesium alloy after forged treatment, in which re-broken Mg17Al12 is partly dissolved into grain. The yield strength, tensile strength and elongation of extruded AZ81 magnesium alloy after forged treatment reach 229MPa, 337MPa and 15.5%, respectively, increased by 9.6% and by 8.7%, 22.3%, respectively, compared with those of extruded ones, greatly improving the mechanical properties. Properties of the AZ81 magnesium alloy are closely related to the refinement of grain and distribution of Mg17Al12 phase. SEM and OM observation show that fracture morphology of extruded-forged AZ81 magnesium alloy is characterized by ductile crack.关键词：AZ81 Magnesium Alloy;Extruded-forged Process;Microstructure
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发布时间：2023-12-18 - 摘要：Effects of gas film on meniscus shape and surface quality of semi-continuous casting 6063 aluminum alloy slab were investigated in the condition of gas-film lubrication. The results reveal that gas film lubrication can narrow un-feeding zone in slab during solidification by controlling meniscus shape, which can eliminate initial hot crack as a result of decreasing internal stress and strain. Meanwhile, gas film can shorten working cooling length of mould by decreasing first-cooling rate, which can be responsible for the elimination of cold shut and segregation tumor. Furthermore, the surface quality of the semi-continuous 6063 aluminum alloy slab is evidently improved due to the soft contact between liquid aluminum alloy and mould by gas confinement resulting in the reduction of friction with mould wall.关键词：Gas Film Semi-continuous Casting;Hot Crack;Meniscus Shape;Surface Quality
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发布时间：2023-12-18 - 摘要：Effects of solution treatment, aging treatment and solution +aging treatment on microstructure and properties of electromagnetic continuous casting AZ31 magnesium alloy slab were investigated. The results indicate that microstructure and properties of the slab are related to different heat treatment processes. Hardness and ductility of solution treated slab are increased, while hardness of the aged slab is increased with the decrease of ductility. Meanwhile, hardness and impact absorption power of the slab treated by solution + aging treatment reach 51.52 and 3.40J, respectively. The impact absorption power and hardness of slab treated by an optimized heat treatment can reach 3.75J and 51.60, respectively.关键词：AZ31 Magnesium Alloy;Electromagnetic Continuous Casting;Heat Treatment;Microstructure;Mechanical Properties
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发布时间：2023-12-18 - 摘要：Design of mould for EPC gray cast iron sleeve was described based on Pro/E software. According to structure of gray cast iron sleeve and features of EPC mould, insert structure was adopted in which dovetail slot was set between movable block and frame-orientation as well as guiding structure. Practical production verifies that mould design and product efficiency can be greatly improved by aid of the Pro/E software. In addition,the EPC mould exhibits the advantages of convenient operation, easy binding and accurate size.关键词：EPC;Mould Design;Pro/E Software
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发布时间：2023-12-18 - 摘要：Visualization of vacuum EPC plowshare was conducted by means of the ProCAST software based on Pro/E modeling. Flow field, temperature field and stress field during filling process were simulated to predict defects in EPC plowshare, and the feasibility of design was confirmed. The practical production was conducted to validate the simulated ones. The simulated results are well in agreement with experimental ones, verifying the availability of visualization.关键词：Plowshare;Simulation;ProCAST Software;Vacuum EPC;Stress Field
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发布时间：2023-12-18 - 摘要：Developing tendency of investment casting industry at home was analyzed, and shell-making materials for investment casting were comparatively described. A new energy-saving binders for investment casting-ZF-801 rapidly dried sol silicate was introduced. Effects of ZF-801 rapidly-dried sol silicate on shell-making time, castings accuracy, surface quality, ambient and high temperature as well as residual strength of shell mold were described. The results indicate that the sol silicate can fully meet the production requirements.关键词：Rapidly Dried Sol Silicate;Energy-Saving;Investment Casting;Shell-making
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发布时间：2023-12-18 - 摘要：According to structure features of aerospace components, bottom gating-feeding system with multi-element structure was designed to produce the components in the condition of non-vacuum main frequency induction furnace with shell mold temperature of 1050℃ and pouring at 1580℃ and 34 kg/s. The produced aerospace components can be passed by XRD and fluorescence detection. Meanwhile, the components can be checked successful by air pressure at 300kPa for 60 s. Finished qualified product rate can reach up to 95%.关键词：Multi-element Structure;Bottom Gating-feeding System;Investment Casting
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发布时间：2023-12-18 - 摘要：Hardness and wear resistance of ternary boride cermet on steel substrate prepared by casting-infiltration method were examined, and microstructure and element distribution in casting-infiltration layer were observed by SEM （scanning electron microscope） and EDS （energy dispersive spectrum）. It is found that the Rockwell hardness and Vickers hardness of the composites reach HRA 74.3 and 789 N/mm2, respectively. The wear mechanism of the composites is characterized by abrasive friction. Mechanism of casting-infiltration was described also.关键词：Casting-infiltration;Ternary Boride;Cermet
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发布时间：2023-12-18 - 摘要：Al2O3 particle reinforced Al matrix composites were prepared in Fe2O3-Al system by in-situ synthesis. The microstructure of the composites was observed by OM （optical microscope）, SEM （scanning electron microscope） and TEM （transmission electron microscope）. The results reveal that net-like Fe-enrichment phase can be observed in the composites and fine in-situ particle with less than 0.5μm in size is uniformly distributed in the microstructure. In addition, Al2O3 particle with round edges can exhibit desirable and clear bonding with matrix. Hardness of the composites is slightly increased, however, ambient tensile strength is somewhat decreased, while tensile strength at 300℃ reaches up to 92.18MPa, increased by 26%, compared with that of matrix.关键词：Aluminum Matrix Composites;In-situ Synthesis;Al2O3 Particle;Fe2O3
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发布时间：2023-12-18 - 摘要：Effects of different SiO2 addition on microstructure, crystal growth and mechanical properties of Al2O3/33ZrO2（4Y） composites prepared by combustion synthesis under high gravity were investigated by XRD（X-ray diffraction）, SEM （scanning electron microscope） and EDS （energy dispersive scalometry）. The results reveal that phase constituent in the ceramic composites can not be changed with SiO2 addition, however, with increasing in SiO2 addition, the structure of ceramic composites is converted from cell eutectic colonies into rod-like ones, in which the length-diameter ratio of rod-like eutectic colonies is gradually raised with the decrease of volumetric fraction. As a result of the dual effects of the SiO2 particle on viscosity of the ceramic melts, the relative density of the composites reaches the maximum value of 97.3% with 6% SiO2 addition. Meanwhile, the hardness of ceramic composites is declined, which is attributed to the formation of SiO2 amorphous phase in ceramic composites. In addition, due to the enhanced toughening effects of crack-bridging and crack deflection contributed by the rod-like eutectic colonies, the fracture toughness of the ceramic composites can reach up to 15.9MPa·m1/2 with 6% SiO2 addition.关键词：Al2O3/ZrO2（4Y） Composites;Combustion Synthesis;High Gravity;Crystal Growth;Additive
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发布时间：2023-12-18 - 摘要：Effects of different Si content and cooling rate on particle agglomeration and mechanical properties of SiCp/Al-Si composites were investigated by SEM （scanning electron microscope）. The results reveal that when Si content in matrix alloy is less than 12%, with increasing in Si content, SiC particle agglomeration in the composites can be distinctly relieved, however, when Si content in matrix alloy is more than 12%, with increasing in Si content, its relief can be neglected. SiC particle in Al-7Si alloy is repelled into eutectoid to cause particle agglomeration in sand casting while it is uniformly distributed in the microstructure in graphite mold casting since high cooling rate restricts the movement of SiC particle. Mechanical properties of the composites are decreased with increasing in Si content in matrix alloy, however, it can be greatly improved with increasing in cooling rate.关键词：Si Content;Cooling Rate;Aluminum Matrix Composites;SiC Particle Agglomeration;Mechanical Properties
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发布时间：2023-12-18 - 摘要：As-cast microstructure and phase constituent of AZ91 magnesium alloy containing 2.5% RE （RE presents Nd or Ce only or mixed Nd and Ce ） were observed by means of SEM （scanning electron microscope） and XRD （X-ray diffraction）, and ambient mechanical properties of the alloy were measured. The results indicate that bulk Al2Nd phase and acicular Al11Ce3 phase can be created in the AZ91 magnesium alloy with Nd addition only and one with Ce addition only, respectively. Meanwhile, both the bulk Al2Nd phase and acicular Al11Ce3 phase can be generated in the AZ91 alloy with mixed addition of Nd and Ce, in which relative content is positively related to the relative concentration of Nd and Ce, in which a part of Nd atom in the Al2Nd phase is substituted by Ce atom and a part of Ce atom in the Al11Ce3 phase is substituted by Nd. Mechanical properties of AZ91 magnesium alloy can be acceptably improved with addition of Nd and Ce, which is attributed to the depletion of Al in matrix by RE phase and the refinement of grain as well as dispersion strengthening, and the tensile strength and elongation of as-cast alloy are 240MPa and 11%, respectively, with 1.0% Nd and 1%Ce mixed addition, exhibiting desirable mechanical properties.关键词：AZ91 Magnesium Alloy;Ce;Nd;Microstructure;Mechanical Properties
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发布时间：2023-12-18 - 摘要：Effects of RE elements Y and Nd on microstructure and mechanical properties of aged Mg-5Al alloy were investigated based on microstructural analysis and mechanical testing. It is found that with trace Y or Nd addition, Al2Y or Al2Nd particle or rod and acicular Al2Nd can be observed in the alloy, which results in the decrease and fine dispersed distribution of Mg17Al12 phase. In addition, grain size in Mg-5Al alloy can be refined from 104.5 μm to 86.1 μm, 83.5 μm and 78.6 μm, respectively, with 0.5% Y or 0.5% Nd or 0.5%Y and 0.5%Nd mixed addition. WithY or Nd addition, tensile strength and elongation of the alloy are improved, in which desirable tensile strength and elongation of the alloy, 225.2MPa and 13.92% , respectively, can be measured with 0.5%Y and 0.5%Nd mixed addition.关键词：Y;Nd;Magnesium Alloy;Microstructure;Mechanical Properties
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发布时间：2023-12-18 - 摘要：Intergranular corrosion and stress corrosion cracking resistance of Al-Zn-Mg-Cu alloy with trace Er addition were examined by means of stress corrosion cracking and intergranular corrosion testing from GB-T7998-2005 and HB5254-83, and microstructure of the alloy was observed by OM （optical microscope） and SEM （scanning electron microscope）. The results indicate that trace Er addition can greatly improve intergranular corrosion and stress corrosion cracking resistance of the alloy, however, with more than 0.4% Er addition, stress corrosion cracking resistance will be descended.关键词：Al-Zn-Mg-Cu Alloy;Er;Intergranular Corrosion;Stress Corrosion Cracking
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发布时间：2023-12-18 - 摘要：Micro-arc oxidation coating was prepared by micro-arc oxidation methods on ZAlSi12Cu2Mg1 alloy in Na2SiO3 electrolytes. Effects of Ce concentration in the electrolyte on electrical conductivity, positive/negative current during micro-arc oxidation process and coating properties were investigated. The results reveal that with increasing Ce concentration from 0 to 0.125g/L in the electrolytes, electrical conductivity of the electrolytes is increased from 15.15 MS/cm to 16.54 MS/cm, meanwhile, current in micro-arc oxidation process is obviously varied also. With increasing in Ce concentration in the electrolytes, coating thickness and micro-hardness are firstly increased then gradually decreased, in which the coating thickness of approximately 258μm and coating micro-hardness of HV620 can be obtained with 0.025g/L Ce concentration.关键词：Micro-arc Oxidation Coating;Ce;ZAlSi12Cu2Mg1 Alloy;Micro-arc Oxidation
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发布时间：2023-12-18 - 摘要：High temperature compression testing for Ti-6Al-2Zr-1Mo-1V alloy was carried out by thermecmastor-Z simulator with strain rate from 0.1 to 10s-1 and 50% deformation degree at 7501100℃. Effects of deformed processing parameters on the flow stress were examined, and stress exponent and activation energy were calculated at different temperatures, meanwhile, the hyperbolic sine constitutive equation for the alloy was established. The results indicate that true stress-strain curves of the alloy are characterized by flow softening behavior at 750950℃ while it is characterized by steady flow behavior at 10001100℃. In addition, deformation activation energy Q is 828.9kJ/mol at 7501000℃ and 197.1kJ/mol at 10001100℃, showing different deformation mechanism at different temperature ranges.关键词：Ti-6Al-2Zr-1Mo-1V Alloy;Constitutive Equation;Deformation Activation Energy;Flow Stress
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发布时间：2023-12-18 - 摘要：Effects of environmental humidity and pouring temperature on the hydrogen absorption in aluminum melt were examined by pressure-reduction solidification method. The results show that with a given humidity, hydrogen content in aluminum melt is increased with increasing in temperature, while with a given pouring temperature, hydrogen content is increased with increasing in humidity also. Theoretical hydrogen partial pressure was estimated by means of relative theory with a fixed environmental humidity and pouring temperature, which was comparatively analyze with actual hydrogen partial pressure from experiment, obtaining the ratio of hydrogen to the aluminum melt.关键词：Aluminum Alloy;Humidity;Pouring Temperature;Hydrogen Content
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发布时间：2023-12-18 - 摘要：Microstructural evolution of a commercial pure aluminum during hot compression at elevated temperatures was observed by OM （optical microscope） and TEM （transmission electron microscope） with Gleeble-1500 dynamic materials testing machine at different compression rates. The results indicate that true stress-true strain curves are characterized by steady state with a strain rate of 0.01 s-1 at 220℃ and 300℃, exhibiting occurrence of dynamic recovery, while occurrence of dynamic recrystallization in the pure aluminum can be observed at temperature more than 380℃. Furthermore, dynamic recrystallization occurs in the pure aluminum with a strain rate of 0.0011 s-1 and at 460℃. Dynamic recrystallization mechanism is characterized by continuous dynamic recrystallization and geometric dynamic recrystallization.关键词：Commercial Pure Aluminum;Hot Compression;Microstructural Evolution;Dynamic Recrystallization
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发布时间：2023-12-18 - 摘要：Effects of Ti modification and holding time on as-cast microstructure and mechanical properties of ZcuZn40Pb2 alloy were described. It is found that as-cast microstructure of the lead brass can be refined with Ti addition, which results in the increase of mechanical properties as a result of coarse α,β plate transforming into short-fine lamellar structure. The satisfactory refinement in microstructure of the lead brass can be observed with addition of 0.06%0.10% Ti. However, modification effects of Ti on the lead brass are faded with increasing in holding time, and desirable refinement can be obtained with pouring after holding time for 30min.关键词：ZCuZn40Pb2 Alloy;Ti;Modification;Fading;Microstructure
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发布时间：2023-12-18 -
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- 摘要：C194 alloy was melted in a main frequency induction furnace with gas protection. The hot rolled C194 alloy ingot which is immediately water-quenched is cold-deformed with deformation rates of 30%, 60% and 90%, respectively, and then it is aged treatment at 550℃ for 2 hours /450℃ for 2 hours （aging treatment A）and at 400℃ for 4 hours （aging treatment B）, in which cold rolling with deformation rates of 30%, 60% and 90% before aging treatment B is conducted. Effects of thermo-mechanical treatments on the microstructural evolution of precipitates and transformation kinetics of the C194 alloy were examined by TEM （transmission electron microscope）. The results indicate that transformation kinetics of the C194 alloy is increased with increasing in aging temperature and cold rolling deformation rate. The C194 alloy with uniformly distributed fine precipitates which exhibits desirable comprehensive properties can be obtained with 60%90% cold deformation+aging treatment A+30%60% cold deformation+aging treatment B.关键词：C194 Alloy;Thermo-mechanical Treatments;Microstructure;Transformation Kinetics
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发布时间：2023-12-18
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