最新刊期
卷 ， 期 6 ， 2006
- 摘要：Effects of Cu on crystallization behavior of Fe 74Al4Ga2P 12B4Si4 amorphous alloy were investigated by observing the isothermal crystallization phenomenons of Fe 74Al4Ga2P 12B4Si4 amorphous alloy and Fe 73Al4Cu1Ga2P 12B4Si4 amorphous alloy at 500550 ℃. Crystallization phase composition from XRD and DSC analysis indicates that Cu can decrease crystallization temperature （Tx） and disappear the glass transition temperature of the alloy, and create the quenched nucleus. Meanwhile, enriched-Cu can take as the site of α-Fe phase to inhibit the growth and to refine the grain size, changing the crystallization mode and finished crystallization product.关键词：Fe-based Amorphous Alloy;Crystallization;Crystallization Temperature;Crystallization Product
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发布时间：2023-12-18 - 摘要：Cylindrical bulk amorphous alloy Cu 60-xZr 30Ti 10Snx （ x=0,1,2） with diameter of 23 mm have been prepared by copper mould sucking casting. The structure and heat stability as well as crystallization behavior of the amorphous alloy were observed by means of XRD （X-ray diffraction） and DSC （differential scanning calorimeter）. Characteristic temperatures of the amorphous alloy Cu 60-xZr 30Ti 10Snx （x=0,1,2）, such as glass transition temperature Tg, crystallization temperature Tx and supercooled liquid region, are controlled by Sn content. For the Cu 58Zr 30Ti 10Sn2 amorphous alloy, Tg and Tx, △Tx are about 703.9 K, 755.5 K and 51.6K, respectively. The characteristic temperatures are gradually tended to high temperature zones with DSC heating rate increase, where the dynamic effect of crystallization is much higher that of glass transition. The activation energies of bulk amorphous alloy Cu 58Zr 30Ti 10Sn2 calculated using Kissinger are list as follows: the glass activation energy, Eg, about 3.30 eV, crystallization activation energy,Ex, about 3.17 eV, that for the first crystallization peak, E p1, about 2.82 eV and that for the second crystallization peak, E p2, about 3.13eV. Although the corresponding values, derived from Ozawa method, are slightly lower, it shows a similar tendency compared with ones derived from the Kissinger.关键词：Cu 58Zr 30Ti 10Sn2;Bulk Amorphous Alloy;Crystallization Behavior;Activation Energy
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发布时间：2023-12-18 - 摘要：A high stable colloid state sodium-based compound phosphate binder is developed by modifying simple sodium phosphate with hydronium. Al 3+, Mg 2+ and B 3+ were introduced to enhance anti-moisture-absorption. At a lower temperature, the metal ions compound modified binder possesses a higher collapsibility.关键词：Sodium Phosphate;Colloid;Stability;Anti-moisture-absorption
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发布时间：2023-12-18 - 摘要：Co-reduction in AB5 type Re hydrogen storage alloy was conducted by a multi-element alloying method. Low Co-AB5 type hydrogen storage alloy containing V can be prepared by substituting V （0.02, 0.05, 0.08） for Co based on M1（NiCoMnAl） 4.5 （CuFeCrZn） 0.5-xVx hydrogen storage alloy. The discharge capacity, cycling stability and microstructure of the alloy were measured. It is found that although low Co hydrogen storage alloy containing V has excellent comprehensive electro-chemical properties, V content should be controlled strictly below 0.08, where the alloy exhibits better comprehensive electro-chemical properties with 0.02% V content.关键词：Hydrogen Storage Alloy;Electro-Chemical Properties;Low Co Alloy
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发布时间：2023-12-18 - 摘要：Effects of electropluse and direct current on supercooling of the Wood′s alloy were examined based on the some popular electromagnetic field theories. The results show that electro-pulse can reduce the supercooling of the Wood′s alloy, while direct current has alternative effects on the supercooling, which can increase the supercooling with low direct current, and reduce supercooling with high direct current. All the experimental results are relative to the selected material, and applied electric parameters have applicable scope.关键词：Melting Metal;Electric-pulse;Direct Current;Cooling Curves;Supercooling
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发布时间：2023-12-18 - 摘要：Amounts of alias during visualization in post-processing occur due to the special topology of hexahedral grid based on the finite difference method. Based on pre-processing the calculated data, through chamfering surface grids and extracting the smooth contour, represented by triangle primitive, of surface grid to render the contour, the high quality graphs with spars alias or no alias can be obtained, having solved the alias problems during visualization in solidification simulation. Results show that accurate, real-time and realistic visualization effects can be realized by the method.关键词：Solidification Simulation;Casting CAE;Post-processing;Alias Smoothing
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发布时间：2023-12-18 - 摘要：The relationship between heat transfer coefficient and surface temperature of aluminum alloy in water cooling stage is described by inverse method based on measuring temperature distribution of aluminum alloy ingot with diameters in 100 mm in semi-continuous casting with direct water-cooling. The calculated results show that the heat transfer coefficient is increased with decrease in surface temperature of the ingot, and especially decreased temperature from 400 ℃ to 130 ℃, the heat transfer coefficient is dramatically increased, where the maximum value about 23 000 W/（m2·K） can be observed at 130 ℃. After that, the heat transfer coefficient is rapidly decreased with temperature decline. A FEM model was built to analyze the temperature field and shell growth of ingot. The calculated results are well in agreement with the experimental ones.关键词：Temperature Field;Casting;Numerical Simulation;Aluminum Alloy
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发布时间：2023-12-18 - 摘要：The electro-negativities, Gibbs free energy of oxidation reaction and physical properties of some alloying elements and their oxides were compared. It is pointed out that alkaline earth and rare earth elements are dominant in ignition-proof of is used to, especially Be element. RE elements is used to substituting Be and Ca due to high toxicity of Be and be inferior to mechanical properties of the Mg alloy with Ca. The oxidation and ignition temperatures of AZ91 magnesium alloy with somew hat Ce addition were measured. The results show that although the oxidation and ignition temperatures of the alloy are raised, their increasing velocity is slowed with Ce addition increase, increasing by 33 ℃ and 61 ℃, respectively, with 1% Ce addition, compared with those of the AZ91 magnesium. The advisable Ce addition is about 0.6% for ignition-proof AZ91Mg alloy.关键词：Magnesium Alloy;Ignition-proof;Alloying;Thermo-dynamics;Oxides;Ignition Temperature
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发布时间：2023-12-18 - 摘要：Effects of electromagnetic filling on microstructure and properties of Al alloy components in low pressure castings were investigated. The key influential factors on microstructure and properties of the Al alloy components were determined by orthogonal testing and metallographic analysis. The results show that the influential orders of electric current, magnetic inductivity and cyclic time on the properties of the ZL104 alloy components are as follows: magnetic inductivity, then electric current, and then cyclic time. Electromagnetic field can effectively refine the microstructure of the components, significantly improving the mechanical properties of the ZL104 alloy components in low pressure casting.关键词：Aluminum Alloy;Electromagnetic Casting;Low Pressure Casting
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发布时间：2023-12-18 -
Design of Gating System and Optimization of Processing Parameters for Magnesium Alloy in Die Casting
摘要：The gating system of S11-1001211cb supporter was designed based on the design principle of the gating system for the die casting magnesium alloys. The optimized design was conducted by simulating filling process using the Flow-3D software. The optimized gating system was determined by analyzing simulation effects of three kinds of gating systems. In addition, effects of filling velocity on formality and quality of the supporter were investigated by the computer simulation to optimize processing parameters. The casting defects are reduced as possible to improve the quality of the supporter by setting overflow slot on the potential defect position.关键词：Die Casting;Magnesium Alloy;Numerical Simulation- 2
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发布时间：2023-12-18 - 摘要：The hot crack in die-casting magnesium alloys was observed, and its forming mechanism was analyzed in detail. The results show that the hot crack is resulted from the low thermal intensity, high hot brittleness and concentration of shrinkage stress in solidifying point area. The hot crack can be eliminated by properly adjusting chemical composition of the Mg alloy, enlarging chamfer size in hot crack position and altering processing parameters.关键词：Die Casting;Mg Alloy;Hot Crack
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发布时间：2023-12-18 - 摘要：Effects of different graphite particle contents on friction and wear behavior of AZ91 magnesium matrix composites were investigated. The results show that friction and wear behavior of the composites is obviously superior to that of the matrix alloy at an investigated range. With graphite particle content increasing from 5% to 20%, wear weight-loss and friction coefficient of the composites are obviously declined, greatly improving wear resistance of the composites. There is different wear mechanisms at different wear stages. Improvement of the wear resistance of the Mg matrix composites is attributed to gradually forming a layer continuous black lubricant film on the wore samples to effectively prevent direct contact of two friction wheel during wear process.关键词：Mg Alloy;Composites;Graphite Particle;Wear and Friction
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发布时间：2023-12-18 - 摘要：Slide-wearing behavior of in-situ （Al3Zr +Al2O3）p/A359 composites prepared in A359- Zr（CO3）2 system was observed in the condition of boundary oil lubricant. The results show that wear weight-losses of the composites is much lower than that of the matrix with increasing load and extending loading time due to wear resistant effects of the reinforced particles. Wear weight-loss of the composites with 12% particle and the matrix are 4.9 mg and 27.5mg, respectively, at loading of 1 176 N, improved by about 6 times. SEM observation shows that wear morphology of the A359 matrix exhibits adhesion wear and eroded wear due to its significant adhesion and deformation, while wear morphology of the composites shows friction wear.关键词：(Al3Zr +Al2O3)p/A359 Composites;In-situ Synthesis;Boundary Oil Lubrication;Wear
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发布时间：2023-12-18 - 摘要：The configuration and various function of automatic control system for arc billet continuous caster are introduced, and practical production as well as computer simulation is conducted. The system is developed based on the automatic control system of rectangular bloom continuous caster in Capital iron & steel designed by DANIELL Co from the Italy. Some helpful experiences are given for the improvement of running continuous casters and design of new caster.关键词：Continuous Caster;Automatic Control;PLC Network
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发布时间：2023-12-18 - 摘要：A simple and feasible method of preparing of semi-solid low alloy steel slurries at near liquidus temperature with medium-frequency induction furnance at holding is described. The effects of holding temperature, holding time and heating ways on the microstructure of the slurries are understood by observing water-quenched and air-cooled microstructures at different holding conditions. Few free nucleus are formed in the melt under the condition of large superheat or supercooling, resulting in coarse water-quenched microstructure, while amounts of free nucleus are created to uniformly distribute into the melt to greatly refine and homogeneousize the water-quenched microstructure at near liquidus temperature （1 508 ℃）, and it do so at air-cooled conditions. Electromagnetic stirring in medium-frequency induction furnace can greatly increase nucleus amounts at near liquidus temperature with short holding time and then keep the morphology and amounts of the nucleus. So change of the water-quenched microstructure of the semi-solid slurries can not be observed at holding for 550 min.关键词：Semi-solid;Near Liquidus Temperature;Low Alloy Steel;Microstructure
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发布时间：2023-12-18 - 摘要：The thixotropic behavior of semi-solid AlSi6Mg2 aluminum alloy slurries was investigated through Couette type viscometer in the condition of isothermally stirring. The results show that apparent viscosity of the semi-solid AlSi6Mg2 aluminum alloy slurries is gradually declined to tend to a steady state with continuously cooling and isothermally stirring. However, the apparent viscosity of the slurries is rapidly increased and then quickly fallen down to a steady state value when stirring for the slurries is stopped at holding temperature for some time and then started again at some shearing rate, showing a typical shearing-thinning behavior. The longer the holding time is, the higher the apparent viscosity in initial shearing stage is and the longer the required steady state time is, meanwhile the steady apparent viscosity is slightly inclined. During isothermal shearing, the apparent viscosity will be declined or increased rapidly and then gradually declined to a steady state value with sharply raising or dropping shearing rate. The experimental results also show that the time required to reach a new steady state with sharply raising shearing rate is much shorter than that required with sharply dropping shearing rate.关键词：Aluminum Alloy;Semi-solid;Thixotropic Behavior;Apparent Viscosity
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发布时间：2023-12-18 - 摘要：Effects of rare earth on the heat fatigue resistance and oxidation resistant of cast iron parts in permanent mould were investigated to improve heat fatigue resistance of cast iron tool materials for glass industry. Ni-Mo-Re cast iron is formed in the low alloying cast iron with adding RE containing 0.05%Ce and 0.1% La. Heat fatigue experiment of the samples annealed at 900 ℃ on a self-developed heat fatigue tester indicates that Re elements can obviously improve the mechanical properties at high temperature of Ni-Mo grey cast iron.关键词：RE;Permanent Mould Castings;Heat Fatigue
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发布时间：2023-12-18 - 摘要：The significance of measurements for high temperature strength of investment casting shell materials was expounded. The structure, measuring principle and operation of a new measuring tester for bending strength at a high temperature are introduced. The measuring tester can obtain high accuracy-position and reduce synchronous-temperature testing time between mould and sample by holding sample in a high temperature model, approximately exhibiting stress state of poured shell mold. Based on above principle, computer can visualize the loading curves and experimental temperature through treating measuring symbol from loading device-measuring-force-sensor-A/D converter. The results show that the measuring error of the measuring tester is below 0.1%, showing high accuracy. Meanwhile, measuring results indicated as loading curves and temperature is accurately visualized, which is helpful to finding out abnormal data and to treating experimental data, meeting the requirements of research institution and enterprises.关键词：Investment Casting;Shell Mold;High Temperature Strength;Measuring Instrument
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发布时间：2023-12-18 - 摘要：Both press mould and gating-riser should be considered in design of investment castings. However, one formed gating-riser, such as round and square, is not proper to assemble on some castings due to the castings shape, the other formed gating-riser can have affected the appearance of the castings, especially some cylindrical castings. So the special arc ingate for this castings should be considered. The application of arc ingate in investment casting was introduced.关键词：Arc Ingate;Investment Castings;Design
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发布时间：2023-12-18 - 摘要：Microstructures of some typical refiners, including Al-Ti-B, Al-Ti-C, Al-Ti and Al-B master alloy, were observed and their refinement effects on A356 alloy were examined. The results show that secondary phase size and distribution in A356 alloy can affect refinement effect with Al-Ti-B master alloy. 4# refiner from the Holand with small Al3Ti size and uniformly distributed TiB2 have the most refining effects on the A356 alloy among these refiners, in which the size of primary Si phase is 500 μm at holding for 30 min with 0.2% addition. As 0.2% and 0.5% additions for these four kinds of refiners, Al-Ti-B has the most refinement effects on the A356 alloy. The refinement effects had no obvious difference at a high cooling rate while Al-3B refiner is better at lower cooling speed for the four kinds of refiners.关键词：A356 Alloy;Refiner;Refinement
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发布时间：2023-12-18 - 摘要：S-N curves of welding joint were established by investigating fatigue behavior of LF2 aluminum alloy joint for stirring friction welding. The experimental results show that fatigue strength of stirring friction welding joint is about 5965 MPa at fatigue life N=106, showing excellent fatigue behavior. Fatigue behavior of the joint was improved due to fine equiaxed grain and narrow heat effect zone inhibiting formation of slide-zone and propagation of crack. Fatigue fracture analysis shows that failure occurs at the condition of alternative stress with crack formation resulting from propagation of stayed slide zone.关键词：Stirring Friction Welding;Mechanical Properties;Fatigue Behavior;S-N Curves;Fatigue Rupture
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发布时间：2023-12-18 - 摘要：Effects of different rare earth contents on refinement efficiency of aluminum ingot with fine grain were investigated by optical microscope, SEM （scanning electron microscope）, EDAX. The results show that mistchmetal Re can effectively refine the grain size in aluminum ingot, where the average diameter of the grain is decreased with MM Re increase. The optimum grain refining efficiency can be observed with 0.30% MM Re additions, while with MM Re addition over 0.30%, refining efficiency can be fade. The refinement mechanism of the aluminum ingot with fine grain with MM RE addition is approached also.关键词：Aluminum Ingot with Fine Grain;Rare Earth;Grain Refinement;Refinement Mechanism
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发布时间：2023-12-18 - 摘要：By means of TEM and SEM observation, the cold tensile test of the residual strength, the effects of the high temperature lasting on microstructure and mechanical properties of Al-Cu-Mg-Ag aluminum alloy were investigated under underaged condition. The results show that the strength of the alloy （165 ℃ for 4 hours） is increased with times in the case of high temperature lasting （ 200 ℃ at 220 MPa）, in which strength reaches maximum value at 20 hours, and then is declined gradually. Fracture morphology at lasting time of 100 hours is ductile rupture, where only the PFZ is increased.关键词：Al-Cu-Mg-Ag Alloy;High Temperature Lasting;Microstructure;Fracture Morphology
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发布时间：2023-12-18 - 摘要：The phase diagram of Zn-Al binary system was investigated by means of differential scanning calorimeter （DSC）, X-ray diffraction （XRD） and pushrod dilatometer （PRD）. Advents of β（ZnAl） phase on XRD curves indicates that there exists β（ZnAl） solid solution single phase zone in the Zn-Al alloy system. DSC analysis shows that eutectoid reaction occurs in the range of 274279 ℃, and PRD analysis reveals that non-transformation is discovered at 340 ℃. Partial Zn-Al binary system phase diagram were sketched based on above results, which provides a reference for application of practical phase transformation in high Al-Zn alloy.关键词：Zn-Al Alloy;DSC;XRD;PRD
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发布时间：2023-12-18 -
- 摘要：During developing the ocean, people are facing the serious problems of the ocean pollution, especially, some parts are not solved by anti-pollution coatings, for ocean engineering, artesian well, drilling platform, shipment, cargo ships, military underwater equipments, which requires themselves possessing anti-pollution characteristics. It was found that only Cu and its copper alloy have the characteristics in more than 100 kinds of metal materials. The research path, application and problems in copper alloy with anti-pollution have been expounded in detail.关键词：Corrosion Resistance;Copper Alloy;Pollution
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发布时间：2023-12-18 -
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