最新刊期
卷 ， 期 9 ， 2007
- 摘要：The mechanical properties and microstructure of Al-4.5Mg-0.7Mn-0.4Er alloy prepared with iron mold, water cooling mold and semi-continuous casting have been described by tensile testing, optical microscope, SEM （scanning electronic microscope）, XRD（X-ray diffraction） and TEM （transmission electron microscope）. It is found that increasing cooling rate can improve the strength of Al-4.5Mg-0.7Mn-0.4Er alloy, and be helpful for the formation of supersaturation solid solubility of Er and Mn element in Al during solidification process and for the precipitation of fine and dispersive Al3Er phase and Al6Mn phase after homogenized annealing treatment. Fine and dispersive Al3Er phase can be acted as the effectively strengthening phase in the Al alloy, which is helpful for improving the mechanical properties and microstructure of the alloy.关键词：Al-Mg Alloy;Solid Solution;Er;Al3Er
- 2
- |
- 307
- |
- 4
发布时间：2023-12-18 - 摘要：The microstructure and micro-hardness of Mg-Gd-Y-Zr magnesium alloy homogenized at different temperatures for different times were investigated by means of metallography analysis and micro-hardness measurement. The results indicate that the hot working performance of the magnesium alloy can be greatly improved as result of the elimination of bulk intermetallic compounds distributed along the grain boundary after homogenizing treatment after homogenizing treatment, in which the homogenizing process strictly depends on the temperature. The optimized microstructure and micro-hardness of as-cast magnesium alloy can be observed by homogenizing treatment at 510 ℃ for 12 h.关键词：Mg-Gd-Y-Zr Magnesium Alloy;Micro-areas Chemical Composition;Homogenization;Microstructure and Properties
- 2
- |
- 597
- |
- 29
发布时间：2023-12-18 - 摘要：The tensile fracture morphology and longitudinal surface structure of the AZ80 magnesium alloy treated by solid solution and ageing methods were observed by FFSEM （field emission scanning electron microscope） and OM（optical microscope）. The results indicate that the fracture morphology of the as-cast AZ80 magnesium alloy is characterized by apparently intergranular brittle fracture, which is mainly created in the boundary where distributed amounts of β-Mg17Al12 phase exist as net structure. After solid solution treatment, the average tensile strength and elongation of the alloy are remarkably improved, however the average yield strength is slightly decreased, and the fracture morphology is characterized by cleavage fracture with plastic deformation. Further more, the plastic deformation is decreased with the increase of distance from tensile rupture. After ageing treatment, the average tensile strength and average yield strength of the alloy are higher while the elongation is lower than that of solid solution treated ones. And the fracture morphology is characterized by brittle cleavage fracture, which is created in weak bonding interface and in lamellar structure of β-Mg17Al12 precipitates.关键词：Heat Treatment;AZ80 Magnesium Alloy;Mechanical Properties;Fracture Morphology
- 2
- |
- 871
- |
- 18
发布时间：2023-12-18 - 摘要：Effects of directional growth rate on solidification structure of Cu-0.5Cr alloy have been described in directional solidification. It is found that the solidification structure of the alloy is evolved from planar to cellular to coarse dendrite to hexagon cellular, and then to fine plate-like structure with varying solidified growth rate from 2 μm/s to 500 μm/s in the condition of 200K/cm temperature gradient. The presence of eutectic phase from non-equilibrium solidification can be observed in directional solidification structure of the alloy with the solidification rate more than 10μm/s, whose volume fraction is reduced with the increase of the solidification rate. The value of primary dendritic arm spacing in Cu-0.5Cr alloy is located between the calculated results of the KF model and the Hunt-Lu model.关键词：Directional Solidification;Cu-Cr Alloy;Microstructure
- 2
- |
- 199
- |
- 1
发布时间：2023-12-18 - 摘要：Microstructure of front swirl in 321/Qd370 explosive welded plate was observed by metallography and TEM （transmission electron microscopy）. It is found that the microstructure in front swirl consists of equiaxed lamellar twin martensile phase grain with about 0.1～1 μm in size , revealing the phase transformation of martensite. Cr15.58Fe7.42C6 carbide with face-centered cubic structure can be observed in front swirl near interface while there exists major Mn-Si-Ti phase with about 100 nm in size and finer nanometer equaixed crystal in front swirl near matrix plate. In addition, it is observed that the lamellar twin martensites may be of parallel arrangement in the very fine austenite.关键词：Explosive Welding;Front Swirl;Lamellar Martensite;Martensite Transformation;Carbide
- 2
- |
- 71
- |
- 2
发布时间：2023-12-18 - 摘要：The effects of particles size on the mechanical properties of the SiCp/2024Al composites with a high volume fraction （50%） of SiC particle prepared by squeezing casting method have been investigated. The results show that with the decrease of particle size from 40 μm to 10 μm, the bending strength of the composites can be increased with little change of fracture toughness. The bending strength and fracture toughness of SiCp/2024Al with particle size of 10 μm are 806 MPa and 11.7 MPa·m1/2, respectively. The main fracture mechanism is changed from particle cracked to particle/matrix interface debonding with the decrease of particle size.关键词：Metal Matrix Composites;Squeezing Casting;Particle Size;Mechanical Properties
- 2
- |
- 276
- |
- 5
发布时间：2023-12-18 - 摘要：The CET of Ti-Al alloy during directional solidification was simulated by the cellar automaton （CA） model based on a solute diffusion controlled solidification. The results show that CET is controlled by temperature gradient and drawing velocity, which are accordant with the analytical model of the Hunt, meanwhile, the nuclei spacing in cross section has a stronger effects on CET than the nuclei spacing in longitudinal section. With increasing nucleation undercooling, the CET is postponed. The columnar grain spacing is not only dependent on temperature gradient and drawing velocity, but also influenced by pre-setting nuclei method, especially showing stronger role of adjusting columnar spacing with temperature gradient at 30～50 K/mm.关键词：Ti-Al Alloy;Directional Solidification;CET;Numerical Simulation
- 2
- |
- 446
- |
- 4
发布时间：2023-12-18 - 摘要：The molding filling and thermal transferring process of die casting A356 alloy wheel were simulated by the finite element simulating and analyzing the software ANSYS under various filling temperatures and injection speeds . The effects of filling temperature and injection speeds on semi-solid slurry flow and temperature distribution have been analyzed by simulated results. The results reveal that the desirable filling of the slurry can be observed with filling temperature at 590 ℃ and injection speeds of 5 m/s, which is favorable for the formation of the wheel with compact structure, providing a reference to the design and optimization of semi-solid A356 Al alloy die casting. The processing parameters obtained from numerical simulation were verified by the experiment.关键词：Semi-solid Forming;Numerical Simulation;Temperature Field;Viscosity;Filling
- 2
- |
- 221
- |
- 3
发布时间：2023-12-18 - 摘要：The filling and solidification of an aluminum alloy wheel in low pressure die casting were simulated by the ProCAST software. The simulated results reveal that the liquid-entrapped area often occurs in the intersection of the wheel rib and collar rim. Based on above-mentioned results, the simulation was conducted again by adjusting cooling system and its parameters at the intersection of the wheel rib and collar rim and decreasing temperature of side mould. The simulated results show that the absence of liquid-entrapped in modified filing process can be observed due to the realization of sequential-solidification. The trial production verifies that the product is well in agreement with the simulated results.关键词：Low Pressure Die Casting;Numerical Simulation;Aluminum Alloy Wheel;ProCAST Software;Casting Defect
- 2
- |
- 589
- |
- 9
发布时间：2023-12-18 - 摘要：Observation and investigation of the American lost foam casting were described, especially foundry market, lost foam casting technologies, mould design and numerical simulation. Some lost foam enterprises, such as the Foseco Morval and the Citation Foam Casting, were introduced for their special mould-making experience and cast iron product in lost foam casting,providing a reference to Chinese enterprises.关键词：Lost Foam Casting;Market;Investigation
- 2
- |
- 349
- |
- 1
发布时间：2023-12-18 - 摘要：The last progress in squeezing casting has been expounded from the viewpoint of commercial scale, technology development and equipment. There exist more than 100 squeezing casting machines for producing automobiles, motorcycles, bearing parts in bike, anti-pressure and gas-sealing parts, wear resistant parts and other parts. Based on improving parts quality and spreading using field, the squeezing casting has been upgraded. It is a prominent innovation to conduct closed whole forging after squeezing casting. In addition, conventional horizontal press can be used for squeezing casting with the successful application of real-time controlling system. Meanwhile, some equipment suitable for semi-solid squeezing casting has been developed to meet the requirements of semi-solid production industrilization. The distance of squeezing casting technologies between China and Japan, the U.S. and so on is from the equipment, so it is key measures to develop and manufacture owned-squeezing casting machine for developing our squeezing casting industry.关键词：Squeezing Casting;Equipment;Aluminum Alloy;Magnesium Alloy
- 2
- |
- 2606
- |
- 30
发布时间：2023-12-18 - 摘要：We have developed a mechanical vibration to successfully prepare the ZL101 aluminum alloy semi-solid slurry. The effects of holding temperature, pouring temperature on the slurry quality have been described. The results indicate that with the decrease of holding temperature, the solid fraction is increased; with increasing holding temperature, the microstructure in the semi-solid slurry can become more and more spheroidal with average size of grain slightly increasing. With decreasing pouring temperature, primary α-Al phase in the semi-solid slurry can be refined and spheroidized, resulting in the higher solid fraction in the slurry. The optimized processing parameters can be obtained including holding temperature at about 590～605℃ and pouring temperature at about 635～660 ℃.关键词：Aluminum Alloy;Semi-solid Slurry;Mechanical Vibration;Holding Temperature;Pouring Temperature
- 2
- |
- 142
- |
- 2
发布时间：2023-12-18 - 摘要：Microstructure and properties of die casting Al-Fe alloy were investigated by SEM （scanning electron microscope） and mechanical property testing, and the problems existed in the die casting process were described. The tensile strength and elongation of the die acsting Al-Fe alloy can reach 242.3 MPa and 2.7%, respectively. There exists small short rod phase in the microstructure, and the ring and strip-like microstructure is distributed in the die casting rod.关键词：Al-Fe Alloy;Die Casting;Heat Resistant Alloy
- 2
- |
- 414
- |
- 5
发布时间：2023-12-18 - 摘要：Some measures for making sure the planeness of long-bar thin-walled aluminum alloy cam shaft castings were expounded, such as increasing the flow volume of turning liquid to make smoothly turning, coincidencing pressing point with bearing point in designing clamp. In addition, the reliability of assistant bearing position can be ensured by measurement and adjustment.关键词：Die Castings;Planeness;Turning;Pressing Point;Bearing Point;Position
- 2
- |
- 48
- |
- 0
发布时间：2023-12-18 - 摘要：The mould structure, gating system and side-core-pulling mechanism of low pressure casting mould were expounded by analyzing structure of diesel engine bracket, especially introducing the application of double-stage linkage core-pulling mechanism to core-pulling in low pressure casting mould. The production verification shows that the mould exhibits economic ment and rational features.关键词：Low Pressure Casting;Gating System;Double-stage Core-pulling Mechanism
- 2
- |
- 56
- |
- 2
发布时间：2023-12-18 - 摘要：在压铸机验收和调试中,有些细节不容忽视,如查看压铸机表面油漆质量和集油盘的设置,对压铸机所使用的进口件标志进行识别,检查对压铸机刚性具有重要作用的型板材料、支架形式、拉杆结构,调整比例板的线性度和增压建压的快慢,控制压射储能器和增压储能器的压力降等。关键词：压铸机;结构;性能
- 2
- |
- 63
- |
- 3
发布时间：2023-12-18 - 摘要：New super-high strength Al alloy ingot was fabricated by horizontal continuous casting with low frequency alternative electromagnetic field. Effects of electromagnetic field on quality of aluminum alloy ingot were observed by the metallography method. The results reveal that electromagnetic field can improve the quality of the ingot through reducing macro-segregation and refining micro-macro structure. The yield strength, tensile strength and elongation of the LFEHC new super-high aluminum alloy reach 742 MPa, 758 MPa and 8.5%, respectively, after heat treatment based on squeezing casting.
- 2
- |
- 255
- |
- 13
发布时间：2023-12-18 - 摘要：Calculation method of cost and price of investment castings was given based on analysis of sol silicate mold shell investment casting process. Factors, including product yield rate, layers of shell mold, technical difficulty, post-treatment process and detecting process, should be comprehensively considered in calculating castings price. The formula for calculating castings cost was given.关键词：Investment Castings;Sol Colloidal Silicate;Cost;Price
- 2
- |
- 148
- |
- 1
发布时间：2023-12-18 - 摘要：Improvement of investment casting for the flange brake valve bush was approached. The key of design of the valve bush housing was provided including the corresponding technical measures through analyzing working state and its working structure. The determination of average dimension of mould design and control of key dimension of wax pattern were considered to make sure the qualification of casting dimension. The vertical ingate was adjusted to horizontal ones with strengthening rib in modified technical sketch, which can improve the dry condition among pattern assemble during shell making and radiator conditions of the poured valve bush, and shorten the feeding distance of gating/riser from hot spot in the valve bush to eliminate the shrinkage hole defects in the valve bush.关键词：Flange Brake Valve Bush;Average Dimension of the Valve Bush;Shrinkage Hole;Strengthening Rib;Feeding Distance
- 2
- |
- 234
- |
- 0
发布时间：2023-12-18 - 摘要：Application of boltonite sand to lost foam casting has been described, especially features and physical changes in application of the boltonite sand were paid attention to. The using effects of the boltonite sand were evaluated. The results show that the consumption volume of the boltonite in per ton castings is decreased by 45% compared with that of SiO2 sand.关键词：Boltonite Sand;Lost Foam Casting;Effect Evaluation
- 2
- |
- 120
- |
- 1
发布时间：2023-12-18 - 摘要：Effects of asynchronous rolling routes on microstructure and properties of AZ31 magnesium alloy sheets have been described. The results show that the microstructure of the sheets with fine grain about 20μm in grain size and little twin crystal can be observed, and the elongation of the sheets reach 26% with higher yield strength and strain-hardening index when it is rolled with rotating direction of 180°per pass and the constant normal direction, while the maximum plastic strain ratio can be observed when it is rolled with rotating direction of 180°both per pass and normal direction, showing complicate effects of asynchronous rolling routes on properties of the magnesium alloy sheets. The comprehensive effects of asynchronous rolling routes should be fully considered and optimized to improve the drawability of AZ31 magnesium alloy sheets.关键词：Asynchronous Rolling;AZ31 Magnesium Alloy;Routes;Properties
- 2
- |
- 393
- |
- 5
发布时间：2023-12-18 - 摘要：The ambient tensile properties of the Mg-5.0Y-3.0Nd-0.5Zr alloy in the condition of casting and homogeneously annealing at different temperatures were tested, and its as-cast microstructure and annealed microstructure were observed by optical microscope and scanning electron microscope. The results indicate that the as-cast microstructure of the magnesium alloy can be refined as a result of occurrence of Mg41Nd5 phase and Mg24Y5 phase in the grain boundary. The tensile strength and elongation of homogeneously annealed alloy can be improved, in which the desirable tensile properties, such as tensile strength increase by 18.6% and elongation increase by 3.5% comparing with that of as-cast ones, can be obtained with homogeneously annealing at 450 ℃.关键词：Mg-Y-Nd-Zr alloy;RE Element;Microstructure;Homogeneous Annealing;Mechanical Properties
- 2
- |
- 134
- |
- 4
发布时间：2023-12-18 - 摘要：High frequency alternative electromagnetic field was implemented on the in-situ （Al2O3+Al3Zr）p/Al composites with 15% volume fraction and particle size of 2～3 μm at 870 ℃for 30 s, in which skin effect depth is 5.314 mm, and input current in coil is 80A, and alundum crucible is set on side of the coil with magnetic flux of 0.1T. The microstructure of water quenched （Al2O3+Al3Zr）p/Al composites was analyzed by scanning electron microscope （SEM）. The results reveal that the particle volume fraction in the center hardly changes while it is decreased by 10%with the distance from coil 5mm , and it is increased by about 20%nearby side of coil, exhibiting gradient effects to a certain, which is attributed to the electromagnetic force. The factors influencing particle evolved effects include particle volume fraction, particle diameter, melt temperature, magnetic induction flux and magnetic field time.关键词：Particle Reinforced Composites;High Frequency Alternative Magnetic Field;Gradient Effects;Electromagnetic Force
- 2
- |
- 134
- |
- 2
发布时间：2023-12-18 - 摘要：The porous section at the bottom of ceramic lined composite pipes prepared by the gravitational SHS method and the influence of additive were investigated. The controlling measures were given by analyzing the formation of porous section. The results reveal that the formation of porous section is attributed to the existence of SiO2 particles, where the porous section can be increased with the increase of SiO2 particles. In addition, additive can be helpful to creating porous section. The volume of porous section can be obviously reduced by adding proper fluoride with the SiO2 particles content less than 2%.关键词：Gravitational SHS;Ceramic-lined Composite Pipes;SiO2 Additive;Porous Section
- 2
- |
- 80
- |
- 1
发布时间：2023-12-18 - 摘要：The effects of grain refiners with different content on microstructure and mechanical properties of as-cast, hot rolled and cold rolled H65 alloy strip have been investigated. The results indicate that the two kinds of grain refiners can both refine the grain size in as- cast microstructure and improve tensile strength, elongation and electric conductivity of the H65 brass alloy strip. In addition, the refining effects can be evidently remained in hot rolled and cold rolled H65 brass alloy. The tensile strength, elongation and electric conductivity of the cold rolled H65 brass strip with 0.2 mm thick reach 687 MPa, 1.94% and 17.6MS/m with 0.075% 2# grain refiner addition, increased by 6.4% and by 6%, by 40.7%, respectively, compared with those of un-refined H65 brass strip.关键词：H65 Brass Alloy;Rolling;Grain Refinement;Tensile Strength and Elongation;Electric Conductivity
- 2
- |
- 301
- |
- 1
发布时间：2023-12-18 - 摘要：The effects of electron beam and directional solidification on the inclusion removal in the multi-crystal silicon were conducted with electron beams and direction solidification purifying 98.8% commercial silicon. The results show that the electron beams can effectively decrease main inclusion elements in the silicon, especially P and Ca element, decreasing by more than 90%, while directional solidification can effectively remove metal element inclusion, such as Fe, Al, Ca elements. The Fe content in silicon can be decreased by less than 0.0001% using single directional solidification.关键词：Electron Beam;Directional Solidification;Solar Silicon;Inclusion
- 2
- |
- 368
- |
- 6
发布时间：2023-12-18 - 摘要：The design of permanent mould for aluminum alloy drill housing of guide-rail in gravitational casting was described. During deigning and manufacturing process,the CAD/CAM was employed to simulate the filling process to observe the potential defect generation during filling, and rational improvement was conducted. Resin sand core-end structure and runner height were adjusted to eliminate the eccentric sand core and shrinkage porosity （hole） occurred in trial-mould process, meanwhile, mould temperature is controlled at about 200 ℃ with temperature of liquid metal at about 750 ℃. The qualified aluminum alloy housing was produced by adopting above-mentioned measures.关键词：Aluminum Alloy;Permanent Mould;Gravitational Casting;CAD/CAE/CAM
- 2
- |
- 121
- |
- 4
发布时间：2023-12-18 - 摘要：Inventing and using copper bell,including closed-tile double-tune bell,Buddhist bell and Western bell,exhibiting different characteristics in shape,sound mechanism and tune effects, and be can used for the music.The relationship between shape and sound features of closed-tile and round-mouth copper bell was expounded by means of vibrationg theory ,and the key technologies for copper bell making as well as tuning measures of them were introduced in brief.关键词：Tune;Closed Tile Bell;Round-mouth Bell
- 2
- |
- 100
- |
- 3
发布时间：2023-12-18 -
- Technical support is provided by Beijing Founder electronics co., LTD 京ICP备09064830号-19
京公网安备11010802024621 - It is recommended to read the content of this site in Chrome&IE9+. Please switch to extreme mode in browser 360.
- Cookies We use cookies to help provide and enhance our service and tailor content. By continuing, you agree to the use of cookies.
0