最新刊期
卷 33 ， 期 2 ， 2013
- 摘要：The inverse pole figures of grain face were calculated with X-ray diffraction patterns to understand the texture evolution of the extruded AZ31magnesium alloy during tensile deformation.The results show that the strong basal texture（0002）appears,and some grains arranged with Caxis are inclined 16°～21°to the extruded direction in the as-extruded samples.The tensile deformation weakens the basal texture and makes the prismatic（1010）plane rotate 45°with Caxis.关键词：AZ31Magnesium Alloy;Deformation Test;Texture
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发布时间：2023-12-18 - 摘要：Thixo-die-forging process in pseudo-semi-solid state was used to prepare W-40Cu cup shell with copper particle size in 10μm,25μm,40μm and tungsten particle size in 3μm.The results show that with the heating temperature of 1 350℃and applied pressure of 500MPa,the decrease of copper particle size is favorable for the improvement of mechanical properties of thixoforged parts.With the copper particle size decrease,conductive properties of thixoforged parts are increased.关键词：W-Cu Alloy;Pseudo-semi-solid Thixo-die-forging;Conductive Properties
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发布时间：2023-12-18 - 摘要：Superfine aluminum oxide powder after pretreatment was used as reinforcement.The as-pretreated aluminum oxide powder was treated with electroless plating copper assisted by ultrasonic field.The copper matrix composites reinforced by alumina oxide were prepared by powder metallurgy.The samples were characterized by X-ray diffractometer（XRD）,scanning electron microscopy（SEM）and energy spectrum analyzer（EDS）.The results show that the aluminum oxide particles are uniformly dispersed into copper matrix composites.In addition,the influencing factors of the sintering process on the physical properties of the composites were analyzed by the orthogonal testing.The optimized processing parameters are as follows:the sintering temperature of 900℃,the sintering pressure of 600MPa and the aluminum oxide content of 2%,respectively.关键词：Al2O3;Dispersion Strengthening;Coppers Matrix Composites;Electroless Plating Copper
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发布时间：2023-12-18 - 摘要：The effects of rolling process on the microstructure and mechanical property of Al-Mg-Si alloy sheet were investigated by the microstructure observation,strength,elongation and hardness properties tests,and the strengthening mechanism of the alloy was discussed.The results show that the microstructure and mechanical properties of the Al-Mg-Si alloy sheet are changed significantly by different rolling process.Under the same total deformation conditions,the tensile strength,yield strength,elongation and hardness of rolling third state and second state are significantly better than those of the rolling first state.In the three kinds of rolling process,rolling third state plate has the best comprehensive mechanical property,where the tensile strength,yield strength,elongation and hardness reach 398.4 MPa,325.8MPa,20%and 112.0,respectively.The strengthening mechanism of rolling third state alloy is characterized by the interaction of deformation strengthening,grain refinement strengthening and second phase strengthening.关键词：Al-Mg-Si Alloy;Rolling Process;Mechanical Property;Strengthening Mechanism
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发布时间：2023-12-18 - 摘要：Aiming at the slag inclusion,shrinkage hole and pinhole defects in 228automobile steering pumps during metal mould casting process,the effects of melt treatment on casting defects and mechanical properties of 228automobile steering pumps were investigated.The results show that the modification effects of Al-Ti-C+Al-Sr compound modifier are obviously superior to those of Al-Ti-B+ Al-Sr compound modifier in refining grain size,and tensile strength and elongation of the steering pump with Al-Ti-C+Al-Sr compound modifier are improved by 10%and approximately 40%～50%,respectively.Compared with the flux method,the rotating bubble floating method exhibits the more acceptable ability to slag removal and degassing.With rotating velocity of 400r/min,gas flow of 5L/min and rotating refining for 15min as well as holding for 9min,the reject rate is decreased from 36.2%to below 1.2%,and the qualified rate is increased by 97%.关键词：Al-10Si Alloy;Steering Pump Casting;Melt Treatment;Casting Defect;Mechanical Properties
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发布时间：2023-12-18 - 摘要：Preparation of Si3N4coating in quartz crucible was conducted by non-sintered process.By adding some solid and liquid binders in the Si3N4slurry,Si3N4powders were adhered strongly with the crucible inter-wall.By putting the silicon material into the crucible directly after spraying process and holding at 70～80℃for 2hours,the traditional process of crucible sintered at 1 050℃for 6～7hours in the sintering furnace can be eliminated,and so the production cycle can be shortened,improving efficiency and decreasing production cost.关键词：Multicrystalline Silicon;Un-sintering;Si3N4Coating;Binder
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发布时间：2023-12-18 - 摘要：<正>作为亚洲规模最大的铜业展,CuChina已经成功举办6届,贯穿铜业上、中、下游产业链,集展览展示、高端技术论坛、特别活动于一身,发展成为全球重要的铜业交流采购平台。第七届中国国际铜业展览会将于2013年3月6～9日移师中国最重要的工业城市之一,中国海水淡化产业的重要基地——天津,并在天津规模最大的展览中心天津梅江会展中心举办,同期举办2013年中国铜加工产品及装备对接会、节能减排的铜冶炼技
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发布时间：2023-12-18 - 摘要：The phase field modeling of L →β directional solidification in Ti-43Al binary alloy was established by coupling the thermodynamic databases to WBM model.Based on the model,the microstructure evolution in solidification process was successfully simulated.The influences of phase field parameters and solidification parameters on the interfacial morphology were analyzed.The simulated results show that,with the decrease of the anisotropy coefficient,the tip growth rate is decreased and branch growth is easier,which is in favor of formation of cellular structures.The grain growth is transformed from shallow cell to deep cell as a result of easy enrichment of solute at groove of cell grain with the interface thickness decrease.In addition,with the increase of the temperature gradient,the interfacial microstructure evolution is transformed from deep cell to shallow cell,then to planar interface.关键词：Ti-Al Alloy;Directional Solidification;Phase-Field;Interfacial Morphology
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发布时间：2023-12-18 - 摘要：Although there are many factors influencing die-casting die failure,thermal stress and mechanical stress subjected in working process are main responsible for the failure.The temperature field of a die casting die from a factory was simulated to understand the key parameters influencing temperature field changes in mould.The die-casting process was divided into four stages:die casting-solidification,open mold-pick up,spraying-clamping,clamping-next die-casting,and coupling numerical simulation for thermal stress and mechanical stress was conducted.Through analyzing stress changes at different area from different cross-sections,stress change mechanism was presented at different processing parameters,providing a data reference to predicting service life of mould.关键词：Segmentation Method;Die-Casting;Thermo-mechanical Coupling;Numerical Analysis
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发布时间：2023-12-18 - 摘要：The temperature field in the solidification process of sand mold casting electro-mobile aluminum alloy wheels was simulated.The mathematical model,geometrical model and FEM model of temperature field were established.The nonlinear features of materials and boundary conditions have been fully considered and the latent heat was treated by using equivalent specific heat method.The temperature fields in solidification process of sand gravity casting aluminum alloy wheels were simulated by FEM simulation Procast,and temperature field distribution was presented.The results show that the numerical simulation can describe well dynamic changes of three dimensional temperature field and provide a reference to improve aluminum alloy wheels quality,determination of solidification time and process optimitation.关键词：ProCAST;Sand Mold Gravity Casting;Solidification;Aluminum Alloy Wheels;Temperature Field
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发布时间：2023-12-18 - 摘要：Since China implemented the economic reform and opening up strategy in 1978,Chinese economy has been booming.At the same time,foreign enterpriseséntrance into China also boosts the development of Chinese economy.After the Second World War,Japanese economy began to develop very fast,occupying an important place in the mold manufacturing industry.Since the second half of 1980s,Japanese mold manufacturing industry has reached the level of advanced countries,which makes a big influence on Japan’s industrial development.However,Japanese mold manufacturing industry is greatly affected by the recession of Japanese economy,which results in such consequences as scale shrinking and practitioner decreasing.After 30years of the reform and opening up,Chinese mold industry has achieved remarkable development mainly due to the introduction of advanced equipment and processing method from foreign countries.By digestion and absorption of these technologies,China’s technical level keeps improving.After the financial crisis,as the export decreases,price of materials rises,labor cost increases and so on,Chinese mold manufacturing enterprises are faced with diversified subjects.In the world economic crisis,the age for Sino-Japan mold enterprises to think their survival carefully is coming.These enterprises must face this reality in the future.It is necessary to take initiative measures quickly after balancing all matters.关键词：Study;Development Trend;Sino-Japan Mold Manufacturing Industry
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发布时间：2023-12-18 - 摘要：With short manufacturing cycle,low manufacturing costs,sand mold and core integrated manufacturing and the development of any complex shaped castings,precision sand casting rapid technology without mold was used to fabricate sand molds or cores with high dimensional accuracy and good surface quality to realize near-net shape of the complex castings,especially suitable for the complex castings of single or small batch production as well as trial of new products.Precision sand casting rapid technology without mold based on laser sintering,3Dprinting and CNC machining principles was reviewed,focusing on the characteristics of the process,the scope of application,and existing problems as well as development prospects.关键词：Precision Sand Casting without Mold;Rapid Casting;Laser Sintering;Three Dimensional Printing;CNC Machining
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发布时间：2023-12-18 - 摘要：<正>审查会召开期间对《铸造用锆砂、粉》标准提出了12条审查意见。为体现《铸造用锆砂》标准对行业发展的指导性和符合性,经专家组一致通过,将原JB/T9223-1999《铸造用锆砂》改名为《铸造用锆砂、粉》。本标准规定了铸造用锆砂、粉的术语和定义,分级、分组及牌号,技术要求,试验方法,检验规则以及包装、标志、运输、贮存和质量证明书。本标准适用于铸造生产造型（芯）用锆砂、粉。
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发布时间：2023-12-18 - 摘要：<正>近日,哈尔滨高新技术产业开发区管理委员会与中国航天科工集团第三研究院在京签署协议,以钛合金为主要产业的航天高技术创新产业园项目正式落户哈尔滨科技创新城。据悉,这是国内首家生产高端钛合金产品的航天高技术创新产业园区。该项目总投资16.75亿元,占地34万平方米,将建成不低于25万平方米的钛合金新材料新工艺研发中心、钛合
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发布时间：2023-12-18 - 摘要：<正>"十二五"期间,农村拥有的大中型拖拉机由140万台增加到384万多台,小型拖拉机由1540万台增加到1780万台,联合收获机由47.7万台增加到97万多台。进入2012年以来,工业原材料价格轮番上涨,牵动大中型拖拉机销售价格攀升。随着工业化、信息化、城镇化、市场化、国际化的深入发展,结构调整和产业升级力度加大,对农
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发布时间：2023-12-18 - 摘要：<正>进入二十一世纪以来,中国铸造业的产出量连续稳坐世界铸造第一把交椅,2011年业已超过4千万吨,占全球铸件产量的40%以上,成了名副其实的世界铸造大国。如今,中国铸造业正瞄准"铸造强国"的宏大目标奋勇直前。中国铸造的历史性成就和强劲发展态势,特别是由此而形成的铸造文化,以及基于和围绕中国铸造业大发展而开展的各项与铸造有关的交流活动之兴盛令世界瞻目。例如,由中铸协连续多年举办的国际铸造博览会、铸造年会、两岸三地铸造论坛、
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发布时间：2023-12-18 - 摘要：<正>2012年12月7～9日,中华全国工商业联合会第十一次会员代表大会在北京召开。大会选举产生了全国工商联第十一届执行委员会,济南市工商联主席、圣泉集团董事长唐一林当选全国工商联第十一届执委。他的当选,说明了济南市工商联各项工作和圣泉集团的发展得到了政府和社会的肯定,济南工商
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发布时间：2023-12-18 - 摘要：<正>进入21世纪后,为了抢占未来经济发展制高点,世界各国特别是一些发达国家都把发展新材料作为产业进步、国民经济发展和保证国防安全的重要推动力。发达国家新材料领域呈现出基础研究受到重视,研发投入加大,研发经费集中于战略性重点领域,政策扶持力度增强,企业在创新中作用突出的发展趋势。
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发布时间：2023-12-18 - 摘要：<正>美国把生物材料、信息材料、纳米材料、极端环境材料及材料计算科学列为主要前沿研究领域,支持生命科学、信息技术、环境科学和纳米技术等发展,以满足国防、能源、电子信息等重要部门和领域的需求。为此,美国制订了一系列与新材料相关的计划,主要包括"21世纪国家纳米纲要"、"国家纳米技术计划（NNI）"、"未来工业材料计划"、"光电
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发布时间：2023-12-18 - 摘要：With a help of a viscometer,the rheological properties of semi-solid Al-17Si-xFe（x=2,3,4,weight percentage,%）prepared were analyzed.The viscosity of Al-17Si-xFe in the constant temperatures of 100℃、50℃above the liquidus and 10℃、40℃below the liquidus,respectively,was measured,and the viscosity-temperature curve in the continuous cooling process was presented.The results show that the viscosities in the previous temperatures reaches 0.745 1、0.787 8、0.922 4、1.082 9Pa·s,respectively,which show with the temperature decreases,the viscosity is increased.With the iron content increasing from 2%to 4%,the viscosity of the alloys is increased too.However,with a higher iron content,the precipitation and sedimentation of the iron phases becomes serious in the temperature of 40 ℃below the liquidus with increasing in the holding time,which results in the decrease of the apparent viscosity of the melt to some extent.With increasing in the shearing time,the apparent viscosity of the alloys in the temperature of 40℃below the liquidus is decreased firstly and then increased.In the continuous cooling process,with the continuous decrease of the temperature,the solid fraction of the melt is gradually increased,and the apparent viscosity of the melt is increased slowly.When the temperature is reduced to some temperature near the solidus,the apparent viscosity of Al-17Si-xFe alloys is increased rapidly.In addition,at the same shear rate and to achieve the same solid fraction,the apparent viscosity of the melt is increased with the increase of cooling rate.关键词：Al-Si Alloy;Semi-solid;Apparent Viscosity;Iron-rich Phases
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发布时间：2023-12-18 - 摘要：The semi-solid slurry of 7075aluminum alloy was prepared through a serpentine pouring channel,and influences of pouring temperature,the curve numbers and the curve diameters in the serpentine channel on the microstructure of semi-solid 7075alloy slurry were investigated.The results demonstrate that the semi-solid 7075aluminum alloy slurry with satisfied quality can be generated by a serpentine pouring channel and the solid shell inside the channel can be avoided with the pouring temperature in the range of 660℃～675℃.With a given pouring temperature,the equivalent size of the primary α-Al grains is decreased and the shape factor is increased with the increase of the curve numbers or the decrease of the curve diameters.During the slurry preparation of semi-solid 7075aluminum alloy,the alloy melt changes flow direction many times when it flows in a curved and closed serpentine channel,which result in the primary nuclei gradually evolving into spherical and near-spherical grains as a result of the effect of"stirring" in the serpentine curve.关键词：7075Al Alloy;Semi-solid Slurry;Serpentine Channel;Primary α-Al
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发布时间：2023-12-18 - 摘要：According to the product assembly requirements,first pre-drilling thread bottom hole,tapping and milling surface in the tube union required by the drawing,and make the galvanized thread plug at the same time,the thread plug is screwed into the tube union as a tube assembly,and then put it into the casting mold.The tube dimensions of the casting would be achieved directly by the die casting process through die-casting mould precision limit insert.When the die casting is complete,remove the recyclable thread plug.The galvanized thread plug can prevent effectively metal from rust caused by the high temperature and oil of the fitting surface between the tube union and the thread plug to ensure the cleanliness requirement,and protect the tube surface against damage.The internal thread of the tube union ensure the tooth shape in the thread plug force in the die casting process,so as to achieve the purpose of directly by the die-casting process.Reduce the cost under the precondition to satisfy the production requirements.关键词：Stainless Steel Tube;Residual Irons;Galvanized Thread Plug;Precision Limit Insert
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发布时间：2023-12-18 - 摘要：The porosity types were determined based on the porosities features through checking the defects in the die castings.The forming mechanism of porosities was described.Origination of porosities was analyzed by CAE analysis and practical investigation.The countermeasures for different gas defects were presented to eliminate or prevent the occurrence of porosity.关键词：Porosity;High Pressure Die Casting;Inspection;Mechanism
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发布时间：2023-12-18 - 摘要：Application of NDT in casting aluminum alloy wheel was introduced.The operating mechanism and characteristics of WRE.THUNDER 3X-Ray were analyzed.Based on a sample,it pointed out the defect image features of casting aluminum alloy wheel in NDT.关键词：Aluminum Alloy Wheel;NDT;WRE.THUNDER 3;Defect Image
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发布时间：2023-12-18 - 摘要：Face layer of mold shell was made with fused corundum instead of zircon sand.The slurry-solution ratio of fused corundum for the face layer adopts 1:（3.1～3.3）.Meanwhile,according to requirements of parts,qualified castings can be produced with using whiteα-Al2O3,brownα-Al2O3and mullite sand in face layer to reduce product cost.关键词：Investment Casting;Fused Corundum;Zircon Sand
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发布时间：2023-12-18 - 摘要：Structure characteristics of RLS bearing bracket was analyzed,and the wax pattern was made through splitting wax pattern and wax mold firstly and then integrating.The casting defects in the RLS bearing bracket were eliminated by rapidly forced cooling to middle flange and combined position of R10 and middle cylinder with compressed air or cooling water.The casting deformation was controlled by processing control in process of shell-broke,blasting and heat treatment and so on.
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发布时间：2023-12-18 - 摘要：The deficiency of the drying room for the lost foam casting was analyzed,and a frozen dehumidifier technology was introduced to dry off the foam coatings.The frozen dehumidifier technology was compared with the traditional steam drying room.It was successfully demonstrated that the frozen dehumidifier technology has advantage in the drying efficiency through the measurement of the foam drying velocities in two different drying rooms,which provided a reference design for the enterprises.关键词：Drying Room;Frozen Dehumidifier;Relative Humidity;Pattern;Drying Velocity
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发布时间：2023-12-18 - 摘要：By investigating weight loss rate,shrinkage and sensory evaluation,the microwave drying behaviors of foam pattern were analyzed under different heating power densities.The results show that with the increase of heating time,weight loss rate is increased gradually to be stable at a given power density.In addition,drying rate is increased with the increase of power density,which results in the more easy formation of defects including coating crack and pattern melt.The relationship between weight loss rate and power density follows parabolic characteristics.Based on the regression analysis of least square method,the suitable power density is presented in ranged from 26to 30.5W/L after comprehensive analysis.关键词：Lost Foam Casting;Microwave;Drying;Power Density
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发布时间：2023-12-18 - 摘要：A new technology of producing the wide breadth and highly purified copper strip with oxygen free by upward casting process was introduced.The highly purified copper strip with oxygen free exhibits better properties as below:wide breath of 450～630 mm,the content of oxygen lower than 0.000 5%,the density higher than 8.9g/cm3,and electric conductivity higher than 58MS/m,the Vikers hardness lower than 80.The tolerance is lower than±0.15mm when the thickness is 12mm.The surface is smooth with milling free.The properties of the sheet after bell-type annealing which was rolled directly to 1.5mm in thickness were similar to those of one with three stages treatment.Absence of properties of the strip resulted from inadequate total processing rate could be observed.The strip after finishing rolling and annealing treatment realizes yield rate of 83%,and content of oxygen lower than 0.000 5%,electric conductivity higher than 58.58MS/m,and tensile strength higher than 230MPa,elongation higher than 40%,presenting aprospect future.关键词：Upward Casting;Product Wide Breadth;Highly Purified;Copper with Oxygen free
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发布时间：2023-12-18 - 摘要：Preforms were prepared with commercial carbon nanotubes、Ni-CNTs and Al with the mass ratio of 1:5.Then the CNTs/AlSi7Mg composites were produced by immersing the preforms into the aluminum alloy melt with bell jar.The ambient mechanical properties of the composites were tested,and the structure and tensile fracture morphology of the composites were observed and analyzed by X-ray diffractometry（XRD）、scanning electron microscopy（SEM）and energy dispersive spectrum analysis（EDS）.The results show that with CNTs addition,the grains of the composite can be refined,and the secondary dendrite arm space of the composites is reduced.Meanwhile,the tensile strength,the microhardness and the elastic modulus of the composites are improved significantly.The tensile strength,the micro-hardness HV and the elastic modulus of the composites with 1.0%CNTs reach 306MPa、118.0 and 132GPa,respectively,increased by 33.4% 、25.5%and 53.9%,respectively,compared with those of the matrix alloy.The fracture of the composites is characterized by quasi-cleavage type brittle fracture.关键词：Carbon Nanotubes;Preforms;AlSi7Mg Aluminum Alloy;Composites;Mechanical Properties
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发布时间：2023-12-18 - 摘要：ER4043aluminum alloy welding wires were prepared by the casting-extrusion-drawing process.The ER4043welding wires prepared were used as filler to weld 5052aluminum plates by TIG.Microstructures and mechanical properties of the alloy and welded joint were investigated by OM（optical microscope）,EDS（energy dispersive spectrometer）,TEM（transmission electron microscope）,tension tests and hardness tests at room temperature.The results show that the wires drew with ingots by the homogenized at 475℃for 24hat 450℃exhibit uniform structure and desirable mechanical properties.The interface of the matrix and heat affected zone（HAZ）is the weakest zone.The formation of easy crack zone in the HAZ is attributed to the welding gas hole from the matrix..关键词：ER4043Aluminum Alloy;Mechanical Properties;Welding Joint;Microstructures
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发布时间：2023-12-18 - 摘要：The effects of ultrasonic melt-treatment parameters,such as power density,stirring time,vibration temperature and preheating temperature of mold,on solidification structure of ignition-proof magnesium alloy AZ91D-3Ca were investigated.The results show that solidification structures of ignition-proof magnesium alloy AZ91D-3Ca can be refined by controlling ultrasonic melt-treatment parameters and solidification conditions.Primary grain in the alloy is refined gradually with increasing in the power density in range of 0～5.56W/cm2.However,with power density more than 5.56W/cm2,changes of primary grain in the alloy can be ignored.With the stirring time of 15s,refinement effect of primary grain exhibits desirable.With stirring time increasing in the range of 30～60s,the effect of microstructure refinement can be ignored.In the range of 600～690℃,with the increase of the ultrasonic vibration temperature,primary grain of the alloy is refined firstly and then coarsened,and the critical point is 630℃.From room temperature to 690℃,with preheat temperature of the mold increase,primary grain in the alloy is coarsened increasingly.关键词：Ignition-Proof Magnesium Alloy;Ultrasonic;Melt Treatment
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发布时间：2023-12-18 - 摘要：Effects of different ultrasonic powers on solidification structure of commercial pure magnesium were investigated,and changes of porosity in surface of commercial pure magnesium were observed by OM（optical microscope）.The results show that the coarse columnar dendrites can be observed in the sample without ultrasonic treatment,where the average length and width reach 19.23mm and 5.96mm,respectively.With the increase of ultrasonic power,the coarse columnar crystals in the ingot are refined firstly and then coarsened.The average length of dendritic crystals is changed from 19.23mm to 14.42mm to 12.07mm and to 14.61mm;and the average width is changed from 5.58mm to 3.08mm to 2.21mm and to 4.99mm,corresponding to ultrasonic power of 250,500,750and to 1 000W.In addition,the porosity of the products obtained is changed to 11.2%、3.4%、1.9%、1.48%and to 2.24%,corresponding to ultrasonic power of 0,250,500,750and 1 000 W.The results show that with the increase of ultrasonic power,the porosities in the ingot is decreased rapidly at first and then increased slowly.关键词：Ultrasonic Power;Commercial Pure Magnesium;Columnar Grain;Porosity
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发布时间：2023-12-18 - 摘要：Effects of Ca addition on the hot tearing susceptibility of Mg-7Al-2Si-0.8Zn-0.5Sr-0.4Mn casting alloys were investigated.The hot crack samples were prepared by metal molds with the same length.Hot tearing susceptibility was evaluated using crack-rod critical diameter and hot tearing sensitive coefficient.The hot tearing behavior of constituent phase of the alloys were analyzed with the help of optical microscopy（OM）,scanning electron microscopy（SEM）and the detector of energy dispersive（EDX）.The results show that the microstructure of the alloys is refined with Ca addition.With 3.0% Ca addition,both the crack-rod critical diameter and hot tearing sensitive coefficient exhibit the minimum value,and fractured areas ofα-Mg dendrite and eutectic are zero and 100%,respectively.Furthermore,the eutectic phase is tended to enrich at the cracks,which establishes the ability to fill the cracks,decreasing the hot tearing susceptibility of alloy.The lower hot tearing susceptibility of the alloy is corresponding to the higher tensile strength.关键词：Magnesium Alloy;Ca;Hot-Tearing Susceptibility;Critical Diameter;Fractured Area
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发布时间：2023-12-18 - 摘要：<正>将Ni作为ZL101A中的强化元素,主要目的是利用富Ni相颗粒的球形形貌和细小尺寸,使它在提高铝合金强度的同时保持材料的高伸长率;Ni在Al-Si-Mg合金中形成Al3Ni、MgNi2等金属间化合物,分布在晶界和基体晶粒中,提高了合金的高温强度以及体积和尺
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发布时间：2023-12-18 - 摘要：ZA4-1alloys were prepared in silicone rubber mould by centrifugal casting.Effects of titanium content on microstructures and mechanical properties of ZA4-1alloys were investigated by scanning electron microscopy（SEM）,metallographic microscope and universal testing machine.The results show that with the increase of titanium content,the average grain degrees in the alloys is decreased firstly and then increased.With the titanium content of 0.08%,grain can be refined obviously with uniform distribution,and the comprehensive mechanical properties of the zinc alloy exhibit desirable.Increasing titanium content to 0.2%,the grains are coarse instead of smaller.The comprehensive mechanical properties are deteriorated as a result of precipitation of eutectic phase in grain boundaries and the enrichment of excessive Ti on the grain boundary resulting in defects.关键词：Titanium;ZA4-1Alloys;Centrifugal Casting;Microstructure;Mechanical Properties
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发布时间：2023-12-18 - 摘要：<正>双色剑（见下页）[1]战国（公元前475年-前221年）通长53.5cm,质量745g由铜-锡合金铸成的青铜兵器,锡多虽硬然而脆,易折断:锡少虽韧然而软,不锋利（见图1）。在钢铁兵器尚未出现之前的青铜时代,如何使青铜兵器具备既锋利又不易折断的性能,实为一大难题。成书于春秋时期的《周礼·考工记》中,已有根据不同使用性能要求,选择不同锡、铜配比锡青铜的所渭"金有六齐（剂）"的记载。
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发布时间：2023-12-18
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