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China foundry 2024年第1期21卷 11-19页

作者： Wen-ning Liu Wei Zhang Peng-yue Wang Yi-xian Liu Xiang-yi Jiao Ao-xiang Wan Cheng-gang Wang Guo-dong Tong Shou-mei Xiong School of Materials Science and Engineering Tsinghua UniversityBeijing 100084China Key Laboratory for Advanced Materials Processing Technology Tsinghua UniversityBeijing 100084Beijing China FAW group Co. Ltd.Changchun 130013China China FAW foundry Co. Ltd.Changchun 130013China

The effect of slow shot speed on externally solidified crystal(ESC),porosity and tensile property in a newly developed high-pressure die-cast Al-Si alloy was investigated by optical microscopy(OM),scanning electron microscopy(SEM)and laboratory computed tomography(CT).Results showed that the newly developed AlSi9MnMoV alloy exhibited improved mechanical properties when compared to the AlSi10MnMg *** AlSi9MnMoV alloy,which was designed with trace multicomponent additions,displays a notable grain refining effect in comparison to the AlSi10MnMg *** elements Ti,Zr,V,Nb,B promote heterogeneous nucleation and reduce the grain size of primaryα-*** a lower slow shot speed,the large ESCs are easier to form and gather,developing into the dendrite net and *** an increase in slow shot speed,the size and number of ESCs and porosities significantly *** addition,the distribution of ESCs is more dispersed and the net-shrinkage *** tensile property is greatly improved by adopting a higher slow shot *** ultimate tensile strength is enhanced from 260.31 MPa to 290.31 MPa(increased by 11.52%),and the elongation is enhanced from 3.72%to 6.34%(increased by 70.52%).

关键词： hypoeutectic Al-Si alloy high pressure die casting porosity externally solidified crystal tensile property

Effects of cooling rate on microstructure and microhardness of directionally solidified Galvalume alloy

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China foundry 2024年第3期21卷 213-220页

作者： Ji-peng Li De-gao Qiao Jian Li Xiao-yang Luo Peng Peng Xian-tao Yan Xu-dong Zhang Gansu Jiu Steel group Hongxing Iron and Steel Co. Ltd.Jiayuguan 735111GansuChina School of Materials and Energy Lanzhou UniversityLanzhou 730000China

The influences of cooling rate on the phase constitution,microstructural length scale,and microhardness of directionally solidified Galvalume(Zn-55Al-1.6Si)alloy were investigated by directional solidification experiments at different withdrawal speeds(5,10,20,50,100,200,and 400μm·s^(-1)).The results show that the microstructure of directionally solidified Galvalume alloys is composed of primary Al dendrites,Si-rich phase and(Zn-Al-Si)ternary eutectics at the withdrawal speed ranging from 5 to 400μm·s^(-1).As the withdrawal speed increases,the segregation of Si element intensifies,resulting in an increase in the area fraction of the Si-rich *** addition,the primary Al dendrites show significant refinement with an increase in the withdrawal *** relationship between the primary dendrite arm spacing(λ_(1))and the thermal parameters of solidification is obtained:λ_(1)=127.3V^(-0.31).Moreover,as the withdrawal speed increases from 5 to 400μm·s^(-1),the microhardness of the alloy increases from 90 HV to 151 *** is a combined effect of grain refinement and second-phase strengthening.

关键词： Galvalume alloy directional solidification microstructure length scale microhardness

Numerical simulation and experimental investigation of two filling methods in vertical centrifugal casting

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中国有色金属学会会刊：英文版 2006年第5期16卷 1035-1040页

作者：吴士平历长云郭景杰苏彦庆雷修桥傅恒志 School of Materials Science and Engineering Harbin Institute of Technology foundry Co Ltd First Automobile Group Corporation

A mathematical model of the centrifugal filling process was established. The calculated results show that the centrifugal field has an important influence on the filling process. Moreover, the process of liquid flow and the location of free surface in sprue were simulated based on the Solution Algorithm-Volume of Fraction (SOLA-VOF) technique. In order to verify the mathematical model and computational results, hydraulic simulation experiment was carried out. The results of experiments and numerical simulation indicate the accuracy of mathematical model. Two kinds of filling methods were investigated and the results show that the bottom filling is better than the top filling that can achieve stable filling and reduce defects.

关键词：钛合金立式离心铸造水力模拟数值模拟炉顶加料底部加料

Research progress in CALPHAD assisted metal additive manufacturing

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China foundry 2024年第4期21卷 295-310页

作者： Ya-qing Hou Xiao-qun Li Wei-dong Cai Qing Chen Wei-ce Gao Du-peng He Xue-hui Chen Hang Su China Iron&Steel Research Institute group Beijing 100081China Thermo-Calc Software AB SolnaSE-169Sweden KTH Royal Institute of Technology StockholmSE-100Sweden Central Iron and Steel Research Institute Beijing 100081China

Metal additive manufacturing(MAM)technology has experienced rapid development in recent *** both equipment and materials progress towards increased maturity and commercialization,material metallurgy technology based on high energy sources has become a key factor influencing the future development of *** calculation of phase diagrams(CALPHAD)is an essential method and tool for constructing multi-component phase diagrams by employing experimental phase diagrams and Gibbs free energy models of simple *** combining with the element mobility data and non-equilibrium phase transition model,it has been widely used in the analysis of traditional metal *** development of CALPHAD application technology for MAM is focused on the compositional design of printable materials,the reduction of metallurgical imperfections,and the control of microstructural *** endeavor carries considerable theoretical and practical *** paper summarizes the important achievements of CALPHAD in additive manufacturing(AM)technology in recent years,including material design,process parameter optimization,microstructure evolution simulation,and properties ***,the limitations of applying CALPHAD technology to MAM technology are discussed,along with prospective research directions.

关键词： metal additive manufacturing CALPHAD integrated computational material engineering powder bed fusion material design microstructure simulation

Mathematical modeling of electromagnetic dimensionless number for electromagnetic casting of metals and its application

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中国有色金属学会会刊：英文版 2005年第3期15卷 606-611页

作者：王辉李廷举金俊泽 Research Center of foundry Engineering Dalian University of Technology Dalian 116023 China National Enterprise Technology Center Wuhan Iron and Steel (Group) Co Wuhan 430080 China

In order to estimate the feasibility of electromagnetic casting (EMC) for different metals, a mathematical model named the electromagnetic dimensionless number (EMDN) was presented, and its validity was proved by the experiments of aluminum and Sn-3%Pb alloy. From the experiment and the analysis of EMDN it can be concluded that the EMC of steel can be attained only when the magnetic flux density is larger than 0.09T, while that required for aluminum is only 0.04T. The mathematical expression of the electromagnetic dimensionless number was given out.

关键词：电磁维度电磁铸造磁流体密度数学模型 EMDN

Complicated hollow turbine blades and surface grain refinement process

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China foundry 2010年第2期7卷 121-126页

作者： Peng Zhijiang Jia Shuqin Zhang Zehai Liu Yan AVIC Shenyang Liming Aero-Engine （group） Corporation Ltd Shenyang 110043 Shenyang Research Institute of foundry Shenyang 110022 China

The control of grain size in superalloys is critical in the manufacture of gas turbine *** aim of the present research is to provide the technology for producing complicated hollow turbine blades with fine surface grains and better comprehensive mechanical *** melt superheating treatment and coating the internal surfaces of shell mould using a cobalt aluminate-bearing coating material,the in-uence of cobalt aluminate as inoculant on the surface grain sizes of turbine blade was studied with addition of cobalt aluminate:0,35%,45%-65% and 100% *** the same time,the effects of cooling circumstances of the blades on surface grain sizes were also experimented under the same addition of cobalt *** results showed that the melt superheating treatment plays a significant role in the grain size and carbide morphology;and fine surface grains were obtained when the internal surfaces of shell mould were coated using cobalt aluminate *** the addition of cobalt aluminate in coating is between 45%-65%,and the melt is poured into preheated shell moulds with fine silica sand as backing sand,the blades satisfied the surface grain size requirement is over 90%.In addition,comparisons of the surface grain size and the mechanical properties were also conducted between home-made and foreign-made blades.

关键词： complicated hollow turbine blades K465 alloy surface grain refinement melt superheating treatment

Effect of pouring temperature on cooling slope casting of semi-solid Al-Si-Mg alloy

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Acta Metallurgica Sinica(English Letters) 2012年第5期25卷 329-339页

作者： Prosenjit Das Sudip K. Samanta Himadri Chattopadhyay Pradip Dutta foundry group CSIR-Central Mechanical Engineering Research Institute Durgapur-713209 India Department of Mechanical Engineering Jadavpur University Kolkata-70032 India Department of Mechanical Engineering Indian Institute of Science Bangalore-560012 India

Present trend of semi-solid processing is directed towards rheocasting route which allows manufacturing of near-net-shape cast components directly from the prepared semi-solid slurry. Generation of globular equi-axed grains during solidification of rheocast components, compared to the columnar dendritic structure of conventional casting routes, facilitates the manufacturing of components with improved mechanical properties and structural integrity. In the present investigation, a cooling slope has been designed and indigenously fabricated to produce semi solid slurry of A1-Si-Mg （A356） alloy and successively cast in a metallic mould. The scope of the present work discusses about development of a numerical model to simulate the liquid metal flow through cooling slope using Eulerian two-phase flow approach and to investigate the effect of pouring temperature on cooling slope semi-solid slurry generation process. The two phases considered in the present model are liquid metal and air. Solid fraction evolution of the solidifying melt is tracked at different locations of the cooling slope, following Schiel＇s equation. The continuity equation, momentum equation and energy equation are solved considering thin wall boundary condition approach. During solidification of the liquid metal, a modified temperature recovery scheme has been employed taking care of the latent heat release and change of fraction of liquid. The results obtained from simulations are compared with experimental findings and good agreement has been found.

关键词： Rheocasting Semi-solid slurry Cooling slope A356 alloy Numerical simulation

Coatings for Automotive Truck Production: Demands and Features for Productivity, the Elimination of Casting Defects, Cleanliness and the Environment

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Coatings for Automotive Truck Production: Demands and Featur...

Influence of AlTi3C0.15 modification treatment on damping properties of ZnAl10 alloy

2019中国铸造活动周

作者： Reinhard St?tzel Yanhui Wang Shengyin Liu Dongshen Yan ASK Chemicals GmbH FAW foundry group No.2 foundry plant FAW foundry group No.1 foundry plant

Capability and casting quality are the focus of enterprises casting truck components due to the great demand for good and high-quality castings. Having new concepts that can quickly match customer key performance indicators(KPIs) is crucial, e.g. by using sustainable solutions through optimization of the casting process, particularly by using core/mold coatings. Increased demand, for thin-walled castings, for example, the use of advanced alloys, and changes in sand quality, are also causing the technical demands on the applied coating technology to rise, making the use of high-grade coatings unavoidable. The VDA 19(ISO 16232) guideline stipulates a very clear requirement for automotive series castings. The residues in the components are supposed to be limited in order to prolong the maintenance intervals for motor vehicles. Residues in the cavities of engine blocks cause the filters to clog early and are detrimental to the longer maintenance intervals required. The peel-off MIRATEC coating, which has already been tested successfully in practical application, has proven to be an excellent solution to satisfy these ever-rising demands of the OEMs regarding casting cleanliness, defect-free castings and lower casting wall thicknesses. These coatings are rheologically tailored in such a way that even core packages with very complex geometries can be coated in a single step causing fewer flaws and giving higher dimensional accuracy instead of coating several cores separately and assembling them afterwards. Lost-foam casting is a casting technology, which provides designers with the maximum degree of freedom. However, these techniques require high-tech performance coatings to achieve a stable, reproducible casting in a fixed and very narrow range of quality. We have shown that these high-performance coatings enable foundries to produce more complex castings for trucks in a less complicated and more efficient way, which means a competitive advantage for these foundries. Las

关键词： Automotive Truck Coating Productivity Casting defects Environment

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China foundry 2017年第4期14卷 292-296页

作者： Grzegorz Piwowarski Janusz Buras Michal Szucki Department of foundry Processes Engineering Faculty of Foundry EngineeringAGH University of Science and TechnologyMickiewicza Al.3030-059 CraconePoland

Zn-Al alloys constitute an interesting group of foundry alloys. Due to a relatively low melting temperature, they allow a decrease in energy-consumption of the melting process and alloy preparation. The vibration damping ability is one of the most interesting properties of the Zn-Al alloys. Zn-Al alloys are divided into two groups: the low-aluminium and high-aluminium alloys. The investigated Zn-10 wt.% Al(ZnAl10) alloy is representative of the high-aluminium alloys, which, on account of its tendency of forming coarse-grained structures, has rather low plastic properties, including elongation. In order to improve the plastic properties, a modification treatment is usually applied. The dependence of the damping coefficient of the ultrasound wave on the amount of the introduced inoculant was studied. Investigations were performed using the AlT i3C0.15 inoculant as the modifier of the ZnAl10 alloy. It was found that titanium additions, in a range from 25 to 100 ppm in relation to the melted charge mass, can reduce the damping coefficient value. An increase of the inoculant addition causes a rise of the damping coefficient, which is probably related to the scattering of the ultrasound wave on Al_3Ti and TiC particles introduced with the inoculant.

关键词： modification damping damping coefficient zinc alloys ZnAl10 ultrasound wave

Production technique of vermicular graphite iron cylinder head of vehicle diesel engine

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China foundry 2008年第3期5卷 153-161页

作者： Zhou Gen Liu Wanhua Wuxi Diesel Engine Works China First Automobile Group Co. Ltd. Wuxi 214026 China Wuxi FAW foundry Co. Ltd. China First Automobile Group Co. Ltd. Wuxi 214026 China

The 25 years＇ production and application have proved that vermicular graphite iron cylinder heads with vermicularity ≥50% satisfy the machinability and performance demand of diesel engine. The method, in which using cupola-induction furnace duplex melting and pour-over process with rare earth-ferrosilicon or rare earthsilicon compound as vermJcularizing alloy plus rare earth-magnesium-ferrosilicon as stirring alloy, is an optimal vermicularizing process for obtaining satisfied vermicularity. Using top kiss risers, enlarging kissing areas and expanding covering width and making ingates to freeze earlier are the effective measures to eliminate shrinkage, blowhole and oxide inclusions in the vermicular graphite iron cylinder heads.

关键词： vermicular cast iron cylinder head melting and treatina process: castina method