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China Foundry 2023年第6期20卷 469-479页

作者： Guang-yu Li Feng Guan Wen-ming Jiang Yuan-cai Xu Zheng Zhang Zi-tian Fan State Key Laboratory of Materials Processing and Die&Mould Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China

Al/Mg bimetal was prepared by lost foam solid-liquid compound casting,and the effects of mechanical vibration on the filling and solidification behavior,microstructure and performance of the bimetal were investigated.Results show that the mechanical vibration has a remarkable influence on the filling and solidification processes.It is found that after mechanical vibration,the filling rate increases and the filling rate at different times is more uniform than that without vibration.In addition,the mechanical vibration also increases the wettability between liquid AZ91D and A356 inlays.The mechanical vibration reduces the horizontal and vertical temperature gradient of the casting and makes the temperature distribution of the whole casting more uniform.Compared to the Al/Mg bimetal without vibration,the shear strength is improved by 39.76%after the mechanical vibration is applied,due to the decrease of the inclusions and Al_(12)Mg_(17) dendrites,and the refinement and uniform distribution of the Mg_(2)Si particles in the interface of the Al/Mg bimetal.

关键词： lost foam casting filling and solidification processes Al/Mg bimetal mechanical vibration microstructure mechanical properties

Modeling of Mold Filling and Solidification in lost foam casting

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Journal of Materials Science & Technology 2003年第5期19卷 395-397页

作者： Fengjun LI, Houfa SHEN and Baicheng LIUDepartment of Mechanical Engineering, Tsinghua University, Beijing 100084, China Dept. of Mech. Eng. Tsinghua Univ. Beijing 100084 China

Based on the characteristics of the lost foam casting (LFC) and the artificial neural network technique, a mathematical model for the simulation of the melt-pattern interface movement during the mold filling of LFC has been proposed and experimentally verified. The simulation results are consistent with the experiments in both the shapes of melt front and filling sequences. According to the calculated interface locations, the fluid flow and the temperature distributions during the mold filling and solidification processes were calculated, and the shrinkage defect of a lost foam ductile iron casting was predicted by considering the mold wall movement in LFC. The simulation method was applied to optimize the casting design of lost foam ductile iron castings. It is shown that the model can be used for the defects prediction and for casting design optimization in the practical LFC production.

关键词： lost foam casting Numerical simulation Artificial neural network

Effects of Parameters on Formation and Microstructure of Surface Composite Layer Prepared by lost foam casting Technique

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Journal of Wuhan University of Technology(Materials Science) 2012年第1期27卷 82-87页

作者：陈东风董选普 FAN Zitian State Key Laboratory of Material Processing and Die&Mold Technology Huazhong University of Science and Technology

Surface composite layer was fabricated on the AZ91D substrate using the lost foam casting （LFC） process. The pre-coating layer reacted with melt substrate and formed the composite layer, and the coating was mainly consist of alloying aluminum powder and low-temperature glass powder （PbO-ZnO-Na20）. The vacuum degree, pouring temperature, mold filling process of melt, and pre-coating thickness played an important role during the formation process of composite layer. The results show that surface morphology of composite layer can be divided into three categories： alloying effect of bad and good ceramic layer, alloying effect of good and bad ceramic layer, composite layer of good quality. The main reason for bad alloying layer is that alloying pre-coating thickness is so thin that it is scoured easily and involved in the melt, in addition, it is difficult for melt to infiltrate into the alloying coating owing to the surface tension of coating when the vacuum degree is excessively low. Bad ceramic layer is because of somewhat lower pouring temperature and the thicker alloying coating, due to the absorption of heat from the melt, making low temperature glass powder pre-coating layer fuse inadequate. Thus, to get good quality composite layer, the process conditions must be appropriate, the result shows that the optimum process parameters are as follows： at a pouring temperature of 800 ~C, vacuum degree of -0.06 MPa, alloying pre-coating thickness ofO.4 mm, and low glass powder pre-coating layer thickness ofl mm.

关键词： lost foam casting aluminum powder low temperature glass powder surface compositelayer pre-coating thickness

HCWCI/Carbon Steel Bimetal Liner by Liquid-Liquid Compound lost foam casting

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Journal of Iron and Steel Research(International) 2012年第10期19卷 13-19页

作者： XIAO Xiao-feng1,2, YE Sheng-ping2, YIN Wei-xin3, XUE Qiong4 (1. School of Mechanical Engineering and Automation, Wuhan Textile University, Wuhan 430073, Hubei, China 2. State Key Laboratory of Material Processing and Die and Mould Technology, Huazhong University of Science and Technology, Wuhan 430074, Hubei, China 3. Wuhan Zhike Abrasive-Resistant Material Science and Technology Development Co Ltd, Wuhan 430073, Hubei, China 4. College of Science, Wuhan University of Technology, Wuhan 430079, Hubei, China) School of Mechanical Engineering and Automation Wuhan Textile University Wuhan Hubei China State Key Laboratory of Material Processing and Die and Mould Technology Huazhong University of Science and Technology Wuhan Hubei China Wuhan Zhike Abrasive-Resistant Material Science and Technology Development Co Ltd Wuhan Hubei China College of Science Wuhan University of Technology Wuhan Hubei China

Impact, friction and corrosion from the grinding balls and the grinding medium during the mineral processing result in liner breakage. Liner, made from Hadfield steel or alloyed steel, could not have served in wet grinding environment for more than ten months. Composite liner, made from HCWCI (high Cr white cast iron) and carbon steel, has been developed successfully with liquid-liquid composing process based on LFC (lost foam casting). The microstructure of composite was analyzed with optical microscope, SEM (scanning electron microscope)/EDX energy-dispersive X-ray and XRD (X-ray diffraction). According to micrograph, the combination region of two metals was staggered like dogtooth, no mixtures occurred between two liquid metals, and its interface presented excellent metallurgical bonding state. The results of mechanical property test show that, the hardness of HRC, the fracture toughness, and the bending strength are more than 61, 16.5 J/cm2 and 1 600 MPa, respectively. Comparison between liners made from bimetal composite and alloyed steel has also been investigated in industrial hematite ball mill. The results of eight months test in wet grinding environment prove that the service life of bimetal composite liner is three times as long as that of one made from alloyed steel.

关键词： composite liner bimetal liquid-liquid compound composite interface lost foam casting high Cr white cast iron

Effect of vibration frequency on primary phase and properties of grey cast iron fabricated by lost foam casting

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China Foundry 2020年第1期17卷 1-7页

作者： Bo-tao Xiao Zi-tian Fan Wen-ming Jiang Jun-huai Xiang Xue-fang Yan Jiangxi Key Laboratory of Surface Engineering Jiangxi Science and Technology Normal UniversityNanchang 330013China State Key Laboratory of Material Processing and Die&Mould Technology Huazhong University of Science&TechnologyWuhan 430074China

The properties of gray cast iron(GCI)are affected by density of matrix,size of flake graphite and primary austenite.In this paper,the Y-type specimen of GCI was prepared by lost foam casting(LFC)with and without vibration,and the influence of vibration frequency on the density of matrix,size of primary phase,and properties of the GCI was studied.The results show that the length of the flake graphite and the size of the primary austenite in GCI firstly decrease and then increase with the increase of the vibration frequency.With a vibration frequency of 35 Hz,the length of the flake graphite is the shortest,the primary austenite is the finest and the density of the matrix is the highest.In addition,the tensile strength,elongation and hardness of the GCI firstly increase and then decrease with the increase of the vibration frequency,due to the refinement of the primary phase and the increase of the matrix density.In order to analyze the refinement mechanism of the primary phase of the GCI fabricated by the LFC with vibration,the solidification temperature fields of the GCI fabricated by the LFC with the vibration frequency of 0 and 35 Hz were measured.The results show that the vibration reduces the eutectic point of the GCI and increases the supercooling degree during the eutectic transformation.As a result,the length of the flake graphite and the size of the primary austenite in GCI fabricated by LFC with the vibration frequency of 35 Hz decrease.

关键词： vibration frequency lost foam casting grey cast iron flake graphite properties

High Cr white cast iron/carbon steel bimetal liner by lost foam casting with liquid-liquid composite process

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China Foundry 2012年第2期9卷 136-142页

作者： Xiao Xiaofeng Ye Shengping YinWeixin Zhou Xiaoguang Xue Qiong State Key Laboratory of Material Processing and Die&Mould Technology Huazhong University of Science and TechnologyWuhan 430074China School of Mechanical Engineering and Automation Wuhan Textile UniversityWuhan 430073China Wuhan ZhiKe Abrasive-Resistant Material S&T Development Co. LtdWuhan 430073China College of Science Wuhan University of TechnologyWuhan 430079China

Liners in wet ball mill for mineral processing industry must bear abrasive wear and corrosive wear, and consequently,the service life of the liner made from traditional materials,such as Hadfield steel and alloyed steels,is typically less than ten months.Bimetal liner,made from high Cr white cast iron and carbon steel,has been successfully developed by using liquid-liquid composite lost foam casting process.The microstructure and interface of the composite were analyzed using optical microscope,SEM,EDX and XRD.Micrographs indicate that the boundary of bimetal combination regions is staggered like dogtooth,two liquid metals are not mixed,and the interface presents excellent metallurgical bonding state.After heat treatment,the composite liner specimens have shown excellent properties,including hardness>61 HRC,fracture toughnessα k >16.5 J·cm-2 and bending strength >1,600 MPa.Wear comparison was made between the bimetal composite liner and alloyed steel liner in an industrial hematite ball mill of WISCO,and the results of eight-month test in wet grinding environment have proved that the service life of the bimetal composite liner is three times as long as that of the alloyed steel liner.

关键词： bimetal liner liquid-liquid composite process lost foam casting high Cr white cast iron

A study on the effect of coating's sorption capacity on the porosity in lost foam aluminum alloy casting

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China Foundry 2004年第S1期1卷 58-61页

作者： G.H.Wu M.Xie W.J.Ding J.R.Luo Shanghai Jiaotong University Shanghai 200030P.R.China Huazhong University of Science and Technology Wuhan 430074HubeiP.R.China

Effects of coating constituent, coating density, coating layer thickness and temperature on coating sorption capacity for polystyrene decomposition products have been studied systematically. It has been found that the effect of attapulgite clay on sorption capacity is the largest among coating constituents. The sorption capacity of the coating with 2% attapulgite clay is elevated by 81%. The relationship between casting porosity and coating sorption capacity has been studied. It has been pointed out that higher coating sorption capacity for polystyrene decomposition products is helpful to decrease the casting porosity. Results also show that the sorption capacity of self-developed HW-1 coating for polystyrene decomposition products is as good as that of Ashland coating from America.

关键词： lost foam casting aluminum alloy coating porosity

lost foam casting Technique Applications for Al/SiC Composite Production

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Lost Foam Casting Technique Applications for Al/SiC Composit...

Wear-resistant Coatings Prepared by Combination of SHS and lost foam casting

第69届世界铸造会议暨2010中国铸造活动周

作者： A.Kisasoz K.A.Guler A.Karaaslan Yildiz Technical University Metallurgical and Material Engineering Dept.Davutpasa Campus TR-34210 Esenler-Istanbul-Turkey

＜正＞Metal matrix composites are engineering materials that have matrix and reinforcement material as constituents.Metal matrix composites have higher mechanical properties as well as light weight,higher hardness and wear resistance than conventional materials by combining the properties of matrix and reinforcement materials.The main restrictions of the liquid fabrication methods for metal matrix composite are the low wettability between the matrix and reinforcement material and higher fabrication costs.Metal matrix composites can be fabricated by various methods such as powder metallurgy,infiltration and squeeze casting.lost foam casting is a new approach for the metal matrix composite fabrication.This process can achieve matrix and reinforcement material wetting with low fabrication costs.In this study,lost foam casting which is an alternative method for the metal matrix composite fabrication was used to fabricate composite specimens.Al/SiC composite specimens were fabricated by lost foam casting method and these specimens were characterized by image analysis,hardness tests and SEM analysis.

关键词： lost foam casting Al/SiC metal matrix composite

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Wear-resistant Coatings Prepared by Combination of SHS and L...

Microstructure and mechanical properties of lost foam cast 356 alloys

中国材料大会2012

作者： Tao Shi Zhimeng Guo Lin Gao Institute for Advanced Materials and Technology University of Science and Technology Beijing

ISBN: (纸本)9783037856093;3037856092

With a brief introduction of self-propagating high-temperature synthesis （SHS） and lost foam casting （LFC）, there goes an issue about the simultaneous produce of casting and wear-resistant coating by the combination of such two techniques, which has a positive significance for energy conservation and sustainable development. Through the statement of some common hard phases generated by SHS such as TiC, WC and TiB2 , it indicated that the hard phases had a good combination with iron, and thus demonstrated the feasibility of the simultaneous produce of casting and wear-resistant coating. In the end, the development and the trend of the future about this issue has been drawn.

关键词： Self-propagating high-temperature synthesis lost foam casting Wear-resistant coating Simultaneous produce.

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China Foundry 2015年第3期12卷 214-221页

作者： Qi-gui Wang Materials Technology Global Powertrain Engineering General Motors Company

Microstructure and mechanical properties of lost foam cast aluminum alloys have been investigated in both primary A356(0.13% Fe) and secondary 356(0.47%). As expected, secondary 356 shows much higher content of Fe-rich intermetallic phases, and in particular the porosity in comparison with primary A356. The average area percent and size(length) of Fe-rich intermetallics change from about 0.5% and 6 μm in A356 to 2% and 25 μm in 356 alloy. The average area percent and maximum size of porosity also increase from about 0.4% and 420 μm to 1.4% and 600 μm, respectively. As a result, tensile ductility decreases about 60% and ultimate tensile strength declines about 8%. Lower fatigue strength was also experienced in the secondary 356 alloy. Low cycle fatigue(LCF) strength decreased from 187 MPa in A356 to 159 MPa in 356 and high cycle fatigue(HCF) strength also declined slightly from 68 MPa to 64 MPa.

关键词： lost foam casting aluminum alloys microstructure mechanical properties fatigue Weibull linear elastic fracture mechanics 356 alloy