检索结果-南通市图书馆

Novel technologies for the lost foam casting process

Frontiers of Mechanical Engineering 2018年第1期13卷 37-47页

作者： Wenming JIANG zitian fan State Key Laboratory of Material Processing and Die & MouldTechnology Huazhong University of Science and Technology Wuhan430074 China

Lost foam casting （LFC） is a green precision casting process categorized as a near net forming technology. Yet, despite its popularity, it still suffers from some technological problems, such as poor filling ability of the castings, coarse and non-dense microstructure, low mechanical properties for the A1 and Mg LFC processes, and defective carburization for the low carbon steel LFC process. These drawbacks restrict the development and widespread application of the LFC process. To solve these problems, the present study developed several novel LFC technologies, namely, LFC technologies under vacuum and low pressure, vibration solidification, and pressure solidification conditions; expendable shell casting techno- logy; and preparation technology of bimetallic castings based on the LFC process. The results showed that the LFC under vacuum and low pressure evidently improved the filling ability and solved the oxidization problem of the alloys, which is suitable for producing complex and thin- wall castings. The vibration and pressure solidifications increased the compactness of the castings and refined the microstructure, significantly improving the mechanical properties of the castings. The expendable shell casting technology could solve the pore, carburization, and inclusion defects of the traditional LFC method, obtaining castings with acceptable surface quality. Moreover, the A1/Mg and A1/A1 bimetallic castings with acceptable metallurgical bonding were successfully fabricated using the LFC process. These proposed novel LFC technologies can solve the current technological issues and promote the technological progress of the LFC process.

关键词： LFC under vacuum and low pressure vibra-tion solidification pressure solidification expendable shellcasting bimetallic castings

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Gating system optimization of low pressure casting A356 aluminum alloy intake manifold based on numerical simulation

引用

China Foundry 2014年第2期11卷 119-124页

作者： Jiang Wenming fan zitian School of Mechanical&Electrical Engineering Wuhan Institute of Technology State Key Laboratory of Material Processing and Die&Mould Technology Huazhong University of Science and Technology

To eliminate the shrinkage porosity in low pressure casting of an A356 aluminum alloy intake manifold casting, numerical simulation on fi lling and solidifi cation processes of the casting was carried out using the ProCAST software. The gating system of the casting is optimized according to the simulation results. Results show that when the gating system consists of only one sprue, the fi lling of the molten metal is not stable; and the casting does not follow the sequence solidifi cation, and many shrinkage porosities are observed through the casting. After the gating system is improved by adding one runner and two in-gates, the fi lling time is prolonged from 4.0 s to 4.5 s, the fi lling of molten metal becomes stable, but this casting does not follow the sequence solidifi cation either. Some shrinkage porosity is also observed in the hot spots of the casting. When the gating system was further improved by adding risers and chill to the hot spots of the casting, the shrinkage porosity defects were eliminated completely. Finally, by using the optimized gating system the A356 aluminum alloy intake manifold casting with integrated shape and smooth surface as well as dense microstructure was successfully produced.

关键词： low pressure casting A356 aluminum alloy numerical simulation optimization intake manifold

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effects of Parameters on Formation and Microstructure of Surface Composite Layer Prepared by Lost Foam Casting Technique

引用

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

作者： CHEN Dongfeng DONG Xuanpu 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

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Performance characteristics of EZhou bentonite of Hubei province and its modification

引用

China Foundry 2009年第4期6卷 308-313页

作者： Long Wei fan zitian Hu Xueting State Key Laboratory of Material Processing and Die ＆ Mould Technology Huazhong University of Science and Technology Wuhan 430074 Hubei China

Both the chemical compositions and performance characteristics of the bentonite raw ores in Ezhou area of Hubei province and Honghuoshan area of Liaoning of these two kinds of bentonites were tested before and province were compared and analyzed. The properties after Na^＋- and Li^＋-modification. The results show that the Ezhou bentonite ore possesses higher montmorillonite content than the Honghuoshan bentonite ore, but the Ezhou Na-bentonite has weaker castability （e.g. wet compression strength and hot wet tensile strength） than the Honghuoshan Na-bentonite, while the performance of Ezhou Li-bentonite, such as colloid index, swelling value, swelling volume and mould coating performance, is equivalent to that of the Honghuoshan Na-bentonite.

关键词： Ezhou bentonite Honghuoshan bentonite Na-bentonite Li-bentonite performance characteristic

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Status quo and development trend of lost foam casting technology

引用

China Foundry 2014年第4期11卷 296-307页

作者： fan zitian Jiang Wenming Liu Fuchu Xiao Botao State Key Laboratory of Material Processing and Die & Mould Technology Huazhong University of Science and Technology School of Mechanical & Electrical Engineering Wuhan Institute of Technology

Lost foam casting(LFC)technology has been widely applied to cast iron and cast ***,the development of LFC for Al and Mg alloys was relatively slower than that for cast iron and cast *** application of LFC to Al and Mg alloys needs more effort,especially in *** this paper,the development history of LFC is reviewed,and the application situations of LFC to Al and Mg alloys are mainly ***,the key problems of LFC for Al and Mg alloys are also pointed ***,the prospects for LFC technology are discussed,and some special new LFC technologies are introduced for casting Al and Mg *** future,the development trends of green LFC technology mainly focus on the special new LFC methods,metal material,coating,heat treatment,new foam materials as well as purification technology of tail gas,etc.

关键词： lost foam casting(LFC) technology actuality development trend aluminum alloy magnesium alloy

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Enhanced mechanical properties of 6082 aluminum alloy via SiC addition combined with squeeze casting

引用

Journal of Materials Science & Technology 2021年第29期88卷 119-131页

作者： Wenming Jiang Junwen Zhu Guangyu Li Feng Guan Yang Yu zitian fan State Key Laboratory of Materials Processing and Die&Mould Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan430074China State Key Laboratory of High Performance Complex Manufacturing Central South University410083 ChangshaChina

In order to improve mechanical properties of 6082 aluminum alloy,the SiC_(p)/Al 6082 composites were prepared by the addition of the micron-sized SiC_(p)articles combined with the squeeze *** effects of the SiC_(p)content and squeeze casting on the microstructure and mechanical properties of the 6082 aluminum alloy were investigated by SEM,EDS,TEM,tensile testing and hardness testing analysis *** results exhibited that the SiC_(p)content and squeeze casting had a significant impact on the microstructure and mechanical properties of the 6082 aluminum *** addition of the SiC_(p)refined the grain size of the 6082 aluminum alloy while caused the increase of the porosity with increasing the SiC_(p)content,especially in the permanent mold casting *** to the permanent mold casting,the squeeze casting obviously reduced pore defects,refined grain size and made the SiC_(p)distribute evenly as well as bond tightly with the Al *** tensile strength,yield strength,elongation,elastic modulus and hardness of the 6082 aluminum alloy obtained with the SiC_(p)and squeeze casting were remarkably improved,and the optimal mechanical properties were obtained with a 2 wt.%SiC_(p),and they increased 10.73%,72.7%,193.9%,23.5%and 25.2%,respectively,compared to those of the6082 aluminum alloy obtained without SiC_(p)and squeeze *** fracture surface of the SiC_(p)/Al 6082 composites obtained with the squeeze casting was dense and exhibited a ductile fracture mode.

关键词： 6082 aluminum alloy SiC_(p) Aluminum matrix composites Squeeze casting Microstructure Mechanical properties

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Research on cracking mechanism of the thin shell mould in expendable pattern shell casting during pattern removal process

引用

China Foundry 2010年第3期7卷 230-235页

作者： Jiang Wenming fan zitian Liao Defeng Zhao Zhong State Key Laboratory of Material Processing and Die ＆ Mould Technology Huazhong University of Science and Technology Wuhan 430074 Hubei China

Aiming at the cracking phenomenon of the thin shell mould in the expendable pattern shell casting during the pattern removing process, some systemic researches are *** influence of the pattern removing method and temperature on the pattern removing were *** shell mould cracking mechanism was analyzed by using thermo-gravimetric analysis (TGA), and combining the temperature field and the volume change of the expanded polystyrene (EPS) foam pattern being *** results indicated that the shell mould was not easily cracked when the pattern removing process was carried out with the furnace being heated little by little because of the shell slowly shrinking with dehydration and shell strength gradually *** shell mould was soon destroyed when it was set directly into the furnace at above 400 oC because of the thin shell mould rapidly shrinking and the foam pattern ***, the shell mould had no cracking when it had been preheated for a long time even if the furnace temperature was above 400 oC and the shell was put into the furnace ***, when the shell mould was directly set into the furnace at lower temperatures, 250 to 300 ℃, the shell would shrink slowly and the foam pattern would stay at the maximum expansion stage temperature of 100 to 110 ℃ for a long time; and the shell mould would experience an expansion force from the foam pattern for a long *** expansion force is related to the pattern removing temperature, holding time, foam pattern thickness and ***, the foam pattern with higher density could make the shell crack.

关键词： expendable pattern shell casting pattern removing cracking shrinkage expansion force

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Improving mechanical properties of AZ91D magnesium/A356 aluminum bimetal prepared by compound casting via a high velocity oxygen fuel sprayed Ni coating

引用

Journal of Magnesium and Alloys 2022年第4期10卷 1075-1085页

作者： Guangyu Li Wenming Jiang Feng Guan Junwen Zhu Yang Yu zitian fan State Key Laboratory of Materials Processing and Die&Mould Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China

In this paper,a Ni coating was deposited on the surface of the A356 aluminum alloy by high velocity oxygen fuel spraying to improve the performance of the AZ91D magnesium/A356 aluminum bimetal prepared by a compound *** effects of the Ni coating as well as its thickness on microstructure and mechanical properties of the AZ91D/A356 bimetal were systematically researched for the first *** demonstrated that the Ni coating and its thickness had a significant effect on the interfacial phase compositions and mechanical properties of the AZ91D/A356 *** 10μm’s Ni coating cannot prevent the generation of the Al-Mg intermetallic compounds(IMCs)at the interface zone of the AZ91D/A356 bimetal,while the Ni coating with the thickness of 45μm and 190μm can avoid the formation of the Al-Mg *** the Ni coating was 45μm,the Ni coating disappeared and transformed into Mg-Mg_(2)Ni eutectic structures+Ni_(2)Mg_(3)Al particles at the interface *** a thickness of 190μm’s Ni coating,part of the Ni coating remained and the interface layer was composed of the Mg-Mg_(2)Ni eutectic structures+Ni_(2)Mg_(3)Al particles,Mg_(2)Ni layer,Ni solid solution(SS)layer,Al_(3)Ni_(2) layer,Al_(3)Ni layer and sporadic Al_(3)Ni+Al-Al_(3)Ni eutectic structures from AZ91D side to A356 side in *** interface layer consisting of the Mg-Ni and Al-Ni IMCs obtained with the Ni coating had an obvious lower hardness than the Al-Mg *** shear strength of the AZ91D/A356 bimetal with a Ni coating of 45μm thickness enhanced 41.4%in comparison with that of the bimetal without Ni coating,and the fracture of the bimetal with 45μm’s Ni coating occurred between the Mg matrix and the interface layer with a mixture of brittle fracture and ductile fracture.

关键词： Magnesium/aluminum bimetal Microstructure Mechanical properties Ni coating Compound casting High velocity oxygen fuel spraying

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effects of Ce and Sb on the microstructure and properties of AZ91D magnesium alloy prepared by the EPC process

引用

Rare Metals 2008年第1期27卷 41-45页

作者： LI Jiqiang DONG Xuanpu fan zitian WANG Yuanqing State Key Laboratory of Material Processing and Die ＆ Mould Technology Huazhong University of Science and Technology Wuhan 430074 China

The effects of small amounts of cerium and antimony additions on the microstructure and the mechanical properties of AZ91D（Mg-9Al-Zn） based alloy were researched via the expendable pattern casting（EPC） *** results show that the microstructure is obviously refined and the tensile strength of the AZ91D based alloy at ambient temperature is significantly *** compared to AZ91D,the AZ91D-1.0%Ce-0.4%Sb alloy has higher ultimate tensile strength and *** ultimate tensile strength and elongation are enhanced by 39% and 47%,*** morphology of the tensile fracture of the AZ91D-1.0%Ce-0.4%Sb alloy has more characteristics of *** indicates that it has had a larger plastic deformation before *** tensile strength and elongation decrease with the increase of Ce and Sb contents because of the coarsening and volume increase of CeSb and Al11Ce3 phases.

关键词： AZ91D Ce Sb microstructure mechanical properties

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A new low-cost method of reclaiming mixed foundry waste sand based on wet-thermal composite reclamation

引用

China Foundry 2014年第5期11卷 402-407页

作者： fan zitian Liu Fuchu Long Wei Li Guona State Key Laboratory of Materials Processing and Die & Mould Technology Huazhong University of Science and Technology

A lot of mixed clay-resin waste sand from large-scale iron foundries is discharged every day; so mixed waste sand reclamation in low cost and high quality has a great realistic significance. In the study to investigate the possibility of reusing two types of waste foundry sands, resin bonded sand and clay bonded sand which came from a Chinese casting factory, a new low-cost reclamation method of the mixed foundry waste sand based on the wet-thermal composite reclamation was proposed. The waste resin bonded sand was first reclaimed by a thermal method and the waste clay bonded sand was reclaimed by a wet method. Then, hot thermal reclaimed sand and the dehydrated wet reclaimed sand were mixed in certain proportions so that the hot thermal reclaimed sand dried the wet reclaimed sand leaving some water. The thermal reclamation efficiency of the waste resin bonded sand was researched at different heat levels. The optimized wet reclamation process of the waste clay bonded sand was achieved by investigating the effects of wet reclamation times, sand-water ratio and pH value on the reclaimed sand characteristics. The composite reclamation cost also was calculated. The research results showed that the properties of the mixed reclaimed sand can satisfy the application requirements of foundries; in which the temperature of the thermal reclamation waste resin bonded sand needs to be about 800 oC, the number of cycles of wet reclamation waste clay bonded sand should reach four to five, the optimal sand-water ratio of wet reclamation is around 1:1.5, and the pH value should be adjusted by adding acid. The mass ratio of hot thermal reclaimed sand to dehydrated wet reclaimed sand is about 1:2.5, and the composite reclaimed sand cost is around 100 yuan RMB per ton.

关键词： sand casting process mixed waste sand high-quality low-cost sand reclamation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：