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Die Casting Technology Develops Steadily
The 5th China International Die Casting Congress & Exhibition,
sponsored by the Chinese Mechanical Engineering Society
(CMES) and the China Productivity Promotion Center of
Machinery Industry; and organized by the Foundry Institution
of Chinese Mechanical Engineering Society (FICMES), Shenyang
University of Technology and Foundry Journal Agency, was
held in Shanghai, China, from June 28 to July 1, 2006. There
are 44 academic papers included in the proceedings of the
congress, which were chosen from a large number of papers
submitted, reflecting the development of China’s die casting
industry in the last two years.
1. Development of the Die Casting IndustryThe globalization of the world economy, demand for light
weight castings for automobile parts, and the sustainable
development of our country’s economy all promote the die
casting industry to transfer gradually from the developed
countries to the developing countries such as China. The
output of die castings in China in 2005 approached 9 x 105 t,
of which aluminum alloys exceeded 6.3 x 105 t, zinc alloy was
2.2 x 105 t, and magnesium alloy was nearly 0.1 x 105 t. The
production value of die castings in 2005 exceeded 40 million
yuan RMB, growing 10.9 % compared with last year.
In the die casting congress, Mr. SONG Cai-fei, a member of
the Die Casting Committee of the China Foundry Association,
presented an overview The Characteristics and Regularity ofThe Characteristics and Regularity ofThe Characteristics and Regularity ofThe Characteristics and Regularity ofThe Characteristics and Regularity of
Development on China’s Die Casting IndustryDevelopment on China’s Die Casting IndustryDevelopment on China’s Die Casting IndustryDevelopment on China’s Die Casting IndustryDevelopment on China’s Die Casting Industry covering several
aspects of the basic survey, the inevitability of continuous
development, diversity, etc. and giving the output of die
castings of varieties of nonferrous alloys in 2005 and their
share in the total output. The diversity of die casting
development in China was discussed in detail covering six
areas of die casting development - production of aluminum
alloy cylinder blocks for automobile engines, production of
aluminum alloy hubs and pistons, the continued increase in
output and sale of motorcycles, the large market for automobile
parts, real estate promoting the rapid development of the
hardware industry, and the output of die castings of magnesium
alloy growing 20% annually. Finally, the problems the die
casting operations facing in China were pointed out.
Mr. TANG Yu-lin, of the Productivity Promotion Center of
Foundry Industry of China, analyzed the development trends
of the die casting industry in China in his paper Making Light-Making Light-Making Light-Making Light-Making Light-
weight Automobiles Promotes the Development of Light Castingweight Automobiles Promotes the Development of Light Castingweight Automobiles Promotes the Development of Light Castingweight Automobiles Promotes the Development of Light Castingweight Automobiles Promotes the Development of Light Casting
Market.Market.Market.Market.Market. The amounts of aluminum used for sedan parts
(including engine, transmission case, hubs, suspension system
& frame, radiator, steering wheel, etc.) in North America,
Western Europe, and Asia in 2001 were compared. Several
proposals on the development of the die casting industry in
China and strengthening market competition were put forward.
Four aspects of the technical progress were pointed out: (1)
Optimization of the die casting process and development of
new alloy materials to adapt the development of automobile
die castings toward thin wall, complex shape, high strength,
and high quality; (2) Reduction of production costs from several
aspects such as integration of design, prolonging service life
of die, etc; (3) Popularization of computer simulation
techniques to shorten the development period of processes;
(4) The importance of the utilization of secondary aluminum
resources and the setting up of a comprehensive scrap recycling
system.
2. Die Casting and Semi-Solid Technology forAluminum Alloy
The die casting production for aluminum alloys still occupies
a very important position in China’s die casting industry and is
used extensively for automobiles, motorcycles, toys, and
hardware. Semi-solid processing, a new forming technique
suitable for preparing high quality parts is receiving more and
more attention. Its fundamental work and applied research
are being conducted in detailed depth.
In the paper Experimental Studies on Rheocasting ProcessingExperimental Studies on Rheocasting ProcessingExperimental Studies on Rheocasting ProcessingExperimental Studies on Rheocasting ProcessingExperimental Studies on Rheocasting Processing
of A356 Alloyof A356 Alloyof A356 Alloyof A356 Alloyof A356 Alloy presented by prof. TANG Jing-lin, of the
Department of Mechanical Engineering, Tsinghua University,
the author used the thin plate specimen with five steps and
rheocasting mould developed independently to study
experimentally a new rheoforming process with separate slurry
preparation systems and component shaping systems for A356
alloy. The results show that with the proper crucible structure
and coating composition, the semi-solid alloy slurry could be
smoothly transferred from the slurry preparation equipment
to the rheocasting shot chamber by the slurry preparation
crucible. Following the optimization of the rheocasting
processing parameters, the tensile strength and elongation of
samples could be increased by 11.6% - 18.2 % and 42.5% - 50 %
respectively, compared with the traditional liquid die casting
YUAN Xiao-guang1, HUANG Hong-jun1, LI Rong-de1, CAO Yang2, SU Shi-fang2
(1. Shenyang University of Technology, Shenyang 110023, Liaoning; 2. FICMES, Shenyang 110022, Liaoning)
Die Casting Technology Develops Steadily-- A Commentary on the 5th China International Die Casting Congress
Vol.3 No.4 Information
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ones. Also during the rheocasting process, the semi-solid alloy
slurries flow smoothly, and the microstructures of samples are
dense and free from pores, so that the samples have the
potential for strengthening by heat treatment.
In the study on Semi-Solid Forming Technology andSemi-Solid Forming Technology andSemi-Solid Forming Technology andSemi-Solid Forming Technology andSemi-Solid Forming Technology and
Properties of Al-Si-FeProperties of Al-Si-FeProperties of Al-Si-FeProperties of Al-Si-FeProperties of Al-Si-Fe by Dr. ZHAO Shu-guo, of Shenyang
University of Technology, the semi-solid forming technology
for hypoeutectic Al alloy was applied to hypereutectic Al alloy.
The results show that the second phase in the semi-solid formed
alloy became fine and spherical, and its distribution is
homogeneous. With the increasing of the extrusion ratio and
the decreasing of the forming temperature, the second phase
broken up increased and d is t r ibuted even more
homogeneously. So better mechanical properties and wear
resistance could be obtained. All these will provide technical
support for the application of the hypereutectic Al-Si alloy in
automobile industry.
Aluminum alloy hubs in a sedan are one of main parts by
light weight fabrication. Its fatigue property is an important
criterion in assessing its quality. In the paper Factors InfluencingFactors InfluencingFactors InfluencingFactors InfluencingFactors Influencing
Fatigue Life of Low Pressure Die Cast A356 Alloy WheelsFatigue Life of Low Pressure Die Cast A356 Alloy WheelsFatigue Life of Low Pressure Die Cast A356 Alloy WheelsFatigue Life of Low Pressure Die Cast A356 Alloy WheelsFatigue Life of Low Pressure Die Cast A356 Alloy Wheels by
engineer WU Han-qi of Dicastal Wheel Mfg. Co. Ltd, two
different kinds of bending fatigue cracks of low pressure cast
A356 alloy wheels were investigated. Their characteristics were
compared, forming reason as well as the effects of
microstructure and defects on the fatigue life of wheel were
analyzed using SEM. On the basis of the above, the measures
to increase the fatigue life are put forward from six aspects:
(1) Degassing for melt, (2) Optimizing the process parameters,
(3) Adopting a thermal isostatic pressure process, (4) Modifying
and fining for melt, (5) Controlling Fe content, (6) Proper heat
treatment. All these will have great instructive action in the
production of aluminum alloy hubs.
3. Die Casting and Semi-solid Technology forMagnesium Alloy
In recent years, the number of die casting enterprises and
science & research organizations engaging in magnesium alloy
production has increased rapidly from the original few to nearly
a hundred. Considering the availability of magnesium resource
in our country, it is hopeful that this research development
might become industrial reality.
The paper Study on Interfacial Heat Transfer CoefficientStudy on Interfacial Heat Transfer CoefficientStudy on Interfacial Heat Transfer CoefficientStudy on Interfacial Heat Transfer CoefficientStudy on Interfacial Heat Transfer Coefficient
between Metal/Die Interface of High Pressure Die Castingbetween Metal/Die Interface of High Pressure Die Castingbetween Metal/Die Interface of High Pressure Die Castingbetween Metal/Die Interface of High Pressure Die Castingbetween Metal/Die Interface of High Pressure Die Casting
Process of AZ91D AlloyProcess of AZ91D AlloyProcess of AZ91D AlloyProcess of AZ91D AlloyProcess of AZ91D Alloy presented by GUO Zhi-peng and
XIONG Shou-mei of the Key Lab. for Advanced Manufacturing
by Materials Processing Technology, Department of Mechanical
Engineering, Tsinghua Unversity, won the silver award of the
‘Wanfeng’ Cup for excellent foundry papers. In the paper the
temperature profiles inside the die were measured based on
high pressure die casting experiments using AZ91D magnesium
alloy. Using a computer program based on solving the inverse
heat problem, the metal/die interfacial heat transfer coefficient
(IHTC) was calculated and studied. The results indicated that
the IHTC between metal and die increases right after the liquid
metal is brought into the cavity by the plunger and decreases
as the solidification process of the liquid metal proceeds until
the liquid metal solidifies completely, when the IHTC tends to
be stable. The interfacial heat transfer coefficient shows
different characteristics under different casting wall thickness
and varies with the change of solidification behavior. This
will have a directive function to theoretical investigation for
the solidification processes of die castings.
High vacuum die casting is a valuable method for the
reduction of gas porosities of the die castings and removal of
air, gas and lubricant vapor from die cavity. Ryobi Limited has
developed the high quality die casting technology to mass-
production of the front sub-frame. This has achieved a 40 %
weight reduction for the front sub-frame in comparison with
the ordinary stamped steel products. At the congress, Mr.
Mamoru Murakami, of the Research and Development Division,
Ryobi Limited, Japan, introduced in detail the high quality die
casting technology. This technique has been used for the large
automobile safety die casting parts requiring high quality.
Mr. LONG Si-yuan of Chongqi Shuolong Science and
Technology Co. Ltd., introduced advanced melting and pouring
furnaces for magnesium alloys all over the world, and described
the effect of the characteristics of magnesium alloy melting
furnaces on its operation, melt quality, and production cost.
A comparison of the national and foreign furnaces was made
in technique, function, material, and economy. The results
show that the gap between our country and developed
countries for magnesium alloy melting furnaces is being
narrowed. Some techniques at home have reached the
international advanced level. This shows that the technology
in China has made a great progress.
In the paper Discussion on Thixocasting Processing ofDiscussion on Thixocasting Processing ofDiscussion on Thixocasting Processing ofDiscussion on Thixocasting Processing ofDiscussion on Thixocasting Processing of
Magnesium AlloysMagnesium AlloysMagnesium AlloysMagnesium AlloysMagnesium Alloys presented by Prof. YAN Feng-yun, of the
Key Lab. for Non-ferrous Metal Alloys, Ministry of Education,
Lanzhou University of Technology, the process and
technological parameters for thixocasting of magnesium alloys
were analyzed in detail by comparision with traditional die
casting technology. Combined with unique features of die
casting machinery, some valuable technological parameters
for thixocasting of magnesium alloys were given to offer
reference for researchers.
4. Progress of Squeeze Casting TechnologyAttention is still being paid to squeeze casting technology.
The paper Study on Bubbling in Heat Treatment Process ofStudy on Bubbling in Heat Treatment Process ofStudy on Bubbling in Heat Treatment Process ofStudy on Bubbling in Heat Treatment Process ofStudy on Bubbling in Heat Treatment Process of
Squeeze CastingSqueeze CastingSqueeze CastingSqueeze CastingSqueeze Casting presented by Mr. QI Pi-xiang, of Ningbo Sub-
academy of the National Weapons Science Research Academy,
won the silver award of the ‘Wanfeng’ Cup for excellent foundry
papers. In the paper, the author pointed out that bubbling is
one of the common defects in the heat treatment process of
squeeze casting, and it has relationships with squeeze mode,
technique, mould, etc. Therefore, for direct squeeze-casting
parts, solution heat treatment can be performed smoothly as
CHINA FOUNDRY Nov. 2006
324
long as oil-based paint is not used and air exhaust is well
arranged; for indirect squeeze casting parts, solution heat
treatment can also be applied when additional factors are taken
into consideration, including well designed internal feeding
system and strictly controlled liquid metal filling velocity to
prevent from inclusions.
The paper Influence of Squeeze Casting Parameters onInfluence of Squeeze Casting Parameters onInfluence of Squeeze Casting Parameters onInfluence of Squeeze Casting Parameters onInfluence of Squeeze Casting Parameters on
Microstructure and Mechanical Properties of Plunger Type ZA27Microstructure and Mechanical Properties of Plunger Type ZA27Microstructure and Mechanical Properties of Plunger Type ZA27Microstructure and Mechanical Properties of Plunger Type ZA27Microstructure and Mechanical Properties of Plunger Type ZA27
Alloy Castings with High Ratio of Height to ThicknessAlloy Castings with High Ratio of Height to ThicknessAlloy Castings with High Ratio of Height to ThicknessAlloy Castings with High Ratio of Height to ThicknessAlloy Castings with High Ratio of Height to Thickness, which
was presented by Prof. LI Rong-de of Shenyang University of
Technology, won the gold award of the ‘Wanfeng’ Cup for
excellent foundry papers. In the paper, the fundamental
problem of plunger type squeeze casting of ZA27 alloy, with
high ratio of height to thickness (M=H/D=7), was investigated.
The influence of the squeeze casting parameters on the
mechanical properties and microstructure of the ZA27 alloy
was analyzed. The plunger type squeeze casting parameters
best suited for ZA27 alloy, with high ratio of height to thickness,
were preliminary decided. Squeeze casting improves the
mechanical properties of ZA27 alloy and offers important
maintenance logistics for developing the applied range of ZA27
alloys.
In addition, Continuous Squeeze Casting Process By MassContinuous Squeeze Casting Process By MassContinuous Squeeze Casting Process By MassContinuous Squeeze Casting Process By MassContinuous Squeeze Casting Process By Mass
ProductionProductionProductionProductionProduction by Mr. YUN Xia, of SPX Contech, USA, and LatestLatestLatestLatestLatest
Development of Fabrication Technique for Ultra-Fine GrainedDevelopment of Fabrication Technique for Ultra-Fine GrainedDevelopment of Fabrication Technique for Ultra-Fine GrainedDevelopment of Fabrication Technique for Ultra-Fine GrainedDevelopment of Fabrication Technique for Ultra-Fine Grained
Mg alloysMg alloysMg alloysMg alloysMg alloys by CHEN Yong-jun, of Light Alloy Net Forming
National Engineering Research Center, Shanghai Jiaotong
University, both have great influence.
5. Application of Computer SimulationTechnology in Die Casting
In the last two years, domestic computer simulation technology
has been developed rapidly, especially for some simulation
softwares now commercially available. At present, more and
more enterprises are using it in the R & D of products. So the
theme of computer application in the congress is still an
important topic for discussion.
In the paper Application of KBE in HPDC OptimizationApplication of KBE in HPDC OptimizationApplication of KBE in HPDC OptimizationApplication of KBE in HPDC OptimizationApplication of KBE in HPDC Optimization by
Prof. WANG Guo-xiang, of Shanghai Jiaotong University, on
constructing the framework for the application of KBE in high
pressure die casting process and die design, the author created
the rules database, based on the rule-based reasoning
technology. It is beneficial to shorten the development period
of new high quality products.
In the paper Application of Numerical Simulation TechnologyApplication of Numerical Simulation TechnologyApplication of Numerical Simulation TechnologyApplication of Numerical Simulation TechnologyApplication of Numerical Simulation Technology
in Die Casting Processin Die Casting Processin Die Casting Processin Die Casting Processin Die Casting Process by Prof. LIAO Dun-ming, of the College
of Materials Science & Engineering, Huazhong University
Science and Technology, the author introduced the main
contents of numerical simulation of die casting process and
some applications of InteCast CAE Software in die casting die
design; and described its function in improving the rationality
and accuracy of structure for die casting dies.
In the paper Numerical Simulation on the Temperature FieldNumerical Simulation on the Temperature FieldNumerical Simulation on the Temperature FieldNumerical Simulation on the Temperature FieldNumerical Simulation on the Temperature Field
of Magnesium Alloy Die Casting Diesof Magnesium Alloy Die Casting Diesof Magnesium Alloy Die Casting Diesof Magnesium Alloy Die Casting Diesof Magnesium Alloy Die Casting Dies by Prof. YU Bao-yi, of
Shenyang University of Technology, the effects of the die
casting process, the variation of temperature field, and the
type of cooling on magnesium alloy automotive mantle were
calculated and analyzed by using Z-cast software. Based on
the results, reasonable process parameters and type of cooling
were pointed out for improving the service life of dies used
for magnesium alloy automotive mantle.
In addition, the papers Application of CASTsoft in LowApplication of CASTsoft in LowApplication of CASTsoft in LowApplication of CASTsoft in LowApplication of CASTsoft in Low
Pressure Casting ProcessPressure Casting ProcessPressure Casting ProcessPressure Casting ProcessPressure Casting Process by ZHANG Zheng, of the Casting
Engineering Centre, North University of China, and
Optimization of Injection Velocity for an AM60 Die - CastOptimization of Injection Velocity for an AM60 Die - CastOptimization of Injection Velocity for an AM60 Die - CastOptimization of Injection Velocity for an AM60 Die - CastOptimization of Injection Velocity for an AM60 Die - Cast
Dynamotor SupportDynamotor SupportDynamotor SupportDynamotor SupportDynamotor Support by ZHANG Yan, of Shenyang University
of Technology, also made a hit.
6. SummaryWe can see from this congress that although the research on
die casting technology and equipment in our country has made
a great progress and the die casting operation level has been
enhanced remarkably, the gap is still large compared with
developed comtries, especially in die casting equipment.
Therefore, the authors think that the future further research
and application on die casting technology in our country should
be conducted on several aspects as follows:
(1) Because of the tremendous contribution of advanced die
casting equipment to die casting operations, the investment in
the development of die casting machines, melting equipment,
and other auxiliary devices should be increased. Replacements
and technical innovations should be made to increase the
manufacturing level of die casting equipment in our country.
(2) Since computer simulation and emulation technology has
gradually matured, enterprises should pay greater attention to
and make full use of such advantages of the technology in the
development of products and process design. Shortening the
period of design and development for products, optimizing
processes, etc., all will increase the productivity, reduce the
costs of production, and enhance market competition.
(3) The automobile industry in our country is being rapidly
developed and the technology level of die casting aluminum
alloys for automobile parts has been increased. Therefore,
the development of complete of die casting technology,
especially for aluminum alloys with thin wall, complex shape,
and high-level properties, should be strengthened.
(4) In recent years, magnesium alloy and its die casting
technology have been developed quickly, and the technology
level has also been increased markedly, but the potential for
further development of magnesium alloy is still large, especially
for automobile parts. Therefore, its development should be
carried through in detailed depth to extend the scope of
application of magnesium alloy and to improve its properties.
(5) Fundamental research on squeeze casting and semi-solid
forming technology has made a great progress, but is still at
an early stage. Therefore, future research work should focus
on the development of related products and advanced
equipment to allow the advanced technology to be applied as
soon as possible.