Under the current global energy crisis and environmental protection pressures, the energy-saving and consumption-reduction policies of various countries have become increasingly stringent. Lightweighting has become a hot topic in the automotive industry as an effective way to save energy and reduce consumption. Especially under the rapid development of new energy vehicles, due to the limitation of the weight of the power battery and the cruising range of the power battery, weight reduction of the body has become the first consideration for new energy vehicle companies. Among the many lightweight materials for bodywork, aluminum alloy is undoubtedly the first choice material for automobile industrialization and lightweight from the comprehensive aspects of beautiful and durable, light weight, energy saving, and low cost.
Lightweight, Xuzhou Dicastal, semi-solid die-casting technology, automotive lightweight
The research and development of high-performance automotive aluminum alloy components will play a significant role in improving the international competitiveness of China's automotive industry, and will also produce significant economic and social benefits. At present, the most important forming method of aluminum alloy parts is conventional die casting. This process has the advantages of high production efficiency and low cost, but the casting has a low density and a high content of pores and shrinkage, which seriously reduces the mechanical properties and fatigue life of the casting. Meet the needs of automotive and other industries for high-quality, high-performance, long-life parts. In response to market demand, the introduction of semi-solid die-casting technology meets automotive manufacturers' requirements for high quality and light weight parts.
Relevant data show that the semi-solid die-casting technology refers to the application of certain external influences when the temperature of the aluminum alloy decreases from the liquid phase to the solid phase (solid-liquid two-phase region) during the solidification process from liquid to solid. Method to make the microstructure of the aluminum alloy into a liquid phase surrounding a spherical solid phase. In this temperature range, the aluminum alloy can have a fixed shape like a solid, or it can be squeezed by a slight external force. It is easy to flow, and the aluminum alloy is used for die-casting in this state.
It is understood that semi-solid die-casting technology was founded in the United States in the 1970s. At present, in developed countries and regions such as Europe, America, Japan, and South Korea, semi-solid die-casting parts have been applied in batches in the automotive field. This technology was introduced into China by Xuzhou Dicaste Co., Ltd. At present, this semi-solid technology has reached the international advanced and domestic leading level.
Break through the foundry "bottleneck" with unique technical advantages
Because the semi-solid die-casting technology breaks the traditional dendrite solidification mode, it has unique advantages in terms of composition and microstructure uniformity, improving the comprehensive mechanical properties of the formed part, and reducing internal defects in the forming. "Semi-solid die-casting temperature is lower than conventional die-casting, with less solidification shrinkage and less casting looseness (or none), smooth filling and less porosity defects and oxide inclusions (or none). T6 heat treatment and subsequent welding can be effectively improved There are casting quality problems with traditional casting methods, "said XU Baoqun, general manager of Xuzhou Dicastal Town, in an interview with Gasgoo.
According to Qi Baoqun, the lower forming temperature of semi-solid die-casting technology makes the thermal shock of the mold less and extends the life of the mold. Compared with hot deformation forming processes such as forging, the deformation resistance of semi-solid forming is small, so that a large amount of deformation can be used to form parts with complex shapes and high precision and performance requirements, which overcomes the high cost of traditional forging and the inability to form complex parts Disadvantages have many unique advantages such as net forming, high quality, high performance, low energy consumption, and low cost. It has been praised by domestic and foreign researchers as one of the most promising metal processing technologies in the 21st century.
Comparison of casting processes
Specifically, compared with other forming processes, the advantages of semi-solid die-casting technology are mainly reflected in the following aspects:
First, semi-solid die casting can effectively control the content of pore defects in the casting. In the flow process, the semi-solid metal presents an orderly and controllable macroscopic flow state, which is different from the chaotic and uncontrollable macroscopic flow state of the liquid metal. Using this feature, the metal fluid can be filled into the mold cavity in order according to the design order, the cavity air is pushed to the end of the cavity, and finally exhausted through the exhaust groove, which avoids the involvement of cavity gas and reduces porosity defects. Improve the compactness of castings.
Semi-solid die-casting can also effectively control the content of shrinkage defects in the casting. Metal solidification from liquid state needs to undergo two volume shrinkage processes: liquid contraction and solidification contraction. From semi-solid state to solid state, it only needs to undergo one volume contraction process. Compared with liquid metals, semi-solid metals have a smaller volume shrinkage during solidification. Under the condition of natural solidification, the same volume of semi-solid metal produces less shrinkage volume than liquid metal.
In addition, semi-solid die casting can effectively reduce the hot cracking tendency of the casting. The source of thermal cracking is the internal stress generated by the alloy during the solidification process. The semi-solid die-casting technology eliminates the internal stress generated by the dendrite overlap, and at the same time reduces the shrinkage of the alloy, thereby reducing the tendency of thermal cracking.
High-quality semi-solid die-casting parts, because there are no pores inside, the casting can be heat-treated at high temperature, which can further increase the production capacity, and the casting has good weldability. Semi-solid die-casting technology also inherits the characteristics of high production efficiency of conventional die-casting, which is very suitable for the preparation of large quantities of parts.
Mature technology industrialization helps vehicle weight reduction
At present, in developed countries such as Europe, the United States, Japan, and South Korea, semi-solid die-casting parts have been used in automobiles in batches. For example, the Italian company Stampal uses semi-solid die-casting technology to prepare a multi-link automobile suspension for the Alfa Romeo Spider sports car, the British Cummins Turbo Technology company uses a semi-solid die-casting turbocharger 319s aluminum alloy impeller, and the US IDRA Prince company uses semi-solid Die-casting technology has prepared an oil pump filter 380 aluminum alloy shell. Thai GISSCO company has used a semi-solid die-casting technology to prepare 7075 aluminum alloy brake calipers. In China, semi-solid die-casting technology has been developed and applied in automotive structural parts, connectors, brackets, brake calipers, and motors, engines, and automotive air-conditioning compressors that have strict requirements on air tightness.
Xuzhou Dicaste Town's products for automotive applications
In fact, semi-solid aluminum alloy die-casting products are widely used in various types of vehicle structural parts due to their excellent mechanical properties and air tightness. Xuan Baoqun introduced the product system of Xuzhou Dicastal Town. He pointed out that semi-solid aluminum alloy die-casting products have excellent mechanical properties and can be used to make passenger car structural parts such as support arms, control arms, engine brackets, suspensions, etc. Mounting brackets, shock-absorbing brackets, brake calipers, dynamic and static scroll compressors, and complex connectors in all-aluminum body; due to the good air-tightness of semi-solid aluminum alloy die-casting products, it can also be used to produce a variety of vehicles Water pumps, oil pumps, high-pressure pumps for diesel vehicles, automotive air-conditioning compressor housings, etc. In addition, in the field of commercial vehicles, semi-solid aluminum alloy die castings can also be used to replace cast iron parts, such as heavy truck No. 1 and No. 2 brackets, heavy truck gearboxes, and shifting plugs.
According to the characteristics of semi-solid aluminum alloy die-casting products, Xuzhou Dicaste Town has formed the above product system to meet the market demand for high-quality aluminum automotive parts. At the same time, the company implements a strict inspection system for products. After the successful trial production of each new product, it is sent to the company's quality inspection center for testing. After passing the test, it is sent to a third-party testing agency for testing. The standard requires a quality report to be issued after strict testing to ensure stable and reliable quality. Xuzhou Dicas Town has the most advanced fully-automatic semi-solid die-casting island in China, and has set up a quality inspection center, CNC machining center and heat treatment center to ensure stable production capacity. Currently it can produce 500,000 to 600,000 molds of semi-solid aluminum every year. Alloy die-casting products.
Under the general trend of energy conservation and environmental protection, various automotive parts are looking for lightweight manufacturing solutions, but cost-effective processes are limited, and there are few high-quality suppliers. Especially in China, there is an urgent need for lightweight processes and buyers. The successful industrialization of Xuzhou Dicaste Town's aluminum alloy semi-solid die-casting molding technology is exactly the demand for lightweighting in the automotive industry. In response to this, Xun Baoqun said frankly, "Xuzhou Dicaste Town products can be widely used in automotive lightweight areas, such as automotive suspension brackets, steering knuckles for automotive chassis, control arms and other key structural products, which will reduce the energy consumption and the automotive industry The automotive industry has a significant effect on environmental pollution. "
National “Thousand Talents Plan” expert team provides solid support
As a high-tech innovative enterprise dedicated to the research and development of high-quality aluminum alloy parts manufacturing technology and industrial automation production, Xuzhou Dicaste Town is located in Kechuang Town, Jiawang District, Xuzhou City, Jiangsu Province. The company covers an area of 80 acres, and the standard workshop area is 17,000 square meters. The company is mainly engaged in the technical development, product production, sales and technical services of high-end aluminum alloy parts. The products have the characteristics of light weight, low energy consumption, high performance, safety and low cost, helping to increase the proportion of aluminum alloys in the automotive field and promote the realization of Lightweight cars. In addition to the automotive field, products are also widely used in aerospace, high-speed rail, engineering machinery, electronic communications and other fields, and have broad development prospects.
Dr. Zhu Qiang, Technical Expert Consultant of Xuzhou Dicastal Town, National Distinguished Expert of "Thousand Talents Plan"
And the back of Xuzhou Dicastal Town's leading industry with advanced semi-solid die-casting technology actually originates from the solid support of the national "Thousand Talents Plan" expert team. It is understood that the company is provided with technical support by the technical team led by Dr. Zhu Qiang, a specially invited expert of the National "Thousand Talents Plan". Dr. Zhu Qiang, as the expert consultant of Xuzhou Dicaste Town, has served as the fifteenth international composite materials and alloys Chairman of Processing Technology Conference and Chairman of China Manufacturing 2025 Equipment Manufacturing Transformation and Upgrade Theme Summit. He has studied and worked at Beijing University of Science and Technology, Cummins Turbo Technology Co., Ltd., and Beijing Nonferrous Metal Research Institute. Mainly engaged in metal material special casting, metal hot deformation behavior. In the past 5 years, he has participated in or hosted national projects such as national international cooperation, "863", scientific and technological support, "13th Five-Year Plan" national key basic material research and development plan, and material genome.
Regarding the future development layout and planning, Yi Baoqun said that in addition to conventional automotive aluminum alloy structural parts, in the future, it will focus on the development of unique structural parts of the new energy all-aluminum body. In addition, the automotive industry requires cylinders and valves with high air tightness The compressor body, the compressor housing, and the moving and stationary plates of the air-conditioning compressor will also be included in the product system. "Due to the different requirements of automotive products for aluminum alloy materials, we need to develop more new materials suitable for semi-solid processes to meet the market, such as particle-reinforced aluminum-based composites. Silicon carbide particle-reinforced aluminum-based composites have high specific strength , High specific rigidity, high abrasion resistance, low thermal expansion and excellent shock absorption, dimensional stability and other comprehensive properties, it is an ideal material for key parts in aerospace, automotive manufacturing and other fields. It is hoped to rely on the core of semi-solid die-casting. Technology to achieve a win-win situation for enterprises and industries under the guidance of the market. "