Create new opportunities for the development of the civil aviation industry as magnesium alloy die-casting industry
As one of the new material to promote a new road to industrialization, magnesium alloy recent concern and Development Forum held recently in Xi'an, China's first private aviation industry, a large number of contracted orders more magnesium alloy die-casting industry called the new development opportunity.
The aviation industry in recent years, especially in the private aviation industry development speed significantly accelerated current new development projects, in addition to the outside of the aircraft itself is required for high-end aluminum, magnesium alloy material, the multi-purpose building aerospace theme park, and in the subject The park gradually build the aircraft fuselage is transformed into a set of popular science, aviation experience, aviation, entertainment, business and tourism as one of the air travel park. The face of such an unprecedented huge market space, and broad prospects for the development of magnesium alloy die-casting industry.
Reduce energy consumption, improve energy efficiency, reduce environmental pollution and conservation of the earth's resources is an important and urgent problems facing humanity today. Processing and manufacturing design products more and more attention to the problem of lightweight. Magnesium alloy has a density, stiffness, high specific strength and ability of good anti-corrosion and anti-electromagnetic radiation, as well as a good filling liquidity and recycling a number of advantages to make it in the automotive, electronics, home appliances, The growing number of communications, instrumentation, and aerospace and other fields of application. Magnesium alloy die-casting auto parts in the automotive industry in Europe and the United States, Japan and other developed countries there has been a sustained and rapid growth momentum. According to estimates of the International Magnesium Association (IMA), the future with the development of the world's automotive industry, will lead to magnesium demand continued to grow. Estimated 2030 car ownership in the world than doubling to $ 1 billion. 2001 is expected to total demand of the automotive industry of magnesium will reach 11 million tons in the next 10 years, the automotive industry will reach 15 percent of the growth rate of the magnesium demand. Magnesium alloy die-cast structural parts will become the 21st century, the most important field of application of magnesium. The rapid growth of magnesium alloy die facing the automotive industry automotive light weight, less fuel consumption, in line with new environmental requirements contributed to by the developed countries of Europe and North America. In addition, magnesium alloy die castings in the car can also improve the structure and dynamic performance of the car is the automotive industry emphasis on one of the reasons for the application of magnesium alloy.
The automotive industry is a world leader in the United States, many auto parts magnesium alloy casting production. In Europe, with the car company shares increasing magnesium alloy plant and the the automotive lightweight, energy-saving and environmental protection requirements, will further promote the application of magnesium alloy in the car. 1999 in Germany GIFA exhibition on magnesium alloy die-finished products and related technologies to become a hot spot. Currently, magnesium alloy die castings, automobile company General Motors, Mercedes-Benz, Chrysler, Fiat - Alpha and other companies have adopted more than 60 kinds of magnesium alloy die-casting auto parts, such as: automotive instrument panels, seat frames, steering parts, hood, gearbox, intake manifold, and hub. The production of magnesium alloy die-casting machine and die casting technology is developing rapidly due to the demand of die-cast magnesium alloy products, well-known die-casting machine manufacturers have launched their own magnesium alloy die-casting machine.
2 at home and abroad magnesium alloy die-casting technology status quo and development trend
21 physical and chemical properties of magnesium alloy die-casting process characteristics
The magnesium alloy density is small, about 1 81g/mm3. Magnesium alloy than the elastic modulus and high strength aluminum alloy and alloy steel are substantially the same. The metal magnesium melting point of 650 ° C, magnesium alloy melting range of about 430 to 620 ℃. The magnesium metal in the liquid state will vigorous oxidation and combustion, when the magnesium alloy is heated temperature reaches above 350 ℃ protective gas-tight covering the surface of the magnesium alloy bath, to prevent oxidation and combustion of the magnesium alloy melt. For this reason, when in the molten magnesium alloy, to pass into the protective gas in the furnace air sent packing, and the melting furnace is in the closed state with the outside air, the protective gas pressure when the furnace temperature reached 350 ° C, should be required transferred to the optimum value. According to the characteristics of the magnesium alloy hot chamber die casting machine, magnesium alloy melting insulation temperature of 630 ~ 650 ℃; cold chamber die casting machine, magnesium alloy melting insulation temperature of 640 to 670 ℃. High magnesium alloy die casting temperature than the die-cast zinc alloy and aluminum alloy, the production of small and thin-walled parts, type temperature control is more stringent. Small due to the specific heat capacity of magnesium alloy, under the same conditions, magnesium alloy filling time than aluminum should be shortened from 30% to about 35%, more than 25% of the inner runner at the outlet of magnesium alloy filling speed is faster than the aluminum alloy (under normal circumstances, the magnesium alloy filling speed of 50 ~ 60m / s, die-casting very thin wall castings even up to 80m / s or more), magnesium alloy die-casting machine punch shot velocity 5m / s above (or even 8m / s), the injection pressure ratio than high hot chamber die casting of zinc alloy and aluminum alloy cold chamber die casting, magnesium alloy die-casting machine this request should have better injection performance.
22 cold chamber die casting machine and die-casting technology
Divided into horizontal die casting machine and two types of vertical die casting machine cold chamber die casting machine, now the world's most widely used cold chamber horizontal die casting machine. Most die castings, especially large, thick-walled, force and special requirements die casting, generally horizontal cold chamber die-casting machine to produce. The world famous manufacturer of die casting machine: Switzerland BUHLER company Germany FRECH company, the IDRA company in Italy and ITALPRESSE Japan UBE company, TOYO Corporation and TOSHIBA, U.S. HPM companies. Cold chamber die casting machine is basically composed by three parts of the locking system, injection system and injection process monitoring system. These companies produced different models of die-casting machine, but much the same principle and structure of the locking system and injection system, the difference is mainly in the injection process monitoring system. Overall, injection process monitoring system features include: recording and assessment of important process parameters of the die-casting machine, die casting type and the parameters of the liquid metal, and compatible with the data of the controller, integrated operation and programming; records display and storage of die casting process, process parameters, and man-machine dialogue programming of the machine after the procedure; operator in the main control panel for easy operation, real-time control of the entire system uses feedback can be realized from diagnosis, self-correction, identify the fault diagnostic display and fault alarm; make use of the internet and intranet, and connected to the die casting machine manufacturers and users of die castings with remote interactive features. There is no special magnesium alloy cold chamber die casting machine. When ordinary cold chamber die casting machine die-cast magnesium alloy die casting machine injection system and an automatic feeding system for the necessary transformation to make it applicable to the magnesium alloy die requirements. The transformation of the contents include: (1) fast injection speed of the injection system from die-cast aluminum 4 to 5m / s to 10m / s; (2) shorten the pressurization process time pressure built; (3 ) injection force; (4) the use of electromagnetic automatic dosing unit to prevent the oxidation of magnesium alloys in the casting process; (5), configure the necessary equipment such as vacuum die-casting and other special die-casting process. With the development of the automotive industry and increasingly strict weight saving and environmental protection requirements, cold chamber die casting magnesium alloy magnesium alloy die-casting technology will become an important development direction. It can be predicted that strong demand for magnesium alloy cold chamber die casting machine, soon formed a series of products will lead to a magnesium alloy special cold chamber die casting machine.
23 magnesium alloy hot chamber die casting machine and die-casting technology
Magnesium alloy hot chamber die casting machine is designed for the physical and chemical properties of magnesium alloy die casting process characteristics, magnesium alloy die abroad most widely used magnesium alloy die-casting equipment. Major foreign manufacturer of die casting machine, such as Germany FRECH company, Italy IDRA and ITALPRESSE Japan TOYO, TOSHIBA, UBA and HISHINUMA companies, both production and provide magnesium alloy hot chamber die casting machine products to the market . Magnesium alloy hot chamber die casting machine by closing institutions, punch gooseneck nozzle injection institutions, melting insulation crucible furnace gas protection device and injection monitoring system. The main difference with ordinary hot chamber die casting machine is: magnesium alloy hot chamber die casting machine requires a higher injection speed (more than 8m / s); require injection system hydraulic shock injection is completed; crucible melting insulation the working temperature of the furnace is higher than zinc alloy hot chamber die casting machine working temperature (about 660 ℃), and more stringent temperature control; magnesium alloy extremely strict control of the content of impurity elements Fe and Cr, magnesium alloy melting insulation the furnace crucible should be very low impurity elements C and Cr content alloy material; magnesium alloy melt easily oxidized burning magnesium alloy melting insulation crucible furnace should be enclosed structure, and configured to prevent the oxidation of magnesium alloy melt protection gas input means. Type casting molten hot chamber die casting magnesium alloy melting insulation crucible furnace closed gooseneck nozzle directly into the pool level, to avoid the cold chamber die casting process, the liquid alloy oxidation and formed oxidation scum, and temperature loss magnesium alloy hot chamber die casting machine is more suitable for the production of cosmetic requirements higher thin-walled castings, such as home appliances, computers, communication, household hardware, instrumentation, and some are not required to bear the load shell parts. Directly to the molten magnesium alloy magnesium alloy hot chamber die casting machine punch through closed gooseneck nozzle directly pressed into the die cavity injection pressure is small and usually non-pressurized generally not used in the production of automotive, aerospace and aircraft higher in the large, thick-walled, high-load part. The United States, Japan, and the United Kingdom and other countries in recent years companies have successfully developed a magnesium alloy semi-solid thixotropic injection pressure casting machine. Magnesium alloy semi-solid thixotropic injection pressure casting machine to a certain pressure, the semi-solid magnesium alloy injection die-casting type within make forming its working principle is similar to the injection molding machine. It preformed non-dendritic state magnesium tablets fed to the screw feed mechanism in a spiral to the feed mechanism of the magnesium particulate is heated to a semi-solid, and by the coil to the other end of the feed mechanism of the magnesium alloy slurry collection chamber of the semi-solid magnesium alloy slurry fed into the injection chamber injection compression molding. Thixotropic semi-solid magnesium alloy injection pressure casting machine to produce automobiles, computers, mobile phones, home appliances, digital cameras, cameras on the requirements of lightweight, refined and high specific strength of magnesium alloy parts. Casting having a high strength, high reliability, close to the finished size, strong regeneration, almost does not produce waste, can greatly reduce the cost of production of the magnesium alloy castings. As of the end of 1998, the global total of about 100 thixotropic semi-solid magnesium alloy injection pressure casting machine into operation. This casting method represents a direction of development of the production of magnesium alloy castings. With the vigorous development of smart appliances, electronics, computer, communications and other emerging industries, will generate strong demand as a green manufacturing materials magnesium alloy, magnesium alloy hot chamber die casting machine will move towards serialization, multi-functional, fully automated, remote man-machine dialogue direction.
24 of magnesium alloy die-casting equipment development status
Magnesium alloy die-casting production near zero, in the automotive industry, only Shanghai Cosmopolitan Automobile Accessory Manufacturing Co., Ltd. production of magnesium alloy die castings; appliances and electronics manufacturing industry, is currently only Jiarui Metal Products Co., Ltd. in Shenzhen a few Hong Kong enterprises producing magnesium alloy die castings; in other areas, such as the Xinhai Aluminum and some other manufacturers over the years with a die-cast magnesium alloy to produce some Fengdonggongju devices, such as forest machinery and parachute some components. Above for the introduction of foreign advanced hot chamber die casting machine and supporting melting equipment manufacturers have provided favorable conditions for the expansion of the domestic die-casting magnesium alloy applications. However, overall, the domestic demand for magnesium alloy die-casting machine is very limited. Currently, there are more than a dozen of the die casting machine manufacturer, die-casting machine annual production capacity of more than 1200 units, cold room and hot chamber die casting machine can produce a variety of series, basic domestic die-casting machine to form a more complete series of products, production greater than domestic demand. Magnesium alloy die casting hot chamber die casting machine is still in the development stage, only Hong Kong LK Machinery (Shenzhen) Co., Ltd. and the Hong Kong University of Science and Technology Source (Asia) Co., Ltd. production of a few models of magnesium alloy die-casting machine. DC-160M Shenzhen LK Machinery Co., Ltd. production of magnesium alloy hot chamber die casting machine can produce the projected area of less than 800cm2 of magnesium alloy die castings, electric control system, hydraulic components and melted insulation crucible furnace parts abroad now basically product, the machine has good overall performance and reliability, the injection speed of up to 6m / s, using SF6 protection gas, and production management, fault diagnosis, type temperature control function. Cold chamber die casting machine for magnesium alloy die the DCC-630M in key core technologies, such as the automatic regulation of the injection parameters monitoring system, hydraulic components and electrical components etc. imported products, not only the production of high strength magnesium alloy thin pieces, but also the production of large thick-walled magnesium alloy die castings. Pneumatic shot speeds of up to 8m / s, injection boost pressure up to 150MPa more time pressure built 20ms. Summary, magnesium alloy hot chamber die casting machine and suitable for magnesium alloy die casting cold chamber die casting machine key core technology to be further
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