Development Trend of Automobile Casting and Casting Technology
Casting is one of the oldest metal forming methods, and about 15% to 20% of the auto parts are castings produced by different casting methods. These castings are mainly key components of the power system and important structural components. At present, Europe and the United States automobile industry developed countries, automobile casting production technology advanced, good product quality, Automobile Casting high production efficiency, environmental pollution. Casting raw and auxiliary materials have been formed series and standardization, the entire production process has been achieved mechanization, automation and intelligence. These countries generally use digital technology to enhance the level of casting process design, casting scrap rate of about 2% to 5%, and has established a multinational service system and network technology support. In contrast, although China's automobile castings larger output, but most of them are low added value and technical content, the structure is relatively simple black castings, and the gap between foreign level. This article mainly from the automobile energy conservation and environmental protection and other aspects of the development needs, discusses the Automobile casting and Automobile technology development direction.
Pressure casting referred to as die-casting, Automobile Casting under a certain pressure to make the melt filled cavity, casting tissue dense, high mechanical properties, size precision, small processing margin. According to the level of pressure can be divided into low-pressure casting and high-pressure casting two categories, the latter's high cost of mold, especially for high-volume production of Automobile castings, high efficiency, the total cost is very low. At present, almost all of the car transmission shell, clutch shell, pump shell, carburetor shell, steering gear, etc. are aluminum die casting.
The main parameters of the die-casting process are the compression force, the specific pressure, the melt filling speed, the filling time, the holding time, the melt temperature and the mold temperature. As the melt in high temperature, high speed, high pressure filling cavity, will inevitably be involved in gas, so developed a number of new processes, such as vacuum die-casting method, oxygen-filled die-casting method, Automobile Casting low-speed filling die casting method "precision "Die casting method (also known as Acumrad method that is acurate, rapid, dense), low-speed medium-pressure filling (NDC) casting method, they are no new technology of non-porous die casting. Therefore, according to the characteristics of die casting scientific control of process parameters, rational design and manufacture of mold (including pouring system, overflow exhaust system, mold cooling system, mold heating and balance control system), use the appropriate coating and spraying technology. Die temperature and heat balance is the most important conditions for the realization of high-quality casting, Automobile Casting for the general die casting to remove the casting mold cavity surface temperature of the alloy melting point of 40% about.