Aluminum Casting Defect Characteristics
Aluminum casting refers to the use of casting processing methods and get pure aluminum or aluminum alloy device devices. Generally, sand or molds are used to melt the liquid aluminum or aluminum alloy into the mold cavity, and the various shapes and sizes of aluminum parts or aluminum parts are usually referred to as aluminum die castings.
Modern Molding Technology for Aluminum Casting
The complex aluminum casting is a new technology to produce high quality aluminum castings with the core technology of electromagnetic pump low pressure casting technology, aluminum smelting and forming composite purification technology and manufacturing core. The electromagnetic pump low-pressure casting metal melt transmission system has a stable flow, flow control is convenient, the process of melting the molten alumina and the ease of realization of the process is easy to use the automation of the process, which not only the casting quality of the aluminum casting casting But also to improve the working environment. Reduce labor intensity, to achieve automation and modernization of the casting production.
An important part of the melted enameled alloy castings is the aluminum smelting and composite purification facilities in addition to gas injection and spin foam ceramic filters with high degassing, unless the performance of metal inclusions. In addition, it uses a new long life lining material, an independent insulation / heating system can be used for a large number of continuous production, but also for intermittent production. The technology of aluminum melting purification efficiency, long life, low cost effective, easy to install, use and flexible. Casting experience tells us that the quality of aluminum to solve complex problems in three main aspects:
(1) aluminum liquid smelting and melting,
(2) a smooth transition of molten aluminum halide lamps
(3) the size and stability of the mold and sand core process.
Core manufacturing process modeling can see the casting quality and yield have a direct impact. Casting porosity, sticky sand, scar, thermal cracking and surface quality, dimensional accuracy, the use of sand performance is very good. Modeling and manufacturing of new technologies is PEPSET core resin binder for the original zirconia sand sand resin from hard sand, difficult kind of hard sand mechanism of a separate, non-hardening chemical reaction Initially, it is time to start hardening, curing The reaction starts once fast. So the coach bag, because in a tough, high-intensity, fat gas collapse of the small, good performance is the complexity of the casting surface to ensure the quality and stability of the dimensional accuracy.
Performance and application
Cast aluminum alloy has some other casting can not match the advantages, such as beautiful, light weight, corrosion resistance and other advantages, it is widely favored by the user, especially in the car since the weight of cast aluminum casting in the automotive industry has been widely Applications.
Cast aluminum alloy density than cast iron and cast steel is small, and the specific strength is higher. Therefore, under the same load conditions using aluminum alloy castings, can reduce the weight of the structure, so in the aviation industry and power machinery and transport machinery manufacturing, aluminum alloy castings are widely used. Aluminum alloy has a good surface gloss, in the atmosphere and fresh water has good corrosion resistance, it is in the manufacture of civilian utensils, with a wide range of uses. Pure aluminum in nitric acid and acetic acid and other oxidizing acid medium has good corrosion resistance, so aluminum casting in the chemical industry also has a certain use. Aluminum and aluminum alloys have good thermal conductivity, heat exchange devices used in chemical production, and parts requiring good thermal performance on powertrain, such as cylinder heads and pistons for internal combustion engines. They are also suitable for use with aluminum alloys manufacture.
Aluminum alloy has good casting performance. As the melting point is low (pure aluminum melting point of 660.230C, aluminum alloy pouring temperature is generally about 730 ~ 750oC or so), it can be widely used metal and pressure casting casting methods to improve the casting of the inherent quality, dimensional accuracy and surface Smoothness and productivity. Aluminum alloy due to solidification latent heat, under the same weight conditions, the solidification process of aluminum liquid longer than cast steel and cast iron much longer, put the flow of good, is conducive to casting thin and complex structure of the casting.
Cast aluminum alloy castings have many advantages, making it the direction of the development of the casting industry and the procurement of customers one of the most popular casting products, the future with the aluminum alloy casting technology progress, it will show their larger stage Style.
Analysis on the Problems to be Solved in the Future Development of Domestic Aluminum Alloy Casting Industry
Reducing energy consumption, reducing environmental pollution and conserving limited resources are a very important and urgent task facing today's countries. In the automotive and other products under the impetus of the general trend of lightweight, can be expected over the next 10 years, China's light metal casting market will have a substantial development. The proportion of aluminum and magnesium alloy castings in the major castings is between 13% and 19%. In some countries (such as Italy), the proportion of aluminum and magnesium alloy castings is as high as 30% to 40% To 10%. More than 90% of the developed countries for aluminum auto parts manufacturing, in China, aluminum alloy castings to form a large-scale production and meet the requirements of automotive lightweight to solve the problem is still a lot: First, the requirements of aluminum to the car Thin-walled, complex shape, high strength, high-quality direction. In order to meet this requirement, the casting process should be further optimized and the development of new alloy materials should be carried out. Second, the cost of production should be reduced from the point of view of design and process, such as the use of multiple molds and automation techniques to increase productivity, extend mold life, and reduce the number of parts with an integrated design. Third, the use of computer simulation technology to shorten the development process of the program cycle. Fourth, increase the recovery of aluminum. Recycled aluminum is the main raw material for aluminum casting. At the same time, China should pay attention to the utilization of recycled aluminum resources, develop the technology of effective separation of aluminum from composite materials and composite materials.
Developed along the grain boundary, often accompanied by segregation, is a crack at higher temperatures formed in larger volume shrinkage of the alloy and the shape of the more complex castings prone to
Heat treatment crack
Due to heat treatment caused by overheating or overheating, often cross-crystal cracks. Often in the stress and thermal expansion coefficient of large alloy cooling too drama. Or when there are other metallurgical defects