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news
2020.12.3
Aluminum alloys are often used to manufacture automotive and car parts as its lightweight and high strength. With the development of die casting services, aluminum alloy die castings are commonly used in the automobile industry, including engine covers, gearbox housings, and other products. However, there are still some problems that occur in the casting process of aluminum automotive parts.
Aluminum alloy is a versatile material in a number of uses, can also be processed with various techniques, such as die casting, CNC machining, turning, milling, and more. Aluminum has been used to manufacture automobile components for over a hundred years, it is the second most used material in the automotive industry based on some excellent characteristics.
– Lighter than steel and many other metals
– Aluminum has high strength and even more strong at low temperatures
– Can flex under load and bounce back from the force of impacts
– The oxide layer on the surface provides resistance to corrosion
– Good conductor of heat and electricity
– Aluminum has excellent malleability, can be extruded into any shape
The front cover of the auto engine needs high density and good mechanical properties, and no internal defects such as cracks, shrinkage porosity, gas porosity, and shrinkage cavity. So when it comes to the material of the automobile engine covers, AlSi9Cu3 aluminum alloy is often selected, it has good fluidity and excellent die casting performance.
The structure of die casting aluminum automobile engine cover is complex, there are a number of bolt holes and reinforcing ribs distributed inside. The wall thickness of the casting part is different in different positions, during the die casting process, stress concentration is easy to happen, which results in uneven density, deformation, shrinkage cavity and shrinkage porosity.
1. Improve the design of the gating system
To improve the quality of die casting parts, manufacturers should ensure the filling speed of each area during the forming process is basically the same, due to the varying wall thickness, it is recommended to add two gates for the thick-wall areas to speed up the filling process, to make the filling speed of the whole process is more stable. This is conducive to the elimination of gas, to avoid shrinkage cavity, shrinkage porosity, and other defects.
2. Use high-pressure spot cooling technology
High-pressure spot cooling technology is an effective measure used in the die casting process, to adjust the cooling water to the ideal state, feed the water into the corresponding pipe, when the cooling water quickly passes through the die casting mold, the target area is cooled. The mold core cools fast in the process, so the shrinkage cavity will not be formed. The high-pressure spot cooling technology can not only reduce the gas porosity defects but also increase the lifespan of the die.