Aluminium Die Casting
Production Technique
The casting process implements a steel mold often capable of producing tens of thousands of castings in rapid succession. The die must be made in at least two sections to permit removal of castings. The casting cycle begins with the two die halves are clamped tightly together by the die casting press. Molten aluminum is injected into the die cavity where it solidifies quickly. These sections are mounted securely in a machine and are arranged so that one is stationary while the other is moveable. The die halves are drawn apart and the casting is ejected. Die casting dies can be simple or complex, having moveable slides, cores, or other sections depending on the complexity of the casting. Most machines use mechanisms actuated by hydraulic cylinders to achieve locking. Others use direct acting hydraulic pressure. Die casting machines, large or small, vary fundamentally only in the method used to inject molten metal into the die.
Sometimes, higher mechanical values are desired and, in those cases, squeeze casting can be used as an alternative to die casting. Squeeze casting is a casting method that combines die casting and forging. It starts with low-pressure casting, followed by the application of very high pressure as the material cools, producing a high-quality casting. This is often carried out using a hydraulic press as part of the casting apparatus.
Squeeze casting was originally created to make stronger metal parts for use in construction industry. The metal parts created by this process are more resistant to wear and heat.
Technical details:
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The dimensional tolerances are listed in table DCTG 6 (standard ISO 8062-3). For wall thickness, table DCTG7 should be used.
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The weight can vary from a couple of grams to approximately 5kg.
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The surface roughness is in general below Ra 7 μm.
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The minimal wall thickness depends on the design of the part but it is recommended to take at least 2mm.
Materials
A380
A380 is one of the most commonly specified aluminum alloys with a number of significant benefits. It offers the best combination of casting, mechanical, and thermal properties. It exhibits excellent fluidity, pressure tightness, and resistance to hot cracking. Therefore, A380 is used for a wide variety of products including chassis for electronic equipment, engine brackets, gearbox cases, household furniture, power, and hand tools.
B390
B390 is an aluminum alloy with high hardness and good wear resistance. This alloy is suitable for many applications including internal combustion engine pistons and cylinder bodies for compressors and brakes.
ADC12
If your component is highly intricate, ADC12 is often used as an alternative to A380. It has better corrosion resistances, is lightweight, and its benefits include ease of casting, good mechanical properties, and dimensional stability.
A413
A413 is an aluminum alloy with excellent pressure tightness. This makes it a good choice for hydraulic cylinders. The castability of this aluminum alloy makes it a great choice for die casting intricate components.