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Home >> Knowledge Bank |
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KNOWLEDGE BANK |
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This section contains a knowledge bank for die casting and mechanical engineering in general . This includes basics of die casting, design of die cast components, die casting alloy selection and mechanical engineering data in general. |
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Introduction to Die Casting |
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Die casting is a process in which molten metal is injected into a hardened steel die (also called mould) under high pressure of 10-210 Mpa (1450-30500 psi). This results in a more uniform part, generally good surface finish and good dimensional accuracy. The process can be used for casting components of aluminum and zinc alloys. A schematic illustrating the basic pressure die casting process is shown here. |
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The Die Casting Process |
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The die casting process essentially involves four steps:
- Die cast part design and specification: This process involves appropriate design of the component in order to ensure trouble-free die casting.
- Die/mould design and fabrication: Once the product dimensions are finalized, the next step involves design of the die and fabrication of the various components of the die and the associated housing.
- Die casting: Upon fabrication of the die, the next step consists of the actual production of the die-cast parts using the mould fabricated for this purpose.
- Post die-casting operations: Finally it is necessary to make the appropriate jigs and fixtures for post die casting operations like drilling, tapping, riveting and machining, and carry out these operations on the die cast components. In addition the die cast products may also be assembled into sub-assemblies or complete products.
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Die Cast Product Design Guidelines |
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Some of the points that need to be considered when developing the part to be cast using pressure die casting are listed below:
- Minimize material in order to minimize material costs.
- Maintain minimum machine stock to avoid porosity.
- Maintain uniform thickness for smooth metal flow & to avoid shrinkage.
- Maintain a minimum thickness of 2.5 mm for aluminum and 1 mm for zinc.
- Do not specify dimensional tolerances closer than those required. Specify tolerances that are just necessary and sufficient.
- Provide a draft of 1 - 2 degrees for trouble-free ejection.
- Maintain as large fillets as possible; avoid sharp corners for smooth metal flow and problem-free ejection and to avoid porosity due to air inoculation.
- Incorporate shrinkage considerations to obtain correct dimensions after casting.
- Provide fillets and ribs at appropriate places for mechanical strength.
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Die Casting Alloys
Die Casting Materials
Pressure die casting is usually carried out in aluminium and zinc. In this section we provide the compositions of aluminium and zinc alloys.
Composition of aluminium alloys
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Percent composition (Single values are maxima) |
| Type of alloy |
BS 1490 |
Cu |
Mg |
Si |
Fe |
Mn |
Ni |
Zn |
Pb |
Sn |
Ti |
| Aluminium – silicon – copper alloy |
LM.2 |
0.7-2.5 |
0.30 |
9.0-11.5 |
1.0 |
0.5 |
0.5 |
2.0 |
0.3 |
0.2 |
0.2 |
| Aluminium – magnesium alloy |
LM.5 |
0.1 |
3.0-6.0 |
0.3 |
0.6 |
0.3-0.7 |
0.1 |
0.1 |
0.05 |
0.05 |
0.2 |
| Aluminium – silicon alloy |
LM.6 |
0.1 |
0.1 |
10.0-13.0 |
0.6 |
0.5 |
0.1 |
0.1 |
0.1 |
0.05 |
0.2 |
| Aluminium – silicon alloy |
LM.20 |
0.4 |
0.2 |
10.0-13.0 |
1.0 |
0.5 |
0.1 |
0.2 |
0.1 |
0.1 |
0.2 |
| Aluminium – silicon – copper alloy |
LM.24 |
3.0-4.0 |
0.30 |
7.5-9.5 |
1.3 |
0.5 |
0.5 |
3.0 |
0.3 |
0.2 |
0.2 |
Composition of zinc alloys
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Percent composition (Single values are maxima) |
| Type of alloy |
BS 1004 |
Cu |
Mg |
Fe |
Ni |
Pb |
Cd |
Sn |
Zn |
| Copper-free zinc alloy |
Mazak 3 |
0.1 |
0.03-0.06 |
0.1 |
0.006 |
0.005 |
0.005 |
0.002 |
Remai-nder |
| 1% copper-zinc alloy |
Mazak 3 |
0.75-1.25 |
0.03-0.06 |
0.1 |
0.006 |
0.005 |
0.005 |
0.002 |
Remai-nder |
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Mechanical Engineering Data |
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In this topic we have provided general mechanical engineering data for the convenience of our customers and other visitors of this website. |
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