Unlike aluminum pressure die casting, gravity die casting is the casting technique that utilizing gravity to fill the mould with liquid aluminum alloy. Such gravity die casting can also be called as aluminum gravity casting in China.
Aluminum Gravity Die Casting Process
Like other casting processes, aluminum gravity die casting process starts from the developping of mold by CNC machines. Then, melt aluminum ingots into liquid status, and pour the aluminum liquid water into the permanent molds to fill the cavity by handwork or by gravity casting machines. Next, cool the poured aluminum alloy for a while for solidification. Finally, take the aluminum gravity die casting blanks from the mould, and remove the flash and carry out necessary post operations like shot blasting, machining and others. Below is a video showing the aluminum gravity die casting process in our foundry:
Aluminum Gravity Die Casting Alloy: A356-T6
A356 is a type of aluminum alloy especially for gravity die casting. A356 cast aluminum alloy has good casting and machining performance, suitable for use in aircraft, pump housings, impellers, high-velocity blowers, and other structural castings that require high strength. This light alloy is often used to manufacture intricate and complex aluminum castings, which provides lightweight, pressure tightness and great mechanical properties. Sometimes, A356 used as an alternative for 6061 aluminum.
Chemical Compositions
| A356 Aluminum Alloy | Elements | ||||||||
| Cu | Mg | Mn | Si | Fe | Zn | Ti | Others | Al | |
| ≤0.2% | 0.25%-0.45% | ≤0.10% | 6.5%-7.5% | ≤0.2% | ≤0.1% | ≤0.2% | ≤0.15% | balance | |
Mechanical Properties
- Elongation at Break: 3-6%
- Fatigua Strength: 50-90 MPa
- Shear Modulus: 26 GPa
- Ultimate Tensile Strength: 160-270 MPa
- Yield Tensile Strength: 83-200 MPa
- Melting Onset: 570℃
- Density: 2.6 g/cm³
After gravity die casting, T6 heat treatment is suggested to improve the mechanical properties of A356 aluminum castings. The hardness, tensile strength and ductility of A356 castings could be improved by 106%, 106% and 214% respectively.
Benefits of Aluminum Gravity Die Casting
- The tolerances and surface finish are good.
- Gravity die casting method is competitive casting method when production quantity is relatively small or when heat treatment is needed to improve the mechanical properties.
- This casting method gives better tolerances and surface finish than sand casting. But the tooling costs are a bit higher than by sand casting.
- Using sand cores in gravity die casting makes it possible to manufacture items with complicated inner shapes in a cost effective way in small and medium quantities.
Aluminum Gravity Die Casting in CFS Foundry
CFS Foundry has been involved in aluminum gravity die casting since 1998. During these years, we have been continuously introducing much advanced gravity die casting machines to improve the production efficiency. For large quantity orders, such machines greatly shorten the production cycle and offer our customers in a much lower price. However, for some small orders, we also reserve our handwork gravity casting processin a cost effective manner.
Currently, our aluminum gravity die cast products are supplied to a wide range of industries, such as automobile industry, oil field industry, agriculture implements, furniture parts, housing appliance, etc. Typical products produced this way are e.g. air intake components for diesel engines, valves for flow systems, tanks for air conditioning systems, etc. Those gravity die casting parts are mostly exported to American and Eourpean countries. We can provide custom aluminum gravity die casting with different aluminum alloys with value added services such as heat treatments, surface treatments (including electroplating, powder coating, painting), assembly, etc.
If you have RFQs for aluminum gravity die castings or other aluminum castings from China, just pls feel free to contact us. We are always waiting online for your service.
Case Study:
Aluminum Gravity Casting for Skateboard Truck Hanger & Baseplate