Aluminium gravity casting, often referred to as gravity die casting or permanent mould casting, is a robust and efficient manufacturing process used to produce metal components by allowing molten aluminium to flow into a reusable mould purely under the force of gravity. At DAC Industries, this technique underpins the production of precision-engineered parts with excellent mechanical properties, tight tolerances, and superior surface finish.
How the Process Works
Mould Preparation
DAC Industries uses CNC-machined steel or iron dies that are designed for longevity and repeatability. These permanent moulds are preheated and treated with a release agent to ensure clean casting and easy part ejection.
Pouring
Molten aluminium alloy is carefully ladled into the mould. Since there’s no external pressure applied, the fill is smooth and controlled, which reduces turbulence and the risk of gas entrapment.
Solidification
The metal cools inside the mould, forming a dense and uniform structure. Controlled cooling helps minimize porosity and internal stress, contributing to strong, reliable castings.
Ejection and Trimming
Once solid, the casting is removed using built-in ejector mechanisms. Excess material like runners and gates is trimmed, either mechanically or via machining.
Finishing and Inspection
The casting is then inspected and undergoes surface treatments such as machining, anodising, or coating to meet dimensional and aesthetic requirements.
Key Benefits
Superior Strength & Density: Gravity casting yields components that are denser and mechanically stronger than those made by sand casting.
Excellent Dimensional Accuracy: The use of precision permanent moulds ensures high repeatability and tight tolerances, reducing the need for post-processing.
High-Quality Surface Finish: The smooth inner surface of the mould results in castings with minimal surface defects, lowering finishing costs.
Cost-Effective Production: While initial tooling investment is higher than sand casting, the long life of the moulds and lower per-piece cost make it economical for medium to large batches.
Material Efficiency & Sustainability: Aluminium is highly recyclable, and the process generates very little waste, making it an eco-friendly choice.
Applications and Flexibility
This process is ideal for manufacturing components weighing from 10 g to 25 kg, using a range of non-ferrous alloys such as aluminium and brass. Typical end-use industries include:
Automotive: Engine parts, housings, brackets
Aerospace: Structural fittings and lightweight assemblies
Industrial & Electronics: Pump casings, connectors, electronic housings
Renewable Energy: Components for solar systems and wind turbines
Challenges & Considerations
Initial Tooling Costs: Permanent moulds require substantial investment and precision machining.
Design Constraints: Features such as undercuts or very thin walls (below ~3 mm) can be difficult to achieve without additional core work.
Production Rate: Gravity casting is slower than high-pressure die casting (cycle times typically range from a few minutes) and may not be ideal for very high-volume, small-part production.
Why Choose DAC Industries for Aluminium Gravity Casting?
DAC Industries brings 70 years of expertise in precision casting, using their own in-house tool design, maintenance, and finishing services to deliver high-integrity castings. Their ISO 9001-certified quality systems ensure reliability and traceability throughout production, making them a trusted partner from prototyping through to full-scale production.
In conclusion, aluminium gravity casting offers a powerful blend of strength, precision, versatility, and cost-efficiency. With a specialist partner like DAC Industries, you can leverage this process to manufacture high-integrity components optimized for performance, repeatability, and sustainability.
For more info, visit here:- industrial casting