The ideal wall thickness range for aluminium alloy die casting is 1.0 mm to 5.0 mm. Less than 1.0 mm is prone to poor flow, cold shuts, and cracks; more than 5.0 mm may cause shrinkage and material waste. Maintaining uniform wall thickness, smooth transitions, and using structural reinforcements can help improve part strength and casting quality.
This article will introduce the standard wall thickness range, key design principles, influencing factors, the consequences of improper design, post-processing considerations, and CEX Casting‘s wall thickness optimization capabilities. Read on to help you achieve the optimal wall thickness design for aluminum die castings.
Standard Wall Thickness Range
Minimum Wall Thickness Recommendation
The standard minimum wall thickness for high-pressure die casting is 1.0 mm to 1.5 mm.
If high-pressure equipment and high-flow alloys are used, the wall thickness can be as low as 0.5 mm.
However, too thin a wall thickness is prone to poor flow, insufficient filling, cracking, and structural instability.
Maximum Wall Thickness Recommendation
The recommended maximum wall thickness range is 3.5 mm to 5 mm.
Too thick areas cool slowly, which is prone to shrinkage and dimensional deformation.
At the same time, it increases the molding cycle and material cost, but cannot effectively improve performance.
Comparison of Wall Thickness of Different Materials
The ideal wall thickness range of aluminum is 1.0–5.0 mm, which is determined by its fluidity and cooling characteristics.
Zinc alloys can support extremely thin wall thicknesses of less than 0.5 mm due to their improved fluidity.
Material selection must be determined in conjunction with thermal properties, casting pressure, and geometric structure.
Key Principles of Wall Thickness Design
Uniform Wall Thickness
Uniform wall thickness ensures the controllability of the cooling and solidification process, reduces internal stress, deformation, and dimensional error.
Wall thickness changes should be minimized during design to improve structural performance and yield.
Smooth Transition Treatment
Avoid sudden changes in wall thickness, otherwise, it will disrupt metal flow and cause cooling problems.
Gradual or smooth transitions should be used to connect thick and thin areas to reduce stress concentration and prevent defects such as hot spots and air inclusions.
Structural Reinforcement Design
Structural strength can be enhanced by reinforcing ribs and plates without increasing the overall wall thickness.
The recommended rib thickness is 0.5–0.7 times the adjacent wall thickness to avoid sink marks and uneven cooling.
Reinforcement plates can improve the bearing capacity and rigidity of corners or large flat areas.
Factors Affecting Wall Thickness
Alloy Properties
ADC12 has good fluidity and is suitable for thin-walled structures of 0.8–1.0 mm, but has high shrinkage and average strength.
A356 alloy has low fluidity and is suitable for medium-thick wall castings over 2 mm, with higher strength and density.
Part Geometry
The more extreme the geometry, the more difficult it is to ensure uniform wall thickness distribution.
Slender or deep cavity structures are difficult to fill and are not conducive to thin walls.
Large flat surfaces or heavy areas cool slowly, which can easily lead to shrinkage or deformation, thus limiting the stability of thick-walled structures.
Mold Design and Precision
The die casting mold‘s runner layout, exhaust system, and cooling configuration directly affect the metal flow path and solidification rate, and are critical to the molding quality of thick-walled areas.
Thin-walled areas are prone to cold shuts due to limited flow, while thick-walled areas may form shrinkage or pores.
High-precision mold design helps achieve consistency and controllability of complex wall thickness structures.
Die Casting Equipment Performance
The clamping force, injection speed, and filling pressure of the equipment determine the ability to achieve a range of wall thicknesses.
High-pressure and high-speed equipment can more easily fill thin-walled areas and reduce defects, and is suitable for structures below 1 mm.
Ordinary equipment may limit the stable molding of thin-walled and large thickness differences.
Simulation Tools
Mold flow analysis is a key means to verify the feasibility of the wall thickness design.
Through simulation, it can be predicted whether thin walls can be filled, whether thick walls are easy to shrink, and optimize the gate and cooling scheme, reduce the risk of mold trial, and improve the one-time molding success rate of thick wall areas.
Consequences of Improper Wall Thickness Design
Too Thin Problem
Wall thickness less than the recommended value is prone to insufficient filling, cracking, and structural instability.
Such die casting parts may fail under stress or thermal deformation during use.
Too thin areas will also increase the difficulty of subsequent processing and assembly.
Too Thick Problem
Excessive wall thickness will cause uneven cooling, resulting in shrinkage and dimensional deformation.
It will also extend the production cycle, increase raw material consumption, and overall weight.
Locally thick walls may also cause excessive stress concentration, affecting structural stability and dimensional accuracy.
Relationship Between Wall Thickness and Mechanical Strength
On the surface, die casting products with thicker walls seem to be stronger, but this is not the case.
Over-thick areas tend to cool slowly, easily forming shrinkage and pores, resulting in local strength reduction.
The true strength of castings comes from reasonable wall thickness distribution, structural reinforcement design, uniform cooling, and suitable alloy selection.
Wall thickness can only be effectively converted into load-bearing capacity under the premise of matching the structure and the die casting process.
Post-Processing Considerations
Machining Allowance
Critical size areas usually require subsequent machining, and sufficient machining allowance should be reserved in the design stage.
The wall thickness of the casting must not only meet the molding requirements, but also ensure that it still has sufficient structural strength after removing excess material.
Surface Treatment Support
Surface treatment processes such as anodizing, powder coating, or painting require a stable and uniform substrate.
Too thin areas may deform or corrode under chemical or heat treatment.
It must be confirmed that the wall thickness of the casting can support the selected surface treatment process.
CEX Casting’s Expertise in Wall Thickness Optimization
Extensive Molding Capabilities
CEX Casting can stably produce aluminium die casting components with wall thicknesses ranging from 2 mm to 15 mm, covering lightweight shells and heavy-duty structural parts.
We can maintain dimensional control and consistent casting quality even with complex structural designs.
Advanced Simulation and Process Control
We optimize wall thickness distribution through mold flow analysis, verify the minimum feasible wall thickness, and identify risk areas.
Simulation can guide the filling path of thin-walled areas and the balanced cooling of thick-walled areas, thereby improving the manufacturability and stability of wall thickness design.
Patented Technology Advantages
We have our patented squeeze casting technology, which is specially developed for complex wall thickness structures.
It can achieve a smooth transition between thin and thick wall areas, avoiding insufficient filling and uneven cooling.
In the case of large wall thickness differences, the organization can still be dense, and the structural strength can be maintained without changing the original design.
CEX Squeeze Casting Workshop
Conclusion
The recommended die casting wall thickness range is 1.0–5.0 mm.
The transition area should be kept smooth, sharp corners and sudden changes in thickness should be avoided, and the structural strength of the casting should be improved by reinforcing ribs instead of thickening.
As a professional aluminum die casting manufacturer, CEX Casting provides simulation-based design solutions and patented squeeze casting technology to ensure stable wall thickness and dense structure of the casting.
Contact us now to learn how we can optimize your next aluminum alloy die casting project.