Shenzhen Alu Rapid Prototype Precision Co., Ltd.

Designing for die casting involves optimizing the part geometry, material selection, and manufacturing process to ensure high-quality, cost-effective production. Below is a concise guide to designing for die casting, covering key considerations and steps:

1. Understand Die Casting Basics

Die Casting Process: Molten metal (e.g., aluminum, zinc, magnesium) is injected under high pressure into a steel mold (die) to create precise, complex parts.

Advantages: High precision, repeatability, smooth surfaces, and ability to produce complex shapes.

Limitations: High initial tooling costs, limited to certain metals, and potential for porosity.

2. Material Selection

Choose a material suitable for die casting, such as:Aluminum: Lightweight, corrosion-resistant, good strength (e.g., A380, ADC12).

Zinc: High precision, excellent for thin walls, good for small parts (e.g., Zamak alloys).

Magnesium: Lightweight, good for complex geometries (e.g., AZ91D).

Consider mechanical properties, corrosion resistance, and cost based on the part’s application.

Ensure material compatibility with the die casting process and mold life.

3. Part Design Guidelines

Uniform Wall Thickness:Maintain consistent wall thickness (typically 1.5–5 mm, depending on material) to ensure even cooling and minimize defects like warping or porosity.

Avoid thick sections to reduce shrinkage and cooling issues.

Draft Angles:Include draft angles (1–3°) on walls perpendicular to the mold parting line to facilitate part ejection.

Use larger drafts for deeper cavities or textured surfaces.

Fillets and Radii:Add fillets (rounded internal corners) and radii (external corners) to reduce stress concentrations and improve metal flow.

Typical radius: 0.5–1.5 mm.

Ribs and Bosses:Use ribs to increase strength without adding thick walls.

Design bosses for mounting or fastening, ensuring they have sufficient draft and are supported by ribs to avoid sink marks.

Undercuts:Minimize undercuts, as they require complex tooling (e.g., side actions or slides), increasing costs.

If unavoidable, design for simple undercuts to reduce mold complexity.

Parting Line:Position the parting line (where mold halves meet) to minimize flash and simplify mold design.

Consider aesthetics and functional surfaces when selecting the parting line locatio.

4. Tolerances and Surface Finish

Tolerances: Die casting allows tight tolerances (e.g., ±0.05 mm for small features), but specify realistic tolerances to avoid unnecessary costs.

Surface Finish: Die-cast parts often have smooth finishes (e.g., 0.8–3.2 µm Ra). Specify finish requirements for functional or aesthetic surfaces, considering post-processing like polishing or coating.

5. Gating and Runner Design

Gates: Design gate locations to ensure proper metal flow and minimize turbulence. Common gate types include edge gates, fan gates, or pinpoint gates.

Runners: Optimize runner systems to deliver molten metal efficiently to all cavities, balancing flow and minimizing material waste.

Overflows and Vents: Include overflows to capture excess metal and vents to allow air and gases to escape, reducing porosity.

6. Ejection and Cooling

Ejector Pins: Place ejector pins in non-critical areas to avoid visible marks. Ensure sufficient pin size and number to prevent part distortion during ejection.

Cooling Channels: Design cooling channels in the mold to ensure uniform cooling and minimize cycle time. Proper cooling reduces warpage and improves part quality.

7. Minimize Defects

Porosity: Avoid sharp corners and ensure proper venting to reduce trapped air or gas.

Shrinkage: Use gradual transitions in thickness and optimize cooling to prevent voids or sink marks.

Flash: Ensure precise mold alignment and clamping force to minimize flash at the parting line.

8. Mold Design ConsiderationsMold Material: Use high-quality tool steel (e.g., H13) for durability and heat resistance.

Mold Life: Design for long mold life by minimizing sharp edges and ensuring proper cooling and maintenance.

Multi-Cavity Molds: For high-volume production, consider multi-cavity molds to increase output, but ensure balanced filling across cavities.

9. Simulation and PrototypingUse simulation software (e.g., MAGMA, Flow-3D) to analyze metal flow, cooling, and potential defects before manufacturing the mold.

Create prototypes (e.g., via 3D printing or soft tooling) to validate design and functionality.

10. Cost OptimizationSimplify part geometry to reduce mold complexity and machining costs.

Minimize secondary operations (e.g., machining, finishing) by designing parts to be as close to final shape as possible.

Balance part quality with production volume to justify tooling costs.

11. Collaborate with ManufacturersWork closely with die casting manufacturers early in the design process to ensure the design is feasible and optimized for their equipment.

Discuss material, tolerances, and production volume to align expectations.