Shenzhen Alu Rapid Prototype Precision Co., Ltd.

Die casting and permanent mold casting are both metal casting processes that use reusable molds, but they differ significantly in their methods, applications, and outcomes. 

Here’s a concise comparison:

1. Process

Die Casting:Molten metal (e.g., aluminum, zinc, magnesium) is injected into a steel mold (die) under high pressure (1,000–30,000 psi) using a hot- or cold-chamber machine.High pressure ensures rapid filling of complex shapes, minimizing porosity.Cycle times are fast (seconds to a minute), enabling high-volume production.

Permanent Mold Casting:Molten metal is poured into a reusable metal mold (typically steel or cast iron) using gravity or low pressure (10–100 psi).

Slower filling process compared to die casting, relying on gravity or minimal pressure.

Cycle times are longer (minutes), suited for lower to medium production volumes.

2. Mold Design

Die Casting:Molds (dies) are highly precise, complex, and expensive ($5,000–$100,000+).Designed for high-pressure injection, with cooling channels and ejector pins.Often multi-cavity for mass production.

Permanent Mold Casting:Molds are simpler and less costly ($2,000–$50,000).

Designed for gravity/low-pressure pouring, often with manual or semi-automated operation.Typically single or dual-cavity.

3. Materials

Die Casting:Best for non-ferrous metals with low melting points (e.g., aluminum alloys like A380, zinc, magnesium).High-pressure process suits alloys that flow well under pressure.

Permanent Mold Casting:Also uses non-ferrous metals (aluminum, magnesium, some copper alloys), but can handle slightly higher-melting-point alloys.Limited to alloys that don’t excessively wear the mold during slower pouring.

4. Part CharacteristicsDie Casting:Produces complex, thin-walled parts (0.5–3 mm walls) with tight tolerances (±0.02–0.05 mm).

Smooth surface finish (as-cast Ra 0.8–3.2 µm), often requiring minimal post-processing.

Can have minor porosity due to rapid cooling, but high pressure reduces it.

Permanent Mold Casting:Suited for simpler shapes with thicker walls (3–10 mm) and looser tolerances (±0.1–0.5 mm).

Good surface finish, but rougher than die casting (Ra 3.2–6.4 µm).

Less porosity due to slower cooling, but less intricate detail.

5. Production Volume and Cost

Die Casting:Ideal for high-volume production (10,000–1,000,000 parts) due to fast cycle times and automation.High initial tooling costs but low per-part costs ($0.50–$5 for high volumes).

Permanent Mold Casting:Better for low to medium volumes (100–10,000 parts) due to slower process and less automation.

Lower tooling costs but higher per-part costs ($5–$20) compared to die casting for large runs.

6. Applications

Die Casting:Automotive parts (engine blocks, transmission housings), consumer electronics (laptop frames), and small intricate components (zippers, toy parts).

High precision and repeatability for mass production.

Permanent Mold Casting:Larger parts like automotive wheels, pump housings, or structural components.Used when moderate precision and lower tooling costs are priorities.

7. Advantages and Disadvantages

Die Casting:Pros: High precision, complex geometries, fast production, excellent surface finish.Cons: High tooling costs, limited to non-ferrous metals, potential for internal porosity.

Permanent Mold Casting:Pros: Lower tooling costs, good mechanical properties due to slower cooling, suitable for slightly larger parts.Cons: Slower process, less intricate shapes, higher labor costs for low automation.

SummaryDie casting is a high-pressure, high-speed process optimized for complex, thin-walled, high-volume parts with excellent surface finish but costly tooling. Permanent mold casting is a slower, gravity-based process suited for simpler, thicker parts with lower tooling costs and moderate volumes.