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Pressure Die Casting Material Selection Guide: Aluminum, Zinc & Magnesium Alloy Comparison

Created on 05.21

Meta Description: A practical pressure die casting material selection guide, comparing aluminum, zinc, and magnesium alloys, matching materials to application scenarios, helping you avoid costly material selection mistakes. #pressure die casting materials #aluminum die casting #zinc die casting #magnesium die casting

Selecting the right alloy is a critical decision for pressure die casting projects—each alloy has unique performance characteristics, applicable scenarios, and cost points. Choosing the wrong alloy leads to part failure: insufficient strength, poor corrosion resistance, excessive shrinkage, inability to undergo surface treatment (e.g., anodizing), or budget overruns. As an OEM pressure die casting manufacturer with years of experience in aluminum, zinc, and magnesium alloy casting, we’ve compiled this guide to help you select the optimal alloy for your project, balancing performance, cost, and manufacturability.

Key Factors to Consider for Pressure Die Casting Material Selection

Before choosing an alloy, align your selection with three core requirements—these factors directly determine alloy suitability for your pressure die casting project:

• Part Function & Performance: Define non-negotiable metrics (mechanical strength, corrosion resistance, heat resistance, weight) based on how the part will be used (e.g., new energy battery shell, automotive structural part, 3C component).

• Application Environment: Consider temperature (high/low), moisture, chemicals, and load-bearing requirements (e.g., outdoor parts need good corrosion resistance; automotive engine parts need high heat resistance).

• Manufacturability & Cost: Evaluate alloy flowability (critical for high-speed filling), mold compatibility, surface treatment potential, and raw material cost—avoid over-specifying high-cost alloys when a lower-cost option meets your needs.

Mainstream Pressure Die Casting Alloys: Comparison & Applications

Below is a detailed comparison of the most common pressure die casting alloys, their performance, and ideal applications—tailored to new energy, automotive, 3C electronics, and industrial fields.

1. Aluminum Alloy (ADC12, A380, A356)

Performance: Lightweight (density: 2.7g/cm³), high mechanical strength (tensile strength: 200-350MPa; ADC12: 200-250MPa, A380: 280-320MPa, A356: 300-350MPa), good heat resistance (continuous use temperature: 120-180℃; A356 can reach 180-200℃), and excellent surface treatment potential (anodizing, powder coating, electrophoresis). Flowability is moderate to good (A380 > ADC12 > A356), suitable for complex-shaped parts. Corrosion resistance is moderate (A356 > A380 > ADC12), which can be significantly improved by surface treatment (e.g., hard anodizing, chemical conversion coating).

Common Models & Differences:
ADC12: Low cost, good flowability, moderate strength, suitable for non-load-bearing parts (3C shells, small industrial components, decorative parts) that do not require high corrosion resistance.
A380: Higher strength and corrosion resistance than ADC12, excellent flowability, suitable for automotive structural parts, new energy battery brackets, and medium-load industrial components.
A356: High strength, good corrosion resistance, and excellent castability, suitable for high-load parts (automotive engine parts, new energy motor shells, structural parts requiring high reliability).

Ideal Applications: New energy battery shells, automotive structural parts, 3C electronic enclosures, industrial equipment components. #aluminum die casting parts #new energy die casting

Cost: Moderate ($2.80-$4.50/kg), cost-effective for medium-to-high volume production.

2. Zinc Alloy (Zamak-3, Zamak-5, Zamak-7)

Performance: High flowability (excellent for small, complex parts with thin walls), good dimensional stability (shrinkage rate: 0.5-0.8%; Zamak-3: 0.5-0.7%, Zamak-5: 0.6-0.8%, Zamak-7: 0.55-0.75%), moderate strength (tensile strength: 180-280MPa; Zamak-3: 180-220MPa, Zamak-5: 230-280MPa, Zamak-7: 200-240MPa), and easy to machine (cutting, drilling, threading). Corrosion resistance is good (better than ordinary aluminum alloy), but heat resistance is poor (continuous use temperature ≤100℃; exceeding 100℃ will cause softening and dimensional deformation).

Common Models & Differences:
Zamak-3: Good flowability and dimensional stability, low cost, suitable for small decorative parts (3C buttons, hardware accessories, decorative trim) with low load requirements.
Zamak-5: Higher strength and hardness than Zamak-3, good wear resistance, suitable for load-bearing parts (automotive brackets, small structural parts, gear components).
Zamak-7: Good corrosion resistance (better than Zamak-3 and Zamak-5), suitable for outdoor parts (security hardware, outdoor connectors, marine accessories) and parts used in humid environments.

Ideal Applications: 3C electronic components, automotive small parts, hardware accessories, security equipment parts. #zinc die casting parts #3C die casting

Cost: Low to moderate ($2.50-$3.80/kg), ideal for cost-sensitive, high-volume projects.

3. Magnesium Alloy (AZ91D, AM60B)

Performance: Ultra-lightweight (density: 1.8g/cm³, 30% lighter than aluminum alloy), high specific strength (strength-to-weight ratio, better than aluminum and zinc alloys), good heat resistance (continuous use temperature: 150-200℃; AM60B can reach 200-220℃), and excellent electromagnetic shielding (suitable for electronic components). Flowability is moderate (AZ91D > AM60B), suitable for lightweight, high-performance parts. Corrosion resistance is poor (prone to oxidation in humid environments), requiring mandatory surface treatment (e.g., powder coating, chemical conversion coating) for use.

Common Models & Differences:AZ91D: Good strength and flowability, moderate toughness, suitable for automotive lightweight parts, 3C high-end enclosures, and non-impact-loaded structural parts.AM60B: Higher toughness and impact resistance than AZ91D, good ductility, suitable for impact-loaded parts (automotive door panels, new energy battery covers, structural parts requiring anti-collision performance).

Ideal Applications: Automotive lightweight parts, high-end 3C enclosures, new energy battery covers, aerospace components. #magnesium die casting parts #lightweight die casting

Cost: High ($5.00-$7.50/kg), suitable for high-performance, lightweight requirements.

Common Material Selection Mistakes to Avoid

• Choosing Zinc Alloy for High-Temperature Applications: Zinc alloy’s heat resistance is poor—use aluminum or magnesium alloy for parts used above 100℃ (e.g., engine parts).

• Using Aluminum Alloy ADC12 for Corrosion-Resistant Parts: ADC12 has poor corrosion resistance—choose A380 or A356, or add surface treatment (anodizing, chrome plating).

• Over-Specifying Magnesium Alloy: Use aluminum alloy for general lightweight parts—magnesium alloy is only necessary for ultra-lightweight, high-performance requirements (cost is 2-3x higher than aluminum alloy).

Our team can help you select the optimal pressure die casting alloy, leveraging our stock of mainstream alloys (ADC12, A380, Zamak-5, AZ91D) to shorten lead times and reduce costs. Contact us for personalized material recommendations. #pressure die casting material guide