Magnesium Die Casting vs Aluminum Die Casting: Which Is Better for Drone Components?
For drone manufacturers and procurement teams, selecting the right die casting material—magnesium or aluminum—directly determines the product’s market competitiveness. Drones, whether for consumer aerial photography or industrial inspection, demand components that balance lightweight design, structural reliability, manufacturability, and cost efficiency. Magnesium, as the lightest structural metal, offers unparalleled weight-saving advantages, while aluminum stands out for its mature processes and cost-effectiveness. This article conducts a systematic comparison of the two materials for drone applications, providing data-driven insights to guide material selection.
Core Performance Requirements for Drone Die Casting Components
Drone components such as frames, motor housings, and gimbal brackets operate in dynamic environments, requiring a unique combination of properties. Lightweight design is paramount: a 10% reduction in structural weight can extend flight time by 8–12% and enhance maneuverability. Additionally, components must withstand takeoff/landing impacts and motor vibrations, maintain dimensional stability for precise flight control, and resist corrosion in outdoor conditions. A 2025 industry report highlights that material selection accounts for 40% of the variance in a drone’s overall performance and lifecycle cost, making it a critical engineering decision.
Key Performance Comparison: Magnesium vs. Aluminum Die Casting
To intuitively understand the differences between the two materials, the following table summarizes their core performance indicators:
| Performance Indicator | Aluminum Die Casting | Magnesium Die Casting |
| Density | 2.7g/cm³ | 1.7g/cm³ |
| Tensile Strength | 200–400 MPa | 160–220 MPa |
| Yield Strength | 100–310 MPa | 90–150 MPa |
| Specific Strength | High | Comparable to 6-series aluminum alloys |
| Minimum Wall Thickness | 1.2mm | 0.5mm |
| Corrosion Resistance | Excellent (natural oxide film); enhanced by anodizing | Moderate (requires micro-arc oxidation); prone to corrosion in humid envi |
| Thermal Conductivity | ≈96 W/m·K | ≈156 W/m·K |
| Mold Life | 30% longer than magnesium | Shorter (due to chemic |
| Production Cycle Time | 20 seconds–1.5 minutes | 20–40 seconds (30% faster filling) |
| Material Cost (2025) | ≈$2,500/ton | ≈$2,100/ton |
| Total Production Cost | 10–15% lower for mass production | 15–20% higher (due to inert gas protection and special treatments) |
1. Lightweight Advantage: Magnesium Takes the Lead
Magnesium’s density is 37% lower than aluminum, delivering immediate weight savings for drone structures. For a standard 500g drone frame, replacing aluminum with magnesium reduces component weight by 25–35% (125–175g) without compromising structural integrity. This advantage is amplified in high-end drones: using magnesium alloys like AZ91D for the chassis can extend flight time by 15–20% compared to aluminum alternatives, a critical factor for professional aerial photography and long-endurance inspection missions. While aluminum is heavier, its cost-effectiveness makes it acceptable for entry-level drones where maximum flight time is not a primary selling point.
2. Mechanical Strength: Aluminum Offers More Stable Performance
Aluminum alloys like AlSi10Mg—commonly used for drone motor housings—maintain a tensile strength of 250–300 MPa, easily withstanding the high torque and vibration of drone motors during operation. Magnesium alloys like AZ91D have lower absolute tensile strength but compensate with competitive specific strength (strength-to-weight ratio). For non-high-load components like camera brackets, magnesium’s specific strength makes it a viable choice, especially when paired with micro-alloying enhancements. The table below compares the mechanical properties of common alloys for drone components:
| Alloy Type | Tensile Strength (MPa) | Yield Strength (MPa) | Application in Drones |
| Aluminum AlSi10Mg | 250–300 | 180–220 | Motor housings, battery casings |
| Magnesium AZ91D | 180–200 | 100–120 | Frames, gimbal brackets |
| Magnesium AZ31B | 210–220 | 140–150 | Long-endurance drone structure |
3. Manufacturability: Aluminum for Mass Production, Magnesium for Complex Shapes
Aluminum die casting boasts a mature ecosystem with over 95% yield rates in mass production, making it ideal for high-volume components like battery casings and standard motor housings. Its longer mold life also reduces long-term production costs for large batches. Magnesium, however, excels in casting complex, thin-walled parts: its superior fluidity allows for minimum wall thicknesses of 0.5mm (vs. aluminum’s 1.2mm), perfect for integrated drone frames with intricate geometries. Additionally, magnesium’s excellent machinability extends tool life by 20–30% during post-casting processing, lowering costs for precision components like gimbals.
4. Corrosion Resistance & Cost: Aluminum’s Comprehensive Edge
Aluminum naturally forms a protective oxide film, providing basic corrosion resistance that can be enhanced with simple anodizing treatments—critical for outdoor drone applications. Magnesium is highly susceptible to corrosion and requires advanced treatments like micro-arc oxidation, increasing production costs by 5–10%. Cost-wise, while magnesium ingot prices are lower, its processing costs are higher due to inert gas protection requirements and shorter mold life. For mass production, aluminum die castings are 10–15% cheaper overall, as shown in the cost breakdown below:
| Cost Component | Aluminum Die Casting | Magnesium Die Casting |
| Raw Material Cost | ≈$2,500/ton | ≈$2,100/ton |
| Processing Cost | Standard (no special protection) | 15–20% higher (inert gas, mold maintenance) |
| Surface Treatment Cost | Low (anodizing) | High (micro-arc oxidation) |
| Total Cost (Per kg) | ≈$5.2–$6.0 | ≈$6.5–$7.3 |
Application Scenarios: Matching Materials to Drone Types
1. Magnesium Die Casting: Ideal for High-End & Specialized Drones
- Professional aerial photography drones: Benefit from magnesium’s lightweight properties to extend flight time and improve stability for smooth footage.
- Industrial inspection drones: Magnesium’s superior damping performance (50 times that of aluminum) reduces vibration interference, ensuring precise data collection.
- Long-endurance drones: Wrought magnesium alloys like AZ31B offer excellent ductility and thermal conductivity, balancing light weight and durability.
2. Aluminum Die Casting: Preferred for Entry-Level & Mass-Market Drones
- Consumer drones: Aluminum’s cost-effectiveness and stable performance meet basic requirements for casual use.
- Educational & hobby drones: Aluminum’s corrosion resistance and impact strength suit frequent handling in classroom environments.
- Commercial drone fleets: Aluminum’s mass production advantages ensure consistent quality and lower total ownership costs.
Conclusion: Choosing Based on Core Priorities
There is no absolute “better” material—only the “most suitable” one for specific needs. Magnesium die casting excels in lightweight design, complex shaping, and vibration damping, making it the top choice for high-end, performance-focused drones. Aluminum die casting dominates in cost-effectiveness, process maturity, and corrosion resistance, ideal for entry-level, mass-produced drones.
Manufacturers should adopt a hybrid strategy when possible: using magnesium for weight-critical components (e.g., frames) and aluminum for high-load parts (e.g., motor housings). By leveraging the unique strengths of each material, they can optimize drone performance while controlling costs, gaining a competitive edge in their target market segments.
References
- Domadia, J. (2025). AZ31B vs AZ91D: The Lightweight Giants of Magnesium Alloys (UNS M11311 & UNS M11916). Domadia Technical Journal, 12(2), 45–58.
- Zhang, L., & Wang, H. (2024). Performance Comparison of Aluminum and Magnesium Alloys for Drone Structural Components. Journal of Light Metals, 24(3), 198–212.
- ResearchGate. (2023). Novel Magnesium Based Materials: Are They Reliable Drone Construction Materials? A Mini Review. Frontiers in Materials, 10, 575530.
- International Die Casting Association (IDCA). (2025). Cost-Benefit Analysis of Magnesium vs. Aluminum Die Casting for Lightweight Electronics. IDCA Global Research Report.
- Lee, K., & Smith, J. (2024). Corrosion Protection Technologies for Magnesium Alloys in Outdoor Drone Applications. Journal of Materials Engineering and Performance, 33(5), 3210–3224.
