Magnesium foils are ultra-thin flat products made from pure magnesium or wrought magnesium alloys, typically with thicknesses from ~5 µm to 200 µm. They are the lightest metallic foils available for industrial, research, and advanced engineering applications.
Unlike magnesium sheets, foils are surface-dominated materials, where performance is governed by thickness, grain size, texture, and oxide-layer behavior.
Chemical Composition – Pure Magnesium Foils
| Element | Typical wt% |
|---|---|
| Magnesium (Mg) | 99.8 – 99.99 |
| Aluminum (Al) | ≤ 0.03 |
| Zinc (Zn) | ≤ 0.02 |
| Manganese (Mn) | ≤ 0.02 |
| Iron (Fe) | ≤ 0.005 |
| Copper (Cu) | ≤ 0.01 |
| Nickel (Ni) | ≤ 0.001 |
| Surface Oxygen (MgO) | Controlled |
Ultra-low Fe, Cu, and Ni levels are critical to prevent accelerated corrosion and galvanic attack in thin foil sections.
Magnesium Alloy Foils (Specialized)
| Alloy | Purpose |
|---|---|
| AZ31 | Improved strength and handling |
| ZK60 | Fine grain, better ductility |
| WE43 | High-temperature & biomedical use |
| Mg–Li alloys | Exceptional room-temperature formability |
Mechanical Properties (Representative)
| Property | Pure Mg Foil | AZ31 Foil |
|---|---|---|
| Tensile Strength | 80 – 120 MPa | 200 – 260 MPa |
| Yield Strength | 15 – 30 MPa | 120 – 180 MPa |
| Elongation | 3 – 12% | 6 – 15% |
| Elastic Modulus | ~45 GPa | |
Physical Properties
| Property | Typical Value |
|---|---|
| Density | 1.74 – 1.85 g/cm³ |
| Melting Point | ~650 °C |
| Thermal Conductivity | 70 – 160 W/m·K |
| Electrical Conductivity | ~38% IACS |
| Reflectivity | High (visible & IR) |
| Magnetic Behavior | Non-magnetic |
Key Characteristics
✔ Lightest metallic foil
✔ High surface reactivity
✔ Excellent EMI shielding per weight
✔ High thermal conductivity
✔ Electrochemically active
✔ Biodegradable potential in physiological environments
Available Forms
Ultra-thin foils (5–20 µm)
Thin foils (20–100 µm)
Thick foils (100–200 µm)
Rolled coils & cut sheets
Laminated and research-grade foils
Applications
Electronics & Energy
EMI/RFI shielding, battery current collectors (R&D),
thermal spreaders, flexible electronics
Biomedical
Bioabsorbable implants, temporary stents, tissue scaffolds
Aerospace & Defense
Lightweight reflective foils, ignition systems,
thermal management layers
Chemical & Laboratory
Reducing agents, reaction substrates, catalysis research
Advantages
✔ Lowest density of all metal foils
✔ Exceptional strength-to-weight ratio
✔ High thermal & electrical conductivity
✔ Weight-efficient EMI shielding
✔ Reactive surface for functional uses
Limitations
❌ Limited room-temperature ductility
❌ High corrosion susceptibility
❌ Handling sensitivity (tearing, oxidation)
❌ Fire risk in trimming and cutting
❌ Higher cost vs aluminum foils
Why Choose Magnesium Foils?
Choose magnesium foils when extreme lightweighting, surface-driven functionality, electrochemical activity, EMI shielding efficiency, or controlled degradation are critical to performance.