AZ91D (Magnesium Alloy)

AZ91D is the most widely used magnesium die-casting alloy in the world, accounting for approximately 90% of all magnesium castings produced. An aluminum-zinc-magnesium alloy with approximately 9% aluminum and 1% zinc (hence the designation "AZ91"), it delivers an exceptional strength-to-weight ratio — the lightest of all structural metals at just 1.81 g/cm³ density. AZ91D is the go-to material for automotive weight-reduction programs, portable electronics housings, aerospace components, power tool bodies, and any application where every gram saved translates into meaningful performance or efficiency gains.

Mechanical Properties

• Density: 1.81 g/cm³
• Tensile Strength: 230 MPa
• Yield Strength: 160 MPa
• Elongation at Break: 3%
• Hardness: HB ~65
• Modulus of Elasticity: 45 GPa
• Thermal Conductivity: 72 W/m·K
• Electrical Conductivity: ~11 % IACS
• Melting Point: 470 – 595 °C (solidus-liquidus range)
• Coefficient of Thermal Expansion: 25.0 × 10⁻⁶ /°C

Note: Values shown are for as-die-cast condition. Die-cast AZ91D typically achieves higher properties than sand-cast or permanent mold versions.

Advantages

✔ Lightest Structural Metal — At only 1.81 g/cm³, it is 35% lighter than aluminum (2.7 g/cm³), 4× lighter than steel (7.85 g/cm³), and the lightest engineering metal available

✔ Excellent Specific Strength — Good strength-to-weight ratio makes it ideal for weight-sensitive applications where reducing mass directly improves performance

✔ Superior Damping Capacity — Naturally absorbs vibration and noise far better than aluminum; valuable for electronic enclosures, power tools, and handheld devices

✔ Good Dimensional Stability — Low casting shrinkage (~0.5–0.7%) enables tight tolerances straight from the die with minimal post-processing

✔ Excellent Electromagnetic Shielding — Effective EMI/RFI shielding for electronics; combined with lightweight, ideal for laptop/tablet/phone housings

Machining & Manufacturing

Common Applications