AZ91B (AZ91B-F, M11912) Magnesium

AZ91B magnesium is an alloy of magnesium. It is typically furnished in the as-fabricated (no temper or treatment) condition. AZ91B is the ASTM designation for this material. M11912 is the UNS number.

Material Properties

Base Metal Price20 % rel

Brinell Hardness63

Compressive (Crushing) Strength160 MPa (23 x 103 psi)

Density1.9 g/cm3 (120 lb/ft3)

Elastic (Young's, Tensile) Modulus49 GPa (7.1 x 106 psi)

Elongation at Break5.0 %

Fatigue Strength (Endurance Limit)100 MPa (15 x 103 psi)

Melting Onset (Solidus)470 °C (880 °F)

Modulus of Resilience (Unit Resilience)260 kJ/m3

Poisson's Ratio0.29

Rockwell F Hardness75

Shear Strength140 MPa (20 x 103 psi)

Specific Heat Capacity990 J/kg-K

Strength to Weight Ratio130 kN-m/kg

Tensile Strength: Ultimate (UTS)240 MPa (35 x 103 psi)

Tensile Strength: Yield (Proof)160 MPa (23 x 103 psi)

Thermal Expansion26 µm/m-K

Unit Rupture Work (Ultimate Resilience)11 MJ/m3

The length of each bar compares the given value to the highest value in the database.

Alloy Composition

Magnesium (Mg)87.9 to 91.2 %

Aluminum (Al)8.3 to 9.7 %

Zinc (Zn)0.35 to 1.0 %

Manganese (Mn)0.13 to 0.5 %

Silicon (Si)0 to 0.5 %

Copper (Cu)0 to 0.35 %

Nickel (Ni)0 to 0.030 %

Further Reading

ASTM B94: Standard Specification for Magnesium-Alloy Die Castings

Environmental Degradation of Advanced and Traditional Engineering Materials, Lloyd H. Hihara et al., 2014.