AZ91D (M11916) Magnesium

AZ91D magnesium is an alloy of magnesium. AZ91D is the ASTM designation for this material. M11916 is the UNS number.

It has three common variants, each represented as a separate material. The Material Properties section below shows ranges encompassing all variants. For more specific values, follow the links in the Variant Materials section.

Material Properties

Base Metal Price20 % rel

Brinell Hardness60 to 80

Compressive (Crushing) Strength310 to 430 MPa (45 to 62 x 103 psi)

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

Elastic (Young's, Tensile) Modulus45 GPa (6.5 x 106 psi)

Electrical Conductivity11 % IACS

Electrical Resistivity Order of Magnitude-7 10x Ω-m

Elongation at Break2.3 to 4.5 %

Fatigue Strength (Endurance Limit)67 to 78 MPa (9.7 to 11 x 103 psi)

Melting Onset (Solidus)490 °C (910 °F)

Modulus of Resilience (Unit Resilience)71 to 190 kJ/m3

Poisson's Ratio0.29

Rockwell F Hardness75

Shear Strength140 MPa (20 x 103 psi)

Specific Heat Capacity1030 J/kg-K

Strength to Weight Ratio84 to 120 kN-m/kg

Tensile Strength: Ultimate (UTS)160 to 220 MPa (23 to 32 x 103 psi)

Tensile Strength: Yield (Proof)80 to 130 MPa (12 to 19 x 103 psi)

Thermal Conductivity78 W/m-K

Thermal Diffusivity40 m2/s

Thermal Expansion27 µm/m-K

Unit Rupture Work (Ultimate Resilience)3.1 to 3.5 MJ/m3

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

Alloy Composition

Magnesium (Mg)88.7 to 91.2 %

Aluminum (Al)8.3 to 9.7 %

Zinc (Zn)0.35 to 1.0 %

Manganese (Mn)0.15 to 0.5 %

Silicon (Si)0 to 0.1 %

Copper (Cu)0 to 0.030 %

Iron (Fe)0 to 0.0050 %

Nickel (Ni)0 to 0.0020 %

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.

Properties and Selection: Nonferrous Alloys and Special-Purpose Materials, ASM Handbook vol. 2, ASM International, 1993