AZ31B (3.5312, M11311) Magnesium

AZ31B magnesium is an alloy of magnesium. AZ31B is the ASTM designation for this material. M11311 is the UNS number.

It has four 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

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

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

Electrical Conductivity18 % IACS

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

Elongation at Break5.8 to 13 %

Fatigue Strength (Endurance Limit)130 MPa (19 x 103 psi)

Melting Onset (Solidus)600 °C (1110 °F)

Modulus of Resilience (Unit Resilience)190 to 360 kJ/m3

Poisson's Ratio0.29

Shear Modulus17 GPa (2.5 x 106 psi)

Specific Heat Capacity1040 J/kg-K

Strength to Weight Ratio120 to 150 kN-m/kg

Tensile Strength: Ultimate (UTS)230 to 280 MPa (33 to 41 x 103 psi)

Tensile Strength: Yield (Proof)130 to 180 MPa (19 to 26 x 103 psi)

Thermal Conductivity64 W/m-K

Thermal Diffusivity32 m2/s

Thermal Expansion26 µm/m-K

Unit Rupture Work (Ultimate Resilience)11 to 12 MJ/m3

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

Alloy Composition

Magnesium (Mg)93.6 to 96.7 %

Aluminum (Al)2.5 to 3.5 %

Zinc (Zn)0.6 to 1.4 %

Manganese (Mn)0.2 to 1.0 %

Residuals0 to 0.3 %

Silicon (Si)0 to 0.1 %

Copper (Cu)0 to 0.050 %

Calcium (Ca)0 to 0.040 %

Iron (Fe)0 to 0.0050 %

Nickel (Ni)0 to 0.0050 %

Further Reading

ASTM B107: Standard Specification for Magnesium-Alloy Extruded Bars, Rods, Profiles, Tubes, and Wire

ASTM B90: Standard Specification for Magnesium-Alloy Sheet and Plate

ASTM B91: Standard Specification for Magnesium-Alloy Forgings

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