# AZ91A (AZ91A-F, M11910) Magnesium

AZ91A magnesium is a magnesium alloy. It is typically furnished in the as-fabricated (no temper or treatment) condition. AZ91A is the ASTM designation for this material. M11910 is the UNS number. It has a moderately low electrical conductivity and a moderately low melting temperature relative to other magnesium alloys. The graph bars on the material properties cards below compare AZ91A magnesium to other magnesium alloys (top) and the entire database (bottom).

## Mechanical Properties

Brinell Hardness

63

Compressive (Crushing) Strength

160 *MPa* 23 *x 10 ^{3} psi*

Elastic (Young's, Tensile) Modulus

46 *GPa* 6.7 *x 10 ^{6} psi*

Elongation at Break

5.0 *%*

Fatigue Strength

99 *MPa* 14 *x 10 ^{3} psi*

Poisson's Ratio

0.29

Resilience: Ultimate (Unit Rupture Work)

11 *MJ/m ^{3}*

Resilience: Unit (Modulus of Resilience)

280 *kJ/m ^{3}*

Rockwell F Hardness

75

Shear Modulus

18 *GPa* 2.6 *x 10 ^{6} psi*

Shear Strength

140 *MPa* 20 *x 10 ^{3} psi*

Strength to Weight Ratio

140 *kN-m/kg*

Tensile Strength: Ultimate (UTS)

240 *MPa* 35 *x 10 ^{3} psi*

Tensile Strength: Yield (Proof)

160 *MPa* 23 *x 10 ^{3} psi*

## Thermal Properties

Melting Completion (Liquidus)

600 *°C* 1100 *°F*

Melting Onset (Solidus)

470 *°C* 880 *°F*

Specific Heat Capacity

990 *J/kg-K* 0.24 *BTU/lb-°F*

Thermal Conductivity

73 *W/m-K* 42 *BTU/h-ft-°F*

Thermal Diffusivity

42 *m ^{2}/s*

Thermal Expansion

26 *µm/m-K*

## Electrical Properties

Electrical Conductivity: Equal Volume

10 *% IACS*

Electrical Conductivity: Equal Weight (Specific)

52 *% IACS*

## Otherwise Unclassified Properties

Base Metal Price

12 *% relative*

Density

1.7 *g/cm ^{3}* 110

*lb/ft*

^{3}Embodied Carbon

22 *kg CO _{2}/kg material*

Embodied Energy

160 *MJ/kg* 68 *x 10 ^{3} BTU/lb*

Embodied Water

990 *L/kg* 120 *gal/lb*

## Alloy Composition

Mg | 88.2 to 91.2 | |

Al | 8.3 to 9.7 | |

Zn | 0.35 to 1.0 | |

Mn | 0.13 to 0.5 | |

Si | 0 to 0.5 | |

Cu | 0 to 0.1 | |

Ni | 0 to 0.030 | |

Fe | 0 to 0.0050 | |

res. | 0 to 0.010 |

All values are % weight. Ranges represent what is permitted under applicable standards.

## Followup Questions

## Similar Alloys

## 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.

Welding and Joining of Magnesium Alloys, Liming Liu ed., 2010

ISO 16220: Magnesium and magnesium alloys - Magnesium alloy ingots and castings