# AZ91E-T4 Magnesium

AZ91E-T4 magnesium is AZ91E magnesium in the T4 temper. To achieve this temper, the metal is solution heat-treated and naturally aged. It has the highest ductility compared to the other variants of AZ91E magnesium. The graph bars on the material properties cards below compare AZ91E-T4 magnesium to other magnesium alloys (top) and the entire database (bottom). A full bar means this is the highest value in the relevant set. A half-full bar means it's 50% of the highest, and so on.

## Mechanical Properties

Brinell Hardness

75

Compressive (Crushing) Strength

310 *MPa* 45 *x 10 ^{3} psi*

Elastic (Young's, Tensile) Modulus

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

Elongation at Break

6.2 *%*

Fatigue Strength

85 *MPa* 12 *x 10 ^{3} psi*

Fracture Toughness

13 *MPa-m ^{1/2}* 12

*x 10*

^{3}psi-in^{1/2}Impact Strength: V-Notched Charpy

2.8 *J* 2.0 *ft-lb*

Poisson's Ratio

0.29

Shear Modulus

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

Shear Strength

140 *MPa* 21 *x 10 ^{3} psi*

Tensile Strength: Ultimate (UTS)

250 *MPa* 36 *x 10 ^{3} psi*

Tensile Strength: Yield (Proof)

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

## Thermal Properties

Latent Heat of Fusion

350 *J/g*

Maximum Temperature: Mechanical

130 *°C* 270 *°F*

Melting Completion (Liquidus)

600 *°C* 1100 *°F*

Melting Onset (Solidus)

500 *°C* 930 *°F*

Solidification (Pattern Maker's) Shrinkage

1.3 *%*

Specific Heat Capacity

990 *J/kg-K* 0.24 *BTU/lb-°F*

Thermal Conductivity

84 *W/m-K* 49 *BTU/h-ft-°F*

Thermal Expansion

27 *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* 67 *x 10 ^{3} BTU/lb*

Embodied Water

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

## Common Calculations

Resilience: Ultimate (Unit Rupture Work)

12 *MJ/m ^{3}*

Resilience: Unit (Modulus of Resilience)

110 *kJ/m ^{3}*

Stiffness to Weight: Axial

15 *points*

Stiffness to Weight: Bending

69 *points*

Strength to Weight: Axial

40 *points*

Strength to Weight: Bending

51 *points*

Thermal Diffusivity

49 *mm ^{2}/s*

Thermal Shock Resistance

14 *points*

## Alloy Composition

Mg | 88.8 to 91.3 | |

Al | 8.1 to 9.3 | |

Zn | 0.4 to 1.0 | |

Mn | 0.17 to 0.35 | |

Si | 0 to 0.2 | |

Cu | 0 to 0.015 | |

Fe | 0 to 0.0050 | |

Ni | 0 to 0.0010 | |

res. | 0 to 0.3 |

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

## Followup Questions

## Further Reading

ASTM B80: Standard Specification for Magnesium-Alloy Sand Castings

Essential Readings in Magnesium Technology, Suveen N. Mathaudhu et al. (editors), 2014

Advanced Materials in Automotive Engineering, Jason Rowe (editor), 2012

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