AZ91D Magnesium vs. SAE-AISI D4 Steel
AZ91D magnesium belongs to the magnesium alloys classification, while SAE-AISI D4 steel belongs to the iron alloys. There are 28 material properties with values for both materials. Properties with values for just one material (7, in this case) are not shown. Please note that the two materials have significantly dissimilar densities. This means that additional care is required when interpreting the data, because some material properties are based on units of mass, while others are based on units of area or volume.
For each property being compared, the top bar is AZ91D magnesium and the bottom bar is SAE-AISI D4 steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 46 | |
| 190 |
| Elongation at Break, % | 2.3 to 4.5 | |
| 8.4 to 15 |
| Fatigue Strength, MPa | 74 to 85 | |
| 310 to 920 |
| Poisson's Ratio | 0.29 | |
| 0.28 |
| Shear Modulus, GPa | 18 | |
| 74 |
| Shear Strength, MPa | 120 to 140 | |
| 460 to 1210 |
| Tensile Strength: Ultimate (UTS), MPa | 160 to 220 | |
| 760 to 2060 |
| Tensile Strength: Yield (Proof), MPa | 80 to 130 | |
| 470 to 1540 |
Thermal Properties
| Latent Heat of Fusion, J/g | 350 | |
| 270 |
| Melting Completion (Liquidus), °C | 600 | |
| 1430 |
| Melting Onset (Solidus), °C | 490 | |
| 1380 |
| Specific Heat Capacity, J/kg-K | 990 | |
| 480 |
| Thermal Conductivity, W/m-K | 78 | |
| 31 |
| Thermal Expansion, µm/m-K | 27 | |
| 12 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 11 | |
| 4.2 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 58 | |
| 5.0 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 12 | |
| 8.0 |
| Density, g/cm3 | 1.7 | |
| 7.7 |
| Embodied Carbon, kg CO2/kg material | 22 | |
| 3.3 |
| Embodied Energy, MJ/kg | 160 | |
| 49 |
| Embodied Water, L/kg | 990 | |
| 100 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 4.2 to 7.7 | |
| 100 to 160 |
| Stiffness to Weight: Axial, points | 15 | |
| 14 |
| Stiffness to Weight: Bending, points | 69 | |
| 25 |
| Strength to Weight: Axial, points | 26 to 34 | |
| 27 to 75 |
| Strength to Weight: Bending, points | 38 to 46 | |
| 24 to 47 |
| Thermal Diffusivity, mm2/s | 45 | |
| 8.3 |
| Thermal Shock Resistance, points | 9.5 to 13 | |
| 23 to 63 |
Alloy Composition
| Aluminum (Al), % | 8.3 to 9.7 | |
| 0 |
| Carbon (C), % | 0 | |
| 2.1 to 2.4 |
| Chromium (Cr), % | 0 | |
| 11 to 13 |
| Copper (Cu), % | 0 to 0.030 | |
| 0 to 0.25 |
| Iron (Fe), % | 0 to 0.0050 | |
| 80.6 to 86.3 |
| Magnesium (Mg), % | 88.7 to 91.2 | |
| 0 |
| Manganese (Mn), % | 0.15 to 0.5 | |
| 0 to 0.6 |
| Molybdenum (Mo), % | 0 | |
| 0.7 to 1.2 |
| Nickel (Ni), % | 0 to 0.0020 | |
| 0 to 0.3 |
| Phosphorus (P), % | 0 | |
| 0 to 0.030 |
| Silicon (Si), % | 0 to 0.1 | |
| 0 to 0.6 |
| Sulfur (S), % | 0 | |
| 0 to 0.030 |
| Vanadium (V), % | 0 | |
| 0 to 1.0 |
| Zinc (Zn), % | 0.35 to 1.0 | |
| 0 |