AZ91D Magnesium vs. AISI 309 Stainless Steel
AZ91D magnesium belongs to the magnesium alloys classification, while AISI 309 stainless steel belongs to the iron alloys. There are 31 material properties with values for both materials. Properties with values for just one material (6, 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 AISI 309 stainless steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 60 to 80 | |
| 180 to 210 |
| Elastic (Young's, Tensile) Modulus, GPa | 46 | |
| 200 |
| Elongation at Break, % | 2.3 to 4.5 | |
| 34 to 47 |
| Fatigue Strength, MPa | 74 to 85 | |
| 250 to 280 |
| Poisson's Ratio | 0.29 | |
| 0.27 |
| Shear Modulus, GPa | 18 | |
| 78 |
| Shear Strength, MPa | 120 to 140 | |
| 420 to 470 |
| Tensile Strength: Ultimate (UTS), MPa | 160 to 220 | |
| 600 to 710 |
| Tensile Strength: Yield (Proof), MPa | 80 to 130 | |
| 260 to 350 |
Thermal Properties
| Latent Heat of Fusion, J/g | 350 | |
| 290 |
| Maximum Temperature: Mechanical, °C | 130 | |
| 980 |
| Melting Completion (Liquidus), °C | 600 | |
| 1450 |
| Melting Onset (Solidus), °C | 490 | |
| 1400 |
| Specific Heat Capacity, J/kg-K | 990 | |
| 480 |
| Thermal Conductivity, W/m-K | 78 | |
| 16 |
| Thermal Expansion, µm/m-K | 27 | |
| 15 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 11 | |
| 2.2 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 58 | |
| 2.5 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 12 | |
| 19 |
| Density, g/cm3 | 1.7 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 22 | |
| 3.6 |
| Embodied Energy, MJ/kg | 160 | |
| 51 |
| Embodied Water, L/kg | 990 | |
| 170 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 4.2 to 7.7 | |
| 200 to 230 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 69 to 170 | |
| 170 to 310 |
| Stiffness to Weight: Axial, points | 15 | |
| 14 |
| Stiffness to Weight: Bending, points | 69 | |
| 25 |
| Strength to Weight: Axial, points | 26 to 34 | |
| 21 to 25 |
| Strength to Weight: Bending, points | 38 to 46 | |
| 20 to 23 |
| Thermal Diffusivity, mm2/s | 45 | |
| 4.3 |
| Thermal Shock Resistance, points | 9.5 to 13 | |
| 14 to 16 |
Alloy Composition
| Aluminum (Al), % | 8.3 to 9.7 | |
| 0 |
| Carbon (C), % | 0 | |
| 0 to 0.2 |
| Chromium (Cr), % | 0 | |
| 22 to 24 |
| Copper (Cu), % | 0 to 0.030 | |
| 0 |
| Iron (Fe), % | 0 to 0.0050 | |
| 58 to 66 |
| Magnesium (Mg), % | 88.7 to 91.2 | |
| 0 |
| Manganese (Mn), % | 0.15 to 0.5 | |
| 0 to 2.0 |
| Nickel (Ni), % | 0 to 0.0020 | |
| 12 to 15 |
| Phosphorus (P), % | 0 | |
| 0 to 0.045 |
| Silicon (Si), % | 0 to 0.1 | |
| 0 to 0.75 |
| Sulfur (S), % | 0 | |
| 0 to 0.030 |
| Zinc (Zn), % | 0.35 to 1.0 | |
| 0 |