Automotive Grey Cast Iron vs. AZ91B Magnesium
Automotive grey cast iron belongs to the iron alloys classification, while AZ91B magnesium belongs to the magnesium alloys. There are 28 material properties with values for both materials. Properties with values for just one material (5, 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 automotive grey cast iron and the bottom bar is AZ91B magnesium.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 160 to 280 | |
| 63 |
| Elastic (Young's, Tensile) Modulus, GPa | 180 | |
| 46 |
| Elongation at Break, % | 9.6 to 14 | |
| 5.0 |
| Poisson's Ratio | 0.29 | |
| 0.29 |
| Shear Modulus, GPa | 69 to 70 | |
| 18 |
| Tensile Strength: Ultimate (UTS), MPa | 140 to 290 | |
| 240 |
| Tensile Strength: Yield (Proof), MPa | 94 to 200 | |
| 160 |
Thermal Properties
| Latent Heat of Fusion, J/g | 260 to 280 | |
| 360 |
| Melting Completion (Liquidus), °C | 1380 to 1390 | |
| 600 |
| Melting Onset (Solidus), °C | 1340 to 1350 | |
| 470 |
| Specific Heat Capacity, J/kg-K | 490 | |
| 990 |
| Thermal Conductivity, W/m-K | 41 to 43 | |
| 73 |
| Thermal Expansion, µm/m-K | 12 to 14 | |
| 26 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 7.4 to 7.6 | |
| 11 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 8.8 to 9.1 | |
| 58 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 1.9 to 3.0 | |
| 12 |
| Density, g/cm3 | 7.5 to 7.6 | |
| 1.7 |
| Embodied Carbon, kg CO2/kg material | 1.5 to 1.7 | |
| 22 |
| Embodied Energy, MJ/kg | 21 to 24 | |
| 160 |
| Embodied Water, L/kg | 44 to 51 | |
| 990 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 18 to 25 | |
| 11 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 25 to 110 | |
| 280 |
| Stiffness to Weight: Axial, points | 13 | |
| 15 |
| Stiffness to Weight: Bending, points | 25 | |
| 69 |
| Strength to Weight: Axial, points | 5.2 to 11 | |
| 38 |
| Strength to Weight: Bending, points | 8.0 to 13 | |
| 49 |
| Thermal Diffusivity, mm2/s | 11 to 12 | |
| 42 |
| Thermal Shock Resistance, points | 4.2 to 8.6 | |
| 14 |