Titanium 4-4-2 vs. Grade 21 Titanium
Both titanium 4-4-2 and grade 21 titanium are titanium alloys. They have 86% of their average alloy composition in common.
For each property being compared, the top bar is titanium 4-4-2 and the bottom bar is grade 21 titanium.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 110 | |
| 140 |
| Elongation at Break, % | 10 | |
| 9.0 to 17 |
| Fatigue Strength, MPa | 590 to 620 | |
| 550 to 660 |
| Poisson's Ratio | 0.32 | |
| 0.32 |
| Reduction in Area, % | 20 | |
| 22 |
| Shear Modulus, GPa | 42 | |
| 51 |
| Shear Strength, MPa | 690 to 750 | |
| 550 to 790 |
| Tensile Strength: Ultimate (UTS), MPa | 1150 to 1250 | |
| 890 to 1340 |
| Tensile Strength: Yield (Proof), MPa | 1030 to 1080 | |
| 870 to 1170 |
Thermal Properties
| Latent Heat of Fusion, J/g | 410 | |
| 410 |
| Maximum Temperature: Mechanical, °C | 310 | |
| 310 |
| Melting Completion (Liquidus), °C | 1610 | |
| 1740 |
| Melting Onset (Solidus), °C | 1560 | |
| 1690 |
| Specific Heat Capacity, J/kg-K | 540 | |
| 500 |
| Thermal Conductivity, W/m-K | 6.7 | |
| 7.5 |
| Thermal Expansion, µm/m-K | 8.6 | |
| 7.1 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 39 | |
| 60 |
| Density, g/cm3 | 4.7 | |
| 5.4 |
| Embodied Carbon, kg CO2/kg material | 30 | |
| 32 |
| Embodied Energy, MJ/kg | 480 | |
| 490 |
| Embodied Water, L/kg | 180 | |
| 180 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 110 to 120 | |
| 110 to 180 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 4700 to 5160 | |
| 2760 to 5010 |
| Stiffness to Weight: Axial, points | 13 | |
| 14 |
| Stiffness to Weight: Bending, points | 34 | |
| 32 |
| Strength to Weight: Axial, points | 68 to 74 | |
| 46 to 69 |
| Strength to Weight: Bending, points | 52 to 55 | |
| 38 to 50 |
| Thermal Diffusivity, mm2/s | 2.6 | |
| 2.8 |
| Thermal Shock Resistance, points | 86 to 93 | |
| 66 to 100 |
Alloy Composition
| Aluminum (Al), % | 3.0 to 5.0 | |
| 2.5 to 3.5 |
| Carbon (C), % | 0 to 0.080 | |
| 0 to 0.050 |
| Hydrogen (H), % | 0 to 0.015 | |
| 0 to 0.015 |
| Iron (Fe), % | 0 to 0.2 | |
| 0 to 0.4 |
| Molybdenum (Mo), % | 3.0 to 5.0 | |
| 14 to 16 |
| Niobium (Nb), % | 0 | |
| 2.2 to 3.2 |
| Nitrogen (N), % | 0 to 0.050 | |
| 0 to 0.030 |
| Oxygen (O), % | 0 to 0.25 | |
| 0 to 0.17 |
| Silicon (Si), % | 0.3 to 0.7 | |
| 0.15 to 0.25 |
| Tin (Sn), % | 1.5 to 2.5 | |
| 0 |
| Titanium (Ti), % | 85.8 to 92.2 | |
| 76 to 81.2 |
| Residuals, % | 0 | |
| 0 to 0.4 |