Materials / Compare
Plastic HDPE vs. Titanium
Compare Plastic HDPE vs. Titanium strength, stiffness, weight and thermal properties.
| Try it on a partA bracket to run stress or thermal on, free in your browser | Open in LessCAD | Open in LessCAD |
|---|---|---|
| Mechanical | ||
| Yield strength | 24MPasourcetypical, tensile stress at yield 23 °C, 50 mm/min ISO 527 | 885MPasourcetypical, plate (>0.187 in), annealed, 0.2% offset |
| Ultimate tensile strength | not sourced | 940MPasourcetypical, plate, annealed |
| Elongation at break | not sourced | 16%sourcetypical, in 2 in., plate annealed |
| Young's modulus (stiffness) | 0.9GPasourcetypical, tensile modulus 23 °C ISO 527 | 107–122GPasourcetypical range, 20 °C |
| Density | 950kg/m³sourcetypical, ISO 1183 | 4,430kg/m³sourcenominal |
| Strength to weight | 25.3kN·m/kg | 200kN·m/kg7.91x higher |
| Stiffness to weight | 0.947MN·m/kg | 25.8MN·m/kg27.3x higher |
| Poisson's ratio | 0.4–0.45sourcebase material: high-density polyethylene family (INEOS Olefins & Polymers USA, Typical Engineering Properties of HDPE) | 0.342sourcemean of TIMET measurements |
| Shear modulus | 0.316GPa | 42.7GPa135x stiffer in shear |
| Bulk modulus | 2GPa | 121GPa |
| Speed of sound | 973m/s | 5,084m/s |
| Thermal | ||
| Thermal conductivity | 0.4–0.49W/m·Ksourcebase material: high-density polyethylene family (INEOS Olefins & Polymers USA, Typical Engineering Properties of HDPE) | 6.6W/m·Ksourcetypical, 20 °C, mill annealed |
| Thermal expansion | 120µm/m·Ksourcebase material: high-density polyethylene family (INEOS Olefins & Polymers USA, Typical Engineering Properties of HDPE) | 9µm/m·Ksourcetypical, mean 0-100 °C |
| 100 mm part over a 50 °C swing | 600µm growth | 45µm growth13.3x less |
| Specific heat | 2,250J/kg·Ksourcebase material: high-density polyethylene family (INEOS Olefins & Polymers USA, Typical Engineering Properties of HDPE) | 580J/kg·Ksourcetypical, 20 °C |
| Heats up and cools (diffusivity) | 0.208mm²/s | 2.57mm²/s12.3x faster |
| Thermal shock resistance | 56.9W/m | 3,730W/m65.6x more resistant |
| Melting point | not sourced | 1,630–1,650°Csourcemelting range |
| Max service temperature | not sourced | 400°Csourceupper recommended use temperature |
| Values for | LyondellBasell Hostalen 23050 B high density polyethylene, typical ISO values | TIMETAL 6-4 (Ti-6Al-4V Grade 5) annealed plate typical (TIMET properties manual) + TIMET datasheet TMC-0150 physical properties |
Every value links to the document that states it. "Not sourced" means no citable source states it (or only a specification minimum); figures computed from it are left out too.
Questions
Is Plastic HDPE stronger than Titanium?
Titanium is stronger: its yield strength is 885 MPa against 24 MPa for Plastic HDPE (36.9x).
Which is lighter, Plastic HDPE or Titanium?
Plastic HDPE is lighter: 950 kg/m³ against 4,430 kg/m³ for Titanium.
Which is stiffer, Plastic HDPE or Titanium?
Titanium is stiffer: Young's modulus 115 GPa against 0.9 GPa for Plastic HDPE, so the same part in Titanium deflects less under the same load.
Which is lighter for the same job, Plastic HDPE or Titanium?
For the same stiffness or strength: Titanium is lighter for a stiff rod or tie (tension), stiff beam (bending), stiff panel or plate, strong rod or tie, strong beam, strong panel or plate.
| Part that must be | Plastic HDPE | Titanium |
|---|---|---|
| Stiff rod or tie (tension) | 27.3x heavier | lighter |
| Stiff beam (bending) | 2.42x heavier | lighter |
| Stiff panel or plate | 8% heavier | lighter |
| Strong rod or tie | 7.91x heavier | lighter |
| Strong beam | 2.38x heavier | lighter |
| Strong panel or plate | 30% heavier | lighter |
For the same stiffness or strength, mass scales with density over stiffness (or strength) raised to a power set by how the part is loaded: 1 for a rod in tension, 1/2 for a beam in bending, 1/3 for a panel (the standard material-selection indices).
Which conducts heat better, Plastic HDPE or Titanium?
Titanium conducts heat better: 6.6 W/m·K against 0.445 W/m·K for Plastic HDPE.
Which expands less with temperature?
Titanium expands less: 9 µm/m·K against 120 µm/m·K for Plastic HDPE.