Point of comparison | S-glass fibers | E-glass fibers |
---|---|---|
Structure | Amorphous (not crystalline) | Amorphous (not crystalline) |
Chemical composition | SiO2 (62–65 wt%), Al2O3 (20–25 wt%), MgO (10%), B2O (< 1 wt%) | SiO2 (53–55 wt%), CaO (20-24 wt%), MgO (20–24 wt%), B2O (6–9 wt%), Al2O3 (14-16 wt%) |
Density | 2.485–2.495 g/cm3 | 2.55–2.6 g/cm3 |
Tensile strength | 4700–4800 MPa | 1950-2050 MPa |
Elastic modulus | 86–93 GPa | 72–85 GPa |
Hardness | 5000–6000 MPa | 3000–6000 MPa |
Endurance limit | 4050–4410 MPa | 2970–3110 MPa |
Fracture toughness | 0.5–1 MPa m½ | 0.5–1 MPa m½ |