NEXTREMA®
SCHOTT NEXTREMA® optical properties
NEXTREMA® offers six transmission profiles in the visible and infrared range depending on material type and material thickness. For engineers and designers, that means NEXTREMA® is the material of choice when it comes to light transmission and infrared radiation, for example in radiant heaters. The six different NEXTREMA® variants offer a transmission portfolio dependant on your needs, making this a reliable material partner for industry and home.
Transmission
Transmission values are measured for a polished sample of a specific thickness.
This graph is based on data from individual measurements. Deviations may result from the manufacturing process. Typical transmission graph of different ceramization states with sample thickness of approximately 4 mm.
SCHOTT NEXTREMA® mechanical properties
NEXTREMA® boasts a very high degree of mechanical strength for a ceramic material and doesn’t require any additional toughening processes. The glass-ceramic also exhibits extraordinary mechanical stability, even at high temperatures. The NEXTREMA® variant with the highest bending strength is tinted (712-3), which can withstand a force of up to 165 megapascals.
| ρ approx. 2.5 – 2.6 g/cm3 | Density |
| E approx. 84 – 95 x 10³ MPa | Modulus of elasticity (ASTM C-1259) |
| μ approx. 0.25 – 0.26 | Poisson‘s ratio (ASTM C-1259) |
| HK0.1 / 20approx. 570 – 600 | Knoop hardness (ISO 9385) |
| σbBapprox. 100 – 165 MPa | Bending strength (DIN EN 1288, Part 5, R45) |
| 0 % | Porosity (ISO 9385) |
|
Material 724-3 (t = 4 mm)Ra≤ 0.20 μm Rms ≤ 0.25 μm |
Roughness |
Impact resistance
The impact resistance of NEXTREMA® depends on the size, thickness and geometry of the panel, kind of installation and type of impact, especially on drilled holes and their position in the material. Therefore, information regarding impact resistance can only be given with knowledge of the respective and defined application, especially in combination with the technical standards regarding impact resistance that have to be met for some applications. The quality of the grinding profile also has an important influence on impact resistance.
SCHOTT NEXTREMA® thermal properties
NEXTREMA® exceeds all expectations when it comes to temperature resistance. The material can withstand both extremely high and low temperatures, offering outstanding resistance up to 950 °C. From white hot to ice cold and back again, quick changes in temperature will have little impact on this heat resistant glass-ceramic, minimizing thermal stress fractures. Thanks to its near-zero thermal expansion, NEXTREMA® can also cope with temperature shocks of up to 820 °C, making it ideal for high-temperature applications.
Thermal expansion depending on the temperature
Maximum Temperature Gradient (MTG) 400-800 K
Resistance of the material to temperature differences between a defined hot zone and cold edge of room temperature, without cracking due to thermal stress.
Thermal shock resistance (TSR) 600-820°C (1,112-1,508°F)
Resistance of the material to thermal shock when the hot material is splashed with cold water at room temperature, without cracking due to thermal stress.
Temperature/time load capacity
The TTLC specifies the maximum permissible temperatures for load times of the material, below which no cracking should occur due to thermal stress. The Temperature/Time Load data for uneven and even temperature distributions (e.g. homogeneous heating conditions) within the material are different.
| CTE in different temperature ranges | |
|---|---|
| α(-50 °C; 100 °C) | -0.8 – 0.6 x 10-6K-1 |
| α(0 °C; 50 °C) | -0.8 – 0.6 x 10-6K-1 |
| α(20°C; 300 °C) | -0.4 – 0.9 x 10-6K-1 |
| α(300°C; 700 °C) | 0.1 – 1.6 x 10-6K-1 |
Specific heat capacity and thermal conductivity (DIN 51936, ASTM E 1461-01)
| Specific heat capacity |
Cp (20 – 100 °C)0.80 – 0.85 J / (g x K) |
| Thermal conductivity (DIN 51936, ASTM E 1461-01) |
λ(90 °C)1.5 – 1.7 W / (m x K) |
Homogeneous and inhomogeneous heating of the material
| Homogeneous heating of the material | |
|---|---|
| TTLC / Short term load (1h) | >650 – 950 °C / 1,202 – 1,742 °F |
| TTLC / Continuous load (5000 h) | >550 – 850 °C / 1,022 – 1,562 °F |
| Inhomogeneous heating of the material | |
|---|---|
| TTLC / Short term load (1h) | 450 – 750 °C / 842 – 1,382 °F |
| TTLC / Continuous load (5000 h) | 400 – 560 °C / 752 – 1,040 °F |
SCHOTT NEXTREMA® chemical properties
NEXTREMA® is chemically resistant and remains stable in aggressive environments. It meets all subsequent ISO and DIN standards in its chemical resistance to acids, bases and hydrolytic influences. With the elimination of degradation enabling reliable material behavior, as well as stable process environments under typical corrosive conditions. This chemical- and base-resistant glass-ceramic is used in all fields of industrial and product design.
Principal constituents (DIN EN 1748-2-1)
| Component | Symbol | Percentage per mass |
|---|---|---|
| Silicon dioxide | SiO2 | 50 % – 80 % |
| Aluminium oxide | Al2O3 | 15 % – 27 % |
| Lithium oxide | Li2O | 0 % – 5 % |
| Zinc oxide | ZnO | 0 % – 5 % |
| Titanium oxide | TiO2 | 0 % – 5 % |
| Zirconium oxide | ZrO2 | 0 % – 5 % |
| Magnesium oxide | MgO | 0 % – 8 % |
| Calcium oxide | CaO | 0 % – 8 % |
| Barium oxide | BaO | 0 % – 8 % |
| Sodium oxide | Na2O | 0 % – 2 % |
| Potassium oxide | K2O | 0 % – 2 % |
| Other (trace content on request) | 0 % – 5 % |
The materials do not contain any harmful substances according to the European directive 2002/95/EC ‘Hazardous Substances in electrical and electronically Equipment’ and fulfill the terms of RoHS without any concerns.
End of life usage
Federal Republic of Germany waste disposal regulations differentiate five classes of waste: Z0 (non-restricted disposal), Z3 (household waste), and up to Z5 (highly toxic waste). All NEXTREMA® materials are classified as non-restricted disposal. Local government regulations may differ. Please contact the local authority if needed. NEXTREMA® must not be disposed of in recycling boxes for standard glass (e g. glass bottles).
Chemical resistance
The chemical resistance of NEXTREMA® is more extensive than that of most other comparable materials.
| Tinted (712-3) |
Translucent bluegrey (712-6) |
Opaque grey (712-8) |
Transparent (724-3) |
Translucent white (724-5) |
Opaque white (724-8) |
|
|---|---|---|---|---|---|---|
| Hydrolytic Resistance HGB (ISO 719) |
1 | 1 | 1 | 1 | 1 | 1 |
| Acid Resistance S (DIN 12116) |
2 | 2 | 2 | 2 | 1 | 1 |
| Alkali Resistance A (ISO 695) |
1 | 2 | 2 | 1 | 1 | 1 |
1 = high resistance / low solubility
2 = medium resistance / medium solubility
3 = low resistance / high solubility
Roberto Perez Castro
Head of NEXTREMA® Product Management