NEXTREMA®

The unique combination of SCHOTT NEXTREMA® technical properties makes it a versatile glass-ceramic that defies even the most severe influences.

Common properties for all six NEXTREMA® variants

Thermal properties

NEXTREMA® is the ideal choice for high- to low-temperature applications thanks to its ability to withstand extreme heat or cold, offering outstanding resistance to temperatures up to 950°C (1,742°F). The material is also able to take dramatic temperature differences of up to 820°C (1,508°F).

Optical properties

The variants of NEXTREMA® offer six different transmission profiles. This optical versatility is great news for designers and engineers as it offers the possibility of a wide range of applications, from stylish infrared glass radiators to industrial applications.

Mechanical properties

For a glass-ceramic, NEXTREMA® boasts a high degree of mechanical strength without any additional toughening processes. All six variants have a high degree of temperature resistance along with a high bending strength of up to 165 MPa (at a thickness of 4 mm (0.157 in)).

Chemical properties

NEXTREMA® is stable in the harsh chemical environments, and meets all subsequent ISO and DIN standards in its chemical resistance to acids, bases and hydrolytic influences. The elimination of degradation enables reliable material behavior, as well as stable process environments even under corrosive conditions.

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.

Key properties Benefits tinted

(712-3)
translucent bluegrey
(712-6)
opaque grey
(712-8)
transparent

(724-3)
translucent white
(724-5)
opaque white
(724-8)
6 transmission profiles in visible range (400 - 800 nm) 6 design options black  blue  grey  transparent white white
Glare reduction yes  yes yes   yes yes
Light diffusion    yes     yes  
Light blocking     yes     yes
 6 transmission profilesin infrared range (800 - 4500 nm) Efficient IR heater cover yes yes   yes yes  
Selective IR transmission     yes     yes
Compatible with different IR heaters yes yes yes yes yes yes

 

Transmission

Transmission values are measured for a polished sample of a specific thickness.

schott-nextrema-transmission-curves_EN_2021_06_02 

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 (0.157 in).

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.

Key properties Benefits tinted

(712-3)
translucent bluegrey
(712-6)
opaque grey
(712-8)
transparent

(724-3)
translucent white
(724-5)
opaque white
(724-8)
Bending strenght of up to 165 MPa (thickness 4mm/0.157 in) High material streght without tempering yes yes yes yes yes yes
Reliable material strenght under high temperatures yes yes yes yes yes yes
Surface/ Knoop harness of up to 620 Good abrasion resistance yes yes yes yes yes yes
 Density of ~2,5 g/cm3 Lightweight compared to technical ceramics yes yes  yes yes yes yes

 

  • Density: ρ approx. 2.5 – 2.6 g/cm3
  • Modulus of elasticity (ASTM C-1259): E approx. 84 – 95 x 10³ MPa
  • Poisson‘s ratio (ASTM C-1259): μ approx. 0.25 – 0.26
  • Knoop hardness (ISO 9385): HK0.1 / 20approx. 570 – 600
  • Bending strength (DIN EN 1288, Part 5, R45): σbBapprox. 100 – 165 MPa
  • Porosity (ISO 9385): 0 %
  • Roughness: Material 724-3 (t = 4 mm/0.157 in) Ra≤ 0.20 μm Rms ≤ 0.25 μ

 

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.

Key properties Benefits tinted (712-3) translucent bluegrey (712-6) opaque grey (712-8) transparent (724-3) translucent white (724-5) opaque white (724-8)
Thermal shock resistance of up to 820°C Reliable performance when exposed to thermal shocks yes yes yes yes yes yes
Rapid cooling down from extreme temperatures without cracking yes yes yes yes yes yes
Near-zero CTE
Operating temperature of up to 950°C
Dimensional accuracy under fluctuating temperature conditions yes yes yes yes yes yes
Higher temperature resistance than most glasses (except fused silica)  yes yes yes yes yes yes
 

 

Thermal expansion depending on the temperature

schott-nextrema-thermal-expansion_EN_2021_06_02 

 

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.

Key properties Benefits tinted
(712-3)
translucent bluegrey
(712-6)
opaque grey
(712-8)
transparent
(724-3)
translucent white
(724-5)
opaque white
(724-8)
High chemical resistance comparable to laboratory glassware Comparable resistance to laboratory glassware yes     yes yes yes
Reliable protection against corrosive environments yes     yes yes yes
 Non-porous, smooth surface No outgassing in vacuum environments yes yes yes yes  yes yes
No generation of particles without external influence yes yes yes yes yes yes
 

 

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 2011/65/EU “Hazardous Substances in electrical and electronically Equipment” and fulfil the terms of RoHS(II) without any concerns. NEXTREMA® glass-ceramics consist of 100% UVCB substance glass. According to REACH, this kind of glass is not classified as a hazardous substance. When used within the limitation of the according material specification, NEXTREMA® glass-ceramics do not release any hazardous substances throughout the entire life cycle (including the disposal), that would violate existing legal limits. 

 

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
Acid Resistance S (DIN 12116)
 2
Alkali Resistance A (ISO 695)
 1

 

1 = high resistance / low solubility
2 = medium resistance / medium solubility
3 = low resistance / high solubility

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