Technical Details of 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. The material is also able to take dramatic temperature differences.

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 80 MPa (at a thickness of 4 mm).

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

translucent bluegrey

opaque grey

transparent

translucent white

opaque white

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

 

 

 yes

 

Light blocking

 

 

yes

 

 

yes

 

Transmission

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

schott-nextrema-transmission-curves_EN

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. All NEXTREMA® types offer bending stength according to DIN EN 1288 part 5R45 of 80 megapascals.

Key properties

Benefits

tinted

translucent bluegrey

opaque grey

transparent

translucent white

opaque white

Knoop hardness HK (ISO 9385) 

 

approx. 600 HK 0.1 / 20

On demand

On demand

approx. 600 HK 0.1 / 20

approx. 600 HK 0.1 / 20

approx. 600 HK 0.1 / 20

Density  ρ

 

2.6 g / cm3

On demand

On demand

2.6 g / cm3

2.5 g / cm3

2.5 g / cm3

 

  • 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. ≥ 80 MPa

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 °C1 (depending on the material type). 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(depending on the material type), making it ideal for high-temperature applications.

1 Applies to NEXTREMA® opaque white for 1 hour at 950°C homogenous heating. For inhomogeneous heating and other NEXTREMA® variants, the operating temperature may vary.
2 Applies to NEXTREMA® transparent. Tested by quenching a homogeneously heated NEXTREMA® transparent panel (820°C) with room temperature water (20°C). Values may differ for other NEXTREMA® variants.

Benefits

tinted

translucent bluegrey

opaque grey

transparent

translucent white

opaque white

Reliable performance when exposed to thermal shocks

yes

yes

yes

yes

yes

yes

Resistance to Temperature Differences (RTD)

Tupper max1 ≤ 700°C 

On demand 

On demand 

Tupper max1 ≤ 700°C 

Tupper max1 ≤ 560°C

Tupper max1 ≤ 580°C 

Rapid cooling down from extreme temperatures without cracking

yes

 yes

yes 

yes

 yes

yes 

Dimensional accuracy under fluctuating temperature conditions

yes

yes

yes

yes

yes

yes

Coefficient of Mean Linear Expansion α(20; 700°C) (DIN ISO 51045-1, DIN ISO 7991)

0 ± 0.2 x 10-6 K-1

On demand

On demand

0 ± 0.5 x 10-6 K-1

1.0 x 10-6 K-1

1.0 x 10-6 K-1

1 Tupper max : Maximum temperature on the upper side at the hottest point
2 Tes, max : Maximum temperature on the exterior side of the panel, that means the reverse side of the heat source, at the hottest point

 

Thermal expansion depending on the temperature

schott-nextrema-thermal-expansion_EN

 

Resistance to Temperature Differences (RTD) 

  • Resistance of the NEXTREMA® material to temperature differences which are measured at a distance of 25 mm between hot and cold zone (room temperature).

  • Translucent white: No cracking due to thermal stress at Tupper max1 ≤ 560°C

  • Opaque white: No cracking due to thermal stress at Tupper max1 ≤ 580°C

  • Tinted & Transparent: No cracking due to thermal stress at Tupper max1 ≤ 700°C

  • Translucent bluegrey & Opaque grey: on demand

1 Tupper max : Maximum temperature on the upper side at the hottest point

 

Thermal schock resistance (TSR) up to 820°C (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. NEXTREMA® transparent is the glass-ceramic with the highest resistance to temperature shocks out of all six NEXTREMA® variants. NEXTREMA® transparent panels resist to thermal shock when homogeneously heated up to 820°C and quenched with 20°C room temperature water.
That means no cracking due to thermal stress. Values differ for other NEXTREMA® variants.

 

Temperature/time load capacity (TTLC)

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. 

Load time

tinted

Translucent bluegrey

Opaque grey

transparent

Translucent white

Opaque white

TTLC/ 10h

≤ 700°C

On demand

On demand

≤ 700°C

≤ 580°C

≤ 600°C

Temperature/time load capacity for nonuniformly heated glass-ceramic panel. Temperature/time load capacity is higher for homogenous heating. Operating temperature for NEXTREMA® opaque white for 1 hour homogenous heating is up to 950°C. For other NEXTREMA® variants, the operating temperature may vary.

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 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. 

 

Chemical resistance

The chemical resistance of NEXTREMA® is more extensive than that of most other comparable materials.

  tinted translucent bluegrey opaque grey transparent translucent white opaque white
Hydrolytic Resistance class HGB (ISO 719)  1 On demand  On demand
Acid Resistance class S (DIN 12116)
 2 On demand On demand
Alkali Resistance class A (ISO 695)
 1 On demand On demand

 

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

Want to know more? Let's talk

Whether you need more information, samples, a quote, or advice for a project, I would be delighted to talk to you.

Contact us
oberto Perez Castro, Head of SCHOTT NEXTREMA® Product Management
Roberto Perez Castro

Head of NEXTREMA® Product Management