Reaction Bonded Silicon Nitride

Alternative and trade names
Nitrasil® R


Reaction Bonded Silicon Nitride is produced by nitriding compacted Silicon powder. This production route is considerably more cost-effective than hot-pressing. Very complex and accurate shapes can be produced, which hold their shape during firing. After firing, as for Hot Pressed Silicon Nitride, it can be diamond ground to tolerances as close as 0.01mm.

Although not as strong as Hot Pressed Silicon Nitride, its strength is held up to 1400 °C, with long term oxidation resistance up to 1150 °C. The thermal and electrical properties of the two forms of Silicon Nitride are however very similar. This form finds use as supports in situations of continuous temperature cycling within ranges of up to 1000 °C, as well as for gas turbine components.

Reaction Bonded Silicon Nitride is resistant to a wide range of chemicals and molten metals.



Density ρ

2.4 g/cm³ at 20 °C


Compressive strength Rmc

550 MPa at 20 °C

Flexural strength σbend

190 MPa at 20 °C

Fracture toughness KIC

3 MPa·√m at 20 °C

Hardness, Vickers HV

1100 [-] at 20 °C

Poisson's ratio ν

0.27 [-] at 20 °C


Coefficient of thermal expansion α

3E-6 1/K at 20 °C

Max service temperature, continuous Tmax,cont

1150 °C

Max service temperature, intermittent Tmax,inter

1400 °C

Thermal conductivity λ

16 W/(m·K) at 20 °C


Electrical resistivity ρel

1.00E+1 Ω·m at 20 °C

Technological properties


Nitrasil® R High-performance NITRASIL exhibits minimal wetting by molten metal contact, meaning NITRASIL components are especially suited for aluminium contact applications. The inert formulation is lightweight and has an excellent resistance to thermal shock and thermal cycling. This ceramic material consists of a high strength, durable silicon nitride which yields superior thermal insulation and electrical insulation properties. Moreover, this material grade is not affected by induction currents. It is available as fully machined finished components, which are resistant to all common industrial chemicals and non-ferrous metals.

This material data has been provided by Goodfellow.

All metrics apply to room temperature unless otherwise stated. SI units used unless otherwise stated.
Equivalent standards are similar to one or more standards provided by the supplier. Some equivalent standards may be stricter whereas others may be outside the bounds of the original standard.