Nitride ceramics

SILICON Nitride (Si ₃N ₄)

This material offers a hitherto unattainable combination of outstanding properties:

• Extremely high strength
• Very high toughness
• Excellent wear resistance
• Very low thermal expansion
• High thermal conductivity
• Outstanding thermal shock resistance
• Very good chemical resistance

The sintering process of silicon nitride has to take place by a very high mechanical pressure in a controlled atmosphere. Depending on the process the result is:

• sintered silicon nitride (SSN)
• gas pressure sintered silicon nitride (GPSSN) or
• hot-pressed silicon nitride (HPSN)

In comparison reaction bonded nitride (RBSN) - starting substance Si-powder - is nitrided shrink free in a specifically set N2-atmosphere

SILICON ALUMINIUM OXYNITRIDE (SIALON)

It is mainly based on compounds or solid solutions of a four-component system silicon - aluminium - oxygen - nitrogen.
On account of its fracture toughness it is often used for

• Cutting tools. Due to the low wettability through non ferrous metals, SIALON is a standard material for
• Thermocouple protection tubes.

ALUMINIUM NITRIDE (ALN)

An irresistible material due to its extraordinary high thermal conductivity: up to 180 Wm-1 K-1. Moreover the combination of properties speak for themselves:

• Best thermal conductivity
• High electrical insulation
• Thermal expansion similar to Si (‹Al2O3)
• Inert behaviour towards melting of the III-V-compounds
• High rigidity.

ALN is especially suitable as

• Substrate for semi-conducting components and
• Power electronic modules.