TaC, NbC, and ZrC coatings resist chemical attack by corrosive liquids and gases at very high temperatures. They are finding increasing acceptance in sealing and protecting graphite hardware from hot ammonia, hydrogen, hydrochloric acid, and molten metals used in compound semiconductor epitaxial processes such as MOCVD and LPE. The following characteristics of these carbide coatings provide long life and low partice generation
- Uniform
- Protective
- Electrically conductive
- Extremely wear resistant
- Conformal on intricate geometry
Typical Properties
|
TaC
|
NbC
|
ZrC
|
Density (gm/cc)
|
15
|
7.9
|
6.7
|
Coating Temp. (°C)
|
2100
|
2100
|
2100
|
Melting Point (°C)
|
3880
|
3760
|
3540
|
Oxidation Limit (°C)
|
700
|
800
|
800
|
Thermal Conductivity W/m-K
|
22
|
13
|
21
|
Emissivity (Normal Spectral)
|
0.5
|
0.6
|
0.4
|
CTE (10-4/°C)
|
6.3
|
7
|
6.7
|
Comp. Str. MPa
|
-
|
2350
|
820
|
Young’s Modulus (GPa)
|
300-500
|
350-500
|
350-400
|
Elec. Resistivity (micro Ω cm)
|
30
|
30
|
50
|