Titanium carbonitride

Titanium carbonitride , or Ti (C, N), is a mixed crystal made of titanium nitride and titanium carbide . The connection is characterized by the extremely high hardness of titanium carbide and the chemical resistance of titanium nitride. This connection is often used, especially when coating cutting tools .

Manufacturing

Physical vapor deposition ( PVD ):

${\displaystyle \mathrm {2\,Ti+N_{2}+2\,CH_{4}\longrightarrow 2\,Ti(C,N)+4\,H_{2}} }$ (here: 50% titanium nitride, 50% titanium carbide)

Chemical vapor deposition ( CVD ):

High temperature carbonitride (HT carbonitride):

${\displaystyle \mathrm {2\,TiCl_{4}+N_{2}+2\,CH_{4}\longrightarrow Ti(C,N)+8\,HCl} }$ (here: 50% titanium nitride, 50% titanium carbide)

Medium temperature carbonitride (MT carbonitride):

${\displaystyle \mathrm {2\,TiCl_{4}+CH_{3}\,\mathbf {CN} (+Sp{\ddot {u}}lgas\,H_{2})\longrightarrow Ti(C,N)+CH_{4}+4\,HCl} }$ (Always: 50% titanium nitride, 50% titanium carbide)

The advantage of the medium temperature carbonitride is the uniform growth of the layer due to the cyanide group of the acetonitrile . However, only 50/50 carbonitride can be produced here. With HT carbonitride, however, the different reaction rates of methane and nitrogen play an essential role.

Web links

• Colors of the titanium carbonitride

Individual evidence

1. ↑ Titanium coatings of cutting tools (English)