Low Temperature CVD
The high thermal stress generated on cooling CVD coated tools, together with a requirement to coat tool steels below their tempering temperature has driven CVD developments:-
- Medium Temperature CVD (700-900oC)
- TiCN from TiCl4 and organic C/N compounds
- Fast process
- reduced thermal stress and eta phase
- Plasma assisted CVD (500oC)
- Plasma breaks up chemical species
- coating of tool steels