Preparation of TiB sub 2 and TiB sub x N sub y Coatings by PACVD

• Published in: Surface & coatings technology 1989-04, Vol.39-40 (1-3), p.293-300
• Main Authors: Karner, H, Laimer, J, Stori, H, Rodhammer, P
• Format: Article
• Language: English
• ISSN: 0257-8972

Thin films of TiB sub 2 and TiB sub x N sub y have been deposited by plasma-assisted chemical vapour deposition (PACVD) in a gas mixture of Ar, H sub 2 , N sub 2 , TiCl sub 4 and BCl sub 3 , using both r.f. and pulsed direct current plasmas. The influence of the BCl sub 3 /TiCl sub 4 ratio and of the N sub 2 flow rate on the chemical composition and the mechanical properties of the coatings and on the formation of different phases has been studied in detail. The TiB sub 2 coatings, deposited at rates of approx 2 mu m h exp --1 reach Vickers hardness values up to 3000 HV0.02 and exhibit a fracture amorphous (r.f. plasma) or fibrous (direct current plasma) structure. They contain < 1 at.% Cl. The TiBi sub x N sub y coatings consisting of the face-centered cubic TiB sub x N sub y , the hexagonal TiB sub 2 and the orthorhombic TiB phase, reach a Vickers hardness up to 3000 HV0.02. At a deposition rate of 2 mu m h exp --1 they contain approx 1 at.% Cl. The coverage of the edges of cemented carbide inserts is excellent. , , . 9 ref.--AA