Direct deposition of diamond films on steel using a three-step process

• Published in: Diamond and related materials Vol. 15; no. 4; pp. 498 - 501
• Main Authors: Gowri, M., Li, H., Schermer, J.J., van Enckevort, W.J.P., ter Meulen, J.J.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01-04-2006; Elsevier
• Subjects: Chemical vapor deposition (including plasma-enhanced cvd, mocvd, etc.); Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Diamond film; Exact sciences and technology; Hot filament CVD; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Physics; Steel; Structure and morphology; thickness; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology; Steel; Diamond film; Hot filament CVD; Methane; Hot filament chemical vapor deposition; Scanning electron microscopy; Nucleation; Synthetic diamond; High temperature; Experimental study; Coatings; Raman spectroscopy; Carbon; Thin films; Polycrystalline diamond; CVD; Tool steels; Nucleation density
• ISSN: 0925-9635; 1879-0062
• DOI: 10.1016/j.diamond.2005.10.040

Diamond coatings were successfully deposited on tool steel substrates without using any external diffusion barrier layers. The diamond film deposition was performed in a hot filament chemical vapour deposition (HFCVD) reactor. In the first step, a high substrate temperature and a high methane percentage were used to achieve a faster critical carbon concentration and hence a shorter incubation time for diamond nucleation. Subsequently, the substrates were taken out of the reactor and subjected to ultrasonic scratching in diamond slurry in order to increase the diamond nucleation density. Then the final deposition was performed in the reactor under typical diamond growth conditions. X-ray diffraction analyses showed that Fe
3C was the dominant carbide phase formed on the steel surface after the first step. The carbides produced in the first step act as a diffusion barrier for both iron and carbon. Thus, they accelerate the diamond nucleation and help further diamond growth. Scotch tape adhesion tests showed that the diamond film adheres well to the substrate.