Microwave plasma chemical vapour deposition diamond nucleation on ferrous subst...

• Author(s): F. J.G. Silva ; A. P. M. Baptista ; E. Pereira ; V. Teixeira ; Q.H. Fan ; A.J.S. Fernandes ; F.M. Costa
• Date: 2002
• Persistent ID: http://hdl.handle.net/10216/526
• Origin: Repositório Aberto da Universidade do Porto
• Document Type: Article
• Language: Portuguese

Description

Diamond coated steel is considered an important issue in synthetic diamond technology due to the great economical importance of enhancing the wear resistance and surface hardness of commercial Fe based alloys. However, direct diamond coating by Chemical Vapour Deposition (CVD) is rather problematic - adhesion and growth are seriously affected. The use of interlayers is a common approach to minimise the referred problems. In this work, it is reported an investigation on the establishment of good nucleation and growth conditions of diamond films by Microwave Plasma CVD (MPCVD) on ferrous substrates coated with Ti and Cr interlayers. Commercial grade ferrous substrates were pre-coated with commercial interlayers by sputtering (Ti, Cr) and electroplating (Cr) techniques. Steel substrates lead to better results than iron cast substrates. The best films were obtained on Ti pre-coated steel substrate. The results on Cr interlayers pointed to the advantage of electroplating over the physical vapour deposition (PVD) sputtering. From the two selected parameter sets for diamond deposition, the one using lower power level conducted to the best results. Initial roughness and growth parameters were found to counteract on the uniformity of the diamond films. The morphology was studied by Scanning Electron Microscopy (SEM), the roughness was estimated by profilometry, while diamond quality and stress state were evaluated by m-Raman spectroscopy.