Diamond thin films have outstanding optical, electrical, mechanical and thermal properties, which make these attractive for applications in a variety of current and future systems. In particular, t...

A review of nucleation, growth and low temperature synthesis of diamond thin films

Chemically vapour deposited diamond coatings on cemented tungsten carbides : Substrate pretreatments, adhesion and cutting performance

Internal stresses in CVD diamond layers

Diamond deposition on various hardmetal tools is widely used. For applications where the mechanical forces are low diamond coatings have long lifetimes, but especially for heavy duty applications the reproducibility of the diamond coating adhesion is not adequate. Wear and lifetime of diamond coated tools are determined by the diamond microstructure, the coating thickness, and the adhesion of the coating. The diamond substrate interface is important for layer adhesion, but in the case of diamond deposition on hardmetal tools, the interface can change during the diamond deposition. For this reason, surface pre-treatments are important, not only for a better diamond nucleation, but also to create a stable interface that allows good coating adhesion. The various aspects of different surface pre-treatments of hardmetal tools will be discussed.

Diamond deposition on hardmetal substrates – Comparison of substrate pre-treatments and industrial applications

Diamond coatings on cemented tungsten carbide tools by low-pressure microwave CVD

Diamond deposition on chromium, cobalt and nickel substrates by microwave plasma chemical vapour deposition

Mo, W, Mb and Ta sheets are widely used as substrates for diamond deposition. These metals are carburized on the surface and this reaction influences diamond nucleation. Diamond growth, however, is not influenced since the vapor pressure of the carbides is very low. Polishing powder remaining on the substrate surface after surface treatment as well as the surface roughness influence the diamond nucleation. The substrates were pretreated with various polishing powders (diamond, B 4 C, SiC, Al 2 O 3 ) of different grain sizes (1–50 μm). The influences of these pretreatments on subsequent diamond nucleation and deposition were then investigated.

Diamond nucleation and growth on refractory metals using microwave plasma deposition

Diamond films were grown on SiAlON substrates from different CH4/H2 gas mixtures by microwave-activated chemical vapor deposition (MW-CVD), and the effects of gas pressure, methane concentration, microwave power and substrate temperature on growth rate and morphology were examined. Scanning electron microscope pictures showed that at low methane concentrations the synthesized diamond crystals were characterized mainly by triangular (111) facets, whereas at higher methane concentrations (100) facets were predominant. Correlations between diamond morphology, diamond growth rates, homogeneity of the deposition and the size of the plasma ball are given. The effects on diamond growth and diamond morphology with respect to deposition area, gas pressure and the variations in plasma intensity will be discussed.

A. Lindlbauer

Papers

Diamond deposition on chromium, cobalt and nickel substrates by microwave plasma chemical vapour deposition

Diamond nucleation and growth on refractory metals using microwave plasma deposition

Effects of microwave plasma deposition parameters on diamond coating formation on SiAlON substrates