Influence of a TiC coating on diamonds

• Published in: Materialwissenschaft und Werkstofftechnik Vol. 45; no. 2; pp. 114 - 122
• Main Authors: de Oliveira, L. J., Cabral, S. C., Filgueira, M.
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 01-02-2014; WILEY‐VCH Verlag; Wiley Subscription Services, Inc
• Subjects: beschichteter Diamant; coated diamond; Coating; Coating effects; Composite materials; cutting tools; Diamond machining; Diamond tools; Diamonds; Diffusion coating; Grafitisierung; Graphitization; heißpressen; Hot pressing; Iron; Mechanical properties; Microstructure; powder metallurgy; Pulvermetallurgie; Raman spectroscopy; Schneidwerkzeuge; Sintering (powder metallurgy); Structural analysis; Titanium carbide; Wear resistance
• ISSN: 0933-5137; 1521-4052
• DOI: 10.1002/mawe.201400129

Some diamond tools use iron in their composition, and it is known that iron is a strong catalyst for the graphitization of diamonds. This graphitization occurs mainly during the processing of composite materials – conventional sintering or hot pressing, and during cutting operations. This work studies the effect of TiC coating on diamond, on structure, microstructure and mechanical properties of the processed composites. Samples were prepared by mixing powders of Fe (˜40 μm) and diamond (˜425 μm), and subsequent hot pressing at 35 MPa/900 °C, during 3 minutes. Microstructural aspects were observed by scanning electron microscopy (SEM) and iron diffusion on diamond was studied by energy dispersive spectrometry (EDS). Structural analysis was performed by X‐ray diffraction and Raman spectroscopy. Compressive tests were carried out, as well as the wear resistance of the diamond composites. The importance of employing coated diamonds is stablished. It was observed that iron has not activated the graphitization of diamond crystals.