X-ray absorption studies of phase formation in a Ti/TiN coating on cubic boron nitride

We report on the use of X-ray absorption spectroscopy as a tool for the identification of the phases formed in the technological process of composite preparation. A composite is a mixture of several compounds and, in many cases, the use of traditional X-ray diffraction to determine the phases can be difficult because of the small amount of phases present. X-ray absorption studies (XANES and EXAFS) of the c-BN Ti/TiN layered system are presented. These materials are models of the powdered composites used in industry for tool production. XANES and EXAFS analyses showed that, after annealing up to 1300 degreesC, a TiB2 phase is formed, but the chemical bonding of the Ti atoms differs slightly from that of standard TiB2 powder, showing the presence of defects in site occupancy. Assuming that the X-ray absorption spectral shape is a linear combination of the spectra of all the components, we estimated the kind and limits of other phase inclusions. (C) 2003 Elsevier B.V. All rights reserved.