The cubic boron nitride (c-BN) Ti composites are multiphase materials attractive due to combined high hardness and low friction, high corrosion resistance, suitable thermal and electrical properties. These materials are synthesized at high-pressure and high-temperature. Chemical reactions between activators (e.g. Ti compounds) and c-BN powder occur resulting in the formation of several phases. Some correlations between amount of these phases and mechanical properties were found. Due to existence of several phases with similar crystal structure and high hardness of these materials, quantitative analysis by powder X- ray diffraction failed. Nevertheless, the X-ray absorption method appears to be good tools for quantitative phase analysis of these hard materials. Most of the X-ray absorption studies (XAS) are performed either in transmission or fluorescence detection. In fluorescence one should avoid the self-absorption therefore the content of analyzed element should be around 1 at%. In transmission there is strict requirement for thickness of the samples, which imposes sample preparation (grinding, pellet pressing, etc.). It results in samples unrepresentative of the active state of materials in industrial practice. In such a case total electron yield (TEY) detection offers a good solution of problems. Highly concentrated as well as inhomogeneous materials can be investigated reliably. Studied samples were electrically isolated from the spectrometer and the drain current from the samples was measured. The edges of several elements were measured for all compounds formed in Ti composites and for composites. The studies were performed at HASYLAB (A1) in Hamburg and at Advanced Light Source (6.3.1) in Berkeley.
Acknowledgements
This work was supported in part by Polish State Committee for Scientific Research (Grant No 2P03B10625 and 2P03B05524) and by the IHP-Contract HPRI-CT-2001-00140 and G1MA-CI-2002-4017 (CEPHEUS) of the European Commission.