X-ray analysis of ground NiAl-Cr3C2-Al2O3 composite powders with nanocrystalline NiAl phase
|Grzegorz Dercz 1, Krystian Prusik , Tomasz Goryczka , Lucjan Pająk , Bolesław S. Formanek|
1. University of Silesia, Institute of Material Science, Bankowa 12, Katowice 40-007, Poland
The composite powder with NiAl, Cr3C2 and Al2O3 phases was prepared by mechanically activated SHS (Self-propagating High-temperature Synthesis) method. As-prepared powder was ground by high-energy attritorial mill up to 40 hours. The Rietveld method based on X-ray powder diffraction data was applied for the verification of qualitative and quantitative phase compositions of as-prepared and ground samples. Micrographs and diffraction patterns were obtained using TEM. The X-ray diffraction data were analyzed using Toraya procedure and Rietveld method. The Rietveld method was applied in the determination of phase abundance using Taylor and Matulis approach. The profile parameters of individual diffraction lines were determined using Toraya PRO-FIT procedure which applies Pearson VII function for the description of line profiles. The crystallite sizes and lattice distortions were estimated using Williamson-Hall method. From the detailed analysis of the breadth of diffraction lines for all phases it was stated that during milling the significant decrease of crystallite size is observed only for NiAl phase. It was stated that the crystallite size of this phase diminishes to nanoscale after 2 hours milling. Prolonged milling time to 10 hours results in further decrease of NiAl crystallite size to 36 nm. The crystallite size of Cr3C2 and Al2O3 phases is still above 100 nm.
Presentation: poster at E-MRS Fall Meeting 2005, Symposium B, by Grzegorz Dercz
See On-line Journal of E-MRS Fall Meeting 2005
Submitted: 2005-05-20 09:52 Revised: 2009-06-07 00:44