학술논문
Thermodynamic aspects of nanostructured TiSi formation during mechanical alloying and its characterization.
Document Type
Article
Author
Source
Subject
*THERMODYNAMICS
*TITANIUM-silicon alloys
*NANOSTRUCTURED materials
*X-ray diffraction
*MOLECULAR structure
*POWDER metallurgy
*TRANSMISSION electron microscopy
*MECHANICAL alloying
*INTERMETALLIC compounds
*MICROHARDNESS
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Language
ISSN
0250-4707
Abstract
Mechanical alloying (MA) was used to produce TiSi intermetallic compound with nanocrystalline structure from elemental powders. The structural changes and characterization of powder particles during milling were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), particle size analyser (PSA) and microhardness measurements. MA resulted in gradual formation of disordered TiSi intermetallic compound with crystallite size of about 15 nm after 45 h of milling. Also a thermodynamic analysis of the process was carried out using Miedema model. The results showed that in the nominal composition of TiSi intermetallic phase ( X = 0·375), formation of an intermetallic compound has the lowest Gibbs free energy rather than solid solution or amorphous phases. So the MA product is the most stable phase in nominal composition of TiSi. This intermetallic compound exhibits high microhardness value of about 1235 HV. [ABSTRACT FROM AUTHOR]