Program and the Book of Abstracts (PDF) - Mrs-serbia.org.rs

Tenth Young Researchers Conference – Materials Science and Engineering
December 21-23, 2011, Hall 2, SASA, Knez Mihailova 35 & 36, Belgrade, Serbia
III/4
Mechanomaking of boron crystal solid solution in fcc Fe-Ni alloys
A. Litvinov, Kirill Lyashkov, V. Shabashov, N. Kataeva
Institute of Metal Physics UB RAS, Yekaterinburg, Russia
Boron does not form equilibrium solid solutions with iron. Using the method of ultra speed
quenching (SQ) it is possible to obtain metastable solid solutions and to widen the area of their
existence. As alternative to SQ, this research studied the possibility of mechanical dissolution of
borides and formation of boron solid solutions in fcc Fe-Ni alloys using intensive cold plastic
rotation deformation in Bridgman anvils.
To analyse the process of solid solutions formation, as in cases with carbon, nitrogen, and
oxygen, it is necessary to take into account the dependent on temperature competitive processes of
decay and extraction of secondary phases – borides in this case.
According to the data of Mossbauer spectroscopy, magnetic susceptibility and X-ray diffraction
analysis the deformation-induced dissolution of boron and boron nitride particles in metal matrix
under compression shear in rotating Bridgman anvils was stated. Boron interstitial supersaturated
solid solution with concentration 1…3 at.% is formed as a result of dissolution of Fe-Ni alloy in fcc
matrix. Supersaturated solid solution is unstable and coexists with metastable borides of (FeNi) 3 B
type.
The possibility of formation of supersaturated crystal boron solid solutions in fcc - iron ( to 3
at.% B) is promoted by the anomalously large growth of crystal lattice spacing and the volume of
octahedral interstitial sites of γ-phase in the invar area of compositions.
The growth of and T C , found with the help of NRG method, in Fe-Ni alloy of invar range
at its mechanical synthesis with boron-containing components is comparable with the similar
growth of these magnetic characteristics for the cases of alloying with carbon and nitrogen. Electron
microscopy data show the formation of submicrostructure in invar matrix with multiple
nanodimensional particles of boride phases and inclusions of undissolved boron. Mechanical
synthesis of supersaturated boron solid solution in crystal matrix of Fe-Ni austenite makes it
possible to use cold plastic compression shear deformation for nanostructurization and creation of
secondary nanoboride phases.
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