Thermodynamics of Advanced Alloys Modification by Exogenous Nanophases


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The thermodynamic analysis of a ceramic compound solubility was carried out for ceramic compounds which may be used for dispersion hardening of advanced nickel alloys. The thermodynamic description of stability conditions was completed for a disperse heterophase systems consists of metal melt – nanosize phases (NSP). For a thermodynamic criterion (К) of stability was selected the specific variation of a free energy of the process of a disperse system degradation (referred to change of unit of a surface phases contact). The analysis was executed in view of formation of thick and thin elastic wetting films and takes in account a disjoining pressure. The above definition of new thermodynamically rigorous criterions becomes physically real, if the isotherm of a disjoining pressure is measured. The derived criterions are simplified in the Young approximation. In this case the criterion are expressed through measurable interfacial performances - interfacial tension and wetting angles. The application of a stability condition gives a simple outcome: aggregation of NSP does not happen at a wetting angles ≤ 600. On a basis of own experimental data the evaluations are carried out for possibility of using of some compounds as exogenous modifiers of a nickel alloys. The example of dispersion hardening of high-temperature strength nickel alloy and improving its heat resisting properties is reduced.



Edited by:

Catalina Spataru




Y.A. Minaev, "Thermodynamics of Advanced Alloys Modification by Exogenous Nanophases", Advanced Materials Research, Vol. 587, pp. 1-5, 2012

Online since:

November 2012





[1] E. N Kablov: Cast blades of gas-turbine engines. Alloys. Process engineering. Cooating. (MISiS Ed., Moscow, 2001).

[2] A.I. Rusanov: Phase equilibrium and surface appearances (Chemistry, Leningrad 1967).

[3] B.V. Derjaguin, N.V. Churaev, V.M. Muller: Surface forces (Science, Moscow, 1987).

[4] Y.A. Minaev, A.I. Rusanov: Izv. ASci. USSR, Metals, № 5 (1971), p.59.

[5] Y.A. Minaev, V.V. Jakovlev: Physical-chemistry in metallurgy. Thermodynamics. Hydrodynamics. Kinetics (MISiS Ed., Moscow, 2001).

[6] B.V. Derjaguin: Acta Physicochim. USSR, V. 12, № 2 (1940), p.181.

[7] I.A. Minaev, in: Symposium Series S36, VII International Conference on Molten slags, fluxes and salts, SAIMM Publ., Johannesburg (2004), p.763.