Prof. Ivan Petrov
Department of Physical Chemistry National University of Science and Technology MISIS, Russia
Title: Role of Solid/Liquid Interface Adsorption in Wetting Dynamics and Infiltration of Ag-Cu Melts on Iron Substrates
Abstract:
This study investigates the
wetting, spreading, and capillary infiltration of Ag–Cu melts on both dense and
porous iron substrates, over a wide range of compositions (0–100 at.% Cu) and
temperatures (900–1250°C). The research employs an advanced sessile-drop setup
with real-time high-speed imaging and infrared thermography to monitor droplet
spreading and front propagation in porous media. Wettability experiments on
non-porous iron substrates reveal a strong composition dependence of the
contact angle, decreasing from 50±5° for pure Ag to 9±5° for pure Cu at 1100°C.
The observed wetting behavior is explained in terms of Cu adsorption at the
solid/liquid interface, as supported by Butler-based thermodynamic modeling [1].
Infiltration kinetics into porous iron (50% porosity, average pore size ~3 μm) were
quantified using a finite-volume droplet method [2]. The melt front velocity
increased by three orders of magnitude with rising Cu content, from 0.44 mm/s
for pure Ag to 420 mm/s for pure Cu at 1100°C. The classical Lucas–Washburn
model [3] predicts infiltration trends qualitatively but fails quantitatively,
overestimating velocities by up to three orders of magnitude for Ag-rich melts.
This discrepancy is attributed to the model’s assumption of cylindrical capillaries,
which poorly represents the real pore structure in sintered powder substrates.
Introduction of a threshold contact angle θth =
50.72°, based on the closely packed equal spheres model [4] for porous media,
significantly improves agreement with experimental data. SEM/EDS analysis
confirms negligible Ag–Fe solubility, whereas significant Cu dissolution into
Fe occurs, although kinetics are slower than infiltration timescales. The study
demonstrates that capillary-driven infiltration in metal–porous systems is
governed not only by melt properties (σlv, η) but
critically by the wetting dynamics and interfacial adsorption at the
solid/liquid boundary. Results contribute to better predictive models for
metal-matrix composite fabrication and reactive infiltration processes.
This work was supported by the Ministry of Education
and Science of the Russian Federation (State Assignment FSME-2023-0007).
References:
1. J.A.V. Butler. The thermodynamics of the surfaces
of solutions. Proc. R. Soc. London, Ser. A 135(827) (1935) 348-375
2. I. Petrov, S. Zhevnenko, Capillary infiltration
measurements by finite size drop method: Wetting, spreading and infiltration of
liquid silver in porous iron, J. Alloys Compd. 1010 (2025) 177913.
3. E.W. Washburn, The dynamics of capillary flow,
Phys. Rev. 17 (1921) 273.
4. K. P. Trumble. Spontaneous infiltration of
non-cylindrical porosity: close-packed spheres. Acta Mater. 46(7) (1998)
2363-2367. https://doi.org/10.1016/S1359-6454(98)80017-7
Biography: