348
H. Karakurkchi et al.
high-temperature phase changes, the strong adhesion to substrate and a uniform
distribution on a surface are provided.
The held analysis of processes at the micro-arc oxidizing AA plurality allows to
formulate backgrounds of control of oxide coatings composition and morphology by
a justified choice of electrolyte components and a synthesis regimes variation. Wide
opportunities for an electrolysis parameters optimization, materials diagnostic, and
their functional properties prediction are provided with application of the systemic
approach to the formalized electrode description. The topology of the electrochemical
systems under study may be visualized in the following way.
Let us inlet designations: M—metal (substrate or carrier); MO x —oxide of metal;
MO x (ε)—the phase (barrier) oxide with high dielectric properties; MO x (p)—
porous oxide; L—electrolyte; L(s)—solid phase electrolyte melt or products of its
transformation in the discharge canal.
With the usage of the pointed designations transition between reversible states (1),
pre-sparking oxidizing (2), micro-arc oxidizing (3) and synthesis of bi-functional
systems (4) reflects sequence of discrete states with transitions intensity λ ij
M|MO x (ε)|L
λ 12
−→
(5)
M|MO x (ε)|M O x (p)|L
λ 23
−→
(6)
M|M | O x (ε)|M | O x (p),L(s)|L
λ 34
−→
(7)
M | |M | O x (ε)|M | O x (p),M || O y (p),L(s)|L
(8)
The portions on forming dependences (Fig. 6) fit the separate states (5)…(8) of
an electrochemical system under study. Intensities of transitions between separate
states λ ij are a multi-parameter function of electrode (E) and chemical (μ i ) potentials,
electrolysis duration (t) and temperatures (T), polarizing current densities (j) and of
some other factors
λ i j = F(E, T, t, μ i , j . . .).
(9)
Determination of the nature and intervals of control actions λ ij variation is a
starting prerequisite not only for optimization of bi-functional systems forming
regimes, but also the (5)…(8) transitions realization as a whole. Regarding difference
of MOS components physical properties and degrees of localization on a surface, it
is possible to expect differentiating of their response on EIS alternative current signal
in a wide frequency range. Therefore, each of the states (5)…(8) can be described by
the equivalent circuit. The variation of its elements gives the information about the
level and dynamics of the functional properties, and also the stability of a material.
H. Karakurkchi et al.
high-temperature phase changes, the strong adhesion to substrate and a uniform
distribution on a surface are provided.
The held analysis of processes at the micro-arc oxidizing AA plurality allows to
formulate backgrounds of control of oxide coatings composition and morphology by
a justified choice of electrolyte components and a synthesis regimes variation. Wide
opportunities for an electrolysis parameters optimization, materials diagnostic, and
their functional properties prediction are provided with application of the systemic
approach to the formalized electrode description. The topology of the electrochemical
systems under study may be visualized in the following way.
Let us inlet designations: M—metal (substrate or carrier); MO x —oxide of metal;
MO x (ε)—the phase (barrier) oxide with high dielectric properties; MO x (p)—
porous oxide; L—electrolyte; L(s)—solid phase electrolyte melt or products of its
transformation in the discharge canal.
With the usage of the pointed designations transition between reversible states (1),
pre-sparking oxidizing (2), micro-arc oxidizing (3) and synthesis of bi-functional
systems (4) reflects sequence of discrete states with transitions intensity λ ij
M|MO x (ε)|L
λ 12
−→
(5)
M|MO x (ε)|M O x (p)|L
λ 23
−→
(6)
M|M | O x (ε)|M | O x (p),L(s)|L
λ 34
−→
(7)
M | |M | O x (ε)|M | O x (p),M || O y (p),L(s)|L
(8)
The portions on forming dependences (Fig. 6) fit the separate states (5)…(8) of
an electrochemical system under study. Intensities of transitions between separate
states λ ij are a multi-parameter function of electrode (E) and chemical (μ i ) potentials,
electrolysis duration (t) and temperatures (T), polarizing current densities (j) and of
some other factors
λ i j = F(E, T, t, μ i , j . . .).
(9)
Determination of the nature and intervals of control actions λ ij variation is a
starting prerequisite not only for optimization of bi-functional systems forming
regimes, but also the (5)…(8) transitions realization as a whole. Regarding difference
of MOS components physical properties and degrees of localization on a surface, it
is possible to expect differentiating of their response on EIS alternative current signal
in a wide frequency range. Therefore, each of the states (5)…(8) can be described by
the equivalent circuit. The variation of its elements gives the information about the
level and dynamics of the functional properties, and also the stability of a material.