K. KERN et al.: EFFECT OF A SCANDIUM ADDITION ON ANODIZING AlMg ALLOYS
155–161
EFFECT OF A SCANDIUM ADDITION ON ANODIZING AlMg
ALLOYS
VPLIV DODATKA SKANDIJA NA ANODIZIRANJE ZLITIN AlMg
Katarina Kern
1
, Janez Kova~
2
, Marta Klanj{ek Gunde
3
, Ale{ Nagode
1
,
Milan Bizjak
1
, Matija Zorc
1
, Borut Kosec
1
, Bla` Karpe
1
1
University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia
2
Jo`ef Stefan Institute, Ljubljana, Slovenia
3
National institute of Chemistry, Ljubljana, Slovenia
Prejem rokopisa – received: 2023-01-18; Sprejem za objavo – accepted for publication: 2023-02-10
doi:10.17222/mit.2023.755
Scandium (Sc) is known to be one of the most effective alloying elements of aluminum alloys. The only drawback is its high
price, but that could change quickly due to the promising results of recent research on its extraction. However, the data on how it
affects anodic oxidation are very scarce. In this research, we analyzed how a micro-addition of Sc to the AlMg alloy affects the
growth mechanism and properties of the protective aluminium oxide layer depending on the anodization parameters. For com-
parison, alloy AA5083 with a similar magnesium content was also anodized with the same anodizing parameters. In all experi-
ments, sulfuric acid (VI) with concentrations of 1.72 M or 2.2 M at temperatures of 21 °C or 35 °C was used as the electrolyte.
Potentiostatic (18 V) and galvanostatic (20 mA/cm
2
) anodizing methods were applied. The results (SED-EDS) show that scan-
dium is uniformly intercalated in the matrix of the oxide layer and decreases its resistivity, which increases the oxide growth
rate during potentiostatic anodizing and decreases the pore density and pore diameters during galvanostatic anodizing. More-
over, it increases the mobility of cations through the oxide layer, thus accelerating the oxidation reaction in concentrated sulfuric
acid electrolytes. On the other hand, the increased cation mobility considerably increases the sensitivity to the temperature of
the electrolyte, which can change the growth mechanism of the oxide layer and thus its morphology.
Keywords: anodization, scandium microalloying, AlMgSc alloys, oxide protective layers
Skandij je eden izmed najbolj u~inkovitih legirnih elementov aluminijevih zlitin. Njegova edina slabost je zelo visoka cena, kar
pa se zaradi obetavnih rezultatov novej{ih raziskav glede njegovega na~ina pridobivanja hitro spreminja. Zelo malo je podatkov
o tem kako vpliva na anodizacijo aluminijevih zlitin. V raziskavi so analizirali vpliv mikrolegiranja AlMg zlitine s skandijem na
rast oksidne plasti med anodno oksidacijo tako v odvisnosti od ~asa kot tehnolo{kih parametrov anodne oksidacije. V vseh
poskusih so za elektrolit uporabili `veplovo (VI) kislino s koncentracijama 1,72 M ali 2,2 M pri temperaturah 21 °C ali 35 °C.
Uporabili so tako potenciostati~no (18 V) kot galvanostati~no metodo anodiziranja (20 mA/cm
2
). Rezultati (SEM/EDS) ka`ejo,
da se skandij enakomerno vgrajuje v matrico oksidne plasti in zmanj{a njeno upornost, kar pove~a hitrost rasti oksidne plasti
med potencionisti~nim anodiranjem ali zmanj{a gostoto por in njihov premer med galvanostati~nim anodiziranjem. Poleg tega
se pove~a mobilnost kationov skozi oksidno plast in tako pospe{i reakcijo oksidacije v koncentriranih elektrolitih `veplove
(kisline. Po drugi strani pa se zaradi pove~ane mobilnosti kationov znatno pove~a ob~utljivost na temperaturo elektrolita, kar
lahko spremeni mehanizem rasti oksidne plasti, s tem pa tudi njena morfologija.
Klju~ne besede: anodizacija, mikrolegiranje s skandijem, zlitine AlMgSc, oksidna za{~ita
1 INTRODUCTION
Anodic oxidation (anodizing) of aluminium or its al-
loys is an electrochemical process that produces a corro-
sion- and abrasion-resistant aluminium oxide (Al
2
O
3
)
layer on the surface of a workpiece. Anodizing is usually
done with direct current (DC) in an acid electrolyte. An
oxide layer consists of a 10–100 μm thick porous layer
with hexagonally shaped cells with a central pore per-
pendicular to the metal surface and a thin (several tens of
nanometers) compact barrier oxide layer between the
metal and the porous oxide layer (Figure 1). The result-
ing anodic layers are generally transparent to visible
light, but various methods have also been developed to
colour the anodic layer and then sealing the porous struc-
ture. The structure, mechanical properties and optical ap-
pearance of the anodized surface depend on the anodiza-
tion parameters as well as on the composition of the alu-
minium alloy and its surface morphology.
1–13
Materiali in tehnologije / Materials and technology 57 (2023) 2, 155–161 155
UDK 621.357.8:669.793 ISSN 1580-2949
Original scientific article/Izvirni znanstveni ~lanek MTAEC9, 57(2)155(2023)
*Corresponding author's e-mail:
blaz.karpe@ntf.uni-lj.si (Bla` Karpe)
Figure 1: a) Schematic representation of the oxide layer and
b) cross-section of the oxide layer
2

Figure 2 shows the change in the voltage during an-
odization at a constant current density (galvanostatic an-
odization), the change in the current density at constant
voltage anodization (potentiostatic anodization), and the
corresponding morphology of the oxide layer. At the be-
ginning, a compact amorphous barrier layer is formed
(range 'a'), which resembles the natural oxide layer on
aluminium. After a few seconds of anodization (range
'b'), the first embryos of the pores in the barrier layer be-
gin to form. The barrier layer thickens (to the end of
range 'b'), increasing its electrical resistance. When the
voltage reaches its maximum (or the current density its
minimum) the barrier layer reaches its maximum thick-
ness. In region 'c' the pores begin to deepen and increase
their diameter to their final size, which leads to a de-
crease in the electrical resistance of the oxide layer. In
region 'd', a uniform growth of the porous layer is gradu-
ally established.
The growth of a barrier and porous oxide layer on
aluminium in an electric field involves the outward mi-
gration of Al
3+
cations and the inward migration of O
2–
or
OH
-
anions through the barrier oxide layer. A stable (uni-
form) growth of the porous oxide layer is possible only if
a dynamic equilibrium is established between the growth
rate of the barrier oxide layer at the metal/oxide interface
and its dissolution rate at the bottom of the pores, at the
oxide/electrolyte interface, which is accelerated by the
electric field.
Scandium is one of the most effective precipitation
strengthener, recrystallization inhibitor, and grain refiner
in aluminium alloys.
14,18
The only drawbacks include its
scarcity, difficult production and the associated high
price. Scandium-alloyed aluminium alloys have therefore
only been used as high-priced niche products in the aero-
space industry or in the sporting goods industry, such as
high-performance frames for mountain bikes and base-
ball bats. As the new process of selective extraction of
scandium from transition metals has proven successful,
promising to transform the production of scandium in the
future, the interest in scandium as a microalloying ele-
ment of aluminium alloys is growing in science and
industry.
19
One of the main advantages of scandium addi-
tion is also the improved superplasticity of some alu-
minium alloys, i.e., the ability of a material to exhibit
highly uniform deformations by more than several hun-
dred percent without visible necking.
14–18
One of the
superplastic aluminium alloys is AlMg microalloyed
with Sc when synthesized with a suitable process. With
this study, we aimed to find how a micro-addition of
scandium to the AlMg alloy affects the anodization pa-
rameters, growth mechanism, and the properties of the
protective aluminum oxide scale. For comparison, the
AA5083 alloy with a similar magnesium content was
also anodized with the same anodizing parameters.
2 EXPERIMENTAL PART
All specimens were fabricated from 1.5 mm thick
cold-rolled sheets and cut into 12 mm square coupons,
wet-ground with SiC abrasive paper (800, 1200, 4000),
mechanically polished with diamond pastes MD-Mol 3
μm and MD-Nap 1 μm, etched in a solution of 100 g
NaOH/L deionized H
2
O at 60 °C for 1 min, neutralized
in a solution of6gHNO
3
/100 mL H
2
O for 4 min, rinsed
in deionized water, and dried in an air flow. The chemi-
cal composition of the cold-rolled sheets used is listed in
Table 1.
Table 1: Chemical composition of cold-rolled sheets
14
El. (w/%) AA5083 AlMgSc
Al 93.63 95.2
Mg 4.72 4.5
Si 0.25 0.008
Cr 0.14 0.0002
Mn 0.79 0.0027
Fe 0.39 0.02
Cu 0.08 0.003
Sc 0.25
Ti 0.0144
Anodizing was performed in a 100 ml anode cell at
different anodization parameters:
• Potentiostatic anodization, at a constant voltage of
18 V in 1.72 M or 2.2 M H
2
SO
4
acid electrolyte at
21 °C or 35 °C for up to 25 min.
• Galvanostatic anodization, at a constant current den-
sity of 20 mA/cm
2
in 1.72 M H
2
SO
4
acid electrolyte
at 21 °C for 25 min.
The electrolyte temperature during anodizing was
continuously monitored with Pt100 RTD (4-wire
method) and NTC 10k and kept constant by stirring and
cooling with a Peltier element (QuickCool® QC-241-
1.0-3.9M). The constant voltage and current density dur-
ing anodization were maintained with a laboratory power
supply (PSI 5080-05A Elektro-Avtomatik Gbmh).
K. KERN et al.: EFFECT OF A SCANDIUM ADDITION ON ANODIZING AlMg ALLOYS
156 Materiali in tehnologije / Materials and technology 57 (2023) 2, 155–161
Figure 2: A) Voltage change during galvanostatic anodization, B) cur-
rent density change during potentiostatic anodization, C) schematic
presentation of oxide growth during the initial phases of anodization
2

The cross-sections of the anodized samples were ana-
lysed using a scanning electron microscope (SEM-EDS
Thermo Fischer Scientific Quattro S) and Olympus
BX61 optical microscope with Material Research Lab
image analysis software.
3 RESULTS
3.1 Potentiostatic anodization
From the curves of the current density measurements
during the initial phase of potentiostatic anodizing
(U=18V ,Figure 3), it is evident that the kinetics of the
formation of the barrier oxide layer is only slightly dif-
ferent for these two alloys. The main difference lies in
the maximum current density i
max
and the current density
during the stationary growth phase of the porous layer,
which are almost twice as large for alloy AlMgSc, result-
ing in a much thicker oxide layer. The average thickness
of the oxide layers after 25 min of anodization at a con-
stant voltage of 18 V was 50 μm for AlMgSc and 25 μm
for AA5083.
Figure 4 shows the specific distribution of elements
(EDS mapping) in the cross-section of the oxide layer. In
addition to Al, O and Mg, Sc was found to be uniformly
distributed in the anodic oxide layer. Parallel pores run-
ning perpendicular to the substrate surface, 14–16 nm in
diameter, can be seen at a higher magnification in the up-
per right micrograph.
A comparison of the pore fractions and pore diame-
ters, measured on the free surface of the oxide layer of
the two alloys, is shown in Table 2. While the thickness
of the oxide layer varies by a factor of 2, the difference
in the proportion of the pores and their diameter is prac-
tically negligible.
Table 2: Pore fractions and their diameters, measured on the free sur-
face of the oxide layer on AA5083 and AlMgSc alloys, anodization
time of 25 min, voltage of 18 V, electrolyte 1.72 M H
2
SO
4
, T
el
=21°C
Alloy
Pore fraction
(%)
Pore diameter
(nm)
Oxide layer
thickness (μm)
AA5083 9.31 15 ± 1.7 25
AlMgSc 7.78 15.8 ± 0.9 50
3.2 Galvanostatic anodization
The curves of the voltage change (Figure 5) during
the initial phase of galvanostatic anodization (20 mA/cm
2
)
K. KERN et al.: EFFECT OF A SCANDIUM ADDITION ON ANODIZING AlMg ALLOYS
Materiali in tehnologije / Materials and technology 57 (2023) 2, 155–161 157
Figure 4: Specific distribution of elements (EDS mapping) in the ox-
ide layer formed on the AlMgSc sample. An anodization time of
25 min, voltage of 18 V, electrolyte 1.72 M H
2
SO
4
, T
el.
=21°C
Figure 3: Current density change during anodization of AA5083 and
AlMgSc aluminium alloy: a) initial phase (10 s); b) first (60 s) and
c) steady state phase of anodization (25 min); a voltage of 18 V, elec-
trolyte 1.72 M H
2
SO
4
, T
el.
=21°C

show a similar trend of the oxide layer growth as the
curves of the current density change during poten-
tiostatic anodization. Distinctive voltages U
max
and U
s
are
higher for the AA5083 alloy, indicating a higher resis-
tance of the porous oxide layer on the AA5083 alloy. On
the other hand, the thickness of the oxide layers is practi-
cally the same for both alloys, indicating that the current
density determines the thickening of the oxide layer,
while the voltage is related to the pore diameter and den-
sity (Table 3, Figure 6).
3.3 Electrolyte temperature effect
With an increase in the electrolyte temperature from
21 to 35 °C, the current densities i
min
, i
max
and i
s
increase
significantly (Figure 8), while the barrier layer growth
time and pore formation time shorten for both alloys.
Despite much higher current densities, the thickness of
the oxide layer increases only slightly for alloy AA5083
(from 25 μm to 29 μm), while it decreases by half for al-
loy AlMgSc (from 53 μm to 24 μm). The average pore
diameter increases significantly, while the pore density
decreases for both alloys. In addition, the mechanism of
the oxide growth changes. Most of the free surface of
both alloys is covered with a "bird’s nest" oxide structure
(Figure 7, Table 4).
20
3.4 Anodization in 2.2 M H
2
SO
4
electrolyte at 21 °C
and constant voltage
A comparison of the current density measurements
during potentiostatic anodizing (U =1 8V )i n1 . 7 2M
and 2.2 M H
2
SO
4
electrolytes shows that the maximum
current density i
max
for both alloys increases significantly
in the concentrated electrolyte, while the current density
K. KERN et al.: EFFECT OF A SCANDIUM ADDITION ON ANODIZING AlMg ALLOYS
158 Materiali in tehnologije / Materials and technology 57 (2023) 2, 155–161
Figure 6: Pores (coloured in red) in the oxide layer (free surface):
a) AA5083, b) AlMgSc; an anodization time of 25 min, current den-
sity of 20 mA/cm
2
, electrolyte 1.72 M H
2
SO
4
,T
el.
=21°C
Table 3: Pore fractions and their diameters measured on the free sur-
face of the oxide layer on AA5083 and AlMgSc alloys, an anodization
time of 25 min, current density of 20 mA/cm
2
, electrolyte 1.72 M
H
2
SO
4
, T
el.
=21°C
Alloy
Pore fraction
(%)
Pore diameter
(nm)
Oxide layer
thickness (μm)
AA5083 12.03 18.9 ± 0.4 21.5
AlMgSc 6.03 15.8 ± 1 22
Figure 5: Voltage change during galvanostatic anodization of AA5083
and AlMgSc alloys: a) initial stage, b) after 60 s and c) steady state
phase of anodization (25 min); a current density of 20 mA/cm
2
, elec-
trolyte 1.72 M H
2
SO
4
, T
el.
=21°C

in the stationary phase i
s
increases only for alloy
AlMgSc (Figure 10). The average thickness of the oxide
layer after 25 min of anodization in 2.2 M H
2
SO
4
is
81 μm for AlMgSc and 31 μm for AA5083 (Figure 9).
From the images of the free surfaces of the oxide lay-
ers formed after 25 min, it can be seen that the pore di-
ameter increased with the increasing electrolyte concen-
tration, especially in the case of alloy AlMgSc (Table 5).
Table 5: Pore diameters, density and proportions of the oxide layers
on AA5083 and AlMgSc alloys; an anodization time of 25 min, volt-
age of 18 V, T
el
=21°C
Alloy
El. conc.
H2
SO
4
Pore frac-
tion (%)
Pore diame-
ter (nm)
Oxide layer
thickness
(μm)
AA5083
1.72 M 9.31 15 ± 1.7 25
2.2 M 10.88 17.5 ± 0.2 31
AlMgSc
1.72 M 7.78 15.8 ± 0.9 53
2.2 M 13.92 17.6 ± 1.3 81
K. KERN et al.: EFFECT OF A SCANDIUM ADDITION ON ANODIZING AlMg ALLOYS
Materiali in tehnologije / Materials and technology 57 (2023) 2, 155–161 159
Figure 8: Current density change during potentiostatic anodization of
AA5083 and AlMgSc alloys at 21 °C and 35 °C, 1.72 M H
2
SO
4
elec-
trolyte, a voltage of 18 V
Figure 7: Pores (coloured in red) in the oxide layer (free surface) of
the AA5083 alloy: a) T
el.
= 21 °C, b) T
el.
= 35 °C; and of AlMgSc:
c) T
el.
= 21 °C, d) T
el.
= 35 °C; an anodization time of 25 min, voltage
of 18 V, electrolyte 1.72 M H
2
SO
4
Table 4: Comparison of pore densities, proportions and diameters for
the oxide layers on AA5083 and AlMgSc alloys after anodizing in
electrolyte 1.72 M H
2
SO
4
at 21 °C or 35 °C; an anodization time of
25 min, voltage of 18 V
Alloy
El. temp.
(°C)
Pore frac-
tion (%)
Pore diam-
eter (nm)
Oxide layer
thickness (μm)
AA5083
21 9.31 15 ± 1.7 25
35 27.42 48.4 ± 1.7 29
AlMgSc
21 7.78 15.8 ± 0.9 53
35 8.08 / 24
Figure 9: Pores (coloured in red) measured on the free surface of the
oxide layer after anodization in electrolytes with different concentra-
tions: a) AA5083, 1.72 M H
2
SO
4
, b) AA5083, 2.2 M H
2
SO
4
,
c) AlMgSc, 1.72 M H
2
SO
4
, d) AlMgSc, 2.2 M H
2
SO
4
; an anodization
time of 25 min, voltage of 18 V, T
el.
=21°C

4 DISCUSSION
The electrical parameters of anodization (voltage and
current density) are inherently related to the resistance of
the growing oxide layer. If we maintain one electrical pa-
rameter constant, the value of the other depends on how
the growing oxide adapts (pore density and pore diame-
ter), which in turn depends on the chemical nature (al-
loying elements) as well as the processing history of the
alloy to be anodized (microstructure, intermetallic
phases on the surface). In addition, the value of a mea-
sured electrical parameter also depends on how the re-
sulting oxide reacts with the electrolyte under certain
conditions (type, concentration and temperature of the
electrolyte). Predicting how a particular alloy will be-
have during anodizing is therefore extremely difficult
without trial and error testing. The current density deter-
mines the thickness of the oxide layer, as it indicates
how many metal anions have reacted with the cations of
the electrolyte on one unit of the workpiece surface. The
higher the current density, the faster is the oxide growth.
However, strictly speaking, this is true only if an oxida-
tion reaction occurs at the metal/oxide interface and the
metal anions are not ejected into the electrolyte or the
rate of chemical dissolution of the oxide at the ox-
ide/electrolyte interface does not become a dominant fac-
tor.
Anodizing the same alloy at different constant volt-
ages also affects the thickness of the barrier layer and the
pore diameter of the porous layer (both of which in-
crease with the increasing voltage). The temperature of
the electrolyte has a large effect on the structure of the
oxide layer as well as on the kinetics and mechanism of
the growth itself. The pore diameter increases signifi-
cantly even with a small increase in the temperature of
the electrolyte, which is due to thermally enhanced dis-
solution of the pore interior supported by the electric
field. At a certain temperature of the electrolyte, the
thickening of the oxide layer stops despite a high current
density, which is due to an altered growth mechanism
(ejection of anions into the electrolyte) or faster dissolu-
tion of the oxide at the oxide/electrolyte interface. In-
creasing the sulphuric acid concentration at a given volt-
age increases the oxide thickness due to the increased
concentration of the cations available for the oxidation
reaction and simultaneously increases the dissolution
rate of the pore interior, increasing the pore diameter. At
a certain concentration threshold, dissolution predomi-
nates and the stable oxide growth is interrupted.
Scandium has a lower Gibbs free energy of the oxide
formation per equivalent ( G/n) and a lower ionization
energy than aluminium, and therefore exhibits preferen-
tial oxidation and faster cation mobility in the oxide
layer, resulting in a higher current density during con-
stant-voltage anodization or a lower voltage required to
keep the current density constant during galvanostatic
anodization. Scandium binds uniformly with the alumina
matrix and decreases its resistivity, which in turn in-
creases the growth rate during potentiostatic anodization
or decreases the pore density and pore diameter during
galvanostatic anodization. Scandium also increases the
mobility of cations through the oxide layer, thus acceler-
ating the oxidation reaction in concentrated sulphuric
acid electrolytes. On the other hand, it significantly in-
creases the sensitivity to electrolyte temperature due to
the increased mobility of ions. Even small variations in
electrolyte temperature can have a large effect on the ox-
ide growth.
5 CONCLUSIONS
Alloy AlMg microalloyed with scandium is suitable
for anodizing and requires a shorter anodizing time (at a
constant current density) for the same oxide layer thick-
ness as alloy AA5083, which is generally considered
suitable for anodizing. The only parameter that must be
carefully controlled is the electrolyte temperature, which
must be kept constantly below room temperature. This is
because the incorporation of Sc into the porous oxide
layer increases the mobility of cations through the oxide
layer, which at a certain electrolyte temperature can alter
the growth mechanism by ejecting anions into the elec-
trolyte instead of thickening the oxide layer at the
metal/oxide interface.
6 REFERENCES
1
H. Dong, Surface engineering of light alloys: aluminium, magnesium
and titanium alloys, [s. l.], Woodhead Publishing Limited, 2010, 662
2
A. Eftekhari, Nanostructured Materials in Electrochemistry,
Wiley-VCH, Weinheim 2008, 489
3
J. Hirsch, T. Al-Samman, Superior light metals by texture engineer-
ing: Optimized aluminium and magnesium alloys for automotive ap-
plications, Acta Materialia, 61 (2013), 818–843, doi:10.1016/
j.actamat.2012.10.044
4
W. S. Miller, L. Zhuang, J. Bottema, A. J. Wittebrood, P. De Smet,
A. Haszler, A. Vieregge, Recent development in aluminium alloys
K. KERN et al.: EFFECT OF A SCANDIUM ADDITION ON ANODIZING AlMg ALLOYS
160 Materiali in tehnologije / Materials and technology 57 (2023) 2, 155–161
Figure 10: Current density change during anodization in 1.72 M and
2.2MH
2
SO
4
electrolytes for AA5083 and AlMgSc alloys; a voltage
of 18 V, T
el.
=21°C

for the automotive industry, Materials Science and Engineering,
A280 (2000), 37–49, doi:10.1016/S0921-5093(99)00653-X
5
X. Zhang, Y. Chen, J. Hu, Recent advances in the development of
aerospace materials, Progress in Aerospace Sciences, 97 (2018),
22–34, doi:10.1016/j.paerosci.2018.01.001
6
G. E. Totten, S. D. Mac Kenzie, Handbook of Aluminum: Volume 2:
Alloy Production and Materials Manufacturing, CRC Press, New
York 2003, 736
7
A. Røyset, T. Aukrust, B. Holme, J. E. Lein, O. Lunder, T. Kolås, Vi-
sual Appearance Characteristics of Industrial Aluminium Surfaces,
Materials Today: Proceedings, 2 (2005) 10, Part A, 4882–4889,
doi:10.1016/j.matpr.2015.10.041
8
S. Kawai, Anodizing and coloring of aluminum alloys, University of
Michigan: Finishing Publications, Michigan 2001, 165
9
M. Aggerbeck et al, Appearance of anodised aluminium: Effect of al-
loy composition and prior surface finish, Surface and Coatings Tech-
nology, 24 (2014), 28–41, doi:10.1016/j.surfcoat.2014.05.047
10
I. Tsangaraki Kaplanoglou, Th. Dimogerontakis, Y. M. Wang, H. H.
Kuo, S. Kia, Effect of alloy types on the anodizing process of alu-
minium, Surface & Coting Technology, 200 (2006), 2634–2641,
doi:10.1016/j.surfcoat.2005.07.065
11
X. Zhou, G. E. Thompson, P. Skeldon, G. C. Wood, K. Shimizu, H.
Habazaki, Film formation and detachment during anodizing of
Al-Mg alloys, Corrosion Science, 41 (1999), 1599–1613,
doi:10.1016/S0010-938X(99)00007-4
12
Y. Liu, P. Skeldon, G. E. Thompson, H. Habazaki, K. Shimizu, An-
odic film growth on an Al–21at.%Mg alloy, Corrosion Science, 44
(2002), 1133–1142, doi:10.1016/S0010-938X(01)00115-9
13
A. C. Crosslanda, G. E. Thompsona, C. J. E. Smithb, H. Habazakic,
K. Shimizud, P. Skeldon, Formation of manganese-rich layers during
anodizing of Al-Mn alloys, Corrosion Science, 41 (1999),
2053–2069, doi:10.1016/S0010-938X(99)00025-6
14
A. Smolej, B. Skaza, E. Sla~ek, Superplasticity of the 5083 alumi-
num alloy with the addition of scandium, Materials and Technology,
43 (2009) 6, 299–302
15
K. A. Padmanabhan, R. A. Vasin, F. U. Enikeev, Superplastic flow:
Phenomenology and mechanics, Springer, Berlin 2001
16
V. Luo, C. Miller, G. Luckey, P. Friedman, Y. Peng, On practical
forming limits in superplastic forming on aluminium sheet, Journal
of Materials Engineering and Performance, 16 (2007) 3, 274–238,
doi:10.1007/s11665-007-9048-9
17
A. Smolej, Razvoj sodobnih zlitin aluminija, Kovine, zlitine,
tehnologije, 26 (1992), 172–177, URN:NBN:SI:DOC-EOL4OQV4
18
C. Xu, W. Xiao, S. Hanada, H. Yamagata, C. Ma, The effect of scan-
dium addition on microstructure and mechanical properties of
Al–Si–Mg alloy: A multi-refinement modifier, Materials Character-
ization, 110 (2015), 160–169, doi:10.1016/j.matchar.2015.10.030
19
W. Bensalah, M. Feki, M. Wery, H. F. Ayedi, Chemical dissolution
resistance of anodic oxide layers formed on aluminum, Transactions
of Nonferrous Metals Society of China, 21 (2011) 7, 1673–1679,
doi:10.1016/S1003-6326(11)60913-8
20
J. Ye, Q. Yin, Y. Zhou, Superhydrophilicity of anodic aluminum ox-
ide films: From "honeycomb" to "bird’s nest", Thin Solid Films, 517
(2009), 6012–6015, doi:10.1016/j.tsf.2009.04.042
K. KERN et al.: EFFECT OF A SCANDIUM ADDITION ON ANODIZING AlMg ALLOYS
Materiali in tehnologije / Materials and technology 57 (2023) 2, 155–161 161