The Influence of Ti and Al on the Evolution of Microstructure and Mechanical Properties in Medium-Entropy and High-Entropy Alloys Based on AlxTixCrFe2Ni2
Materials,
Journal Year:
2025,
Volume and Issue:
18(6), P. 1382 - 1382
Published: March 20, 2025
This
study
focuses
on
the
cobalt-free
medium-to-high-entropy
alloys
AlxCrFe2Ni2
and
AlxTixCrFe2Ni2,
investigating
influence
of
Alx
Tix
(where
x
=
0.2,
0.3,
0.4,
0.5,
0.6)
development
microstructural
mechanical
properties
in
as-cast
annealed
states.
Structural
changes
were
examined
using
optical
microscopy,
scanning
electron
microscopy
(SEM),
X-ray
diffraction
(XRD)
measurements,
while
evaluated
through
Vickers
hardness
testing
compression
testing.
analysis
confirmed
that
increasing
Al
content
state
leads
to
formation
a
BCC
phase,
which
completely
dissolves
into
FCC
matrix
after
homogenization
annealing.
These
single-phase
exhibit
good
ductility
with
relatively
high
strain
hardening,
such
as
Al0.6CrFe2Ni2
alloy,
achieved
maximum
compressive
strength
σmax=1511
MPa
at
50%
deformation.
A
significant
strengthening
effect
Ti
was
observed
AlxTixCrFe2Ni2
alloys,
are
closely
linked
higher
phase
homogenized
structure.
The
highest
strength,
σmax=2239
MPa,
by
Al0.5Ti0.5CrFe2Ni2
fractured
via
transcrystalline
brittle
fracture
43%
All
investigated
offer
an
excellent
balance
between
ductility,
could
meet
requirements
demanding
structural
applications.
Language: Английский
Hydrogen Embrittlement Resistance of Ferritic–Pearlitic Pipeline Steel with Non-Electrochemically Deposited Copper- or Nickel–Phosphorus-Based Coating
Coatings,
Journal Year:
2025,
Volume and Issue:
15(5), P. 585 - 585
Published: May 15, 2025
This
work
deals
with
the
effects
of
a
non-electrochemically
deposited
copper-
or
nickel–phosphorus-based
coating
on
resulting
resistance
traditional
X42
grade
pipeline
steel
against
hydrogen
embrittlement
(HE).
The
susceptibility
to
HE
was
determined
by
evaluation
index
(HEI)
from
results
conventional
room-temperature
tensile
tests
using
cylindrical
specimens.
Altogether,
three
individual
material
systems
were
studied,
namely
uncoated
(X42)
and
two
coated
steels,
specifically
either
copper-based
(X42_Cu)
(X42_Ni-P).
HEI
values
calculated
as
relative
changes
in
mechanical
properties
corresponding
non-hydrogenated
electrochemically
hydrogen-precharged
test
conditions.
Both
applied
coatings
considerably
improved
investigated
terms
decreasing
related
yield
stress,
ultimate
strength,
reduction
area.
In
contrast,
hydrogenation
both
had
detrimental
value
total
elongation,
which
resulted
an
increase
value.
behavior
likely
earlier
onset
necking
during
straining
due
strain
localizations
induced
coatings’
surface
imperfections.
findings
fractographic
observations
indicated
that
studied
acted
like
protective
barriers
permeation.
However,
quality
pores
other
superficial
defects
considered
remains
challenging
issue.
Language: Английский