Effect of Solutionising And Ageing On Hardness Of Al2024-Beryl Particulate Composite
Effect of Solutionising And Ageing On
Hardness Of Al2024-Beryl Particulate Composite
Bhaskar H. B.*1 and Abdul Sharief2
Research scholar, Department of Mechanical Engineering,
Sri Siddhartha Institute of Technology, Maralur Post,
Tumkur - 572105. Karnataka, India,
1
Department of Mechanical Engineering,
P.A. College of Engineering,
Mangalore -574153, Karnataka, India.
2
Email: [email protected]
ABSTRACT
In the present investigation, Al2024–Beryl particulate composites were
fabricated by liquid metallurgy route by varying the weight percentage of
beryl particulates from 0 wt% to 10 wt% in steps of 2 wt%. The cast matrix
alloy and its composites have been subjected to solutionizing treatment at
a temperature of 495°C for 2 hrs followed by quenching in different media
such as air, water and ice. The quenched samples are then subjected to both
natural and artificial ageing. Microstructural studies have been carried out
to understand the nature of structure. The density values obtained using
rule of mixtures and the experimental values obtained for Al2024 alloy and
its composites were compared. The Brinell hardness test was conducted on
both matrix Al2024 and Al2024–Beryl particulate composites before and
after heat treatment. The density of the composite material decreases as the
reinforcement content increases in the matrix material. However, under
identical heat treatment conditions Al2024–Beryl particulate composites
exhibited better hardness when compared with Al2024 matrix alloy.
KEYWORDS: AMMC’s, Solutionizing, Artificial Ageing, Density,
BHN.
1.0INTRODUCTION
Aluminium and aluminium alloys are widely used in automobile,
aerospace and mineral processing applications, because of their excellent
properties like low density and high thermal conductivity. To increase
the mechanical and tribological properties, hard reinforcement phase
such as hard ceramic particulates, fibers or whiskers are uniformly
ISSN: 2180-1053
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81
Journal of Mechanical Engineering and Technology
distributed in the soft matrix phase. As a result of reinforcement phase,
the modulus and strength of the composites were increased while the
ductility of the matrix material was decreased [N. R. Prabhu Swamy
et.al., 2010]. Metal matrix composites (MMCs) are gaining wide spread
popularity in several technological fields owing to its improved
mechanical properties when compared with conventional alloys
[Surappa M. K, 2003]. Among the several categories of MMCs, Al based
composites are finding wide spread acceptance especially in applications
where weight and strength are of prime concern. Presently, Al alloy
based metal matrix composites are being used as candidate materials
in several applications such as pistons, pushrods, cylinder liners and
brake dics etc. [Hoskings F.M, et.al., 1982]. In recent years, aluminium
alloys are gaining much popularity as a matrix material to prepare
MMCs owing to its excellent mechanical properties and good corrosion
resistance [Pramila Bai B.N et.al., 1992 and Ramesh C. S et.al., 2005]. In
addition, Al2024 & Al6061 alloy is heat treatable and as a result further
increase in strength can be expected [Appendino P et.al., 1991]. The
density of the Al2O3/ SiC particle reinforced Al6061 and other aluminum
alloys enhance the density of the base alloy when they are added to
the base alloy to form the composite. Moreover, the theoretical density
values match with the measured density values of these composites
[M.R. Rosenberger et.al., 2005, L.J. Yang, 2003, A.R. Riahi et.al., 2001,
Szu Ying Yu et.al., 1997, S.Wilson et.al., 1996, A.B.Gurcan et.al., 1995
and C.garcia Cordovilla et.al., 1996]. Further, Miyajima et.al., [2003]
reported that the density of Al2024-SiC particle composites is greater
than that of Al2024-SiC whisker reinforced composites for the same
amount of volume fraction. The increase in density can be reasoned to
the fact that the ceramic particles possess higher density. The particulate
reinforcements such as SiC, Al2O3 and aluminide [F.M. Husking et.al.,
1982 and Debdas Roy et.al., 2005] are generally preferred to impart
higher hardness. J.M. Wu et.al., [2000] and Deuis et.al., [1996] attributed
this increase in hardness to the decreased particle size and increased
specific surface of the reinforcement for a given volume fraction. The
aluminium based composites exhibit excellent heat and wear resistance
due to the superior hardness and heat resistance characteristics of the
particles that are dispersed in the matrix [Mortensen A et al., Alpas A.T
et.al., 1992, Kulkarni M.D et.al., 1996, Kim C.K et.al., 1984 and Dermirci
A.H et.al., 1988]. C. Subramanian [1992] incorporated Silicon in Alalloys and concluded that the higher wt.% of Si improves the hardness
of the composites increased particle size improves the load carrying
capability of the composites [M. Chen et.al., 2007]. The heat-treated
alloy and composite exhibits better hardness [S. Sawla et.al., 2004,
W.Q. Song et.al., 1995 and S. Das et.al., 2008], however, the over-aged
condition may tend to reduce the hardness significantly [Wang A et.al.,
82
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January-June 2012
L.J. Yang, 2003, A.R. Riahi et al., 2001, Szu Ying Yu et al., 1997, S.Wilson et al., 1996,
A.B.Gurcan et al., 1995 and C.garcia Cordovilla et al., 1996]. Further, Miyajima et al., [2003]
reported that the density
Al2024-SiC
than Particulate
that of Al2024-SiC
Effect ofofSolutionising
Andparticle
Ageing composites
On Hardness is
Of greater
Al2024-Beryl
Composite
whisker reinforced composites for the same amount of volume fraction. The increase in density can
be reasoned to the fact that the ceramic particles possess higher density. The particulate
reinforcements
suchheat-treated
as SiC, Al2O3 and
aluminide
Husking etshowed
al., 1982 and
Debdas
Roy et al.,
1991]. The
alloy
and [F.M.
composite
better
strength
2005] are generally preferred to impart higher hardness. J.M. Wu et al., [2000] and Deuis et al.,
andattributed
hardness
resulted
in fewer
for crack
nucleation
and
[1996]
this that
increase
in hardness
to theproperties
decreased particle
size and
increased specific
showed
enhancement
wear
resistance
[S.aluminium
Sawla et.al.,
In exhibit
the
surface
of the reinforcement
for a in
given
volume
fraction. The
based 2004].
composites
excellent
heat work,
and wearthe
resistance
duealloy
to the&
superior
hardness and
heat resistance
characteristics of
present
Al2024
Al2024/Beryl
metal
matrix composites
the particles that are dispersed in the matrix [Mortensen A et al., Alpas A.T et al., 1992, Kulkarni
were fabricated by liquid metallurgy route by varying reinforcement
M.D et al., 1996, Kim C.K et al., 1984 and Dermirci A.H et al., 1988]. C. Subramanian [1992]
from 0 wt.%
10 wt.%and
in concluded
steps of that
2. The
effectwt.%
of quenching
andof
incorporated
Silicon to
in Al-alloys
the higher
of Si improvesmedia
the hardness
the the
composites
increased
particle
the of
load
carryingalloy
capability
thecomposites
composites [M.
ageing
duration
on size
theimproves
hardness
Al2024
andofits
Chen
et al.,characterized.
2007]. The heat-treated alloy and composite exhibits better hardness [S. Sawla et al.,
were
2004, W.Q. Song et al., 1995 and S. Das et al., 2008], however, the over-aged condition may tend
to reduce the hardness significantly [Wang A et al., 1991]. The heat-treated alloy and composite
showed better strength and hardness that resulted in fewer properties for crack nucleation and
showed
in wear resistance [S. Sawla et al., 2004]. In the present work, the Al2024
2.0 enhancement
MATERIALS
alloy & Al2024/Beryl metal matrix composites were fabricated by liquid metallurgy route by
varying
fromselected
0 wt.% to 10
steps of 2. The effect
of quenching media
and the
Thereinforcement
matrix alloy
forwt.%
theindevelopment
of composite
material
ageing
duration on thealloy
hardness
of Al2024
alloy and by
its composites
were characterized.
is Al-Cu-Mg
and
designated
the aluminium
association as
Al2024-T6. The chemical composition of the matrix material is given
1. Beryl, which is naturally occurring and chemically
having beryllium–alumina–silicate [Be3Al2(SiO3)6] was used as the
The matrix alloy selected for the development of composite material is Al-Cu-Mg alloy and
reinforcement material. The sizes of particles used were of 45-65 μm.
designated by the aluminium association as Al2024-T6. The chemical composition of the matrix
Theyis have
of chemically
7.5 to 8.5having
on
material
given aindensity
the table of
1. 2760
Beryl, kg/m3,
which is having
naturally hardness
occurring and
beryllium–alumina–silicate
Al2(SiO
as the reinforcement
The sizes of
Mho’s scale and [Be
it 3has
hexagonal
structure.material.
The chemical
3)6] was usedcrystal
particles
used were ofof45-65
μm.particles
They have used
a density
2760 kg/m3, having
of 7.5 to 8.5
composition
beryl
forof development
of hardness
the composite
on Mho’s scale and it has hexagonal crystal structure. The chemical composition of beryl particles
mentioned
thecomposite
table 2.is mentioned in the table 2.
usedisfor
development in
of the
the table
2.0 in
MATERIALS
TABLE
TABLE 1
1
Compositionof
of Al
Al 2024-T6
(wt.
%) %)
Composition
2024-T6alloy
alloy
(wt.
Al
Cu
Fe
91.9 4.63 0.35
Mg
1.4
Mn
0.6
Si
Ti
Ni
0.41 0.05 0.01
Zn
0.2
Cr
Pb
Sn
0.38 0.04 0.03
TABLE
TABLE 22
Compositionof
of Reinforcement
Reinforcement material
Composition
material(wt.
(wt.%)%)
SiO2
Al2O3
BeO
Fe2O3 CaO MgO
68.01 16.74 12.01
1.91
0.86
0.08
2
3.0 PREPARATION OF THE COMPOSITES
3.0 PREPARATION OF THE COMPOSITES
The Aluminium
2024-T6 / Beryl
metal matrix
composites
were fabricated
by liquidwere
metallurgy
The Aluminium
2024-T6
/ Beryl
metal matrix
composites
route with varying weight percentage of reinforcement particles from 0 wt% to 10 wt% in steps of
fabricated by liquid metallurgy route with varying weight percentage
2. This method is the most economical to fabricate composites materials. The matrix material was
of reinforcement
particles
from 0 wt%
to 10 wt%
steps of were
2. This
first superheated
to above its melting
temperature
and preheated
berylin
particulates
added into
method
is
the
most
economical
to
fabricate
composites
materials.
molten metal. The molten metal was stirred for duration of 8 min using a mechanicalThe
stirrer and
material
was first
to above
its melting
temperature
speed of matrix
the stirrer
was maintained
at superheated
300 rpm. The melt
at 750°C
was poured
into the pre-heated
cast iron and
molds.
The castings
wereparticulates
tested to knowwere
the common
defects using
ultrasonic
preheated
beryl
addedcasting
into molten
metal.
The flaw
detector. molten
The cast metal
composites
the base
alloyof
were
subjected
to a
solutionizing
treatment
wasand
stirred
forAl2024
duration
8 min
using
mechanical
at a temperature
of
495°C
for
a
duration
of
2
hrs
and
then
quenched
in
three
different
quenching
stirrer and speed of the stirrer was maintained at 300 rpm. The melt
media viz. air, water and ice. Artificial ageing was carried out at 199°C for duration of 4–12 hrs in
steps of 2 hrs.
ISSN: 2180-1053
4.0 TESTING OF COMPOSITES
Vol. 4
No. 1
January-June 2012
83
TION OF THE COMPOSITES
Journal of Mechanical Engineering and Technology
3.0 PREPARATION
THE
COMPOSITES
2024-T6
/ Beryl metal OF
matrix
composites
were fabricated by liquid metallurgy
ng weight percentage of reinforcement particles from 0 wt% to 10 wt% in steps of
Aluminium
2024-T6
/ Beryl
metal
composites
fabricated
by The
liquidcastings
metallurgy
sThe
the most
economical
towas
fabricate
composites
The were
matrix
material
was
at 750°C
poured
intomatrix
thematerials.
pre-heated
cast
iron
molds.
route
withitsvarying
weight
percentage
of
reinforcement
particles
from
0
wt%
to
10
wt%
steps of
to
above
melting
temperature
and
preheated
beryl
particulates
were
added
into
were tested to know the common casting defects using ultrasonicinflaw
This method
thestirred
most economical
composites
materials.
Theand
matrix material was
he2. molten
metal is
was
for durationtooffabricate
8 min using
a mechanical
stirrer
detector. Theitscast
composites
and the
base Al2024
alloy were subjected
first
superheated
temperature
beryl
er
was
maintainedtoatabove
300 rpm.melting
The melt
at 750°C and
was preheated
poured into
the particulates
pre-heated were added into
to
solutionizing
treatment
at
a
temperature
of
495°C
a duration
molten
metal.
Thetested
molten
metalthe
wascommon
stirred casting
for duration
of using
8 minultrasonic
using a for
mechanical
stirrerofand
The
castings
were
to know
defects
flaw
2
hrs
and
then
quenched
in
three
different
quenching
media
viz.
air,
of the and
stirrer
maintained
at 300
rpm.
The melt
750°C was treatment
poured into the pre-heated
stspeed
composites
thewas
base
Al2024 alloy
were
subjected
to at
solutionizing
ice.
Artificial
ageing
carried
out at defects
199°C
for duration
cast495°C
iron molds.
Theand
castings
tested
toquenched
knowwas
the in
common
casting
using
ultrasonicofflaw
of
forwater
a duration
of
2 were
hrs
and
then
three different
quenching
detector.
TheArtificial
cast composites
and
the
base
alloy
subjected
to hrs
solutionizing
treatment
ater
and ice.
was
outAl2024
at 199°C
forwere
duration
of 4–12
in
4–12
hrsageing
in steps
ofcarried
2 hrs.
at a temperature of 495°C for a duration of 2 hrs and then quenched in three different quenching
media viz. air, water and ice. Artificial ageing was carried out at 199°C for duration of 4–12 hrs in
steps of 2 hrs.
4.0 TESTING OF COMPOSITES
OF COMPOSITES
The metallographic, density and hardness tests were carried out on
4.0 density
TESTING
OFunheat
COMPOSITES
hic,
and
hardness
tests
were and
carried
outtreated
on both samples
unheat treated
and
heat standards.
both
treated
heat
as per
ASTM
as per ASTM
standards.
Density
is theproperty
physical that
property
that reflects
the
Density
is the
physical
reflects
the characteristics
of
The
metallographic,
density
and
hardness
tests
were
carried
out
on
both
unheat
treated
and
composites.
The
machined
and
polished
composite
specimens
(10
mm
diameter
composites. The machined and polished composite specimens (10 mmheat
treated
as for
per density
ASTM measurement
standards. Density
is Archimedian
the physical method
propertyat that reflects the
ght)
weresamples
considered
using considered
the
diameter
and 10 mm
height) were
for density measurement
composites.
The machined
and kept
polished
composite
specimens
recharacteristics
28 °C. The of
beaker
with water
was initially
on the
electronic
balance(10 mm diameter
using
the
Archimedian
at
room
temperature
28°C.
The beaker
and
height)
were
formethod
density
measurement
the Archimedian
method at
mg) 10
setmm
to read
zero.
Theconsidered
initially weighed
specimen
(say W1using
mg) was
freely
with
water
was
initially
kept
on
the
electronic
balance
(accuracy
ofbalance
0.1
room
temperature
28
°C.
The
beaker
with
water
was
initially
kept
on
the
electronic
ully immersed in the beaker. The final weight (W2 mg) shown by the balance
mg)
set water
to
zero.
The
weighed
specimen
(say
mg)
was
(accuracy
0.1 mg)
setread
tois read
zero.
The
weighed
specimenThe
(say
WW1
mg)
was
freely
lume
of theofdisplaced
equivalent
toinitially
theinitially
volume
of the specimen.
ratio
1
freely
in al.,
the2001
beaker.
The
final
weight
mg)
shown
by
the
balance
suspendedtheand
fullysuspended
immersed
inand
the fully
beaker.
The final weight
(W
epresents
density
of the specimen.
[M.D.immersed
Bermudez
et
amd
S.C.
2
represents the(W2
volume
the displaced
is equivalent
to thethe
volume
of the
The ratio
mg)ofshown
by thewater
balance
represents
volume
ofspecimen.
the displaced
of W1 to W2
represents
the
density
of
the
specimen.
[M.D.
Bermudez
et
al.,
2001
amd
water is equivalent to the volume of the specimen. The ratio of W1 toS.C.
Sharma, 2003]
W2 represents the density of the specimen. [M.D. Bermudez et.al., 2001
amd S.C./ Volume
Sharma,
= Mass of the specimen
of 2003]
the displaced water …………..[1]
ρc = Mass of the specimen / Volume of the displaced water …………..[1]
ensity values were determined by rule of mixture [B.K. Prasad, 2007] as shown in
(1)
The
theoretical
density
values
rule2007]
of mixture
The theoretical
density
values were
determined
by were
rule of determined
mixture [B.K. by
Prasad,
as shown in
equation [2]. [B.K. Prasad, 2007] as shown in equation [2].
ρc = (ρr Vr + ρm Vm) …………….. [2]
(2)
Where,
ρc = (ρr Vr + ρm Vm) …………….. [2]
Vr is the volume fraction of reinforcement in cc
Vm is the volume fraction of matrix in cc
ρc is the density of the composite in g/cc
ρr is the density of the composite in g/cc
ρm is the3 density of the matrix in g/cc
(m stands for matrix and r for reinforcement material)
3
The Brinell hardness tests were carried out as per ASTM-E10-93
standard. The hardness test conducted as per HB 500 and tester which
have a ball indenter of 10 mm diameter. The tests were conducted
84
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January-June 2012
is the volume
fraction
in cc
Where,
EffectVofr Solutionising
And
Ageingof
Onreinforcement
Hardness Of Al2024-Beryl
Particulate Composite
Vm is the volume fraction of matrix in cc
ρc is the density of the composite in g/cc
ρr is the density of the composite in g/cc
on five locations
the
sample
counter
ρm on
is the
density
of theto
matrix
in g/cc the possibility of indenter
resting on hard(m
particle,
may
in anomalous
stands forwhich
matrix and
r forresult
reinforcement
material) value.
The Brinell hardness tests were carried out as per ASTM-E10-93 standard. The hardness test
conducted as per HB 500 and tester which have a ball indenter of 10 mm diameter. The tests were
5.0 RESULTS
ANDonDISCUSSIONS
conducted
on five locations
the sample to counter the possibility of indenter resting on hard
particle, which may result in anomalous value.
5.1 Microstructure analysis
samples
the microscopic
5.0The
RESULTS
ANDfor
DISCUSSIONS
examination were prepared by
standard metallographic procedures etched with killer’s agent
5.1and
Microstructure
examinedanalysis
under optical microscope. The optical micrograph
of
Al2024
alloy,
Al2024/4wt.% and Al2024/6wt.% beryl particulate
The samples for the microscopic examination were prepared by standard metallographic procedures
composites
Theunder
micrographs
clearly
indicate
the of
etched
with killer’srespectively.
agent and examined
optical microscope.
The optical
micrograph
Al2024
alloy, of
Al2024/4wt.%
and Al2024/6wt.%
particulate
composites
respectively. The
evidence
minimal porosity
in both beryl
Al2024
alloy and
its Al2024/Beryl
micrographs
clearly
indicate the evidence
of minimal
porosity
in both distribution
Al2024 alloy and
composites.
Micrograph
indicates
the nearly
uniform
of its
Al2024/Beryl composites. Micrograph indicates the nearly uniform distribution of the
the reinforcement
particles
in the composite.
reinforcement
particles in the
composite.
FIGURE
of Al2024
alloy,alloy,
Al2024/4
wt.% and
Al2024/6
wt.% beryl
FIGURE11Micrograph
Micrograph
of Al2024
Al2024/4
wt.%
and Al2024/6
composites.
wt.% beryl
composites.
5.25.2Density
Density
The
theoretical
densitydensity
was determined
by the rule of mixture
the of
experimental
values
The
theoretical
was determined
by theand
rule
mixture density
and the
were obtained by Archimedes principle for both as-cast and its composites. The figure 2 shows the
experimental
density
wereonobtained
principle
effect
of weight percentage
of values
reinforcement
theoreticalby
andArchimedes
experimental densities.
The for
density
as-castmaterial
and itsdecreases
composites.
The figurecontent
2 shows
theineffect
of weight
ofboth
the composite
as the reinforcement
increases
the matrix
material [7,
8].percentage
From the figure
it can be seen that on
experimental
and theoretical
density valuesdensities.
are in line with
of2,reinforcement
theoretical
and experimental
each
other
and confirms
thecomposite
stability of thematerial
liquid metallurgy
technique
for successful
development
The
density
of the
decreases
as the
reinforcement
of the composite material.
content increases in the matrix material [7, 8]. From the figure 2, it can
be seen that experimental and theoretical density values are in line with
each other and confirms the stability of the liquid metallurgy technique
for successful development of the composite material.
4
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January-June 2012
85
Journal of Mechanical Engineering and Technology
Theoretical
Experimental
Theoretical
Experimental
2.79
2.78
Density g/cc
2.76
2.79
Density g/cc
2.77
2.73
2.76
2.75
2.78
2.74
2.77
2.72
2.75
2.74
0%
2%
4%
6%
Wt.% of Reinforcement
8%
10%
FIGURE 2 2.73
Effect of reinforcement
on 2theoretical and experimental
FIGURE
2.72
density
Effect of reinforcement on theoretical and experimental density
0%
2%
5.3 Hardness
5.3 Hardness
4%
6%
Wt.% of Reinforcement
8%
10%
Brinell Hardness
Brinell
(HB Hardness
500)
(HB 500)
FIGURE 2
Hardness
is asdescribed
resistance
to ofsurface
indentation
Hardness
is described
resistance
toas
surface
indentation
the material.
The
variationofof the
hardness
Effect
of
reinforcement
on theoretical
and experimental
density
of matrix
and its composite
materials of
are shown
in the of
Figure
3. Thisand
graphits
explains
the effect of
material.
The variation
hardness
matrix
composite
particulate
reinforcement
on the Brinell
hardness
of the Al2024/10wt.%
materials
are shown
in thehardness
Figure(HB
3. 500).
ThisThe
graph
explains
the effect of
5.3
berylHardness
composite
increased
by
around
37%
as
compared
to
Al2024
matrix
alloy.
It
is observed
of particulate reinforcement on the Brinell hardness (HB 500).
The that
with increased content of beryl in the matrix alloy, there was a significant improvement in the
Hardness
is described
as resistance
to surface
indentation
of theofmaterial.
The variation
of
hardness
of the
Al2024/10wt.%
of
beryl
increased
by [1,
around
hardness
of
the composites.
This trend
is similar
to thecomposite
result
other
researchers
17,hardness
19-29].
of
matrix
and
its
composite
materials
are
shown
in
the
Figure
3.
This
graph
explains
the
effect
of
37%
as
compared
to
Al2024
matrix
alloy.
It
is
observed
that
with
This increase in hardness is expected since beryl particulates being very hard ceramic
material
particulate
reinforcement
on
the
Brinell
hardness
(HB
500).
The
hardness
of
the
Al2024/10wt.%
whichincreased
contributes positively
hardness
of thematrix
composite.
content toofthe
beryl
in the
alloy, there was a significant of
beryl composite increased by around 37% as compared to Al2024 matrix alloy. It is observed that
improvement
of the
composites.
trendimprovement
is similar toin the
with increased
content in
of the
berylhardness
in the matrix
alloy,
there was aThis
significant
the
result
of
other
researchers
[1,
17,
19-29].
This
increase
in
AS
C
ast
Without
heat treatment
hardness of the composites. This trend
is similar
to the result of other researchershardness
[1, 17, 19-29].
100
This increase
in hardness
expected
since beryl being
particulates
hard ceramic
material
is expected
sinceisberyl
particulates
verybeing
hardvery
ceramic
material
whichwhich
contributes
positively
to
the hardnesstoofthe
the hardness
composite. of the composite.
contributes
positively
90
80
AS C ast
Without heat treatment
70
100
60
90
50
80
40
70
30
60
0%
2%
50
4%
6%
8%
10%
Wt%. of Reinforcement
40
FIGURE 3
Variation of 30
Brinell hardness of Al2024/beryl composites with increase of beryl
0%
2%
4% heat 6%
10%
content
before
treatment8%
Wt%. of Reinforcement
FIGURE 3 Variation of BrinellFIGURE
hardness3of Al2024/beryl composites
Variationwith
of Brinell
hardness
of
Al2024/beryl
composites
with increase of beryl
increase of beryl content before
heat treatment
content before heat treatment
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Effect of Solutionising And Ageing On Hardness Of Al2024-Beryl Particulate Composite
Al2024+0%Be
Al2024+0%Beryl
ryl
Al2024+4%Be
Al2024+4%Beryl
ryl
Al2024+8%Be
Al2024+8%Beryl
ryl
Brinell hardness
hardness (HB
(HB 500)
500)
Brinell
110
110
Al2024+2%Be
Al2024+2%Beryl
ryl
Al2024+6%Be
Al2024+6%Beryl
ryl
Al2024+10%Be
Al2024+10%Beryl
ryl
100
100
90
90
80
80
70
70
o
Solutionizing
Solutionizingtemp.:
temp.:495
495 oCC
Quenching
Quenchingmedia:
media:Air
Air
o
Ageing
temp.:199 oCC
Ageingtemp.:199
60
60
50
50
aal l
ur r
aat tu
/r rN/ N
H
00 H
rss
Hr
44 H
rss
Hr
66 H
rss
Hr
88 H
ss
HHr r
1122
ss
HHr r
1100
Ageing
Ageingtime
timein
inhrs.
hrs.
FIGURE
FIGURE44with increase in ageing time
FIGURE 4 Variation of Brinell hardness
Variation
of
Brinell
hardness
increase
time
for
and
Al2024/beryl
Variation
ofand
Brinell
hardnesswith
withcomposites
increasein
inageing
ageing
time
forAl2024
Al2024and
anddifferent
Al2024/beryl
for
Al2024
Al2024/beryl
for air
quenched
composites
quenched
and
hear
compositesfor
forair
air
quenched
anddifferent
different
heartreatment
treatmentcondition
condition
hear
treatment
condition
Al2024+0%Be
Al2024+0%Beryl
ryl
Al2024+4%Be
Al2024+4%Beryl
ryl
Al2024+8%Be
Al2024+8%Beryl
ryl
Brinell Hardness
Hardness (HB
(HB 500)
500)
Brinell
110
110
Al2024+2%Be
Al2024+2%Beryl
ryl
Al2024+6%Be
Al2024+6%Beryl
ryl
Al2024+10%Beryl
Al2024+10%Beryl
100
100
90
90
80
80
70
70
o
Solutionizing
Solutionizingtemp.:
temp.:495
495 oCC
Quenching
Quenchingmedia:
media:Water
Water
o
Ageing
Ageingtemp.:199
temp.:199 oCC
60
60
HHrrs
s
1122
1100H
H rs
rs
88 H
H rs
rs
66 H
H rs
rs
44 H
H rs
rs
00 H
H r/
r/ NN
aattu
urra
all
50
50
Ageing
Ageingtime
timein
inhrs.
hrs.
FIGURE
55 increase in ageing time for
FIGURE
FIGURE 5 Variation of Brinell hardness
with
Variation
of
Brinell
hardness
with
increase
in
ageing
time
for
and
Al2024/beryl
Variation
of
Brinell
hardness
with
increase
in
ageing
time
forAl2024
Al2024
anddifferent
Al2024/beryl
Al2024 and Al2024/beryl composites for water
quenched
and
composites
quenched
and
different
hear
treatment
condition
compositesfor
forwater
water
quenched
and
different
hear
treatment
condition
hear treatment condition
The
variation
hardness
under
treatment
conditions
are
in
Thevariation
variation of
of Brinell
Brinell
hardness
under heat
heatunder
treatment
conditions
are shown
shown
in figure
figure 4-6.
4-6. Heat
Heat
The
of
Brinell
hardness
heat
treatment
conditions
treatment
has
aa significant
influence
on
the
the
alloy
as
treatment
hasin
significant
influence
on treatment
the hardness
hardness of
of
the matrix
alloy as
as well
well
as its
its composites.
composites.
are
shown
figure 4-6.
Heat
has
amatrix
significant
influence
For
For aa solutionizing
solutionizing temperature
temperature of
of 495°C,
495°C, solutionizing
solutionizing duration
duration of
of 22 hrs,
hrs, ageing
ageing temperature
temperature of
of
on199°C,
the hardness
of the
alloy significantly
as
well asalters
its composites.
athe matrix
quenching
and
ageing
the
both
199°C,
quenching media
media
andmatrix
ageing duration
duration
significantly
alters
the hardness
hardness of
of For
both the
matrix
solutionizing
temperature
of 495°C,
solutionizing
duration
of
2 hrs,
alloy
The
hardness
was
both
alloy
alloy and
and its
its composites.
composites.
The maximum
maximum
hardness
was observed
observed for
for
both the
the matrix
matrix
alloy and
and the
the
composites
for
of
when
was
water,
composites
for ageing
ageing duration
duration
of 88 hrs
hrs
when the
the quenching
quenching
mediaageing
was ice
ice and
and
water, while
while the
the
ageing
temperature
of 199°C,
quenching
media media
and
duration
maximum
hardness
for
the
matrix
alloy
and
its
composites
was
achieved
only
after
10
hrs
of
ageing
maximum
hardness
for
the
matrix
alloy
and
its
composites
was
achieved
only
after
10
hrs
of
ageing
significantly alters the hardness of both the matrix alloy and its
on
onair
airquenching.
quenching.
composites. The maximum hardness was observed for both the
matrix alloy and the composites for ageing duration of 8 hrs when the
quenching media was ice and water, while the maximum hardness for
the matrix alloy and its composites was achieved only after 10 hrs of
ageing on air quenching.
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Journal of Mechanical Engineering and Technology
Al2024+0%Be ryl
Al2024+4%Be ryl
Al2024+8%Be ryl
110
100
90
80
rs
10
H
8
rs
H
6
rs
H
4
0
H
r/ N
at
ur
a
l
50
12
60
Hr
s
Solutionizing temp.: 495 oC
Quenching media: Ice
Ageing temp.:199 oC
70
Hr
s
Brinell Hardness (HB 500)
120
Al2024+2%Be ryl
Al2024+6%Be ryl
Al2024+10%Be ryl
Ageing tim e in hrs.
FIGUREwith
6 increase in ageing time
FIGURE 6 Variation of Brinell hardness
Variation
of and
Brinell
hardness withcomposites
increase in ageing
for Al2024
Al2024/beryl
for Al2024
Al2024/beryl
for icetime
quenched
andand
different
composites for ice
quenched
and different
hear treatment condition
hear
treatment
condition
In
quenching
media and
underand
all ageing
exhibits
higher hardness when
Inallallthethe
quenching
media
undertimes
all composites
ageing times
composites
compared
the matrix
alloy. when
After solutionized
with
ice quenching
andalloy.
aged for
a duration of 8
exhibits with
higher
hardness
compared
with
the matrix
After
hrs at a temperature of 199°C results in obtaining maximum hardness of the matrix alloy and its
solutionized with ice quenching and aged for a duration of 8 hrs at a
composites. Ice quenching and ageing for 8 hrs, the matrix Al2024 alloy exhibited a maximum
temperature
of 199°C
in obtaining
maximum
of theexhibited a
improvement
in hardness
of results
around 49%,
while Al2024–10
wt.% ofhardness
Beryl composites
matrix alloy
and its in
composites.
Ice quenching
andquenching
ageing for
hrs, the
maximum
improvement
hardness of around
32%. On water
and8ageing
for 8 hrs, the
matrix
alloy
exhibited
a maximum
improvement
of hardnessinofhardness
around 43%, while
matrixAl2024
Al2024
alloy
exhibited
a maximum
improvement
Al2024–10wt.%
of beryl
composites
exhibited
maximum
improvement in
hardness of around
of around 49%,
while
Al2024–10
wt.%a of
Beryl composites
exhibited
21%. On air quenching and ageing for 10 hrs, the matrix Al2024 alloy exhibited a maximum
a maximum improvement in hardness of around 32%. On water
improvement in hardness of around 36%, while Al2024–10 wt.% of beryl composites exhibited a
quenching
and ageing
for 8ofhrs,
the19%.
matrix Al2024 alloy exhibited a
maximum
improvement
in hardness
around
maximum improvement of hardness of around 43%, while Al2024–
10wt.% of beryl composites exhibited a maximum improvement in
6.0
CONCLUSIONS
hardness
of around 21%. On air quenching and ageing for 10 hrs, the
matrix Al2024 alloy exhibited a maximum improvement in hardness
Based on the results of this study, the following conclusions are arrived.
of around
36%, while Al2024–10 wt.% of beryl composites exhibited a
•
The Aluminium
2024-T6
/ Beryl particulate
reinforced
maximum
improvement
in hardness
of around
19%. composites were successfully
developed using liquid metallurgy route. (stir casting technique)
The microstructural study clearly reveals the nearly uniform distribution of reinforcement
particulates in the Al 2024 matrix alloy.
The density of the composite material decreases as the reinforcement content increases in
6.0• CONCLUSIONS
the matrix material and confirms the stability of the liquid metallurgy technique for
Basedsuccessful
on the results
of this
the following
development
of study,
the composite
material. conclusions are arrived.
•
The Brinell hardness of the composites increased significantly with increased content of
Beryl
treatment has
a significant
effect
on Brinellreinforced
hardness of Al2024 matrix
• particles.
TheHeat
Aluminium
2024-T6
/ Beryl
particulate
alloy and its composites. Ice quenching followed by artificial ageing for 8 hrs resulted in
composites were successfully developed using liquid
maximum hardness of matrix alloy and its composites.
•
•
•
metallurgy route. (stir casting technique)
The microstructural study clearly reveals the nearly
uniform distribution of reinforcement particulates in
the Al 2024 matrix alloy.
The density of the composite material decreases as
7
88
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Effect of Solutionising And Ageing On Hardness Of Al2024-Beryl Particulate Composite
•
the reinforcement content increases in the matrix
material and confirms the stability of the liquid
metallurgy technique for successful development of
the composite material.
The Brinell hardness of the composites increased
significantly with increased content of Beryl particles.
Heat treatment has a significant effect on Brinell
hardness of Al2024 matrix alloy and its composites.
Ice quenching followed by artificial ageing for 8 hrs
resulted in maximum hardness of matrix alloy and
its composites.
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