Grain size and mechanical properties of metals subjected to equal channel angular pressing

39 Pages·2017·8.78 MB·English

Proceedings of Mechanical Engineering Research Day 2017, pp. 301-302, May 2017

Grain size and mechanical properties of metals subjected to equal
channel angular pressing (ECAP) process
M.A. Hisyam*, D.N. AwangShri

Faculty of Mechanical Engineering, Universiti Malaysia Pahang, 26600 Pekan, Pahang, Malaysia

*Corresponding e-mail: [e-mail]

Keywords: ECAP; severe plastic deformation; grain refinement

ABSTRACT – Equal Channel Angular Pressing (ECAP)
is one of the most efficient technique in metal forming
process which induced severe plastic deformation (SPD)
to produce bulk ultrafine-grained metals. This research
used Titanium CP Grade 2 and Aluminum Alloy 6061 to
investigate the grain size and mechanical properties of
both materials after ECAP process. The materials were
extruded through die channel angle of 126º internal and
10º external under pressure of 60 bar. The result shows
that there is significant increase in grain refinement and
hardness after ECAP process for both materials.

1. INTRODUCTION
Equal Channel Angular Pressing (ECAP) has been
one of the most popular Severe Plastic Deformation
(SPD) techniques for refining grain on metals and
composites [1]. The development of this process has been Figure 1 Principle of ECAP process.
improvised especially by Valiev and Langdon [2] to get
better product. ECAP process will produce better grain 2. METHODOLOGY
refinement, with improved strength but retain
The ECAP die used for this research was a
approximately the same size and shape of the billet before
removable die in circular channel with internal angle of
and after the process.
126º and external angle of 10º as indicated on Figure 2.
Sanusi et al. [3] stated that SPD technique is a

generic term describing a group of metal working
techniques that involve using extreme plastic straining to
produce materials by imposing very high shear
deformation on the materials under superimposed
hydrostatic pressure. Several SPD techniques have been
developed such as High Pressure Torsion (HPT),
Accumulative Roll Bonding (ARB), Accumulative Back
Extrusion (ABE) and Equal Channel Angular Pressing
(ECAP).
Figure 1 shows that the basic principle of ECAP
process which the sample will be extruded through two
intersecting channels which have the same cross-section
with die internal angle (φ) and die external angle (ψ) by
using a plunger as stated by Djavanroodi et al. [4]. The
cross-section of the die can either be circular or square. Figure 2 The die used for the experiments.
Because ECAP process can be repeated for several times,
shear deformation will influence the production of high
The removable die consists of two plate bolted
strength and lightweight materials without compromising together to form the circular channel which then will be
their dimension. locked by die holder. The samples are in the form of
In this research, the objective is to conduct ECAP
cylindrical rod which 10mm in diameter and 100mm in
process on Titanium CP Grade 2 (Ti ASTM Grade 2) and length. The samples were lubricated by using
Aluminium Alloy 6061 (AA 6061); and to compare the molybdenum disulfide (M S ) lubricant. The samples
O 2
grain size and mechanical properties of both materials
undergo ECAP process by using Hydraulic Pressure
before and after ECAP process. machine under the pressure of 60 bar at room
temperature. The ECPD samples hardness was tested
using Vickers hardness Matsuzawa hardness machine
__________
© Centre for Advanced Research on Energy
Hisyam and AwangSri, 2017

type MMT-X7 which uses diamond indenter in the shape Table 1 Average calculation of grain size of Ti ASTM
of pyramid with square base. The result of the sample Grade 2.
hardness will be calculated by using the following
formula:

136/2
Vickers Hardness, HV = 2Fsin [1]
𝐷2

The microstructure of ECPD samples is analyzed

under optical microstructure test by using Wilson
Table 2 Average calculation of grain size of AA6061.
Hardness Machine to observe the grain size.

3. RESULTS AND DISCUSSION
The hardness test result across the surface of the
samples are shown on Figure 3 and Figure 4. It was
clearly shown that there is an increase of hardness value

after ECAP process. After ECAP, the average hardness
for Ti ASTM Grade 2 is increased for 127% while for AA 4. CONCLUSION
6061 is increased for 194%. Based on the calculation of
In this research, experiments are conducted to
the formula, it showed that as the diagonal length
investigate the hardness and the microstructure of Ti
decreases, the value of hardness increase.
ASTM Grade 2 and AA 6061 after ECAP process. The

data collected shows that there is significant increase in
term of grain refinement and also hardness for both of
materials even after single pass.
Based on the results, we can see that ECAP process
is indeed proved to be the alternative technique to
produce bulk materials under SPD technique which does
not sacrifice the dimension of the materials. The
material’s grain size is indeed will be refined to be more
even throughout the workpiece while at the same time
increase the hardness value of the workpiece.

5. ACKNOWLEDGEMENT
Figure 3 Graph of hardness of Ti ASTM Grade 2.
This work is supported by Univeristi Malaysia
Pahang (RDU150385). We also would like to thanks
Nurul Izzati Binti Mohamad Sobri and Norhafizah Wati
Rizal Binti Yusoh for their supports.

REFERENCES
[1] T.G. Langdon, "Processing by severe plastic
deformation: historical developments and current
impact,” Materials Science Forum, Vols. 667-669,
pp. 9-14, 2011.
[2] R.Z. Valiev and T.G. Langdon, "Developments in

the use of ECAP processing for grain refinement,”
Figure 4 The hardness profile of AA 6061.
Reviews on Advanced Materials Science, vol.13,

no.1, pp.15-26, 2006.
The microstructure of the samples after ECAP are
[3] O. Sanusi, D. Makinde and J. Oliver, "Equal
in term of grain sizes and shown in the Table 1 and Table
channel angular pressing technique for the
2 for both of materials. The grain sizes of the samples
formation of ultra-fine grained structures,” South
decrease significantly after ECAP process. For Ti ASTM
African Journal of Science, vol.108, no.9-10, pp.1-
Grade 2, there is approximately 61% decrease in grain
7, 2012.
size compared to as received condition while for AA
[4] F. Djavanroodi, B. Omranpour, M. Ebrahimi and M.
6061, there is approximately 83% decrease in grain size
Sedighi, "Designing of ECAP parameters based on
compared to as received condition.
strain distribution uniformity,” in Progress in

Natural Science: Materials International, vol.22,

no.5, pp.452-460, 2012.

302
Proceedings of Mechanical Engineering Research Day 2017, pp. 303-304, May 2017

Experimental evaluation of impact based flexible piezoelectric
P(VDF-TrFE) thick-film
K.K. Chow1, S.L. Kok2,*, K.T. Lau3

1)Department of Electrical Engineering, Politeknik Ungku Omar,
Jalan Raja Musa Mahadi, 31400 Ipoh, Perak, Malaysia
2) Faculty of Electronics and Computer Engineering, UniversitiTeknikal Malaysia Melaka,
Hang Tuah Jaya, 76100 Durian Tunggal, Melaka, Malaysia
3) Faculty of Manufacturing Engineering, UniversitiTeknikal Malaysia Melaka,
Hang Tuah Jaya, 76100 Durian Tunggal, Melaka, Malaysia

*Corresponding e-mail: [e-mail]

Keywords: Thick film; piezoelectric P(VDF-TrFE); impact

ABSTRACT – This paper discusses on the evaluation TrFE) thick film was measured using digital
of an impact based energy harvesting material using oscilloscope (Agilent Technologies: DSO-X2012A,
poly(vinylidene fluoride) trifluoroethylene P(VDF- Figure 3). The result shows the instantaneous of
TrFE) in the form of thick film on a flexible substrate. electrical voltage when the plasticine is released to be
When an impact force from free-fall of 0.2N was free-fall onto piezoelectric P(VDF-TrFE) thick film.
applied to the film, as an energy harvester, a maximum
peak-to-peak voltage of about 3.0V was generated
which derived a maximum output power of 4.36 µW at
an external load of 1kΩ.

1. INTRODUCTION
Piezoelectric materials have been widely used for
biomedical engineering, smart sensor detection,
structural health monitoring applications and are usually
in the form of resonant based sensing devices [1-2].
After the discovery of PZT in the 50s, it has been
developed as energy harvester [3]. However, PZT has a
high brittleness and low compliance therefore it is not
applicable to be fabricated on flexible structure. In most
cases for optimum energy harvesting from impact based
application, flexible structure is desirable. P(VDF-
TRFE) thick film have advantages such as higher elastic
compliance and acoustic impedance matching than the
(a)
PZT counterpart. Furthermore, P(VDF-TrFE) has a

better bonding layer on a flexible structure compared to
piezoceramic material [4-5].
This paper reports a voltage generation from the
P(VDF-TrFE) thick film and the maximum electric
power when it underwent a free-fall drop impact test.

2. EXPERIMENTAL SETUP
(b)
Figure 1 shows the layout of the piezoelectric
Figure 1 (a) Plan view and (b) side view of the
P(VDF-TrFE) thick film device. The P(VDF-TrFE)
schematic diagram of the sandwiched thick film.
layer was sandwiched between top and bottom

electrodes on a flexible Melinex substrate. Its dimension
Table 1 Dimension of Fabricated sensor device.
is shown in Table 1. The details of the fabrication
process of the P(VDF-TrFE) thick film had been Layer Dimension (mm) L x W
described in our previous paper [6]. A free-fall drop
P(VDF-TrFE) 2.5 x 2.0
impact test was conducted on the device by dropping a
known mass of plasticine with varying weights from Top electrode 3.4 x 1.0
0.03 N to 1 N (refrains from falling out of the traget by
Bottom electrode 3.4 x 0.8
using a plastic cylinder as shown in Figure 2) at a fixed

height of 20cm.

The output voltage from the piezoelectric P(VDF-
__________
© Centre for Advanced Research on Energy
Chow et al., 2017

power of 4.36 µW is being measured across an optimum
external load of 1kΩ.

Voltage
65 Power
4

3 60
W mV
wPuoe/r 2 55Vgoae/tl

1 50

Figure 2 Experiment setup. 0 45
1 2 3 4 5
R/ k Ohm

3. RESULTS AND DISCUSSION

Figure 3 shows an AC voltage of waveform was Figure 5 Power and Voltage vs Resistive load.
generated when an impact force applied onto the
piezoelectric P (VDF-TrFE) material. 4. CONCLUSION
The piezoelectric P(VDF-TrFE) thick film which
has been developed in this project exhibited a consistent
electric voltage and power output when exerted a range
of free-fall impact force. The output volage achieved a
maximum of about 3V with an impact force of 0.2N
which derived a power of 4.36 µW when connected
with 1kΩ external resistive load.

ACKNOWLEDGEMENT
The authors would like to thank the Ministry of
Higher Education of Malaysia for the research grant of
FRGS/2/2014/SG02/FKEKK/02/F00244 and also the
Figure 3 Output AC voltage peak when impact force. support facility provided by Advanced Sensors and
Embedded Control Systems Research Group (ASECs),
The peak-to-peak AC voltage versus the free-fall UTeM.
impact force shows a saturation at about 3V when a
impact force of 0.2N is applied (see Figure 4) A highest REFERENCES
output voltage of 3.06V was generated at 0.2N load.
[1] D.F. Berdy, B.Jung, J.F. Rhoads and D. Peroulis,
When the force exceeding 0.7 N, the average output
“Wide-bandwidth, meandering vibration energy
voltage settled down to 2.70V.
harvester with distributed circuit board inertial

mass,” Sensors and Actuators A, vol.188, pp. 148-

157, 2012.

[2] D. Zhu, M.J. Tudor and S.P. Beeby, “Strategies for

increasing the operating frequency range of

vibration energy harvester: a review” Meas. Sci.

Technol, vol.21 (2). 022001, pp.29, 2010.

[3] E. Sawaguchi, G. Shirane and Y. Takagi, “Phase

transition in lead zirconate,” Journal of The

Physical Society of Japan, vol. 6, No.5, pp.333-

339, 1951.

[4] J. Sirohi and I Chopers, “Fundamental

understanding of piezoelectric strain sensors,” J.

Intell. Mater. Syst. Struct, vol 11, no, 4, pp. 246-

257, 2000.
Figure 4 Voltage output vs force.
[5] G. Shirane, E. Sawaguchi and Y. Takagi.

“Dielectric properties of lead zirconate,” Physical
Figure 5 shows the electrical output power of
Review, vol.84, no. 3, pp. 208-209, 1951.
piezoelectric P(VDF-TrFE) thick film when the output
[6] K.K. Chow, S.L. Kok, K.T. Lau “Flexible
terminal of the film is connected to external resistive
piezoelectric micro-generator based on P(VDF-
load varied from 700Ω to 5 kΩ. This was after the
TrFE),” in Proceedings of Mechanical Engineering
impact force was fixed at 0.2N. A maximum output
Research Day, 2016, pp. 98–99.
304
Proceedings of Mechanical Engineering Research Day 2017, pp. 305-307, May 2017

The effect of varying pressure on mechanical performance of pineapple
leaf fiber reinforced poly lactic acid biocomposites
S.N.R Ramli1,2, S.H.S.M. Fadzullah1,2,*, Z. Mustafa3, M.R.M. Rejab4, M.Z. Hassan5

1) Faculty of Mechanical Engineering, Universiti Teknikal Malaysia Melaka,
Hang Tuah Jaya, 76100 Durian Tunggal, Melaka, Malaysia
2) Centre for Advanced Research on Energy, Universiti Teknikal Malaysia Melaka,
Hang Tuah Jaya, 76100 Durian Tunggal, Melaka, Malaysia
3) Faculty of Manufacturing Engineering, Universiti Teknikal Malaysia Melaka,
Hang Tuah Jaya, 76100 Durian Tunggal, Melaka, Malaysia
4) Faculty of Mechanical Engineering, Universiti Malaysia Pahang, P. O. Box 12, 25000 Kuantan. Malaysia
5) Universiti Teknologi Malaysia Kuala Lumpur,
Jalan Sultan Yahya Petra, 54100 Kuala Lumpur, Malaysia

*Corresponding e-mail: [e-mail]

Keywords: Poly lactic acid; pineapple leaf fibers; mechanical properties

ABSTRACT –The biocomposites fabricated in this Researchers have attempted various methods to
study is produced by reinforcing poly lactic acid with fabricated composites which results in a wide range of
pineapple leaf fibers with length of 200 mm and 30 mechanical performance. Islam et al. [8] have fabricated
wt.% fiber loading, with consideration on using alkaline 30 wt.% aligned untreated and alkaline treated hemp
treatment for the fibers. The aim of this study is to fibers reinforced PLA using compression molding using
evaluate the effect of pressure applied during four different ways. In the first method, the PLA powder
compression molding on the mechanical performance of was manually spread onto short random fiber mat. In the
the biocomposites. The unidirectional biocomposites second method, the PLA powder was mixed with short
plates with nominal thickness of 3 mm were fibers using water. Method three was established in
characterized in terms of their flexural and tensile which PLA was dissolved in DCM and poured over
properties in accordance to ASTM D790 and D3039 untreated and treated fiber mat. Lastly, in the fourth
respectively. From the experimental results, it was method, PLA film was sandwiched in between fiber
found that the biocomposites fabricated using a pressure mats. All the composites were pressed at a setting
of 1700 psi exhibit superior tensile and flexural temperature of 170oC and a pressure of 1 MPa for 10
properties in comparison to those fabricated using 200 minutes except for the manually spread PLA on fiber
psi pressure. Moreover, the alkaline treated pineapple mat, that was pressed at 1.2 MPa of pressure
leaf fibre reinforced biocomposites disclosed much respectively [8]. They found that 30 wt.% alkaline
higher flexural strength and modulus in comparison to treatment long hemp fibers reinforced PLA via
those of the untreated samples. compression molding by film stacking was the best
method established with flexural strength of 13 MPa,
1. INTRODUCTION flexural modulus of 6.5 GPa, tensile strength of 83 MPa
and young modulus of 11 GPa.
Biocomposites are gaining increasing attention due
In this study, pineapple leaf fiber reinforced PLA
to cost effective and environmental-friendly. Many
biocomposites were prepared by compression molding
studies have been done on the use of natural fibers such
with two pressure conditions; these being 200 psi and
as kenaf, sisal, jute and flax to replace the synthetic
1700 psi, respectively. Prior to fabrication, the fibers
fibers [1-2]. However, despite the fact that these
were pre-treatment using sodium hydroxide (NaOH).
materials are low cost and biodegradable, pineapple leaf
The experimental results for the biocomposites using
fiber reveal superior mechanical properties in
both pressure used are presented and discussed in terms
comparison to other naturals fibers due to higher
of their flexural and tensile properties.
cellulose (70-82 %) and low lignin (5-12 %) contents

[3–5].
2. METHODOLOGY
At present, polylactic acid is used in various field
of applications such as food packaging, biocompatible 2.1 Material
medical devices, film and interior automotive parts [2-
Polylactic acid grade 6100D was purchased by
3]. PLA is a thermoplastic biopolymer that is produced
NatureWorks, LLC, USA. Pineapple leaf fibers from
by microbial fermentation process of fully renewable
Josapine species were supplied from villagers in
resources such as corns, tapiocas and sugarcane [2,6].
Pontian, Johor. Sodium Hydroxide (NaOH) supplied by
Moreover, pineapple leaf fibers are found in abundance
Merck Chemicals Sdn. Bhd. was used to treat the fibers.
and easily available since Malaysia is one of the main

exporters of pineapple in the world market, after

Thailand, Philippine and Brazil [7].
__________
© Centre for Advanced Research on Energy
Ramli et al., 2017

2.2 Composites preparation flexural modulus also shows an improvement of 144 %
from 2.58 to 6.29 GPa for the two cases. The high
PALF and PLA were dried overnight to minimise
pressure allows the matrices penetrates into the surface
moisture content at 60○C and 80○C respectively. Prior to
fibers, thus increases the strength and stiffness of the
fabrication of composites, PLA pellets were pressed into
biocomposites. In addition, by introducing alkaline pre-
1 mm thin plate with dimensions of 200 mm long x 200
treatment on the fibers also enhanced the performance
mm wide x 1 mm thickness at temperature of 175 oC
of flexural strength and modulus respectively [3].
and a pressure of 200 psi, for a contact time of 20

minutes which was followed by cooling at zero
3.2 Tensile properties of biocomposites
pressure. Then, the thin plates were used to produce
composites by 30 wt.% of PALF of 200 mm long fibers The effect of applied pressure used (200 psi and
were sandwich in between of 1 mm thin PLA sheet 1700 psi) during fabrication of the biocomposites on
compressed moulded at temperature 175 oC and tensile properties of neat PLA, alkaline treated PALF
pressure of 200 psi, with a contact time of 10 minutes reinforced biocomposites are given in Table 1. From the
and followed by cooling under zero pressure. The same result, the tensile strength and modulus of neat and
steps were repeated for fabricated the biocomposites for unidirectional long treated biocomposites at applied
the fabrication process using a pressure of 1700 psi. pressure at 1700 psi are superior in comparison to
applied pressure at 200 psi. At higher pressure (1700
2.3 Mechanical characterizations psi) the tensile strength shows an improvement from
36.62 to 51.9 MPa for neat PLA and 68.13 to 100.63
Specimens with dimensions of 74 mm x 12 mm x
MPa for unidirectional long treated biocomposite
3 mm were prepared for flexural testing in accordance
compared to those fabricated using applied pressure of
to ASTM D790. The tests were conducted at crosshead
200 psi.
displacement rate of 2 mm/min and maximum load of 1

kN. As per ASTM 3039 tensile test, specimens with
3.3 Scanning electron microscopy
dimensions of 150 mm x 15 mm x 3 mm were prepared.
A Universal Testing Machine (UTM) via an Instron Figure 1 (a), represented physical microstructural
5585 was used to conduct the flexural test. Five samples of biocomposites fabricated at pressure of 200 psi
per test were prepared and average values for each test consists of defect such voids and poor wetting
were calculated. interfaces. Meanwhile, Figure 1 (b) proven that an
improvement adhesion interfaces between PALF fibers
3. RESULTS AND DISCUSSION and PLA matrix are achieved resulting from sufficient
pressure allow the matrices to penetrate into fibers
3.1 Flexural properties of biocomposites
during fabrication process. Thus, minimise probability
The effect of applied pressure used (200 psi and of defect such as voids and pull out fibers.
1700 psi) during fabrication of the biocomposites on
mechanical properties of neat PLA, untreated fibers
a
(LUT) and alkaline treated fibers (LT) of PALF
reinforced biocomposites are discussed, with the main
results given in Table 1.

Table 1 Mechanical properties of neat PLA and
PLA/PALF biocomposites.
Neat LUT LT
Neat LT 200
Properties 1700 1700 1700
200 psi psi
psi psi psi
Flexural
Strength 88.25 90.42 63.24 40.87 124.41
±10.70 ±3.52 ±10.55 ±13.21 ±1.72
[MPa]
Flexural
1.65 3.11 4.52 2.58 6.29
Modulus b
±0.10 ±0.14 ±0.64 ±1.41 ±0.59
[GPa]
Tensile
36.62 51.9 83.63 68.13 100.63
Strength
±4.99 ±4.71 ±5.52 ±10.58 ±12.92
[MPa]
Tensile
1.62 0.84 2.63 2.80 2.86
Modulus
±0.09 ±0.10 ±0.18 ±0.44 ±0.24
[GPa]

Clearly, the biocomposites fabricated using an
applied pressure of 1700 psi shows higher flexural
strength and modulus compare to those fabricated at
much lower applied pressure, of 200 psi. The strength of Figure 1 SEM images of PALF reinforced PLA
the biocomposites using 1700 psi of pressure is three following mechanical testing at pressure a) 200 psi and
times better in comparison to the 200 psi case, with the b) 1700 psi.
values of 124.42 MPa and 40.87 MPa, respectively. The
306
Ramli et al., 2017

4. CONCLUSIONS biocomposites,” Composite Interfaces, vol. 15, no.
2–3, pp. 169–191, 2008.
It has been shown that there is a significant effect
[4] S. Kaewpirom and C. Worrarat, “Preparation and
in the used of different pressure during the fabrication of
properties of pineapple leaf fiber reinforced
the biocomposites on the mechanical performance of the
poly(lactic acid) green composites,” Fibers and
composites. Higher pressure allows the matrix to
Polymers, vol. 15, no. 7, pp. 1469–1477, 2014.
penetrate into the fiber surface, thus resulting in an
[5] S.H.S. Fadzullah and Z. Mustafa, “Chapter 6
increase in the strength and stiffness of the
Fabrication and Processing of Pineapple Leaf
biocomposites.
Fiber Reinforced Composites,” in Green
Approaches to Biocomposite Materials Science
REFERENCES
and Engineering, vol. i, 2016, pp. 125–17.
[1] S.N.R. Ramli, S. Fadzullah, and Z. Mustafa, [6] S.H.S. Fadzullah, Z. Mustafa, S.N.R. Ramli, Q.A.
“Mechanical performance of pineapple leaf fiber Yaacob, A. Fatihah, and M. Yusoff, “Preliminary
reinforced poly lactic acid (PLA) biocomposites,” Study on the Mechanical Properties of Continuous
Proceeding Mechanical Enginering Research Day Long Pineapple Leaf Fiber Reinforced PLA
2016, 2016, pp. 131–132. Biocomposites,” Key Engineering Materials, vol.
[2] M.S. Huda, L. T. Drzal, A.K. Mohanty, and M. 694, no. i, pp. 18–22, 2016.
Misra, “Effect of fiber surface-treatments on the [7] J.D.L.C. Medina and H. S. García, Post-harvest
properties of laminated biocomposites from Operations. 2005.
poly(lactic acid) (PLA) and kenaf fibers,” [8] [8] M.S. Islam, K.L. Pickering, and N.J. Foreman,
Composite Science Technology, vol. 68, no. 2, pp. “Influence of alkali treatment on the interfacial and
424–432, 2008. physico-mechanical properties of industrial hemp
[3] M.S. Huda, L. T. Drzal, A. K. Mohanty, and M. fibre reinforced polylactic acid composites,”
Misra, “Effect of chemical modifications of the Composites Part A Appied Science and
pineapple leaf fiber surfaces on the interfacial and Manufacturing, vol. 41, no. 5, pp. 596–603, 2010.
mechanical properties of laminated

307
Proceedings of Mechanical Engineering Research Day 2017, pp. 308-309, May 2017

Comparison of two different composite process using hand lay-up and resin
transfer moulding for tensile properties
A. Zailinda1, A. Rivai1,*, M.Y. Yuhazri2, M.K.M. Rus1

1) Faculty of Mechanical Engineering, Universiti Teknikal Malaysia Melaka,
Hang Tuah Jaya, 76100 Durian Tunggal, Melaka, Malaysia
2) Faculty of Manufacturing Engineering, Universiti Teknikal Malaysia Melaka,
Hang Tuah Jaya, 76100 Durian Tunggal, Melaka, Malaysia

*Corresponding e-mail: [e-mail]

Keywords: Resin transfer moulding (RTM); hand lay-up; tensile test

ABSTRACT – Currently autoclave process is used for 1. The specimen left for 24 hours to be cured completely
composite manufacturing in aerospace industries which before it is removed from the mould.
is require high cost. This paper will present the
comparisons of mechanical properties of composites
carbon/epoxy fabricated by using Resin Transfer
Moulding and Hand Lay-up process. The tensile test
will be done on two plies of woven dry carbon
specimens. The result of this study shows that the
composites manufactured by using RTM process have
better surface finished and almost same mechanical
properties.

1. INTRODUCTION
Figure 1 Hand lay-up process.
Nowadays laminate composites have been

extensively replacing the conventional materials and
RTM process involved closed mould which use
widely applied in varies field such as aerospace
bottom and top surface mould clamped together. There
structures and military industry [1]. Due to this reason,
are five important components in the RTM equipment
few fabrication processes of laminate composite are
which are resin and catalyst container, pumping unit,
being investigated. RTM has a lot of advantages such as
mixing chamber, resin injector, and mould. Dry carbons
good dimensional tolerances, possibility to mould high
are positioned in the cavity of mould then the mould is
complex shape, and have good surface finish on both
closed. Liquid resin and catalyst are mixed in the
sides of composites part [2]. RTM have good net shape
mixing chamber before it is pumped using pumping unit
forming capabilities reinforcing fibers and have good
under low to moderate pressure into the mould cavity
ability to tailor the properties of the final part to meet
using the resin injector. When the mould completely
the requirements for the desired application [3].
filled with resin, it is cure rapidly in room temperature.
Parameters that affect RTM process are mould, injection
Once the resin cured, the mould is opened and the part
pressure, temperature, viscosity, volume fraction, mould
will be removed. The schematic of the RTM Process
filling time, and resin curing time [4]. This paper will
shown in Figure 2.
compare the mechanical properties of laminate

composite made of epoxy and dry carbon fabrics
fabricated by using RTM process and Wet Hand Lay-up.

2. METHODOLOGY
2.1 Specimen preparation
The fabrications of specimen are using
Conventional Wet Hand Lay-up and RTM process.
Hand Lay-up process begins by layering a mould
release agent on the mould surface to prevent the epoxy
Figure 2 Schematic of the RTM process.
from sticking to the mould. Then, ply of woven dry

carbon is placing on one side of mould either male or
2.2 Experimental procedure
female. Resin is poured on top of the carbon ply. By
using hand roller, resin is distributed uniformly and help Specimens consist of two plies of dry carbon
to force it penetrate into the dry carbon bundles. The prepared by RTM and Wet Hand Lay-Up process. Five
hand roller is also used to remove excess bubbles. The specimens will be prepared for each process. The
process is repeated until the last ply, as shown in Figure specimens will undergo tensile test followed ASTM
__________
© Centre for Advanced Research on Energy
Zailinda et al., 2017

D3039 standard. Tensile test will be performed by using process. RTM process is using closed mould where the
Universal Testing Machine (Instron) with maximum resin will be uniformly distributed on the surface of the
load of 50 kN. The appropriate dimensions of the specimen and during RTM process; uniformity of
specimen are 160 mm of length, 20 mm of width and 2 desired thickness of composite can be controlled since
mm of thickness as shown in Figure 3. Cross head speed the resins will fully fill up the mould cavity. In contrary,
is 2mm/min. by using Hand Lay-Up process the thickness of the
composite cannot be controlled since the dry carbon is
lay-up by hand and the force applied is not uniform.

Figure 3 Specimen dimension (based on 50 kN Instron
universal testing material standard). Figure 5 Surface finished specimen fabricated by RTM
process.
3. RESULTS AND DISCUSSION
The results of stress-strain diagram for RTM
specimen obtained from tensile test are shown in
Figure 4.

Figure 6 Surface finished specimen fabricated by hand
lay-up process.

4. CONCLUSION
The results show that the Resin Transfer Moulding
(RTM) Process produce a good surface composites
compared to Hand Lay-Up process and almost same

mechanical properties.
Figure 4 Graph of tensile test result.

REFERENCES
Table 1 shows the comparison of ultimate stress
for RTM and Wet Hand Lay-up specimens. [1] M.V. Hosur, J. Alexander, U.K. Vaidya and S.
Jeelani, “High strain rate compression response of
Table 1 Ultimate tensile stress for rtm and hand lay-up carbon/epoxy laminate composites,” Composite
process. Structures, vol. 52, no.3, pp. 405-417, 2001.
No. Ultimate Tensile Stress [MPa] [2] K. Hoes, D. Dinescu, H. Sol, M. Vanheule, R.S.
RTM Process Hand Lay-Up Process % Parnas, Y. Luo and I. Verpoest, “New set-up for
1
248.41 250.20 0.72 measurement of permeability properties of fibrous
reinforcements for RTM,” Composites Part A:
Ultimate tensile stress for specimens fabricated by applied science and manufacturing, vol. 33, no. 7,
RTM and Hand Lay-up process are 248.41 MPa and pp. 959-969, 2002.
250.20 MPa. The difference values of ultimate strength [3] V. Jovanovic, S. Manoochehri and C. Chassapis,
between both specimens are 0.72%, which is too small “Parameter estimation for resin transfer
and not significant. It demonstrates that specimens molding,” Engineering Computations, vol. 18,
fabricated from both processes RTM and Hand Lay-up no.8, pp. 1091-1107, 2001.
has almost same mechanical properties. [4] V.M. Calado and S.G. Advani “Effective average
Figure 4 and Figure 5 show the picture of surface permeability of multi-layer preforms in resin
finish of the specimens fabricated by both processes transfer molding,” Composites Science and
RTM and Hand Lay-Up process. RTM process give Technology, vol. 56, no. 5, pp. 519-531, 1996.
good surface finished compared to Hand Lay-Up

309
Proceedings of Mechanical Engineering Research Day 2017, pp. 310-311, May 2017

Prelimenary study on fatigue strain signal of automobile steering
knuckle
F.H.A. Suhadak, K.A. Zakaria*, M.B. Ali

Faculty of Mechanical Engineering, Universiti Teknikal Malaysia Melaka,
Hang Tuah Jaya, 76100 Durian Tunggal, Melaka, Malaysia

*Corresponding e-mail: [e-mail]

Keywords: Automobile steering knuckle; fatigue; strain signal

ABSTRACT – A steering knuckle is an automobile of steering knuckle is scanned with 3D scanner to be
component that responsible in providing support to analysis using a computational aided design. The critical
maneuvering and suspension system in an automobile. point of steering knuckle is determined by conducting a
Previously, most of the research studied the fatigue finite element analysis. In the analysis, the model is
strain signal behavior in one direction only. Therefore, constraint at the hub of steering knuckle. The forces are
the objective of this research is to study the effect of subjected to 3 main part of steering knuckle which are
multi-direction of strain signals on steering knuckle. strut mount, lower ball joint and steering arm. Then, the
The material of steering knuckle is analyzed using a steering knuckle is installed with strain gauge. The
scanning electron microscope (SEM) and it shows that strain gauge is located at the critical area as previous
steering knuckle is made from Cast Iron ASTM A536. study [3]; with different orientation of directions, x
Meanwhile, the steering knuckle is modeled using direction, y direction and z direction as shown in Figure
computational aided design software with assist of 3D 1. The automobile was driven through a residential road
scanner. Then finite element analysis is performed to shown in Figure 2, in order to investigate the
determine their critical area. The strain gauge is characteristics of strain signal of steering knuckle at
installed on steering knuckle at this critical point and the different orientations. The speed of automobile is
signal is then captured through data acquisition system. constant at the range of 15-25 km/h. The strain signal is
The result showed that the different direction of steering then recorded within 5 minutes duration using a data
knuckle varies significantly to each other. acquisition system.

1. INTRODUCTION
The steering knuckle can be categorized into three
main parts which are strut mount, steering arm and
lower ball joint. Strut mount is critical in supporting the
suspension system and weight of a car and steering arm
will translate linear motion angular motion on the front

wheel. Meanwhile, lower ball joint support the car while
Figure 1 Direction of strain gauge.
driven onto different types of road conditions such as

potholes, bumper and etc.
The direction of steering knuckle is decided based
on x- direction as it a movement of moving forwards
and backwards, y-direction is a movement of moving
upwards and downwards and z-direction is a movement
of moving right and left.
Zakaria et. al. [1] studied the effect of two different Figure 3 Steering knuckle material image from SEM
types of road surfaces, such as residential and highway
road on strain signal which is measured on engine
mount bracket. It is recorded that residential road has
3640 cycles of strain load and highway road has 3406

cycles. Meanwhile, Azrulhisham et al. [2] used road
simulator to capture the strain signal. In both papers, the Figure 2 Residential road.
direction of strain signal was recorded in y-direction
only which is upwards and downwards. 3. RESULTS AND DISCUSSION

Image from Figure 3 shows surface condition of
2. METHODOLOGY
steering knuckle taken from SEM. The result of
chemical composition from SEM can be seen in the
In this study, the fatigue strain signal was captured
Table 1. The result obtained identifies the material as
from 1300cc car steering knuckle. The material of
Cast Iron ASTM A536 by comparing the result of
steering knuckle is distinguished using SEM. The image
material composition provided by supplier and
__________
© Centre for Advanced Research on Energy