1. INTERNATIONALMechanical Volume 4, Issue 1, January - February (2013) © IAEME–
International Journal of JOURNAL OF MECHANICAL ENGINEERING
6340(Print), ISSN 0976 – 6359(Online)
Engineering and Technology (IJMET), ISSN 0976
AND TECHNOLOGY (IJMET)
ISSN 0976 – 6340 (Print)
ISSN 0976 – 6359 (Online)
Volume 4, Issue 1, January- February (2013), pp. 109-114 IJMET
© IAEME: www.iaeme.com/ijmet.asp
Journal Impact Factor (2012): 3.8071 (Calculated by GISI)
www.jifactor.com ©IAEME
FABRICATION AND CHARACTERISATION OF IN-SITU AL-TIC
COMPOSITE
D.Sai Chaitanya Kishore1, Dr. K.Prahlada Rao2, Dr. A.Mahamani3
1
( Department of Mechanical Engineering, Chiranjeevi Reddy Institute of Engineering &
Technology, Bellary Road, Anantapur, India, mail: saichaitanyakishore@yahoo.co.in)
2
(Department of Mechanical Engineering, Jawaharlal Nehru Technological University,
Anantapur, India)
3
(Department of Mechanical Engineering, Swetha Institute of Technology & Science for
Woman, Tirupati, Andhra Pradesh, India)
ABSTRACT
Materials are playing vital role in recent past, in-situ Al-Tic with 5% TiC composite
was produced by the reaction with the halide salt K2TiF6. SEM and EDX tests were
performed on the prepared Al-TiC test specimen. As the micro hardness test was performed
for the test loads of 100 grams and 300 grams. By the addition of TiC the hardness of the
material was increased. There was a small variation in hardness value for 100 grams and 300
grams test load conditions.
Keywords: EDX, Halide salt, In-situ, Micro hardness and Scanning Electron Microscope
I. INTRODUCTION
There is always a scope of research in the fabrication of new materials, in the present
scenario there is so much need in the development of lightweight materials with the
properties like high strength, stiffness, hardness, fatigue and wear resistance. Metals are very
useful in making different components and their properties can be improved by adding
reinforcement like B, C, Al203, TiB, BiC and TiC e.t.c. Aluminium matrix composites
(AMCs) are the competent material in the industrial world [1]. The AMCs are fabricated by
different methods such as stir casting, squeeze casting, spray deposition, liquid infiltration,
and powder metallurgy [2]. Casting route is particularly attractive as it is economical and
practical [3]. The composite prepared by ex-situ method suffers thermodynamic instability
between matrix and reinforcements, thus limiting their ambient and high temperature
mechanical properties [4]. Ex-situ process possesses drawbacks like agglomeration, poor
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2. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –
6340(Print), ISSN 0976 – 6359(Online) Volume 4, Issue 1, January - February (2013) © IAEME
wetting and heterogeneity in microstructure [5]. Ex-situ composite fabrication method
consists of many stages, like sorting, alignment, infiltration and sintering [4].
As in In-situ process the ceramic reinforcement is incorporated into the matrix by the
chemical reaction of the halide salt with molten metal matrix. The in-situ formation of a
ceramic second phase provides greater control of size and level of reinforcements, as well as
the matrix reinforcement interface, yielding better tailorability of the composites [6]. In-situ
composites are having advantages like they are more homogeneous in their microstructure
and thermodynamically more stable and they also have strong interfacial bonding between
the reinforcements and the matrices [4]. Applications of in-situ composites include wear parts
for pumps, valves, chute liners, jet mill nozzles, heat exchangers, gun barrel liners [7].
Different reinforcements like TiB2, zrB2, B4C and TiC can be incorporated into the matrix by
In-situ reaction. As several researchers did research on In-situ composites and found that
halide salts plays a major role in the development of reinforcement in the metal matrix
composites. Aluminium alloys have high strength at room temperature. The strength and
other mechanical properties are reduced when the aluminium alloy is used at high
temperatures. The above problem can be solved by incorporating TiC reinforcement into the
aluminium matrix [8]. TiC is particularly attractive as it offers high hardness and elastic
modulus, low density, good wettability yet low chemical reactivity with aluminium melts [9].
In-situ Al-TiC MMC were synthesized and properties like hardness, tensile strength and wear
characteristics were studied by S. Natarajan et al. [3]. A. Mahamani et al. [15] performed
machinability study on Al-5cu-TiB2 MMC.
The Al–B4C composites were produced by modified stir cast route with different weight
percentage of reinforcement and the microstructure, mechanical properties were evaluated by
K.Kalaiselvan et al. [1]. Birol et al. [9] produced Al-TiC with different blends by varying the
melt temperature and found that Al3Ti particles were gradually replaced by TiC particles
when the powder blend was heated above 800о C. Birol [10] performed SEM and XRD
analysis and found that TiC particles apparently formed in increasing numbers with
increasing reaction temperatures when Ti was introduced into molten aluminium in the form
of a halide salt, together with graphite and also the particle size also get reduces with the
increased temperature.
A.Mahamani [4] fabricated Al-TiB2 and performed EDX analysis and micro hardness testing
and stated that hardness of the aluminium is increased by adding TiB2 particles. M.S.Song et
al. [11] fabricated Al-TiC by self-propagating high-temperature synthesis (SHS) reaction and
performed SEM analysis and stated that the size of the TiC particulates decreased with
increasing Al contents in the blends. As the present work mainly focus on to fabricate Al-TiC
composite by In-situ process by the reaction of K2TiF6 and graphite powder with the molten
Aluminium. An investigation is done on the hardness by the addition of the TiC particles to
the Al-6061 by using micro hardness testing. Quantitative elemental analysis is performed by
EDX testing to know the presence of TiC particles and SEM is performed to know the
orientation and arrangement of the TiC particles.
II. EXPERIMENTAL PROCEDURE
The matrix used for fabrication of the Al-TiC composite was Al6061, for 5% TiC
reinforcement 1500 grams of Al6061, 300.9 grams of K2TiF6 (Potassium hexafluorotitanate)
and 19.5 grams of graphite powder was used. The schematic representation of the composite
processing [12] was shown in Figure. 1.
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3. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –
6340(Print), ISSN 0976 – 6359(Online) Volume 4, Issue 1, January - February (2013) © IAEME
Figure 1: In-situ Processing
The Al6061 was melted in crucible and premixed K2TiF6 and graphite powder of measured
quantity were added to the molten aluminium and melt temperature was maintained as 900о c.
The molten material was held for 20 minutes and for the proper mixing the molten metal was
stirred with a graphite rod during this exothermal reaction will take place between the molten
e
aluminium and halide salt K2TiF6. After 20 minutes the slag is removed from the molten mix
and the molten mix is poured into the mould. Figure.2 shows fabricated composite rod.
Figure. Al- TiC composite rod (5% TiC)
.2:
III. CHARACTERISATION OF AL-5% TIC COMPOSITE
RISATION AL
The fabricated composite was subjected to EDX, SEM and hardness test to know the
characterisation. EDX and SEM tests were performed on F E I Quanta FEG 200 - High
Resolution Scanning Electron Microscope Micro hardness test was performed on Vickers
Microscope.
hardness testing machine. The test specimen prepared for SEM and EDX testing were shown
in Figure.3, as the test specimen is circular in shape and the dimensions are 5mm in diameter
and 5 mm in thickness. The test specimen is well polished by using belt grinder and disc
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4. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –
6340(Print), ISSN 0976 – 6359(Online) Volume 4, Issue 1, January - February (2013) © IAEME
polisher. Fabricated composite was examined under scanning electron microscopy (SEM) to
ascertain the formation of TiC particles and their distribution. Figure.4 shows scanning
electron micrograph of the fabricated Al-5% TiC composite material. The SEM image
discovers the presence of TiC particles in the aluminium matrix and the TiC particles are
distributed homogeneously in the matrix. The size of the reinforcement particles are less than
1µm.
Figure 3: Test specimen for SEM and EDX Figure.4: SEM Image of Al-TiC 5%
Quantitative elemental analysis is performed by EDX testing to know the presence of TiC
particles. Figure.5 shows EDX spectrum of the Al-TiC 5% composite.
Figure.5: EDX analysis of Al-5% TiC
In EDX analysis[14] Y-axis represents the counts that is number of X rays received and
processed by the detector and X- axis represents energy level of those no of counts.
Moseley’s Law is basis for the EDX analysis. Moseley’s Law was shown in the equation 1.
E= C1 (Z- C2)2 ″equation 1 ″
Where E= energy of the emission line
Z= atomic number of the emitter
C1 and C2 are constants
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5. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –
6340(Print), ISSN 0976 – 6359(Online) Volume 4, Issue 1, January - February (2013) © IAEME
If the energy of the respected X-ray is determined then the atomic number of the element
producing the line can be determined. Figure.5 shows the presence of Ti and C particles in
the fabricated Al-TiC composite. To know the improvement of hardness in the fabricated Al-
5% TiC composite micro hardness test was performed at a load of 100 gram and 300 gram
with 15 seconds dwell time and the specimen prepared for micro-hardness was shown in
Figure.6. The shape of the specimen is cube 10mm side. The test specimen was well polished
before performing micro hardness test by using belt grinder and disc polisher.
Figure.6: Test Specimen prepared for Testing Micro Hardness (Al-TiC 5%)
The average hardness of the aluminium 6061 was 51 HV as specified by the supplier, by the
addition of the TiC reinforcement to the matrix the average hardness of Al-5% TiC was
increased to 55.4 HV at 300 gram test load. Hardness value of the fabricated Al-5% TiC
composite for 100 gram and 300 gram test load are given in Table.1
Table.1: Micro hardness value of the fabricated composite
Test load Trial 1 Trial 2 Trial 3 Average
Hardness
100 gram 71.3 68.5 71.2 70.33
300 gram 56.7 52.7 57.0 55.46
In Vickers micro hardness test the hardness is caliculated by using the equation 2.
HV=1854(F/d2) ″equation 2 ″
Where HV= Vickers hardness value
F= Indentation load in grams
d= Diagonal of the indentation in µm
The hardness value increases with the decrease in the test load. As the test load increases the
indentation size increases [13] and which will affect the hardness value. Depending upon
material, type of indenter and size of indentation a proper test load can be selected.
IV. CONCLUSION
Fabrication of Al- 5% TiC MMC was successfully done by in-situ process by the
reaction of the halide salt K2TiF6. Scanning electron microscopy (SEM) was performed on
the fabricated composite material and it shows that TiC reinforcement is properly distributed
over that matrix and size of the reinforcement was less than 1µm. Energy – dispersive X-ray
spectroscopy(EDS) was done on the fabricated composite and investigated the presence Ti
and C elements in the Al-5% TiC composite material. Vicker’s micro hardness test was
conducted and it reveals that by the addition of TiC reinforcement to the Al6061 matrix the
hardness value was increased.
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6. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –
6340(Print), ISSN 0976 – 6359(Online) Volume 4, Issue 1, January - February (2013) © IAEME
V. ACKNOWLEDGEMENT
The Authors would like to thank the management of Chiranjeevi Reddy Institute of
Engineering & Technology, Anantapur for the encouragement and support. The thanks also
extend to the management of SRM University and MICROLAB Chennai for providing lab
facility.
REFERENCES
[1] K. Kalaiselvan, N. Murugan, Siva Parameswaran, Production and characterization of
AA6061–B4C stir cast composite, Materials and Design 32 (2011) 4004-4009.
[2] Kaczmar JW, Pietrzak K, Wlosinski W, The production and application of metal matrix
composite materials, J Mater Process Technol 2000, 106, 58–67.
[3] S. Jerome , B.Ravisankar,PranabKumarMahato,S.Natarajan, Synthesis and evaluation of
mechanical and high temperature tribological properties of in-situ Al–TiC composites, Material
Science and Engineering A 428 (2006) 34-40.
[4] A. Mahamani, Mechanism of In-situ Reinforcement Formation in Fabrication of AA6061-
TiB2 Metal Matrix Composite, Indian foundry journal, Vol 57, No 3, March 2011.
[5] C. Cui, Y. Shen and F. Meng, 2000, Review on Fabrication Methods of In-situ Metal Matrix
Composites, Journal of Material Science Technology, Vol.16, pp.619-626.
[6] B.S.S. Daniel,V.S.R. Murthy and G.S. Murty, 1997, Metal Ceramic Composites Via In-situ
Methods, Journal of Materials Processing Technology, Vol. 68, pp.132-155.
[7] D. Lewis, In-Situ Reinforcement of Metal Matrix Composites, Metal Matrix Composites:
Processing and Interface (Academic Press London 1991 121-150).
[8] Kerti Isil, Production of TiC reinforced aluminium composites with the addition of elemental
carbon, Mater Lett, 2005, 59, 3795–3800.
[9] Yucel Birol, Response to thermal exposure of Al/ K2TiF6/C powder blends, Journal of Alloys
and Compounds 455 (2008) 164-167.
[10] Y.Birol, In situ synthesis of Al–TiCp composites by reacting K2TiF6 and particulate graphite
in molten aluminium, Journal of Alloys and Compounds 454 (2008) 110-117.
[11] M.S. Song, M.X. Zhang, S.G. Zhang, B. Huang, J.G. Li, In situ fabrication of TiC
particulates locally reinforced aluminium matrix composites by self-propagating reaction during
casting, Materials Science and Engineering A 473 (2008) 166–171.
[12] Anandakrishnan, A. Mahamani, Investigations of flank wear, cutting force, and surface
roughness in the machining of Al-6061–TiB2 in situ metal matrix composites produced by flux-
assisted synthesis, Int J Adv Manuf Technnol (2011) 55, 65-73.
[13] Dentin Chanya Chuenarrom, Pojjanut Benjakul, Paitoon Daosodsai, Effect of Indentation
Load and Time on Knoop and Vickers Microhardness Tests for Enamel, Materials Research, Vol
12, No 4, 473-476, 2009.
[14] Bob Hafner, Energy Dispersive Spectroscopy on the SEM: A primer (University of
Minnesota 1-26).
[15] A. Mahamani, Machinability Study of Al-5Cu-TiB2 In-situ Metal Matrix Composites
Fabricated by Flux-assisted Synthesis, Journal of Minerals & Materials Characterization &
Engineering, Vol .10,No.13,2011pp.1243-1254
[16] P. Kurmi, S. Rathod and P. Jain, “Abrasive Wear Behavior of 2014 Al-Tic In Situ
Composite” International Journal of Mechanical Engineering & Technology (IJMET), Volume 3,
Issue 3, 2012, pp. 229 - 240, Published by IAEME
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