Fabrication and Characterisation of in-situ Al-tic Composite-2

7/27/2019 Fabrication and Characterisation of in-situ Al-tic Composite-2

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International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976

6340(Print), ISSN 0976 6359(Online) Volume 4, Issue 1, January - February (2013) IAEME

109

FABRICATION AND CHARACTERISATION OF IN-SITU AL-TIC

COMPOSITE

D.Sai Chaitanya Kishore1, Dr. K.Prahlada Rao

2, Dr. A.Mahamani

3

1( Department of Mechanical Engineering, Chiranjeevi Reddy Institute of Engineering &

Technology, Bellary Road, Anantapur, India, mail: [email protected])2(Department of Mechanical Engineering, Jawaharlal Nehru Technological University,

Anantapur, India)3(Department of Mechanical Engineering, Swetha Institute of Technology & Science for

Women, 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 wereperformed 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 veryuseful 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

INTERNATIONAL JOURNAL OF MECHANICAL ENGINEERING

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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 aceramic 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 thealuminium 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 AlB4C 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 800

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 formof 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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International Journal of Mech

6340(Print), ISSN 0976 6359(O

The Al6061 was melted in cruc

quantity were added to the molte

The molten material was held fo

stirred with a graphite rod durin

aluminium and halide salt K2Ti

and the molten mix is poured int

Figure.

III. CHARACTERISATION

The fabricated composit

characterisation. EDX and SE

Resolution Scanning Electron

hardness testing machine. The t

in Figure.3, as the test specimen

and 5 mm in thickness. The te

nical Engineering and Technology (IJMET),

line) Volume 4, Issue 1, January - February (201

111

Figure 1: In-situ Processing

ible and premixed K2TiF6 and graphite powder

n aluminium and melt temperature was maintai

r 20 minutes and for the proper mixing the mol

this exothermal reaction will take place betwe

6. After 20 minutes the slag is removed from t

o the mould. Figure.2 shows fabricated composi

2: Al- TiC composite rod (5% TiC)

F AL-5% TIC COMPOSITE

was subjected to EDX, SEM and hardness tes

tests were performed on F E I Quanta FE

icroscope. Micro hardness test was performe

st specimen prepared for SEM and EDX testin

is circular in shape and the dimensions are 5m

t specimen is well polished by using belt gri

ISSN 0976

3) IAEME

of measured

ned as 900

c.

en metal was

en the molten

e molten mix

te rod.

t to know the

200 - High

d on Vickers

were shown

in diameter

der and disc


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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 aredistributed homogeneously in the matrix. The size of the reinforcement particles are less than

1m.

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.

Moseleys Law is basis for the EDX analysis. Moseleys Law was shown in the equation 1.

E= C1 (Z- C2)2equation 1

Where E= energy of the emission line

Z= atomic number of the emitter

C1 and C2 are constants


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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 gramwith 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 m

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 1m. 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. Vickers 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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V. ACKNOWLEDGEMENT

The Authors would like to thank the management of Chiranjeevi Reddy Institute ofEngineering & 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 ofAA6061B4C stir cast composite, Materials and Design 32 (2011) 4004-4009.[2]Kaczmar JW, Pietrzak K, Wlosinski W, The production and application of metal matrixcomposite materials, J Mater Process Technol 2000, 106, 5867.

[3]S. Jerome , B.Ravisankar,PranabKumarMahato,S.Natarajan, Synthesis and evaluation ofmechanical and high temperature tribological properties of in-situ AlTiC 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 MatrixComposites, 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-situMethods, 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 elementalcarbon, Mater Lett, 2005, 59, 37953800.[9]Yucel Birol, Response to thermal exposure of Al/ K2TiF6/C powder blends, Journal of Alloysand Compounds 455 (2008) 164-167.

[10]Y.Birol, In situ synthesis of AlTiCp composites by reacting K2TiF6 and particulate graphitein 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 TiCparticulates locally reinforced aluminium matrix composites by self-propagating reaction duringcasting, Materials Science and Engineering A 473 (2008) 166171.

[12]Anandakrishnan, A. Mahamani, Investigations of flank wear, cutting force, and surfaceroughness in the machining of Al-6061TiB2 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 IndentationLoad 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 ofMinnesota 1-26).

[15]A. Mahamani, Machinability Study of Al-5Cu-TiB2 In-situ Metal Matrix CompositesFabricated 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 SituComposite International Journal of Mechanical Engineering & Technology (IJMET), Volume 3,

Issue 3, 2012, pp. 229 - 240, Published by IAEME

Fabrication and Characterisation of in-situ Al-tic Composite-2

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