INTERNATIONALMechanical Volume 4, Issue 1, January - February (2013) © IAEME– International Journal of JOURNAL OF MECHANIC...
International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –6340(Print), ISSN 0976 – 6359(Online) V...
International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –6340(Print), ISSN 0976 – 6359(Online) V...
International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –6340(Print), ISSN 0976 – 6359(Online) V...
International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –6340(Print), ISSN 0976 – 6359(Online) V...
International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –6340(Print), ISSN 0976 – 6359(Online) V...
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Fabrication and characterisation of in situ al-tic composite


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Fabrication and characterisation of in situ al-tic composite

  1. 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: Impact Factor (2012): 3.8071 (Calculated by GISI) ©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: 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 109
  2. 2. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –6340(Print), ISSN 0976 – 6359(Online) Volume 4, Issue 1, January - February (2013) © IAEMEwetting and heterogeneity in microstructure [5]. Ex-situ composite fabrication methodconsists of many stages, like sorting, alignment, infiltration and sintering [4]. As in In-situ process the ceramic reinforcement is incorporated into the matrix by thechemical 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 asthe matrix reinforcement interface, yielding better tailorability of the composites [6]. In-situcomposites are having advantages like they are more homogeneous in their microstructureand thermodynamically more stable and they also have strong interfacial bonding betweenthe reinforcements and the matrices [4]. Applications of in-situ composites include wear partsfor 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 byIn-situ reaction. As several researchers did research on In-situ composites and found thathalide salts plays a major role in the development of reinforcement in the metal matrixcomposites. Aluminium alloys have high strength at room temperature. The strength andother mechanical properties are reduced when the aluminium alloy is used at hightemperatures. The above problem can be solved by incorporating TiC reinforcement into thealuminium matrix [8]. TiC is particularly attractive as it offers high hardness and elasticmodulus, 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 wearcharacteristics were studied by S. Natarajan et al. [3]. A. Mahamani et al. [15] performedmachinability study on Al-5cu-TiB2 MMC.The Al–B4C composites were produced by modified stir cast route with different weightpercentage of reinforcement and the microstructure, mechanical properties were evaluated byK.Kalaiselvan et al. [1]. Birol et al. [9] produced Al-TiC with different blends by varying themelt temperature and found that Al3Ti particles were gradually replaced by TiC particleswhen the powder blend was heated above 800о C. Birol [10] performed SEM and XRDanalysis and found that TiC particles apparently formed in increasing numbers withincreasing 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 theincreased temperature.A.Mahamani [4] fabricated Al-TiB2 and performed EDX analysis and micro hardness testingand stated that hardness of the aluminium is increased by adding TiB2 particles. M.S.Song etal. [11] fabricated Al-TiC by self-propagating high-temperature synthesis (SHS) reaction andperformed SEM analysis and stated that the size of the TiC particulates decreased withincreasing Al contents in the blends. As the present work mainly focus on to fabricate Al-TiCcomposite by In-situ process by the reaction of K2TiF6 and graphite powder with the moltenAluminium. An investigation is done on the hardness by the addition of the TiC particles tothe Al-6061 by using micro hardness testing. Quantitative elemental analysis is performed byEDX testing to know the presence of TiC particles and SEM is performed to know theorientation and arrangement of the TiC particles.II. EXPERIMENTAL PROCEDURE The matrix used for fabrication of the Al-TiC composite was Al6061, for 5% TiCreinforcement 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 compositeprocessing [12] was shown in Figure. 1. 110
  3. 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 ProcessingThe Al6061 was melted in crucible and premixed K2TiF6 and graphite powder of measuredquantity 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 wasstirred with a graphite rod during this exothermal reaction will take place between the molten ealuminium and halide salt K2TiF6. After 20 minutes the slag is removed from the molten mixand 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 thecharacterisation. EDX and SEM tests were performed on F E I Quanta FEG 200 - HighResolution Scanning Electron Microscope Micro hardness test was performed on Vickers Microscope.hardness testing machine. The test specimen prepared for SEM and EDX testing were shownin Figure.3, as the test specimen is circular in shape and the dimensions are 5mm in diameterand 5 mm in thickness. The test specimen is well polished by using belt grinder and disc 111
  4. 4. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –6340(Print), ISSN 0976 – 6359(Online) Volume 4, Issue 1, January - February (2013) © IAEMEpolisher. Fabricated composite was examined under scanning electron microscopy (SEM) toascertain the formation of TiC particles and their distribution. Figure.4 shows scanningelectron micrograph of the fabricated Al-5% TiC composite material. The SEM imagediscovers 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 than1µm.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 TiCparticles. Figure.5 shows EDX spectrum of the Al-TiC 5% composite. Figure.5: EDX analysis of Al-5% TiCIn EDX analysis[14] Y-axis represents the counts that is number of X rays received andprocessed 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 112
  5. 5. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –6340(Print), ISSN 0976 – 6359(Online) Volume 4, Issue 1, January - February (2013) © IAEMEIf the energy of the respected X-ray is determined then the atomic number of the elementproducing the line can be determined. Figure.5 shows the presence of Ti and C particles inthe 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 inFigure.6. The shape of the specimen is cube 10mm side. The test specimen was well polishedbefore 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 theaddition of the TiC reinforcement to the matrix the average hardness of Al-5% TiC wasincreased to 55.4 HV at 300 gram test load. Hardness value of the fabricated Al-5% TiCcomposite 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 55.46In 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 µmThe hardness value increases with the decrease in the test load. As the test load increases theindentation size increases [13] and which will affect the hardness value. Depending uponmaterial, 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 thereaction of the halide salt K2TiF6. Scanning electron microscopy (SEM) was performed onthe fabricated composite material and it shows that TiC reinforcement is properly distributedover that matrix and size of the reinforcement was less than 1µm. Energy – dispersive X-rayspectroscopy(EDS) was done on the fabricated composite and investigated the presence Tiand C elements in the Al-5% TiC composite material. Vicker’s micro hardness test wasconducted and it reveals that by the addition of TiC reinforcement to the Al6061 matrix thehardness value was increased. 113
  6. 6. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –6340(Print), ISSN 0976 – 6359(Online) Volume 4, Issue 1, January - February (2013) © IAEMEV. ACKNOWLEDGEMENT The Authors would like to thank the management of Chiranjeevi Reddy Institute ofEngineering & Technology, Anantapur for the encouragement and support. The thanks alsoextend to the management of SRM University and MICROLAB Chennai for providing labfacility.REFERENCES[1] K. Kalaiselvan, N. Murugan, Siva Parameswaran, Production and characterization ofAA6061–B4C 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, 58–67.[3] S. Jerome , B.Ravisankar,PranabKumarMahato,S.Natarajan, Synthesis and evaluation ofmechanical and high temperature tribological properties of in-situ Al–TiC composites, MaterialScience 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, 3795–3800.[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 Al–TiCp 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) 166–171.[12] Anandakrishnan, A. Mahamani, Investigations of flank wear, cutting force, and surfaceroughness 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 IndentationLoad and Time on Knoop and Vickers Microhardness Tests for Enamel, Materials Research, Vol12, 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 114