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Study on physical and mechanical properties of TiO2 filled A380 Alloy Composites

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  • Save International Journal of Composite M aterials 2013, 3(3): 69-72 DOI: 10.5923/j.cmaterials.20130303.05 A Study on the Physical and Mechanical Properties of TiO2 Filled A380 Alloy Composites Swati Gangwar1, Amar Patnaik2,* 1M echanical Engg and M ining M achinery Engg, Indian School of M ines (ISM ) Dhanbad, India 2M echanical Engineering Department, M .N.I.T. Jaipur, 302017, India Abstract Metal Matrix Co mposites (MMCs) have evoked a keen interest in recent times fo r potential applications in aerospace and automotive industries owing to their superior strength-to-weight ratio and high temperature resistance. The widespread adoption of particu late filled metal mat rix co mposites (PRMM Cs) for engineering applications has been hindered by the high cost of producing components. Therefore, PRMM Cs are increasingly attracting the attention of automotive and consumer goods industries. The physical and mechanical properties for the mic ro TiO2 (1, 3, 5, 7 and 9wt.-%) filled A 380 alloy co mposites are studied and it is concluded that the results of mechanica l properties for TiO2 (micro) filled A 380 alloy composites are satisfactory except the fle xura l strength and impact strength. The physical properties such as void fraction of TiO2 (micro) filled A 380 alloy composites increases (2.22 to 3.02%) with the increased in filler contents (1-9wt.-%) and the hardness of the composites increases from 35.5 Hv to 62.5Hv respectively. Similarly, the result for impact strength varies fro m 6.11J to 4.22J fro m 1wt.-% to 9wt.-% respectively for micro TiO2 filled A380 alloy. Keywords A 380 A lloy, Tio2 Micro Part icles, Mechanical Properties 1. Introduction Metal mat rix co mposites (MM Cs) have received major attention in the recent decades as used as an engineering material in various industrial applications. The introduction of reinforcement into a metal mat rix p roduces a composite material with an attract ive co mb inat ion o f physical and mechan ical propert ies that cannot be obtained in unfilled monolith ic alloys. Hen ce, MM Cs are primary cand idate materia ls for industrial applications such as in the aerospace, auto mo t ive and p o wer ut ilit y ind ust ries resp ect iv ely . However, their properties such as strength, toughness, and corrosion resistance and wear properties depend to a great extent on number of factors of which mat rix p roperties are v ery imp o rt ant [1]. Park et al.[2] was fou nd t hat t he co mpos it es wh ich hav e h igher elast ic modu li than t he unreinfo rced alloy and the elastic modu lus increased as particle volu me fraction was increased but in a progressively decreasing in rate. The composites have better tensile and yield strengths then the unreinforced alloy and also lo wered ductility than the unreinforced alloy. Hence, the nature and morphology of the composites, their behavior and properties can be predicted and the factors such as intrinsic properties, structu ral arrang ement and the interact ion bet ween the * Corresponding author: amar_mech@si (Amar Patnaik) Published online at Copyright © 2013 Scientific & Academic Publishing. All Rights Reserved constituents are of much importance as reported by Kumar et al.[3]. The factors that determined the properties of composites are volume fract ion, microstructure, homogeneity and isotropy of the system and these are strongly influenced by reinforcement proportions and properties of the mat rix materials. Similarly, Koker et al.[4] predicted the bending strength and hardness of particulate filled Al–Si–Mg metal mat rix co mposites (MMCs) by using different types of algorithms used in neural network applications and concluded that Levenberg–Marquardt (LM) learning algorith m shown the best predictive results for both bending strength and harness of aluminiu m metal matrix co mp o s ites . This study covered the fabricat ion of titania filled A380 alloy co mposites by stir casting technique and study their physical and mechanical properties respectively. The physical/ mechanical properties of the fabricated part iculate filled alloy composites were studied experimentally. 2. Experimental details 2.1. Composites Preparation This paper consider TiO2 as a reinforcing material with particles size o f 80 µm, wh ich is filled in A 380 alloy (Co mposition according to ASTM.SC114A ) with five different weight percentages (1, 3, 5, 7 and 9wt. %) respectively. The preparation of co mposite was done by conventional method i.e. stir casting technique. In this 70 Swati Gangwar et al.: A Study on the Physical and M echanical Properties of TiO2 Filled A380 Alloy Composites technique A380 alloy were melted at 750°C in a graphite crucible by using muffle furnace, after that particulates of TiO2 (micro) was added and stirred with stainless steel stirrer (for 4-5 min at 750 rp m) which having alu minite coating. After that the molten mixer was poured into a mold and then cools down gradually. Then the samp les were sized as per our experimental requirement and then surface is grounded with fine emery paper. Lastly, samples were ready for different physical, mechanical and surface mo rphology etc, also the surface morphology was examined via SEM (scanning electron microscopy) using apparatus with EDAX attachment. 2.2. Physical and Mechanical Testing In the present study, Archimedes principle was being used for analysis of theoretica l density and the experimental density of the TiO2 (micro) filled A380 alloy co mposites were calculated by simp le water immersion techniques. The void fraction was then calculated by the ratio of difference of theoretical and experimental density divided by theoretical density respectively. Hardness was performed on Balancing Instruments and Equip ment (Miraj) Private Limited, Model No. TSM, SR. No. 014. Bo mbay, India. The diamond indenter of 1/16” diameter and load of up to 10N was specified for the measurement. The tensile test was performed on universal testing machine (UTM) Instron 1195 (ASTM D 3039-76) to carry out on a flat rectangular specimen with straight end tab of 150 mm × 10 mm × 10 mm with a span length of 75 mm, at 2mm/s cross-head speed. Similarly, the flexural strength of the proposed composites were determined using same universal testing machine (UTM ) Instron 1195 fo llo wing as per ASTM D2344-84 standard. The standard size of specimen was 50 mm × 4 mm × 4 mm with span length of 40 mm at 2mm/s cross-head speed. The fle xura l strength was calculated by Equation, as: FS = 3PL 2bt 2 (1) where, P is the maximu m load, b the width of specimen and t the thickness of specimen and L is the span length of the s amp le. The impact strength test was performed as per ASTM D-256 using impact tester. The standard specimen for ASTM D-256 is 64 × 12.7 × 3.2 mm3 and the depth under the notch is 10.2 mm. The respective values of impact energy of different specimens are recorded directly from the dial indicator. In this work, micro TiO2 with the particle size of 80 µm which is filled with A 380 alloy co mposites system has been studied for d ifferent given percentage of reinforcement (fro m 1 to 9wt.-%). Fro m the result it has found that the values which co me after experimental procedure is lower than the theoretical result and with the increasing percentage of reinforcement the value of density become decreases (Figure 1). So that fro m the reading it has found that void fraction increases with the increasing in weight percentage of filler content in A 380 alloy co mposites. This shows that the theoretical consideration is based on idealistic assumptions which is differs fro m experimentally. Justice et al.[5] studied about Dual energy X-ray microtomography measurements above and below the Zr K absorption edge have been used to make separate reconstructions of ZrO2 particle and void distributions in failed metal matrix co mposite tensile test specimens and concluded that the Dual energy XMT has been used successfully to determine the spatial distribution of voids and reinforcement in model ZrO2 reinforced Al alloy MM Cs. 3.2. Effect of Hardness on Ti O2 Filled Alloy Composites The hardness of the TiO2 (micro) filled A380 alloy composites is determined experimentally and the results show that the value of particu late filled metal alloy composite increases with the increased in filler content of the composites as shown in Figure 2. This may be occurred due to the presence of harder particle of TiO2 (micro) ceramic phases then A 380 alloy phases in the co mposite. For 9 wt.-% TiO2 (micro) reinforcement the experimental value of hardness is maximu m i.e. 62.6 Hv. The hardness specimens prepared in accordance with ASTM E10 were subjected to the hardness test in a Brinell hardness testing machine in the research paper by Sharma et al.[6]. The result shows an increase in hardness by about 10% as the content of zircon in the co mposite is increased fro m 1 to 5%. 3.0 2.7 2.4 Void fraction (%) 3. Result and Discussion 3.1. Effect of Voi d Fraction on TiO2 Filled Alloy Co mpos ites By the use of Archimedes principal, experimental density for TiO2 (micro) filled A 380 alloy composites are calculated. 2.1 1 3 5 7 9 Titania content (wt.%) Figure 1. Effect of void fraction on titania filled alloy composites International Journal of Composite M aterials 2013, 3(3): 69-72 71 65 60 55 Hardness (Hv) 50 45 40 35 30 1 3 5 7 9 Titania content (wt.%) Figure 2. Effect of hardness on titania filled alloy composites 3.3. Effect of Tensile Strength on TiO2 Filled Alloy Co mpos ites The tensile strength result results were calculated at different wt.-% of TiO2 (micro ) filled A 380 alloy composites as shown in Figure 3. The variations in strength may be due to the improper mixing of filler contents in the metal alloy material. Similar, observations by McDanels[7] has investigated for SiC-particle reinforcement in different alloy matrices and reported that upto 60% increase in the ultimate tensile strength (UTS), depending upon the type of alloy and the amount of reinforcement respectively. Similarly, Doel and Bowen[8] concluded that the material reinforced with 13 p m SiC was found to have greater 0.2% proof stress and tensile strength then the material reinforced with 5 p m SiC. alloy co mposites were linearly increased. Therefore, automatically the bending strength decreases with the increase in t itania content in the matrix alloy. The flexu ral strength decreases with the increased in TiO2 content in A 380 alloy co mposites as bending strength strongly depends on the micro-structural characteristics and matrix alloying elements. Hence, during bending test the interfacial bond unable to transfer properly between the mat ix and the titania filler part icles. There may be another reason with the decrease in bending strength is the reinfo rced hard part icles dissolved in the matrix which causing material emb rittlement and possibly loss of strength in the composites. 3.5. Effect of Impact Strength on TiO2 Filled All oy Co mpos ites 400 375 350 325 300 275 250 Flexural strength (MPa) 1 3 5 7 9 Titania content (wt.%) Figure 4. Effect of flexural strength on titania filled alloy composites 3.4. Effect of Flexural Strength on TiO2 Filled Alloy Co mpos ites 6.0 Impact strength (J) 300 5.5 Tensile strength (MPa) 285 5.0 270 4.5 255 240 225 1 3 5 7 9 Titania content (wt.%) Figure 3. Effect of tensile strength on titania filled alloy composites The flexu ral strength of the titania filled A380 alloy composites are shown in Figure 4. The dramat ic reduction in flexu ral strength was observed in Figure 4 due to with the increase in titania content in the base alloy the porosity of the 4.0 1 3 5 7 9 Titania content (wt.%) Figure 5. Effect of impact strength on titania filled alloy composites During the Izod impact test the Impact strength of the TiO2 (micro) filled A380 alloy co mposites in terms of impact energy absorbed in Joules (Figure 5). It was observed that the impact strength decreases with the addition of filler content in alloy material. The reason for decreasing in impact strength may be the toughness of the matrix material because the impact strength was strongly influenced by toughness. 72 Swati Gangwar et al.: A Study on the Physical and M echanical Properties of TiO2 Filled A380 Alloy Composites The significant improvement in mechanical properties on effect of TiO2 (mic ro) was due to proper mechanical bonding occurred between the filler and matrix materials. Sharma et al.[6] observed that impact strength (in terms of impact energy absorbed in Joules during the Charpy impact test) of the composite specimens as well as the base alloy along with standard deviation plotted against the zircon content. It was observed that the toughness of the composites decreases monotonically with the increased in zircon content. 4. Conclusions The following silent points have been drawn for TiO2 (micro) filled A 380 alloy co mposites in this study as below, ● The void content for the TiO2 (micro) filled A 380 alloy co mposites increases with the increment of filler content up to 9wt.-% fro m 2.219 to 3.026%. The reason behind the increment of void content may be the imp roper mixing of reinforcement with the A 380 alloy material. However, as far as hardness was concerned, it increases with the increasing in filler content in A 380 alloy material. ● For the tensile strength it’s concerned that it will be higher with the addition of filler content in the alloy composites. Fro m this analysis it was concluded that few weight percentage of TiO2 (micro) not properly mix with A380 alloy materia l because the presence of hard particles in alloy co mposites. ● The flexural strength of TiO2 (micro) filled A 380 alloy co mposites was decreased with the increasing in filler content in alloy material. Similarly, the impact strength was showing the same results for unfilled and part iculate filled alloy co mposites like flexu ral strength. REFERENCES [1] S.C.Sharma, B.M .Girish, R. Kamath, B.M. Satish, “Effect of SiC particle reinforcement on the unlubricated sliding behavior of ZA- 27 alloy composites”, Wear, vol. 213, pp.33-40, 1997. [2] B.G. Park, A.G. Crosky, A.K. Heller, “M aterial characterization and mechanical properties of Al2O3-Al metal matrix composites”, Journal of materials science, vol. 36, pp.2417:2426, 2001. [3] G. B. Veeresh Kumar, C. S. P. Rao, N. Selvaraj, “M echanical and Tribological Behavior of Particulate Reinforced Aluminum M etal M atrix Composites – a review”, Journal of M inerals & M aterials Characterization & Engineering, vol. 10, pp. 59:91, 2011. [4] R. Koker, N. Altinkok, A. Demir, “Neural network based prediction of mechanical properties of particulate reinforced metal matrix composites using various training algorithms”, M aterials and Design, vol. 28, pp. 616–627, 2007. [5] I. Justice, B. Derby, G. Davis, P. Anderson, J. Elliott, “Characterization of void and reinforcement distributions in a metal matrix composite by X-ray edge-contrast microtomography”, Scripta M aterialia, vol. 48, pp. 1259-1264, 2003. [6] S.C. Sharma, B.M . Girish, D.R. Somashekar, “Rathnakar Kamath, B.M . Satish, M echanical properties and fractography of zircon-particle-reinforced ZA-27 alloy composite materials”, Composites Science and Technology, vol. 59, pp.1805-1812, 1999. [7] D.L. M cDanels, “Analysis of stress-strain, fracture, and ductility behavior of aluminum matrix composites containing discontinuous silicon carbide reinforcement”, M etal Trans, vol.16, pp.1105-1114, 1985. [8] T. J. A. Doe1, P. Bowen, “Tensile properties of particulate-reinforced metal matrix composites”, Composites Part A, vol. 27, pp.655-665, 1996.

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