STUDIES ON MECHANICAL AND WEAR PROPERTIES OF Al7075

International Conference on Current Research in Engineering Science and Technology (ICCREST-2016)

E-ISSN :2348 - 8360 www.internationaljournalssrg.org Page 15

STUDIES ON MECHANICAL AND WEAR PROPERTIES OF Al7075/ZIRCON/FLYASH HYBRID METAL MATRIX COMPOSITES

JITHIN JOSE PG Scholar, Department of Mechanical Engineering

Anna University Regional Campus Madurai, India

Dr. P. MUTHU Assistant Professor, Department of Mechanical Engineering

University College of Engineering Ramanathpuram, India

Abstract— Two phases namely a matrix and a reinforcement phase constitute composite materials. Most of studies shows that the material used for components should posses better mechanical and tribological properties. In this paper four samples were prepared by using stir casting. First sample is Al7075, second sample consist of Al7075 with 3% Zircon, third sample consist of Al7075 with 6% Fly Ash and the fourth sample is of Al7075 with 3% Zircon and 6% Fly Ash. It was found that tensile strength and hardness is increased when Zircon and Fly Ash is added to Al7075. Wear is decreased when Zircon and Fly Ash is added to Al7075. Microstructure is also studied using Scanning Electron Microscope to understand the wear.

Keywords—Metal matrix composite; Reinforcements; Mechanical properties; Tribological properties

I. INTRODUCTION Current engineering applications require materials

with broad spectrum of properties like stronger, lighter and less expensive which are quite difficult to meet using monolithic material systems. Metal matrix composites (MMCs) have been noted to offer such tailored property combinations required in a wide range of engineering applications. Some of these property combinations include: high specific strength, low coefficient thermal expansion and high thermal resistance, good damping capacities, superior wear resistance, high specific stiffness and satisfactory levels of corrosion resistance. Metal Matrix composites (MMC) are advanced materials formed by combining a ductile metal/metallic alloy with one or two hard phases, called reinforcements, to exploit the advantages of both. Alumina, boron, Silicon Carbide etc are the most commonly used non-metallic reinforcements, combined with Aluminum, Magnesium etc., to obtain composites. It provides unique combination of properties such as high strength-to-weight ratio, stiffness, hardness, wear resistance, thermal/electrical conductivity, fatigue resistance etc. The particulate reinforced composites are gaining importance in now days because of their low cost with advantages like isotropic properties and the possibility of secondary processing facilitating fabrication of secondary components. Composite materials are multiphase materials that exhibits a significant proportion the properties of both constituent phases such that a better combination of

properties is realized. According to this principle of combined action, better property combinations are fashioned by the judicious combination of two or more distinct materials. A typical definition of composite is “a multiphase material that is artificially made in which the constituent phases must be chemically dissimilar and separated by a distinct interface”. Many composite materials are composed of just two phases; one termed the “matrix”, which is continuous and surrounds the other phase, often called the “reinforcement”. The properties of composites depend upon the type of reinforcement, their amounts, orientation, and the geometry of the reinforcement.

Metal Matrix Composites (MMC) are composed of a metallic matrix (aluminium, magnesium, iron, cobalt, copper) and a dispersed ceramic (oxides, carbides) or metallic (lead, tungsten, molybdenum) phase. Ceramic reinforcement may be silicon carbide (SiC), boron, alumina, silicon nitride, boron carbide (B4C), boron nitride etc. whereas metallic reinforcement may be tungsten, beryllium etc . MMCs are used for Space Shuttle, commercial airliners, electronic substrates, bicycles, automobiles, golf clubs and a variety of other applications. From a material point of view, when compared to polymer matrix composites, the advantages of MMCs lie in their retention of strength and stiffness at elevated temperature, good abrasion and creep resistance properties. Most MMCs are still in the development stage or the early stages of production and are not so widely established as polymer matrix composites. The biggest disadvantages of MMCs are their high costs of fabrication, which has placed limitations on their actual applications. There are also advantages in some of the physical attributes of MMCs such as no significant moisture absorption properties, non-inflammability, low electrical and thermal conductivities and resistance to most radiations. MMCs have existed for the past 30 years and a wide range of MMCs have been studied. Based on the potential benefits of MMC, in this work an attempt has been made to examine the various factors like effect of various reinforcement, mechanical behaviour and tribological behavior of Aluminium Al7075/Zircon/flyash metal matrix composites were discussed.



II. LITERATURE REVIEW

A. Mechanical Properties Muruganandan et al. (2015) used Aluminium 7075 as a

matrix material with fly ash and titanium carbide as reinforcement materials. A comparison has been made between the reinforced and unreinforced alloys such as Al6061, Al7075 and concluded that the tensile strength and hardness of the proposed composite is increased by increasing the weight percentage of fly ash and titanium carbide. Sachin Malhotra et al.(2013) investigated the effect of reinforcement of Zirconia and Fly Ash on mechanical properties of Al 6061 aluminium alloy composites samples, processed by stir casting method. Two sets of composites were prepared with fixed percentage of fly ash (10%) and varying percentage of Zirconia (5% and 10%) by weight fraction. The author has revealed that increase in percentage increases the properties such as tensile strength and hardness. Sreenivasa Reddy et al.(2012) investigated on formation of a hybrid composite by using industrial waste fly ash and E glass short fibers by dispersing them into Al7075 alloy by Stir casting method. The MMC was obtained for the different compositions of E-glass and Fly ash particulates. The specimens were tested for tensile test at different loads by using Universal Test Machine. The results are plotted and it is concluded that the MMC obtained has got better tensile strength compared to Al7075 alloy alone. Further, tensile strength slightly increased with 1 hour aging heat treatment. For 3 hour and 5 hour aging tensile strength decreases. Jebeen Moses et al.(2014) investigated the effect of Al6061 reinforced with various amounts (0, 5, 10 and 15 wt. %) of SiC. The microstructures of the AMCs were studied using optical and scanning electron microscopy. It was observed that the distribution of SiC particles in the matrix was uniform and SiC particle clusters were also seen in a few places. SiC particles were properly bonded to the aluminum matrix. Microhardness and ultimate tensile strength was tested and it was found that reinforcement of SiC particles improved the microhardness and ultimate tensile strength (UTS) of the AMCs.

Pradeep et al. (2014) studied the effect of reinforcement of red mud and silicon carbide with Al7075 aluminium metal matrix composite under different working conditions. The samples are fabricated using stir casting technique. The samples are heat treated to enhance the mechanical properties. They found that the combination of a matrix material with SiC and red mud particles improves mechanical properties like tensile strength, compressive strength, hardness and yield strength. Also microstructure studies indicated the presence of fine inter metallic particles SiC and Red mud reinforced in between Aluminium dendrite structure. Jenix Rino et al. (2013) compared the properties of Al6063 MMC reinforced with Zircon Sand and Alumina with four different volume fractions of Zircon sand andAlumina with varying volume fractions of (0+8)%, (2+6)%, (4+4)%, (6+2)%and (8+0)%. The hardness and the tensile strength of the composites are higher for (4+4) %. In this combination, the particle dispersion is uniform and the pores are less where inter-metallic particles are formed.

Flores et al. (2010) used Al7075 aluminum alloy with carbon-coated silver nanoparticles prepared by mechanical milling process. It had been found that carbon-coated silver nanoparticles have an effect in refining the powder and in the crystal size. MgZn2 phase present in annealed samples was dissolved by milling process. Microstructure was analysed using scanning electron microscope. The Vickers microhardness (HVN) values are higher at higher carbon-coated silver nanoparticle contents. It has been found that a saturation point exists where microhardness does not vary even after increasing the percentage of carbon-coated silver nanoparticles. Mobasherpour et al. (2013) produced nano-crystalline Al7075 alloy powders reinforced with 1, 3 and 5 vol. % of Al2O3 powder at nano-size level. Hot pressing was employed to accelerate and gain the actual properties of powder metallurgy products. After manufacturing the nano metal matrix composite the nano-composite powders were characterized by Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM), and X-ray Powder Diffraction (XRD). Crystallite size and lattice strain of various Al7075 composite powders were estimated with broadening of XRD peaks. XRD results showed that the crystallite size of aluminum reached 42.30 nm, 36.25nm and 32.22 nm, respectively, after 20 hour milling in case of Al7075/1, 3, and 5 vol. % of Al2O3 nano-composite powder with uniform particle size distribution. TEM observation confirmed the nano-crystalline nature of Al7075/5 vol. % of Al2O3 milled powder. It was found that for Al7075-nano Al2O3 hardness and ultimate tensile strength increased with increasing percentage of nano Al2O3.

Ravesh and Garg (2012) reported that the hardness of fly

ash-SiC-reinforced hybrid aluminium composites increased with increasing volume fraction reinforcements. The Rockwell hardness on the C scale was observed to be 61, 70, 81 and 93 for 2.5%, 5%, 7.5% and 10% of SiC, respectively, with a constant 5% fly ash-reinforced hybrid Al 6061-T6-treated hybrid matrix composites. Mahagundappa et al. (2006) have studied the influence of reinforcement and thermal aging on the mechanical properties of Al 6061 based hybrid composites, and concluded that the ultimate tensile strength, compression strength, young’s modulus and hardness increases with increasing the reinforcement content but the ductility decreases substantially. And all these things also increase with increase in the aging duration with the marginal improvement in the ductility which may be due to the formation of precipitate in matrix alloy.

B. Tribological Properties Deepak Singla et al. (2013) analyzed that sliding speed

and effect of load on the friction coefficient and wear properties of Al 7075-Fly Ash composite material on pin on disc apparatus. Result shows that the coefficient of friction increases as the fly ash content increases and improves the ability to resist the wear. This is due to the favorable effect of fly ash particles which increases the hardness of composite material up to some range. However the addition of 30gm fly ash particles in the Al 7075 was very effective to improve its



ability to resist the material loss. Vinitha et al. (2014) investigated the tensile strength, impact strength and wear resistance of Al 7075 Alloy reinforced with Fly ash, SiC and Redmud. They observed that the tensile and impact strength was higher in Al7075-SiC-Redmud composite than Al7075-SiC-Flyash. The wear resistance of the composite Al7075-SiC-Flyash, was higher by maintaining the constant weight percentages of SiC and Fly ash while it decreases by increasing the weight percentage of Fly ash. In Al7075-SiC-Redmud, wear resistance increases with increase in Red mud content. Sucitharan et al. (2013) studied the wear behaviour of Al6063 Aluminium alloy with Zircon sand composite produced by the stir casting technique by controlling various casting parameters. The combination for studying wear behavior of composites investigated is 0, 2, 4, 6, 8 wt% of ZrSiO4 with the matrix and it was found that the increase in reinforcement increase the wear resistant property.

Viney kumar et al.(2014) investigated the effect of speed on wear rate and mechanical properties of Al6061+4%MG and Al6061+ 4%MG+4%Graphite with varying composition of Fly ash i.e. 10%, 15% and20% as reinforcement. It was found that hardness and tensile strength increased with addition of fly ash but when graphite was added then a decrease in tensile and hardness was observed. The composite with 4%Mg, 15%Fly ash found to be maximum tensile whereas composite of 4%Mg, 20%Fly ash was found to be of maximum hardness. Wear rate decreased with addition of fly ash up to a certain volume and with addition the graphite it also decreases further. Veeresh kumar et al.(2010) studied the hardness, tensile strength and wear resistance properties of Al6061-SiC and Al7075-Al2O3 composites. The composites are prepared using the liquid metallurgy technique, in which 2-6 wt. % of reinforcement were added in the base matrix. The SiC and Al2O3 improved the hardness and density of their respective composites. Further, the increased percentage of these reinforcements contributed in increased hardness and density of the composites. The microphotographs showed the uniform distribution of the particles in the matrix system. The dispersed SiC in Al6061 alloy and Al2O3 in Al7075 alloy contributed in enhancing the tensile strength of the composites. trained ANN were found in good agreement with measured values. Prashant Kumar Suragimath et al.(2013) fabricated light metal (LM6) aluminium based metal matrix composite and SiC, Fly Ash and then studying its microstructure and mechanical properties such as tensile strength, impact strength and wear behavior of produced test specimen. Experiment has been conducted by varying weight fraction of Fly Ash (5% and 15%) while keeping SiC constant (5%). The results revealed that the increase in fly ash, increased the tensile strength, impact strength, wear resistance of the specimen and decreased the percentage of elongation. Balaji et al. (2015) conducted various tests on Al7075 reinforced with SiC to know the various properties such as tensile strength, hardness and wear. It was observed that there was an increase in strength, hardness and wear resistance by about 10 percent compared to Al6061. From Micro structure

analysis conducted on the material revealed that uniform distribution of SiC particles in the metal matrix system.

Deaquino Lara et al. (2015) fabricated Al7075 with graphite composites produced by using mechanical alloying and hot extrusion. Effects of milling time and graphite concentration on friction, hardness and wear resistance of the aluminium metal matrix composite were studied by varying milling time and graphite percentage. Results showed that there is considerable improvement in hardness and wear resistance of aluminium metal matrix composite by adding 1.5% of graphite (wt.). Also, it was found that abrasion wear is the dominant wear mechanism in all extruded composites. Rajesh et al.(2014) studied the wear properties of Al6061 aluminium metal matrix composite reinforced with boron carbide processed using stir casting at lower temperature of 775 oC using halide salt K2TiF6 with ratio 0.05Ti/B4Cp . They observed improved wettability of B4C due to the addition of Ti compound in the form of K2TiF6 halide salt and uniform distribution of reinforcement from SEM micrographs. They also found that the porosity of the increased with increased volume fraction of B4C and the wear rate was minimum for Al6061+6%B4C compared to Al6061+4%B4C at a sliding velocity of 6.67m/s, load of 49.05N with a sliding distance of 565.4m.

Ravindra Singh Rana et al.(2014) studied the dry sliding wear performance of Al5083 with 10 weight percentage of SiC composites fabricated by Ultrasonic assisted stir casting process. They found that applied load has the highest influence on wear rate followed by sliding distance and sliding speed for Al-5083/10% SiC composites. Veeresh kumar et al. (2014) investigated the wear behavior of Al7075 aluminium matrix composites reinforced with SiC particulates. The wear properties of the composites containing SiC were better than that of the matrix material and further, the composite containing 6 wt% SiC content exhibited superior wear resistance. An Artificial neural network model was developed to predict the tribological properties of the Al7075-SiC composites. The predicted values of tribological properties using a well trained ANN were found in good agreement with measured values.

C. Summary of Litarature Review The above review for the aluminium based metal matrix composite leads to the following conclusions:

Among the different fabrication procedure, Stir casting method is an effective casting method to develop the metal matrix composites, to obtain uniform distribution of the reinforcement and homogeneous properties of the casting. It is also widely acceptable method due to its low cost and easy portability.

The addition of alumina, SiC, B4C, fly ash, TiC etc. particles in aluminium improves the hardness, yield strength, tensile strength and ductility.

Aluminium and its alloys reinforced with ceramics particles have shown an improvement in mechanical properties and tribological properties.



The addition of graphite increases the wear rate and decreases the hardness and coefficient of friction.

III. RAW MATERIALS

A. AL7075 Aluminium 7075 (Al7075) is chosen as the matrix

material since, it is low cost and has better properties like good thermal conductivity, high shear strength, abrasion resistance, high-temperature operation, non flammability, minimal attack by fuels and solvents, and the ability to be formed and treated on conventional equipment. It possesses excellent casting properties and reasonable strength. This alloy is best suited for mass production of lightweight metal castings. Fig. 1 shows Al7075.

Fig. 1. AL7075

B. Zircon Zircon (Zirconium Silicate - ZrSiO4) (usually of size 2-4

micron) is used for reinforcement in the form of particulates. Zircon is a very hard material, its hardness is 7.5 on Mohr’s scale and specific gravity is 4.6-4.7. The principal structural unit of zircon is a chain of alternating edge-sharing SiO4 tetrahedron and ZrO8 triangular decahedra. Fig. 2 shows Zircon.

Fig. 2. Zircon

C. Fly Ash Fly ash particles (usually of size 0.5-100 micron) which

are extracted from residues generated in the combustion of

coal. Fly ash has low density having good wetability between fly ash & matrix Al alloy. It has low cost with advantages like isotropic properties and the possibility of secondary processing. It has high electrical resistivity and low thermal conductivity. It posses low density of fly-ash may be helpful for making a light weight composites. Fig. 3 shows Fly Ash.

Fig. 3. Fly Ash

IV. SPECIMEN PREPARATION Four specimens were prepared by using stir casting.

Table I shows composition of different reinforcements which were added in matrix material Al7075. TABLE I COMPOSITION OF DIFFERENT RAW MATERIALS USED Sample No. Zircon(in Wt.%) Fly ash(in Wt.%)

1 NIL NIL 2 3 NIL 3 NIL 6 4 3 6

A. Stir Casting Procedure Al7075 was melted by raising its temperature to 9500C

and degassed using a solid dry hexachloroethane compound.

Fig. 4. Stir Casting Machine



The zircon and fly ash particles were preheated for 30 min at 4000C for improving the wetability and added to the molten metal, and stirred continuously with an impeller at a speed of 600 rpm for 5 min. The melt with reinforcement particles was poured into a cylindrical permanent metallic mold with a diameter of 20 mm and 100 mm length and ϕ20mm x 200mm. The cast rods were rapidly cooled to room temperature by knocking them out, 5mins after casting. Fig.4. shows the Stir Casting Machine.

V. RESULTS AND DISCUSSION

A. Mechanical Tests 1) Tensile Test

Tensile strength is a measurement of the force required to pull something to the point before it breaks.Tensile test was done using Universal Testing Machine (UTM). The Specimen used is of ASTM E8 standard. Fig 5 (a) and (b) shows the specimens before and after tensile testing.

Fig.5. (a) Specimens before testing

Fig.5. (b) Specimens after testing Table II shows the tensile strength and yield stress of

the composites. For Al7075 tensile strength is 112.39 Mpa

and yield stress is 101.26 Mpa. But for of Al7075 + 3% Zircon and Al7075 + 6% Fly Ash tensile strength and yield stress decreases. For Al7075 + 3% Zircon + 6% Fly Ash tensile strength is 173.1 Mpa and yield stress is 165.71 Mpa. The tensile strength increase upto nearly 65%. It is clear that tensile strength and yield stress of AL7075+ 3%Zircon+ 6% Fly Ash is increased due to bonding of AL7075, Zircon and Fly Ash. Fig. 6 describes tensile strength and yield stress of the composites

TABLE II TENSILE STRENGTH AND YIELD STRESS OF THE COMPOSITES

Al7075 Al7075+ 3% Zircon

Al7075+ 6% Fly Ash

Al7075+ 3%Zircon

+6%Fly Ash TENSILE

STRENGTH (Mpa)

112.39 68.15 99.29 173.1

YIELD STRESS

(Mpa) 101.26 60.98 94.47 165.71

Fig.6. Tensile Strength and Yield Stress of the composites

2) Hardness Test Hardness is the resistance of a material to localized

deformation. A hard material surface resists indentation or scratching and has the ability to indent or cut other materials. Hardness of the four stir casted samples was tested on Brinell Hardness Tester. In the Brinell hardness test, a hardened steel ball is pressed into the flat surface of a test piece using a specified force. The ball is then removed and the diameter of the resulting indentation is measured using a microscope.The Specimen used is of IS 1500 standard. Readings on 3 locations were taken and average reading of each sample was considered. Fig. 7 shows the specimens after hardness test.



Fig.7. Specimens after Hardness Test

Table III shows the hardness of the composites. Among the different specimen, Al7075 reinforced with 3% Zircon and 6% Fly Ash has the highest hardness of 121 BHN. But for Al7075 + 3% Zircon, Al7075 + 6% Fly Ash and Al7075 Hardness value decreases to 100.66 BHN, 90.53 BHN and 99.2 BHN respectively. Fig. 8 shows the comparison of hardness of the composites.

TABLE III HARDNESS OF THE COMPOSITES

Al7075 Al7075+3%Zircon

Al7075+ 6%Fly Ash

Al7075+ 3%Zircon + 6%Fly Ash

HARDNESS (BHN) 99.2 100.66 90.53 121

Fig.8. Comparison of hardness of composites

3) Impact test

In an impact test a notched bar of material, arranged either as a cantilever or as a simply supported beam, is broken by a single blow in such a way that the total energy required to fracture it may be determined. The energy required to fracture a material is of importance in cases of -shock loading when a component or structure may be required to absorb the K.E of a moving object. Energy absorbed is the energy which is absorbed by the material. The energy is calculated in joules. The energy absorbed is calculated the energy available at the end. The energy absorbed can be found with the help of Charpy impact tests. The standard specimen size for Charpy impact testing is 10mm×10mm×55mm. Fig.9 (a) and (b) shows the specimens before and after testing.

Fig.9. (a) Specimens before testing

Fig.9. (b) Specimens after testing

Table IV shows the energy absorbed by the composites. For Al7075, Al7075 + 3% Zircon, Al7075 + 6% Fly Ash and Al7075 + 3% Zircon + 6% Fly Ash energy absorbed are 2J. It is clear that energy absorbed is same for all compositions. Fig. 10 shows energy absorbed by the composites

TABLE IV ENERGY ABSORBED BY THE COMPOSITES

Al7075 Al7075+3%Zircon

Al7075+6% Fly Ash

Al7075+ 3%Zircon

+6%Fly Ash IMPACT (JOULS) 2 2 2 2

Fig.10. Energy Absorbed



B. Wear Test The dry sliding wear tests were performed on pin-on-disc

apparatus. Wear test samples were made of size ø7×50mm. The rotating disc material is made of EN-31 steel with the hardness of 63 HRC. Sliding wear tests were conducted on track diameter 15mm with load 10N, sliding speed 0.314 m/s and sliding distance 113.097 m. The dry sliding wear was observed by measuring weight loss. Weight loss of pins was converted into volume loss using density of specimens. Fig.11 shows the specimens used for wear tests.

Fig.11. Specimens for wear testing For Al7075, the wear rate is 0.022026 mm3/m, Specific Wear rate is 0.002202625 mm3/Nm and Coefficient of Friction is 0.486. For Al7075 + 3% Zircon, the wear rate is 0.009337 mm3/m, Specific Wear rate is 0.000933682 mm3/Nm and Coefficient of Friction is 0.426. For Al7075 + 6% Fly Ash Wear rate is 0.007189 mm3/m, Specific Wear rate is 0.000718859 mm3/Nm and Coefficient of Friction is 0.374. Finally for Al7075 + 3% Zircon + 6% Fly Ash Wear rate is 0.00355 mm3/m, Specific Wear rate is 0.000354957 mm3/Nm and Coefficient of Friction is 0.349. It is clear that Wear rate, Specific Wear rate and Coefficient of Friction is less for Al7075 + 3% Zircon + 6% Fly Ash. Table V shows Wear rate, Specific Wear rate and Coefficient of Friction. TABLE V WEAR RATE, SPECIFIC WEAR RATE AND COEFFICIENT OF FRICTION

Sl No Load Sliding Speed

Sliding Distance

Wear Rate

Specific Wear Rate

Coeff. Of Friction

Μ (N) (m/s) (m) (mm3/m) (mm3/Nm)

Al7075 10 0.314 113.097 0.022026 0.002202625 0.486 Al7075 + 3%Zircon 10 0.314 113.097 0.009337 0.000933682 0.426

Al7075 + 6% Fly

Ash 10 0.314 113.097 0.007189 0.000718859 0.374

Al7075 + 3%Zircon + 6% Fly

Ash

10 0.314 113.097 0.00355 0.000354957 0.349

C. Microstructure Analysis For Wear Test Specimen After conducting of wear test at conditions load 10N,

sliding speed 0.314 m/s and sliding distance 113.097 m of Al 7075, Al7075 + 3% Zircon , Al7075 + 6% Fly Ash and Al7075 + 3% Zircon + 6% Fly Ash compositions surfaces the

microstructure is analysed using scanning electron microscope. SEM image shows the wear on the surface of composites in the form of grooves and scratches. Figure.12(a), (b), (c)&(d) shows the microstructure of Al 7075, Al7075 + 3% Zircon , Al7075 + 6% Fly Ash and Al7075 + 3% Zircon + 6% Fly Ash respectively.

Fig.12. (a) Microstructure of Al 7075

Fig.12. (b) Microstructure of Al7075 + 3% Zircon

Fig.12. (c) Microstructure of Al7075 + 6% Fly Ash



Fig.12. (d) Microstructure of Al7075 + 3% Zircon+ 6% Fly Ash

In Al 7075, it is observed that scratches and depth of grooves along the sliding direction were much larger. In Al7075 + 3% Zircon scratches can be seen but grooves become smaller than the Al7075 alone. In Al7075 + 6% Fly Ash scratches become smaller than the previous compositions. For Al7075 + 3% Zircon + 6% Fly Ash scratches become much smaller than the all previous compositions. As the Zircon and Fly Ash content is added, the grooves along the sliding direction were smaller. This is due to the properties of zircon and fly ash. Hence ability to resist the wear is improved when Zircon and Fly Ash is added. Figure.12 shows the surfaces of Al 7075, Al7075 + 3% Zircon, Al7075 + 6% Fly Ash and Al7075 + 3% Zircon + 6% Fly Ash compositions.

VI. CONCLUSION From the experiments on Al7075/Zircon/Fly Ash hybrid

metal matrix composites, the following conclusions are obtained. Tensile strength and yield stress increases when

3%Zircon and 6% Fly Ash is added to AL7075. Hardness is more for AL7075+ 3%Zircon+ 6% Fly Ash

than composition of AL7075, Al7075 + 3% Zircon and Al7075 + 6% Fly Ash.

Impact energy absorbed is same for all four compositions. Wear rate, Specific Wear rate and Coefficient of Friction

is less for Al7075 + 3% Zircon + 6% Fly Ash than that of Al7075 + 3% Zircon, Al7075 + 6% Fly Ash and AL7075+ 3%Zircon+ 6% Fly Ash.

Amoung the four composition, AL7075+ 3%Zircon+ 6% Fly Ash is better than others when comparing its tensile strength, hardness and wear resistance.

References [1] P. Muruganandhan, M. Eswaramoorthi, and K. Kannakumar,

“Aluminium fly ash composite – an experimental study with mechanical properties perspective”, Int. J. Eng. Res., vol. 3, pp.78-83, 2015.

[2] Sachin Malhotra, Ram Narayan and R.D Gupta, “Synthesis and Characterization of Aluminium 6061 Alloy-Flyash and Zirconia Metal Matrix Composite” , Int. J curr Eng. Tech., vol. 3, pp.1717-1719, 2013.

[3] M.Sreenivasa Reddy, Soma V. Chetty and Sudheer Premkumar , “Effect of reinforcements and heat treatment on tensile strength of Al-Si-Mg based hybrid composites” , Int. J. Appl. Sci. Eng. Res., vol. 1, pp.176-183, 2012.

[4] J.Jebeen Moses, I.Dinaharan, S.Joseph Sekhar , “Characterization of silicon carbide particulate reinforced AA6061 aluminum alloy composites produced via stir casting” , Proc. Mat. Sci., vol. 5, pp.106 – 112, 2014.

[5] R. Pradeep, B.S Praveen Kumar, and B.Prashanth, “Evaluation Of Mechanical Properties Of Aluminium Alloy 7075 Reinforced With Silicon Carbide And Red Mud Composite”, Int. J. Eng. Res. Gen. Sci., vol. 2, pp.1081-1088, 2014.

[6] J.Jenix Rino, D. Sivalingappa, Halesh Koti and V.Daniel Jebin, “Properties of Al6063 MMC Reinforced With Zircon Sand and Alumina”, J Mech. and Civil Eng., vol.5, pp.72-77, 2013.

[7] R. Flores-Campos, D.C. Mendoza-Ruiz, P. Amezaga-Madrid, I. Estrada-Guel, M. Miki-Yoshida, J.M. Herrera-Ramirez and R. Martinez-Sanchez , ‘Microstructural and mechanical characterization in 7075 aluminum alloy reinforced by silver nanoparticles dispersion’ , J. of Alloys and Comp., Vol. 495, pp.394–398, 2010.

[8] I. Mobasherpour, A.A. Tofigh and M. Ebrahimi , ‘Effect of nano-size Al2O3 reinforcement on the mechanical behavior of synthesis 7075 aluminum alloy composites by mechanical alloying’, Mat. Che. and Phy., Vol. 138, pp.535-541, 2013.

[9] S.K.Ravesh, and T.K. Garg, “Preparation & analysis for some mechanical property of aluminium based metal matrix composite reinforced with SiC & fly ash”, Int. J.Eng. Res. Appl., vol. 2, pp.727–731, 2012.

[10] M.B. Mahagundappa, H.K. Shivanand and M. Muralidhara, “Influence of Reinforcements and Thermal Ageing on the Mechanical Properties of Al (6061) Based Hybrid Composites”, Ind. Found. J., vol.52, pp. 20-43, 2006.

[11] Deepak Singla and S.R. Mediratta, “Effect of load and speed on wear properties of al 7075-fly ash composite material”,Int. J. Innov. Res. Sci. Eng. Tech., vol. 2, pp.1 – 9, 2013.

[12] Vinitha and B. S. Motgi, “Evaluation of Mechanical Properties of Al 7075 Alloy, Flyash, SiC and Redmud Reinforced Metal Matrix Composites”, Int. J. Sci. Res. Devel., vol. 2, pp.190–193, 2014.

[13] K.S.Sucitharan , P.SenthilKumar, D.Shivalingappa and J.Jenix Rino, “Wear Behaviour of Al6063-Zircon Sand Metal Matrix Composite” ,Int. org Scientific Res., vol. 3, pp.24-28, 2013.

[14] Viney Kumar ,Rahul Dev Gupta and N.K. Batrab , ‘Comparison of Mechanical Properties and effect of sliding velocity on wear properties of Al 6061, Mg 4%, Fly ash and Al 6061, Mg 4%, Graphite 4%, Fly ash Hybrid Metal matrix composite’, Pro. Mat. Sci., Vol. 6, pp.1365 – 1375, 2014.

[15] G. B. Veeresh Kumar, C. S. P. Rao, N. Selvaraj and M. S. Bhagyashekar , “Studies on Al6061-SiC and Al7075-Al2O3 Metal Matrix Composites”, J. Min. Mat. Charact. Eng. , vol. 9, pp.43-55, 2010.

[16] Prashant Kumar Suragimath and Dr. G.K. Purohit , ‘A Study on Mechanical Properties of Aluminium Alloy (LM6) Reinforced with SiC and Fly Ash’, IOSR J. of Mech. and Civil Eng. , Vol. 8, No.5, pp.13-18, 2013.

[17] V. Balaji, N. Sateesh and M. Manzoor Hussain , ‘Manufacture of Aluminium Metal Matrix Composite (Al7075-SiC) by Stir Casting Technique’, Mat. Today Pro., Vol. 2, pp.3403 – 3408, 2015.

[18] R. Deaquino-Lara , N. Soltani,A. Bahrami,E. Gutierrez-Castaneda, E. Garcia-Sanchez and M.A.L. Hernandez-Rodriguez, ‘Tribological characterization of Al7075–graphite composites fabricated by mechanical alloying and hot extrusion’ , Mat. and Des., Vol. 6, pp.224–231, 2015.

[19] G.L.Rajesh, V.Auradi , Umashankar and S.A.Kori , “Processing and evaluation of dry sliding wear behavior of B4C reinforced aluminum matrix composite” , Proc. Mat. Sci., vol. 5 , pp.289 – 294, 2014.

[20] Ravindra Singh Rana, Rajesh Purohit, Anil kumar Sharma and Saraswati Rana , “Optimization of Wear Performance of Aa 5083/10 Wt. % Sic



Composites Using Taguchi Method” , Proc. Mat. Sci., vol. 6, pp.503 – 511, 2014.

[21] G. B. Veeresh Kumar and R.Pramod, “Artificial Neural Networks for Predicting the Tribological Behaviour of Al7075-SiC Metal Matrix Composites” , Int. J. Mat. Sci. Eng. , vol. 1, pp.6-11, 2014.

Documents

STUDIES ON MECHANICAL AND WEAR PROPERTIES OF Al7075