Wear Behavior of Hybrid (AL+SIC+AL 2 3) Metal Matrix Composites

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International Journal of Emerging Technology and Advanced Engineering

Website: www.ijetae.com (ISSN 2250-2459,ISO 9001:2008 Certified Journal, Volume 5, Issue 12, December 2015)

Wear Behavior of Hybrid (AL+SIC+AL

2

O

3

) Metal Matrix

Composites

R. Balamurugan

1

, N. Sethuraman

2

, S. Sudagar

3

,

A. Arun

4

1,2,3,4_{Assistant Professor, Department of Mechanical Engineering, IFET College of Engineering, Villupuram, India.}

Abstract--In recent years, a metal matrix application have been raised in aerospace and automobile industries. Due to its inherent high thermal conductivity of a metal and low coefficient of thermal expansion in ceramic. In this paper, wear behavior of aluminum (Al) reinforced with Sic and Al2O3particulate in different proportions like 10:20, 15:15 and 20:10 respectively based on their mass fraction. During the above mentioned proportions the MMC were formed by using sintering process. During the sintering process temperature and pressure of furnace are 540ºC and150N.m2 inch respectively. The heating rate maintained was 20ºC/min in the finance. The lubrication of zinc stearate of 0.9 % to 1.0% used to provides tight bonding between ceramic and metal. The MMC wear subjected into various test like wear test, hardness (Rockwell test). SEM analysis as per the ASTM standards. From the results the wear resistance and hardness were decrease and increase for the 20 :10 metal, ceramic composition respectively. The SEM analysis shows the micro structure of MMC.

I. INTRODUCTION

Metal matrix composite material are finding increasing application in aerospace and automobile industries due to their enhanced properties such as high strength, high stiffness, and good wear resistance, hybrid composite materials are advanced composite materials in order to achieve the high hardness, tensile strength at room temperature[1-3]. Wear is the progressive loss of material due to the relative motion between a surface and the contacting substance. The wear damage may be in the form of micro cracks or localized plastic deformation. The tribological principle parameter that control the wear and friction performance and material characteristics as well as a test parameter such as applied pressure, sliding speed, environment and that type of sliding interaction. Among the variant of reinforcements, the low aspect ratio particle reinforcement are much of significant in imparting the

hardness of fibre reinforcement MMC<whisker

reinforcement MMC<particle dispersed MMC. The volume fraction of reinforcement has the strongest effect on the wear resistance.

The addition of hard particle in the matrix of the composite materials influence the wear properties. The hard ceramic particle such as Al2O3,Sic, Tic etc[4,5].

embedded in the matrix of the hybrid composite material have shown to reduce the wear loss compared to the base alloy. The studies indicated that the wear loss normally decrease with increase in the hard phase volume fraction and particle size. The studies on wear of composite material indicated that wear rate of Al2O3 reinforced

composites decrease by two-fold as the particle size increase for 5 to 142µm. at the fixed volume fraction. During sliding at higher wear rates, high temperature is developed at the sliding due to which the specimen softens and becomes plastics. It reacts with the oxygen and their respective oxides. The hard brittle oxide formed on the surface of the specimen becomes thicker and continuous, covering the entire surface. The mechanical mixed layer formed and partly as an insulator form of thermal conductivity and responsible for increase in wear resistance of the composites.

The mixed layer had micro structural features comparing of a mixture of ultrafine grained structure in which the constituents varied depending on the sliding loads. The wear rate thus would be influenced by the formation and detachment of the matrix layer in the load.

The main aim of the present investigation is to evaluate the dry sliding metal-metal wear behavior of Al matrix, discontinuously reinforced with two different types of particles such as Sic and Al2O3. The vacuum sintering

furnaces is chosen for the manufacturing of hybrid metal matrix composites. The effect of Al2O3 & Sic addition on

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International Journal of Emerging Technology and Advanced Engineering

II. RAW MATERIAL 2.1 Aluminum Matrix Material

The name aluminum is derived from the ancient name for alum (potassium aluminum sulphate), which was alumen (Latin, meaning bitter salt). Comprising a little over 8% of the earth’s crust, aluminum is the most abundant metal on the planet. It is the third most common element after oxygen and silicon. Aluminum is lightweight, strong, recyclable, corrosion-resistant, and an essential part of daily life.

In our lifestyles and built environment, aluminum products are just as abundant. Since its commercial production began little more than a century ago, aluminum has become the material of choice for a diverse range of applications and utilities. Aluminum is a soft and lightweight metal. It has a dull silvery appearance, because of a thin layer of oxidation that forms quickly when it is exposed to air. Aluminum is nontoxic (as the metal) nonmagnetic and non-sparking.

It is very reactive so that in the atmosphere a thin but equally protective oxide layer forms rapidly. For this reason it is very resistant to corrosion. By a special treatment, anodizing, i. e. an electrolytic oxidation process, the aluminum surface protected by the oxide layer can even be strengthened and made more resistant to corrosion. It is a silvery white, soft, ductile metal. Aluminium is the third most abundant element (after oxygen and silicon), and the most abundant metal, in the Earth's crust. It makes up about 8% by weight of the Earth's solid surface.

Aluminum has a unique and unbeatable combination of properties that make it into a versatile, highly usable and attractive construction material. Aluminum is light with a density one third that of steel, 2.700 kg/m3. Aluminum is strong with a tensile strength of 70 to 700 MPa depending on the alloy and manufacturing process. Extrusions of the right alloy and design are as strong as structural steel.

The Young’s modulus for aluminum is a third that of steel (E = 70,000 MPa). This means that the moment of inertia has to be three times as great for an aluminum extrusion to achieve the same deflection as a steel profile. A thin layer of oxide is formed in contact with air, which provides very good protection against corrosion even in corrosive environments. This layer can be further strengthened by surface treatments such as anodizing or powder coating. The thermal and electrical conductivities are very good even when compared with copper. Furthermore, an aluminum conductor has only half the weight of an equivalent copper conductor. Aluminum has a relatively high coefficient of linear expansion compared to other metals. This should be taken into account at the design stage to compensate for differences in expansion.

2.1.2 Aluminum Matrix Selection

MMC materials have a combination of different, superior properties to an unreinforced matrix which are; increased strength, higher elastic modulus, higher service temperature, improved wear resistance, low electrical and thermal conductivity, low coefficient of thermal expansion and high vacuum environmental resistance. These properties can be attained with the proper choice of matrix and reinforcement

2.2 Silicon Carbide Reinforcement election

A total of 5–25 wt% silicon carbide particles is added. Then the microstructure of the alloy particulate composites produced was examined, the physical and mechanical properties measured include: densities, porosity, ultimate tensile strength, yield strength, hardness values and impact energy. The results revealed that, addition of silicon carbide reinforcement, increased the hardness values and apparent porosity by 75 and 39%, respectively, and decreased the density and impact energy by 1.08 and 15%, respectively, as the weight percent of silicon carbide increases in the alloy. The yield strength and ultimate tensile strength increased by 26.25 and 25% up to a maximum of 20% silicon carbide addition, respectively. These increases in strength and hardness values are attributed to the distribution of hard and brittle ceramic phases in the ductile metal matrix.

2.3. Alumina

Aluminum oxide is a chemical compound of aluminium and oxygen with the chemical formula Al2O3. It is the most

commonly occurring of several aluminium oxides, and specifically identified as aluminium(III) oxide. It is commonly called alumina, and may also be called aloxide, aloxite, or alundum depending on particular forms or applications. It commonly occurs in its crystalline polymorphic phase α-Al2O3, in which it comprises the

mineral corundum, varieties of which form the precious gems ruby and sapphire.

Aluminum oxide, commonly referred to as alumina, possesses strong ionic interatomic bonding giving rise to its desirable material characteristics. It can exist in several crystalline phases which all revert to the most stable hexagonal alpha phase at elevated temperatures.

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International Journal of Emerging Technology and Advanced Engineering

Alumina is one of the most cost effective and widely used material in the family of engineering ceramics. The raw materials from which this high performance technical grade ceramic is made are readily available and reasonably priced, resulting in good value for the cost in fabricated alumina shapes. With an excellent combination of properties and an attractive price, it is no surprise that fine grain technical grade alumina has a very wide range of applications.

2.3.1Alumina Reinforcement Selection

High purity alumina products can withstand very high temperature under reducing, inert or high vacuum condition.

They remain good chemical resistance under high temperatures, and have excellent wear and abrasion resistance. Alumina products can withstand up to 1750°C (3182°F).

Table 1:

physical composition of raw material

Phase Solid Solid Solid

Molecular

Al SiC Al2O3

formula

Appearanc White black White

e powder powder powder

Density

2.7 3.21g/cm3

3.75g/cm 3

.

g/cm3 _.

Melting p

933K, 6 2730 °C,3 2096 °C,

60°C, 000 K,49 2369 K,

oint 1220o_F

50 °F 3804 °F

Boiling po

2500°C, 3580°C,3 2977°C, 32

2773K, 853 K,64 50K, 5391°

int 4550o_F

53°F F 500 250 250 grams Quantity grams grams 400

400 mesh 400 mesh

mesh

(54 (54

size (54

microns) microns)

microns)

99.5% 99.5% 99.5%

purity

(metal (metal (metal

basis) basis) basis)

[image:3.612.322.600.136.486.2]

Table 2:

Weight composition of Samples

Al₂

Wt of

Si O₃ Wt Wt Al₂O₃ Total

Al % of

Si.No C % of (g) mass

% ρ SiC

% Al(g) (g)

(g)

1

70

20

10

9

1.714

17.1

5

11.99

3.42

4

8

2 70 15 15 9 12.07 2.58 2.587 17.2

5

1

7

5

3

70

10

20

9

12.15

1.73

3.472

17.3

5

1

6

III. PREPARATION OF HYBRID METAL MATRIX COMPOSITE MATERIAL

The preparation of aluminum metal matrix (Al+Sic) and hybrid aluminum metal matrix composite (Al+ Sic+Al2O3)

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International Journal of Emerging Technology and Advanced Engineering

The metal sintering technique used for manufacturing the composite. Powder is to be blended properly for obtaining the required properties after sintering. In this process the powder and blender are mixed together very finely. A lubricant is also employed to reduce the friction and hence obtaining a finer mixing[10-11]. The metal powder is mixed with lubricant and optical alloying element to form a homogeneous blend 0.5 to 1.5% lubricant is normally added in the mix, and metallic stearate. The compacting is due for shaping of the powder in to required shape. Pressure applied on the powder should to strictly regulated as it low pressure are applied on the part generated will be very fragile in nature. If the pressure applied is more tit may be a deformed. In general pressure of 1 to 150 N.m2.

Fig:1 Bonding

Fig:2 Sintered Component Fig:3 Die Design

Table: 3

Molecular Compositions After Sintering

Sample :1 Sample:2 Sample :3

70% Al – 70% Al – 70% Al –

Elem 20%SiC – 15%SiC – 10%SiC –

ent 10%Al2O3 15%Al2O3 20%Al2O3

Line

Weig Form Weig Formul Weight Form

ht % ula ht % a % ula

Al K 68.9 Al 69.3 Al 70.4 Al

SiC K 20.9 SiC 14.3 SiC 8.9 SiC

Al2O3

9.6

Al2

15.6 Al2O3 20.2

Al2O

K O3 3

Mg K 0.6 Mg 0.7 Mg 0.5 Mg

IV. RESULT AND DISCUSSION

4.1Hardness of Composite Material

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International Journal of Emerging Technology and Advanced Engineering

[image:5.612.48.288.138.436.2]

Table-4 Harness Test Results

Test Test Test

Sample Material 1 2 3

No. composition

HRC HRC HRC

70% Al –

1 20%SiC – 55.75 56.31 55.93

10%Al2O3

70% Al –

2 15%SiC – 54.23 53.74 54.62

15%Al2O3

70% Al –

3 10%SiC – 52.14 52.89 53.08

20%Al2O3

From the table-8, the hardness of Sample 1: 70% Al – 20%SiC –10%Al2O3 is more than the remaining two

samples.

Sample 1: 70% Al –20%SiC –10%Al2O3

56.31HRC Sample 2: 70% Al –15%SiC –15%Al2O3

= 54.74HRC

= 53.08HRC

4.2Wear Resistance of Composites

The sliding experiments are conducted at room temperature in a pin on disc wear testing machine. The pins are loaded against the disc by a dead weight loading system. The pin specimen is spherical ended with low friction coatings such as diamond like carbon coating on valve train. In the experiment, the user typically has the ability to control and measure the applied normal load, unidirectional speed or oscillation frequency and environmental parameter such as temperature, pressure, pressure of a lubricant. Wear rates (wear per unit time) determine by mass or volume loss with the aid of a profile meter.

Although ASTM G99-04 states that a spherical pin be used many different specimen geometries may be employed to best simulate the operation of an actual system. The machines used to conduct this testing are called this testing are called tribo meter.

The wear report shows that the wear rate of

Sample 1: 70% Al –20%SiC –10%Al2O3 is less than the

wear rate of remaining two samples

= 0.0018mg/sec for 2N

Since the wear resistance of Sample 1: 70% Al –20%SiC –10%Al2O3 is higher than remaining two samples, we can

use sample-1 composites in the engine components where the wear resistance plays a vital role.

4.3Microstructure analysis SEM & EDX of sample.

Microstructure analysis (SEM) & EDX of sample:

(a)Surface morphology through SEM

(b) EDX

[image:5.612.336.539.388.692.2]

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International Journal of Emerging Technology and Advanced Engineering

(a) Surface morphology through SEM

[image:6.612.329.563.118.322.2]

(b) EDX

Figure 5: Sample 2: 70% Al –15%SiC – 15%Al2O3

(a) Surface morphology through SEM

(b) EDX

Figure 6: Sample 3: 70% Al –10%SiC –20%Al2O3

V. CONCLUSION

Al–SiC–Al2O3 Metal Matrix Composite are synthesized

by powder metallurgy technique by varying the composition of SiC and Al2O3 by 10%, 15%, 20% (mass

fraction) under density (95%,) using by vacuum sintering furnace at 540°C under vacuum atmosphere. The purpose of this paper was to highlight dry sliding wear of aluminum composites containing Silicon carbide and Alumina reinforcement particles. The incorporation of SiC and Al2O3 particles into the Al improves the sliding wear

resistance as compared to the unreinforced alloy. Similarly, the hardness of the composite is also increased when compared to unreinforced alloy. This work evaluates the sliding wear behavior of reinforced Al based composite materials under load of 2N.

As the percentage of SiC reinforcement increases, the wear of the composite decreases.

[image:6.612.48.252.133.426.2]

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International Journal of Emerging Technology and Advanced Engineering

Figure 2:obtained from SEM confirms that distribution of Sic and Al2O3 (reinforcement) over the Al matrix.

Figure 3: obtained from EDX confirms that the elements Al, SiC & Al2O3 are present in the prepared specimens.

Figure 4: obtained from EDX confirms that the concentration of elements & wt% Al, SiC & Al2O3 in the

prepared specimens.

REFERENCES

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and Raviraj Shetty .., “Review on Effect of Silicon Carbide (SiC) on Stir Cast Aluminium Metal Matrix Composites”International Journal of Current Engineering and Technology ISSN 2277 - 4106 on 2013. [3] Mohan Vanarotti, SA Kori, BR Sridhar, Shrishail B.Padasalgi .., “Synthesis and Characterization of Aluminium Alloy and Silicon Carbide Metal Matrix Composite”2012 2nd International Conference on Industrial Technology and Management (ICITM 2012) IPCSIT vol. 49 (2012), Singapore DOI: 10.7763/IPCSIT.2012.V49.3.

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[9] T.G.Nieh, K.R. Forbes, T.C. Chou and J. Wadsworth, “Microstructure and deformation properties of an Al2O3-Ni3Al composite from room temp to 14000C”,High performance Composites for the 1990’s Eds. S. K. Das, C. P. Ballard and F.Marikar, TMS-New Jersey, 1990, pp 85-96.

[10] T. W. Clyne, An Introductory Overview of MMC System, Types and Developments, in Comprehensive Composite Materials, Vol-3; Metal Matrix Composites, T. W. Clyne (ed), Elsevier, 2000, pp.1-26. [11] L.M.Manocha & A.R. Bunsell “Advances in composite