Machenical

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1. INTRODUCTION

1.1 BACKGROUND

In the continuing quest for improved performance, which may be specified by various

criteria including less weight, more strength and lower cost, currently used materials

frequently reach the limit of their usefulness. Thus material scientists, engineers and

scientists are always striving to produce either improved traditional materials or completely

new materials. Composites are an example of the latter category.

Within last forty to fifty years, there has been a rapid increase in the production of

synthetic composites, those incorporating fine fibers in various plastics (polymers)

dominating the market. With the increasing global energy crisis and ecological risks,

scientists all over the world are shifting their attention towards alternative solution to

synthetic fiber. Since 1990s, natural fiber composites are emerging as realistic alternative

to glass-reinforced composites in many applications.

Natural fiber composites are claimed to offer environmental advantages such as

reduced dependence on non-renewable energy/material sources, lower pollutant emissions,

lower green-house gas emissions, enhanced energy recovery and end of life

biodegradability of components. Such superior environmental performances are important

driver of increased future use of natural fiber composite.

India endowed with an abundant availability of natural fiber such as Jute, Coir, Sisal,

Pineapple, Ramie, Bamboo, Banana etc. has focused on the development of natural fiber

composites primarily to explore value-added application avenues. Such natural fiber

composites are well suited as wood substitutes in the housing and construction sector.

The development of natural fiber composites in India is based on two pronged strategy

of preventing depletion of forest resources as well as ensuring good economic returns for

the cultivation of natural fibers.

The developments in composite material after meeting the challenges of aerospace

sector have cascaded down for catering to domestic and industrial applications.

Composites, the wonder material with light-weight; high strength-to-weight ratio and

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stiffness properties have come a long way in replacing the conventional materials like

metals, wood etc. The material scientists all over the world focused their attention on

natural composites reinforced with Jute, Sisal, Coir, Pineapple etc. primarily to cut down

the cost of raw materials.

1.2 WHY A COMPOSITE?

Over the last thirty years composite materials, plastics and ceramics have been the

dominant emerging materials. The volume and number of applications of composite

materials have grown steadily, penetrating and conquering new markets relentlessly.

Modern composite materials constitute a significant proportion of the engineered materials

market ranging from everyday products to sophisticated niche applications.

While composites have already proven their worth as weight-saving materials, the current

challenge is to make them cost effective. The efforts to produce economically attractive

composite components have resulted in several innovative manufacturing techniques

currently being used in the composites industry. It is obvious, especially for composites,

that the improvement in manufacturing technology alone is not enough to overcome the

cost hurdle.

It is essential that there be an integrated effort in design, material, process, tooling, quality

assurance, manufacturing, and even program management for composites to become

competitive with metals.

The composites industry has begun to recognize that the commercial applications of

composites promise to offer much larger business opportunities than the aerospace sector

due to the sheer size of transportation industry. Thus the shift of composite applications

from aircraft to other commercial uses has become prominent in recent years.

Increasingly enabled by the introduction of newer polymer resin matrix materials and high

performance reinforcement fibers of glass, carbon and aramid, the penetration of these

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advanced materials has witnessed a steady expansion in uses and volume. The increased

volume has resulted in an expected reduction in costs.

Further, the need of composite for lighter construction materials and more seismic resistant

structures has placed high emphasis on the use of new and advanced materials that not only

decreases dead weight but also absorbs the shock & vibration through tailored

microstructures. Composites are now extensively being used for rehabilitation

strengthening of pre-existing structures that have to be retrofitted to make them seismic

resistant, or to repair damage caused by seismic activity.

Unlike conventional materials (e.g., steel), the properties of the composite material can be

designed considering the structural aspects. The design of a structural component using

composites involves both material and structural design. Composite properties (e.g.

stiffness, thermal expansion etc.) can be varied continuously over a broad range of values

under the control of the designer. Careful selection of reinforcement type enables finished

product characteristics to be tailored to almost any specific engineering requirement.

1.3 Types of Composite Materials

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The composite materials are broadly classified into the following categories as shown in the

above figure. (Table 1.1)

1.3.1 Fiber-Reinforced Composites:

Reinforced-composites are popularly being used in many industrial application because of their

inherent high specific strength and stiffness. Due to their excellent structural performance, the

composites are gaining potential also in tri - biological applications. In this type composite the

second phase is in the form of fibers dispersed in the matrix which could be either plastic or

metal. The volume fraction (Vf) varies from a few percentage to as high as 70%. Usually the

fiber reinforcement is done to obtain high strength and high modulus. Hence it is necessary for

the fibers to possess higher modulus than the matrix material, so that the load is transferred to

the fiber from the matrix more effectively.

1.3.2 Dispersion Hardened Material:

In this type of material, fine particles of sizes ranging from 0.01μm to 0.14μm are

dispersed in matrix. Their concentration varies from 1% to 15% by volume. These fine

particles impede dislocation movement in the material and therefore result in very high

strength. Also these materials possess improved high temperature strength and creep

resistance.

1.3.3 Particulate composite

In this type of composites, 1μm to 200μm size particles are dispersed in the matrix

and volume fraction is generally between 0.01 Vf to 0.85 Vf.

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1.4 Natural Fibers Composite: Initiative in Product Development

Now-a-days, research and engineering interest have been shifting from traditional

Synthetic fiber composite to lignocellulosic natural fiber composite due to their advantages

like high strength to weight ratio, non-carcinogenic and bio-degradability. Besides the

availability of natural fibers and easy of manufacturing have tempted researchers to try

locally available inexpensive fiber and to study their feasibility of reinforcement purpose

and to what extent they satisfy the required specifications of good reinforced polymer

composite for different applications.

With low cost and high specific mechanical properties, natural fiber represents a good

renewable and biodegradable alternative to the most common synthetic reinforcement, i.e.

glass fiber. The term “natural fiber” covers a broad range of vegetable, animal and mineral

fibers.

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However in the composite industry, it is usually refers to wood fiber and agro based

bast, leaf, seed, and stem fibers. These fibers often contribute greatly to the structural

performance of plant and, when used in plastic composites, can provide significant

reinforcement. Despite the interest and environmental appeal of natural fibers, their use is

limited to non-bearing applications due to their lower strength compared with synthetic fiber

reinforced polymer composite.

Fig. 1.2 Overview of Natural Fiber

The stiffness and strength shortcomings of bio composites can be overcome by

structural configurations and better arrangement in a sense of placing the fibers in specific

locations for highest strength performance. Accordingly extensive studies on preparation

and properties of polymer matrix composite (PMC) replacing the synthetic fiber with natural

fiber like Jute, Sisal, Pineapple, Bamboo and Kenaf were carried out. These plant fibers

have many advantages over glass fiber or carbon fiber like renewable, environmental

friendly, low cost, lightweight, high specific mechanical performance. Increased technical

innovation, identification of new applications, continuing political and environmental

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pressure and government investments in new methods for fiber harvesting and processing

are leading to projections of continued growth in the use of natural fibers in composites,

with expectation of reaching 100,000 tons per annum by 2010.

Fig 1.3 Classification of natural fiber that can be used as reinforcements in polymers

The easy availability of natural fibers and manufacturing have motivated researchers

worldwide recently to try locally available inexpensive fibers and to study their feasibility

of reinforcement purposes and to what extent they satisfy the required specifications of good

reinforced polymer composite for tribological applications. There are many natural

resources which India has in abundance. Most of it comes from the forest and agriculture.

However in most cases residues from traditional crops such as rice husk or sugarcane

bagasse or from the usual processing operations of timber industries do not meet the

requisites of being long fibers. This biomass left over are abundant, and their use as a

particulate reinforcement in resin matrix composite is strongly considered as a future

possibility.

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1.5 What is Fly Ash?

Fly ash is a coal combustion byproduct, which accumulates due to electrostatic precipitation

of the flue gases in thermal power plant. The spherical shaped materials blown out from the

furnace during combustion of coal in thermal power stations make up 75% of ash generated. The

spherules when empty are called cenospheres and when filled up with smaller spheres are known as

plerospheres. The cenospheres comprise of 0.5–1.0 weight percentage of the fly ash individual

particles are chemically fairly homogeneous, but the pronounced compositional variation exists

among particles with similar physical and structural attribute. Cenospheres are compressed of nearly

stoichiometric mullite (3Al2O3·2SiO2) needles bonded by aluminosilicate glass of similar

composition that offers excellent thermal, elastic, and mechanical characteristics for use in

thermostructural applications. Elemental map study through energy filtered TEM shows the

aluminosilicate-based and iron oxide based-nanoparticles are present in the fly ash. Unburned

organic matter during combustion of coal leaves carbon in three different forms in the fly ash. Fly

ash contains toxic elements like Co, Pb, Ni, Cd, Cu, Fe, and Zn in trace. Particle filled polymer

composites have become attractive because of their wide applications and low cost. Polymers such

as Nylon 6, Natural Rubber, Styrene Butadiene Rubber, Epoxy, Poly styrene, Poly Aniline, and

HDPE, incorporating inorganic mineral fillers into plastic resin, improve various physical properties

of the materials such as mechanical strength, modulus, and heat distortion temperature as

compared to neat resin components. In general, the mechanical properties of particulate filled

composites depend strongly on size, shape, and distribution of filler particles in the matrix and

good adhesion at the interface surface.

The demand for the light-weight materials such as for surfaces of ships had led to the

development of fly –ash based thermosetting resins.

1.5.1 Fly Ash as a Filler Material

When coal is burnt in thermal power plant the ash is carried forward in flue gases as fused

particles, which solidifies as a spherical particle. Most of these spherical particles have a

gas bubble at the center. The constituents of fly ash particles as obtained from coal in are

silica (59.5%), Alumina (20.3%), FeO /Fe2O3 (6.5%), remaining being FeO, MgO and

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unburnt coal etc. Fly ash depending upon the source of coal, contain different proportions

of silica, alumina, oxides of iron, calcium, magnesium etc. along with elements like carbon,

Ti, Mg, etc. So the fly ash has properties combined of spherical particles and that of metals

and metal oxides. Filler materials are generally the inert materials which are used in

composite materials to reduce material costs, to improve mechanical properties to some

extent and in some cases to improve processability.

1.6 Why Double reinforced composite?

Use of PMCs imposes some real constraints on structural applications due to

comparatively weak matrix, imbibe water, and other liquids to a significant degree cannot

perform well at moderate elevated temperature, internal cracking is so common, higher

thermal expansion, maintaining good adhesion is difficult, chemical and thermal

degradations in service often occurs.

The addition of short Sugarcane fibers matrix allows stress transfer across the matrix

crack to improve toughness. Therefore, in the present work, the addition of fly ash to the

epoxy resin with the additional reinforcement of sugarcane fibers was carried out to

fabricate composite. These composites were characterized and it was seen that the

additional reinforcement with the fly ash as filler could improve the strength of the

composites as compared to single reinforcement.

In fiber epoxy composites the addition of fly ash led to a reduction of the density and

increase in modulus of composites. At present, epoxy resins are widely used in various

engineering and structural applications such as electrical industries, and commercial and

military aircrafts industries.

In order to improve their processing and product performances, and to reduce cost,

various fillers are introduced into the resins during processing

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2. LITERATURE

2.1 Structure of Plant Fiber

Natural plant fibers are constituents of cellulose fibers, consisting of helically wound

cellulose micro fibrils, bound together by an amorphous lignin matrix. Lignin keeps

the water in fibers; acts as a protection against biological attack and as a stiffener to

give stem its resistance against gravity forces and wind. Hemicellulose found in the

natural fibers is believed to be a compatibilizer between cellulose and lignin. The cell

wall in a fiber (Figure 2.1) is not a homogenous membrane.

Fig 2.1 Structure of an elementary plant fiber (cell)

Each fiber has a complex, layered structure consisting of a thin primary wall which is the

first layer deposited during cell growth encircling a secondary wall. The secondary wall is

made up of three layers and the thick middle layer determines the mechanical properties of

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the fiber. The middle layer consists of a series of helically wound cellular micro-fibrils

formed from long chain cellulose molecules.

The angle between the fiber axis and the micro-fibrils is called the microfibrillar angle. The

characteristic value of microfibrillar angle varies from one fiber to another.

These micro-fibrils have typically a diameter of about 10-30 nm and are made up of 30-

100 cellulose molecules in extended chain conformation and provide mechanical strength

to the fiber.

2.2 Matrix Material

Many materials when they are in fibrous form exhibit very good strength properties but to

achieve these properties the fiber should be bonded by a suitable matrix. The matrix isolates

the fibers from one another in order to prevent abrasion and formation of new surface flaws

and acts as a bridge to hold the fibers in place. A good matrix should possess ability to

deform easily under applied load, transfer the load on to the fibers and evenly distribute

stress concentration.

A study of the nature of bonding forces in laminates indicates that upon initial

loading there is a tendency for the adhesive bond between them account for the high

strength properties of the of the laminates.

The polymer matrix binds the fibers together so as to transfer the load to and

between them and protect them from environments and handling. Polymer or resin system

used to manufacture advanced polymer matrix composites (PMCs) are of two basic types,

thermosets and thermoplastics (including bio-derived ones).

2.2.1 Thermosets

Much of the early work used thermosetting resins as matrix material for composite

production. Products like tufnol which is made from cotton fibres and epoxy resin, have

been available for some time, having good stiffness and strength. In the last few years there

has been renewed interest in these products for use in automotive applications. To achieve

reinforcing effects in composites it is necessary to have good adhesion between the fibres

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and resins. Epoxy and phenolic thermosetting resins are known to be able to form covalent

cross-links with plant cell walls via -OH groups. Composite manufacture can be achieved

using low viscosity epoxy and phenolic resins that cure at room temperature. In addition

epoxy resin does not produce volatile products during curing which is most desirable in

production of void free composites. Therefore, although epoxy resins are relatively more

expensive than polyester, they have potential for the development of high added value plant

fiber composites, where long fibres at a high content are required.

The functional group in epoxy resins is called the oxirane, a three-membered

strained ring containing oxygen. Epoxy resins, depending on their backbone structure, may

be low or high viscosity liquids or solids. In low viscosity resin, it is possible to achieve a

good wetting of fibres by the resin without using high temperature or pressure. The

impregnation of fibres with high viscosity resins is done by using high temperature and

pressure.

A wide range of starting materials can be used for the preparation of epoxy resins

thereby providing a variety of resins with controllable high performance characteristics.

These resins generally are prepared by reacting to a poly functional amine or phenol with

epichlorohydrin in the presence of a strong base. The commercially available diglycidyl

ether of bisphenol-A (DGEBA), figure 2.4, is characterized by epoxy equivalent weight,

which can be determined either by titration or quantitative infrared spectroscopy. The

presence of glycidyl units in these resins enhances the processability but reduces thermal

resistance.

Figure-2.2 Chemical structure of DGEBA

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The most widely used curing agents for epoxy resins are primary and secondary

amines. The overall reaction rate of an amine with an epoxide is influenced by the steric

hindrance and the electron withdrawing or electron donating groups present in the amine.

During curing, epoxy resins can undergo three basic reactions:

1. Epoxy groups are rearranged and form direct linkages between themselves.

2. Aromatic and aliphatic -OHs link up to the epoxy groups.

3. Cross-linking takes place with the curing agent through various radical groups.

The advantages of epoxy resins are low polymerization shrinkages unlike polyesters during

cure, good mechanical strength, excellent resistance to chemicals and solvents and

excellent adhesion to fibres. The epoxy molecule also contains two ring groups at its centre,

which are able to absorb both mechanical and thermal stresses better than linear groups,

giving epoxy resin very good stiffness, toughness and heat resistance.

The primary disadvantages of the epoxy resins are that they require long curing

times and in general, their mould release characteristics are poor. The epoxy resins are

characterized by their high adhesive strengths. This property is attributed to the polarity of

aliphatic -OH groups and ether groups that exist in both the initial resin and cured system.

The polarity associated with these groups promotes electromagnetic bonding forces

between epoxy molecules and the polar fibers.

2.2.2 Bio-derived Thermoplastic Matrices

Cellulose fibers (e.g. hemp, flax, jute) are widely used with conventional

thermoplastic polymers (e.g. PP, PE) as reinforcement in composite production to improve

mechanical properties. In fact, the history of composites from renewable resources is far

longer than conventional polymers. The study and utilization of natural polymers is an

ancient science. Typical examples, such as paper, silk, skin and bone arts can easily be

found in museum around the world. In the biblical Book of Exodus, Moses’s mother built

the ark from rushes, pitch and slime - a kind of fibre reinforced composite, according to

the current classification of material.

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During the opium war more than 1000 years ago, the Chinese built their castles to

defend against invaders using a kind of mineral particle reinforced composite made

from gluten rice, sugar, calcium carbonate and sand. However, the availability of

petroleum at a lower cost and the bio-chemical inertness of petroleum based

products have proven disastrous for the market of natural polymers. It is only about

last two decades when the significance of eco-friendly materials has been realized.

Now polymers from renewable resources have started drawing an increasing

amount of attention. The two main reasons for that are environmental concerns, and

the realization that the petroleum resources are limited.

Generally, polymers from renewable resources can be classified into three groups:

1. Natural polymers such as starch, protein, and cellulose

2. Synthetic polymers from natural monomers, such as PLA

3. Polymers from microbial fermentation, such as polyhydroxy butyrate

(PHB).

Like numerous other petroleum based polymers, many properties of

polymers from renewable resources can be improved through composite

production.

The development of synthetic polymers like PLA using monomers from natural

resources has been a driving force for the development of biodegradable polymers from

renewable resources. Therefore, in today’s world PLA is the most promising among

bioderivable polymers. PLA can be processed (e.g. compression moulding, pultrusion,

extrusion and injection moulding) like petroleum based polyolefins and its mechanical

property is better than the widely used polymer PP. On degradation PL does not emit any

carbon dioxide to the environment like other biodegradable materials from renewable

resources.

The degradation occurs by hydrolysis to lactic acid, which is metabolized by micro-

organisms to water and carbon dioxide. If PLA is comprised together with other biomass,

the biodegradation occurs within a couple of weeks and the material can fully disappear

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within a month. Chemically, it is linear aliphatic polyester of lactic acid which can be

obtained by fermentation of renewable agricultural materials like corn, sugarcane and sugar

beets. Lactic acid is converted to a cyclic lactide dimer which is then polymerized to PLA

through a ring opening reaction.

The major applications of PLA products are in household wastes as plastic bags,

barriers for sanitary products and diapers, planting, and disposable cups and plates.

However, a number of authors reported the possibilities of developing fully bio-degradable

composite products by using biodegradable polymers as matrix and natural fibres as

reinforcements. Keller et al reported that PLA should produce fiber reinforced composites

with high mechanical properties for light weight construction materials. Oksman et al

observed that PLA had good potential as a polymer matrix in flax fibre reinforcement for

composites production.

They reported that the composite strength produced with PLA/flax was about 50%

better than that of PP/flax composites. Due to the increasing commercial interest for natural

fiber reinforced polymer composites for use in automotive applications and building

constructions as well as demands for environmentally friendly materials, the development

of fully biodegradable composites for many applications could be an interesting area of

research.

2.3 Natural Fiber Reinforced Polymer Composites

Polymer materials by themselves have found extensive use in noncritical products.

Such products are used in advanced engineering applications when reinforced with stronger

materials. Therefore fiber reinforced composites comprised of thermoplastics and natural

fibers are a well research area at present for their high specific strength and modulus. The

advantages of natural lignocellulosic fibers over traditional reinforcing materials such as

carbon, glass fibers, talc and mica are low cost, acceptable specific strength properties, low

density, non abrasivity, good thermal properties, enhanced energy recovery and

biodegradability. The use of natural fibers in plastic matrix includes many benefits such as

low volumetric cost, increase of heat deflection temperature, increase of stiffness of

thermoplastics and improvement of wood surface appearance. So natural fibers have

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achieved applications in making several complex structures such as tubes, interior

paneling, sandwich plates, decking, furniture parts, sports usages etc.

One of the largest areas of recent growth in natural fiber plastic composites in world-wide

is the automotive industry, where natural fibers are advantageously used as a result of their

low density and increasing environmental pressures. They are also used in electrical and

electronic application for their nonconductive and excellent insulation against heat and

noise. Natural fibers composites found application where load bearing capacity and

dimensional stability under moist and high thermal conditions are of second order

importance.

For example, flax fiber reinforced polyolefins are extensively used today in the automotive

industry, but the fiber acts mainly as filler material in non-structural interior panels. Natural

fiber composites used for structural purposes do exist, but then usually with synthetic

thermo-set matrices which of course limit the environmental benefits. Natural fibers like

sisal, jute, coir, oil palm, bamboo, wheat and flax straw, waste silk and banana have proved

to be good and effective reinforcement in thermoset and thermoplastic matrices due to their

high aspect ratio and high specific strength- and stiffness.

Apart from good specific mechanical properties and positive environmental impact, other

benefits from using natural fibers worth mentioning are low cost, friendly processing, low

tool wear, no skin irritation and good thermal and acoustic insulating properties.

A complete biodegradable system may be obtained if the matrix material also comes from

a renewable resource. Examples of such materials are lignophenolics, starch and polylactic

acid (PLA). Some of these systems show encouraging results. For example Oksman et al

have reported that flax fiber composites with PLA matrix can compete with and even

outperform flax/polypropylene composites in terms of mechanical properties.

In a recent study it was found that composites of poly-L-lactide acid (PLLA) reinforced by

flax fibers can show specific tensile modulus equivalent to that of glass/polyester short

fiber composites. The specific strength of flax/PLLA composites was lower than that of

glass/polyester, but higher than that of flax/polyester.

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The limited use of natural fiber composites is also connected with some other major

disadvantages still associated with these materials. The fibers generally show low ability

to adhere to common non-polar matrix materials for efficient stress transfer. Furthermore,

the fibers inherent hydrophilic nature makes them susceptible to water uptake in moist

conditions. Natural fiber composites tend to swell considerably with water uptake and as a

consequence mechanical properties, such as stiffness and strength, are negatively

influenced. However, the natural fiber is not inert. The fiber-matrix adhesion may be

improved and the fiber swelling reduced by means of chemical, enzymatic or mechanical

modifications.

There are many application of natural fiber composite in everyday life. For example, jute

is a common reinforcement for composites in India. Jute fiber with polyester resins is used

in buildings, elevators, pipes, and panels. Natural fiber composites can also be very cost

effective material for application in building and construction areas (e.g. walls, ceiling,

partition, window and door frames), storage devices (e.g. bio-gas container, post boxes,

etc.), furniture (e.g. chair, table, tools, etc.), electronic devices (outer casting of mobile

phones), automobile and railway coach interior parts (inner fenders and bumpers), toys and

other miscellaneous applications (helmets, suitcases).

During the last few years, a series of works have been done to replace the conventional

synthetic fiber with natural fiber composites. For instant, hemp, sisal, jute, cotton, flax and

broom are the most commonly used fibers to reinforce polymers like polyolefins,

polystyrene, and epoxy resins. In addition, fibers like sisal, jute, coir, oil palm, bamboo,

wheat and flax straw, waste silk and banana have proved to be good and effective

reinforcement in the thermoset and thermoplastic matrices.

Nevertheless, certain aspects of natural fiber reinforced composite behaviour still poorly

understood such as their visco elastic, visco plastic or time-dependent behavior due to creep

and fatigue loadings, interfacial adhesion, and tribological properties. Little information

concerning the tribological performance of natural fiber reinforced composite material has

been reported. In this context, long plant fibres, like hemp, flax, and bamboo have

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considerable potential in the manufacture of composite materials. Likewise, bagasse fibers

may also have considerable potential as reinforcement for polymer and may provide

advantages when used as a substitute for conventional synthetic glass fiber.

After reviewing the exiting literature available on the natural fiber composite efforts are

put to understand the basic needs of the growing composite industry. The conclusions

drawn from this is that, the success of combining vegetable natural fibers with polymer

matrices results in the improvement of mechanical properties of the composite compared

with the matrix material.

These fillers are cheap and non - toxic can be obtain from renewable source and are easily

recyclable. Moreover despite of their low strength, they can lead to composites with high

specific strength because of their low density. Thus the priority of this work is to prepare

polymer matrix composites (PMCs) using bagasse fiber as reinforcement material. To

improve the interfacial strength between the fiber and the matrix, the surface modification

of the fiber has to be done by chemical treatment. The composite will then be subjected to

different weathering condition like steam, saline and subzero condition. The potential of

bagasse fiber for tribological application has to be investigated through performing

different tribological tests like abrasive wear test, two body abrasion test and solid particle

erosion test as per ASTM standard. The fiber characterization will be done by Fourier

Transfer Infrared (FTIR) spectroscopy before and after the chemical treatment. The

flexural strength of the composite will be evaluated along with other mechanical tests.

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3. OBJECTIVES

3.1 To Develop A Composite Material With Improved Wear Property

And Hardness By Addition Of Fly Ash And Natural Fibers

The project started with various compositions of Fly Ash, Fiber and Epoxy. It was

required to test and decide upon the composition which will give best wear and

compression properties.

It was decided to make two sets of samples, which will have same amount of Epoxy but

different composition of Fly Ash by weight. Through this we were able to compare the

effect of increase in both fly ash content and fiber over the wear properties.

3.2 To Find a Suitable Substitute for Synthetic Fiber by Using Natural

Fiber

With low cost and high specific mechanical properties, natural fiber represents a

good renewable and biodegradable alternative to the most common synthetic

reinforcement, i.e. glass fiber. The Natural Fibers are easy to obtain, and are not

harmful to the environment.

One of the reason, synthetic fibers are preferred over Natural Fibers is that they have

high strength, this issue was resolved by the addition of Fly Ash.

Hence, it was expected that the composite formed will have high strength and good

mechanical properties which are comparable to synthetic composites.

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3.3 To Make Optimum Use of Industrial Waste in the Form of Fly Ash

by Using it as a Filler Material in Composite

One reason to use Fly Ash was to help with the mechanical properties. The other

main reason was to utilize it as Industrial Waste, and use it as a Filler Material

Composites thereby also reducing the amount of Matrix Material used in Composite.

With the increase in Fly Ash the holding capacity of Epoxy increased, which helped

in holding the Fiber.

3.4 To Develop a Suitable Application for The Composite Material

Developed

After obtaining the Optimum Composition of Fly Ash, Fiber and Epoxy it is required

to use the material obtained in a suitable application. This was supposed to be

decided according the results obtained in the various tests conducted throughout the

Project.

A suitable application of the material, to be used in everyday application.

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4. METHODOLOGY

For Preparation of Composite the following materials were used:

1. Bagasse Fiber

2. Fly Ash

3. Epoxy

4. Hardener

4.1 Preparation of Bagasse Fiber

The Sugarcane Stalk is composed of an outer rind and inner pith. The upper layers of

bagasse consist of a hard fibrous substance called rind while inside is soft material called pith. The

pith contains small fibers and the majority of the sucrose, while the rind contains longer and finer

fiber, arranged randomly throughout the stem and bound together by lignin and hemicelluloses. It

is reported that fibers are often located adjacent to the inner wall of the rind particle. For the present

investigation, fresh bagasse fibers were collected from local Juice Venders located in Manipal.

4.1.1 Treatment of Fiber

These fibers were then spread on a water proof sheet and kept under sunlight for a day to

reduce the moisture content. Then these fibers were then shredded using the Champ Agro Machine

in Composite Lab of Manipal Institute of Technology.

After shredding, these were then treated by NaOH, an Alkali reaction takes place, as shown:

Bagasse-OH + NaOH Bagasse-O-Na+ + H2O

The NaOH reacts with hydroxyl groups of the cementing material HemiCellulose, and it

brings on the destruction of the cellular structure and thereby the fibers split into Filaments. These

fibers were kept in 4% NaOH solution, then washed thoroughly using distilled water in order to

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remove all the enzymes present on the fiber. Then was kept to dry under sunlight for further 12

hours.

After approximately two days, the long bagasse fibers (rind proportion only) were shortened into

a length of approximately 10mm and width of 1mm with a pair of scissor. Due to low moisture of

the bagasse samples, no fungi grew during the storage.

4.2 Epoxy Resin and Hardener

Epoxy resins are relatively low molecular weight pre-polymers capable of being

processed under a variety of conditions. Two important advantages of these over unsaturated

polyester resins are: first, they can be partially cured and stored in that state, and second they

exhibit low shrinkage during cure.

However, the viscosity of conventional epoxy resins is higher and they are more expensive

compared to polyester resins. The cured resins have high chemical, corrosion resistance, good

mechanical and thermal properties, outstanding adhesion to a variety of substrates, and good and

electrical properties.

Approximately 45% of the total amount of epoxy resins produced is used in protective coatings

while the remaining is used in structural applications such as laminates and composites, tooling,

moulding, casting, construction, adhesives, etc. The type of epoxy resin used in the present

investigation is Epoxy L-12 which chemically belongs to epoxide family.

Both Epoxy and Hardener were supplied by Atul Polymer Ltd, Gujarat.

4.3 Preparation of Composite Laminates

A plastic frustum shaped mold (fig 4.1) was used for casting the composite sample. The first group

of samples was manufactured with 1.5g of Fiber, 50g of Epoxy and 20, 30, 40, 50 and 60 % by

weight of fly ash. (Table 4.1)

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Usual hand lay-up technique was used for preparation of the samples. A calculated amount of

hardener (ratio of 10:1 by weight, epoxy to hardener) was thoroughly mixed in a glass jar and

placed to settle. This procedure was performed for 5 minutes initially.

Fig. 4.1 Mold Used

After mixing the contents properly in the glass jar, they were poured into the mold. Care was taken

to avoid formation of air bubbles. A plastic sheet was placed on the contents and pressure was

applied from the top and the mold was allowed to cure at room temperature for 24 hours.

During Application of pressure some amount of epoxy and hardener squeezes out. Care has been

taken to consider this loss during manufacturing of composite sheets. After 72 hours, the samples

were taken out of the mold and then cured under sunlight.

24

Material Designation % Fly Ash (by weight) Resin(by weight, in g) Fiber (by weight, in g)

C1 20 50 1.5

C2 30 50 1.5

C3 40 50 1.5

C4 50 50 1.5

C5 60 50 1.5

C6 20 50 3

C7 30 50 3

C8 40 50 3

C9 50 50 3

C10 60 50 3

Table 4.1 Material Designation

Fig.4.2. Mixing of Fiber, Fly Ash and Resin

25

4.4 TESTING OF MECHANICAL PROPERTIES OF COMPOSITE

The study of mechanical properties such as wear strength, impact strength and hardness of treated

bagasse fiber and fly ash reinforced (randomly distributed in the epoxy matrix) composite have

been conducted as per ASTM standard.

4.4.1 Wear Test

Fig 4.3 Wear and Friction Monitor (TR-201 CL)

Two body Wear - Pin Disc test was conducted on, Wear and Friction Monitor (TR-201CL).

During the experiment, The Arm Length was kept constant at 60mm, and the Speed of the Disk

(in rpm) was varied with each sample (300, 600 rpm), along with the Load applied over the sample

(1kg, 2kg). In all 4 tests were conducted on each sample as shown:

1. 1 Kg load, 300 rpm, 60 mm

2. 1 Kg load, 600 rpm, 60 mm

3. 2 Kg load, 300 rpm, 60 mm

4. 2 Kg load, 600 rpm, 60 mm

Each test was conducted 3 times to get the average value, as the samples were made using Random

Orientation, hence the results vary. Each test was conducted for the duration of 10 min to get the

wear rate. Weight of the sample, before and after the test was noted to get the weight difference,

hence the wear of the sample by weight. After each test, the plate was allowed to cool, in order to

avoid the thermal lubrication by the debris material collected over the plate.

This was compared to study the samples, in order to reach the most optimum composition.

26

4.4.2 Impact Test

The Charpy impact test, also known as the Charpy V-notch test, is a standardized high strain-rate

test which determines the amount of energy absorbed by a material during fracture. This absorbed

energy is a measure of a given material's notch toughness and acts as a tool to study temperature-

dependent ductile-brittle transition. It is widely applied in industry, since it is easy to prepare and

conduct and results can be obtained quickly and cheaply

The impact strength of the composites was done by using Charpy impact testing machine. The

specimens were of rectangular shape having dimensions 10X10X50 mm with a V-notch at the

center. The test has been done at an impact speed of 4m/s and an incident energy of 15J. A span

of 20 mm was employed maintaining a hammer weight of 20kg.

Fig.4.4 Impact Test - Charpy

27

4.4.3 Hardness Test

The Rockwell scale is a hardness scale based on indentation hardness of a material. The

Rockwell test determines the hardness by measuring the depth of penetration of an indenter

under a large load compared to the penetration made by a preload. There are different scales,

denoted by a single letter, that use different loads or indenters. The result is a dimensionless

number noted as HRA, HRB, HRC, etc., where the last letter is the respective Rockwell scale.

Rockwell hardness test was done on all the samples of each composition. A diamond indenter

of 1/16 inch was used.

Fig.4.5 Rockwell Hardness Testing Machine

28

5. RESULT ANALSIS

5.1 Impact Tests

Material Designation % Fly Ash (by weight) Fiber-1.5g Fiber-3g

C1 20 3 4

C2 30 2.5 4

C3 40 2 3

C4 50 2 2.5

C5 60 1.5 2

Table 5.1 Impact Test Result Comparison between 1.5g and 3g

(a) (b)

Fig 5.1 Impact Test Result (a) 1.5g Fiber (b) 3g Fiber

3

2.5

2 2

1.5

0

0.5

1

1.5

2

2.5

3

3.5

20 30 40 50 60

IMP

AC

T ST

REN

GTH

J

% FLY ASH (BY WEIGHT)

IMPACT STRENGTH -1.5 g

FIBER

4 4

3

2.5

2

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

20 30 40 50 60

IMP

AC

T ST

REN

GTH

J

%FLY ASH(BY WEIGHT)

IMPACT STRENGTH-3g FIBER

29

Fig 5.2 Impact Test Result Comparison

Table 5.2 Impact Test Result – Only Fiber in Epoxy

Table 5.3 Impact Test Result – Only Fly Ash and Epoxy

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

C1 C2 C3 C4 C5

Impact Test Comparison

Fiber-1.5g Fiber-3g

Fiber (by weight g) Impact Strength(Joules)

C-1.5 1

C-3 1.5

Material Designation %Fly Ash(by weight g) Impact Strength(Joules)

C1 20 1

C2 30 1

C3 40 0.75

C4 50 0.5

C5 60 0.5

30

(a) (b)

Fig. 5.3 Impact Test Result – (a) Only Fiber, (b) Only Fly Ash

With increase in fiber content Impact strength increases (Fig.5.3.a), higher the amount of fly ash

content in the composite, lower is the impact strength in the composite.

However for composite having same fiber content and different amount of fly ash there is decrease

in impact strength with increase in the fly ash content (Fig.5.2).

When samples with just fly ash and epoxy were taken, the impact strength decreases with increase

in the fly ash content (Fig.5.3.b).

1 1

0.75

0.5 0.5

0

0.2

0.4

0.6

0.8

1

1.2

20 30 40 50 60

imp

act

stre

ngt

h j

%fly ash (by weight)

Imapact Strength(Joules)

1

1.5

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.5 3

IMP

AC

T ST

REN

GTH

J

FIBER (in grams)

Imapact Strength(Joules)

31

5.2 Rockwell Hardness Test

Material Designation % Fly Ash (by weight) Rockwell Hardness

1.5g Fiber 3g Fiber

C1 20 57 69

C2 30 68 81

C3 40 75 92

C4 50 84 98

C5 60 92 104

Table 5.4 Rockwell Hardness Test Results

(a) (b)

Fig.5.4 Rockwell Hardness Results (a) 1.5g Fiber (b) 3g Fiber

57

6875

8492

0

10

20

30

40

50

60

70

80

90

100

20 30 40 50 60

Ro

ckw

ell H

ard

nes

s

%fly ash (by weight)

Rockwell Hardness-1.5g Fiber

69

81

9298

104

0

20

40

60

80

100

120

20 30 40 50 60

Ro

ckw

ell H

ard

nes

s

%Fly Ash (By Weight)

Rockwell Hardness-3g Fiber

32

Fig 5.5 Hardness Comparison on Different Fiber Content

Material Designation %Fly Ash(by weight g) Rockwell Hardness

C1 20 B-51

C2 30 B-59

C3 40 B-71

C4 50 B-78

C5 60 B-85

Table 5.5 Rockwell Hardness Number – Only Fly Ash and Epoxy

Fig. 5.6 Rockwell Hardness Number – Only Fly Ash

0

20

40

60

80

100

120

20 30 40 50 60

Rockwell Hardness

1.5g Fiber 3g Fiber

5159

7178

85

0

10

20

30

40

50

60

70

80

90

20 30 40 50 60

rock

we

ll h

ard

ne

ss

%fly ash(by weight)

Rockwell Hardness

33

Table 5.6 Rockwell Hardness Number – Only Fiber and Epoxy

Fig 5.7 Rockwell Hardness Number – Only Fiber and Epoxy

For same fiber content and different amount of fly ash, hardness increases. It is also seen that with

increase in both fly ash content and increasing fiber content, hardness increases (Fig 5.4). Even

in the case where only one reinforcement (either only fly ash, or fiber) was mixed with epoxy, the

Hardness of the sample increased with increase in the Reinforcement used. (Fig.5.6&5.7).

43

52

0

10

20

30

40

50

60

1.5 3

rock

wel

l har

dn

ess

Fiber (in grams)

Rockwell Hardness

Fiber (by weight g) Rockwell Hardness

C-1.5 B-43

C-3 B-52

34

5.3 Wear Test

5.3.1 1.5g of Fiber, 50g of Epoxy – Varying Fly Ash (%by Weight)

Fig 5.8 Weight Difference Before and After the Wear Test

(In the figure (fig 5.8) on the Y-Axis, the values are read as “%FlyAsh_Load_RPM”)

0

0.005

0.01

0.015

0.02

0.025

0.03

Weight Difference (W1-W2)

Sample w1 w2 w1-w2

60_1_300 0.786 0.782 0.004

50_1_300 1.027 1 0.001

40_1_300 1.026 1.023 0.003

30_1_300 1.295 1.292 0.003

20_1_300 0.85 0.842 0.008

0

0.002

0.004

0.006

0.008

0.01

60_1_300 50_1_300 40_1_300 30_1_300 20_1_300

1 Kg, 300 RPM

w1-w2

Table 5.7 1Kg load, 300 RPM

Fig 5.9 Change in Wear w.r.t. Change in Fly Ash Content

35

Sample w1 w2 w1-w2

60_1_600 0.92 0.907 0.013

50_1_600 1.484 1.478 0.006

40_1_600 0.939 0.933 0.006

30_1_600 1.201 1.196 0.005

20_1_600 0.855 0.85 0.005

Sample w1 w2 w1-w2

60_2_300 0.9078 0.885 0.0228

50_2_300 1.485 1.484 0.001

40_2_300 1.032 1.026 0.006

30_2_300 1.205 1.201 0.004

20_2_300 0.842 0.835 0.007

Sample w1 w2 w1-w2

60_2_600 0.885 0.86 0.025

50_2_600 1.026 1.012 0.014

40_2_600 0.933 0.923 0.01

30_2_600 1.268 1.264 0.004

20_2_600 0.746 0.642 0.104

0

0.002

0.004

0.006

0.008

0.01

0.012

0.014

60_1_600 50_1_600 40_1_600 30_1_600 20_1_600

1 Kg_600 RPM

w1-w2

Table 5.8 1Kg load, 600 RPM

Fig 5.10 Change in Wear w.r.t. Change in Fly Ash Content

0

0.005

0.01

0.015

0.02

0.025

60_2_300 50_2_300 40_2_300 30_2_300 20_2_300

2 Kg_300 RPM

w1-w2

Table 5.9 2 Kg load, 300 RPM

Fig 5.11 Change in Wear w.r.t. Change in Fly Ash Content

0

0.02

0.04

0.06

0.08

0.1

0.12

60_2_600 50_2_600 40_2_600 30_2_600 20_2_600

2 Kg_600 RPM

w1-w2

Table 5.10 2 Kg load, 600 RPM

Fig 5.12 Change in Wear w.r.t. Change in Fly Ash Content

36

Wear test with 1.5g of Fiber, it is found that with increase in fly ash content there is also decrease

in wear, however this phenomenon is observed only until a certain upper limit i.e. in the wear

resistance increases from 20% to 50 % fly ash but decreases at 60%.

5.3.2 3g of Fiber, 50g of Epoxy – Varying Fly Ash (%by Weight)

Fig 5.13 Weight Difference Before and After the Wear Test

(In the figure (fig 5.13) on the Y-Axis, the values are read as “%FlyAsh_Load_RPM”)

0.012

0.003

0.0012

0.0040.003

0.0016

0.005

0.008

0.0040.0034

0.01

0.0085

0.0030.004

0.0127

0.0101

0.0030.002

0.0040.0049

0

0.002

0.004

0.006

0.008

0.01

0.012

0.014

Weight Difference (W1-W2)

Sample w1 w2 w1-w2

60_1_300 1.258 1.246 0.012

50_1_300 1.071 1 0.003

40_1_300 0.734 0.73 0.004

30_1_300 0.573 0.57 0.003

20_1_300 0.732 0.729 0.003

0

0.002

0.004

0.006

0.008

0.01

0.012

0.014

60_1_300 50_1_300 40_1_300 30_1_300 20_1_300

1 Kg_300 RPM

w1-w2

Table 5.11 1 Kg load, 300 RPM

Fig 5.14 Change in Wear w.r.t. Change in Fly Ash Content

37

Fig 5.17 Change in Wear w.r.t. Change in Fly Ash Content

However on increasing the fiber content from 1.5g to 3g the wear resistance increases from 20 to

60 % fly ash but decreases at 70%.

Sample w1 w2 w1-w2

60_1_600 1.2445 1.2415 0.003

50_1_600 0.9814 0.9798 0.0016

40_1_600 0.6339 0.6305 0.0034

30_1_600 0.57 0.566 0.004

20_1_600 0.7285 0.7265 0.002

Sample w1 w2 w1-w2

60_2_300 1.246 1.2448 0.0012

50_2_300 0.997 0.992 0.005

40_2_300 0.643 0.633 0.01

30_2_300 0.566 0.5533 0.0127

20_2_300 0.7265 0.7225 0.004

Sample w1 w2 w1-w2

60_2_600 1.437 1.433 0.004

50_2_600 0.992 0.984 0.008

40_2_600 0.7297 0.7212 0.0085

30_2_600 0.4836 0.4735 0.0101

20_2_600 0.6584 0.6535 0.0049

0

0.001

0.002

0.003

0.004

0.005

60_1_600 50_1_600 40_1_600 30_1_600 20_1_600

1 Kg_600 RPM

w1-w2

Table 5.12 1 Kg load, 600 RPM

Fig 5.15 Change in Wear w.r.t. Change in Fly Ash Content

Table 5.13 2 Kg load, 300 RPM

0

0.002

0.004

0.006

0.008

0.01

0.012

0.014

60_2_300 50_2_300 40_2_300 30_2_300 20_2_300

2 Kg_300 RPM

w1-w2

Fig 5.16 Change in Wear w.r.t. Change in Fly Ash Content

0

0.005

0.01

0.015

60_2_600 50_2_600 40_2_600 30_2_600 20_2_600

2 Kg_600 RPM

w1-w2

Table 5.14 2 Kg load, 600 RPM

38

6. CONCLUSIONS

6.1 Impact Test

6.1.1 Only Fiber

There is an increase in impact strength of composite with increase in fiber content

due to energy absorbed in fiber pull out but the overall impact strength of natural

fiber is less than synthetic fiber (Fig. 5.3 (a))

6.1.2 Only Fly Ash

Addition of fly ash to the epoxy has led to the decrease in impact strength. This can

be attributed to the property of particulate reinforced composite where in fly ash

acts as the particulate reinforcement and decreases the overall flexibility making

the composite relatively brittle when added in high amount and due to decreased

availability of epoxy material to bond all the fly ash particles in the matrix, thereby

reducing the impact strength. This can be concluded from the results as shown

(Fig.5.3 (b))

6.1.3 Double Reinforced –Sugarcane Fiber and Fly Ash

After reinforcing the fly ash composite with sugarcane fiber impact strength has

been increased due to energy absorbed in fiber pull out and the fly ash particles.

But as the amount of fly ash increases impact strength falls due to the inability of

epoxy to bond both the fiber and fly ash in the matrix. For two composites having

same fly ash composition but different amount of fiber it can be seen the impact

strength has been increased for high amount of fiber. (Fig 5.1)

39

6.2 Rockwell Hardness

6.2.1 Only Fiber

There is an increase in Rockwell hardness number as fiber content increases

because there is proper interfacial bonding between the fiber and matrix material.

In lesser fiber content there may be areas with in the campsites wherein no fiber is

present but in increase in fiber content these areas reduce and proper bonding

fiber and matrix material is achieved which results in increased hardness.

(Fig.5.7)

6.2.2 Only Fly Ash

As seen from Fig.5.6, an increasing trend of hardness was observed with increase

in weight fraction of fly ash particles .This can be attributed to the presence of

hard fly ash particles in the composites which enhances the dislocation density

which resists the deformation when it is subjected to strain. When the fly ash

content increased from 20 to 60 weight percentage, hardness increased .It can be

explained by the fact that the fly ash particles possess higher hardness, because of

their spherical shape (micro level) it prevents any indentation.

6.2.3 Double Reinforced –Sugarcane Fiber and Fly Ash

After reinforcing fiber and fly ash Rockwell hardness number increases. This is

because the fly ash fuses appropriately around the fiber forming a strong bond

with it.

As it can be seen from the results with increase in fly ash on same fiber content

hardness increases, this can be attributed to the more fly ash content which resists

deformation to strain (Fig5.5).

40

6.3 Wear Test

6.3.1 For 1.5 gram Fiber Content

The sample of wear test in which least material is lost has the best wear property.

From the graphs it can be observed that specimen to 30% from 50% weights have

better wear property as compared to others. The spherical microstructure of fly ash

is assumed to be one of the reason due to which god wear resistance is obtained

with increase in fly ash content.

Wear grooves and scratches along the sliding direction were smaller due to the

presence of fly ash particulates. This shows that the presence of fly ash in the matrix

improves resistance to wear. Applied load affects the wear behavior of composites

and is the most dominating factor in controlling the wear rate

When the two surfaces are in sliding contact, wear mechanisms such as surface

abrasion, oxidation, delamination and adhesion may happen either separately or in

combination.

6.3.2 For 3 gram Fiber Content

The lowest wear loss was obtained for composite with 50 weight % at 1.5g Fiber

whereas 60 weight % had the least wear loss in 3g fiber as compared to composites

reinforced with 20 weight %, 30 weight %, 40weightt% fly ash at varying speeds

and load conditions. This is because incorporation of fly ash particles have

increased the hardness of the composites (Fig.5.5) .This increase in wear resistance

can also be attributed to a better interfacial bonding between matrix material,

fiber and fly ash particles and thus helps in preventing the damages caused due to

sliding action.

Incorporation of fly ash particles to the sugarcane matrix was very effective in

reducing its wear loss. This is because of the strong interfacial bond which plays a

41

vital role in transferring loads from the sugarcane matrix to the hard fly ash

particles.

As the fly ash content increases beyond some proportion the wear loss increased

with increasing the load. This may be due to clustering of fly ash particles and poor

interfacial bonding between sugarcane matrix and fly ash particles. This was proven

by the fact that the wear resistance increased from 50% by weight fly ash (in case

of 1.5g fiber content) to 60% by weight fly ash (in case of 3g fiber content). Beyond

these two cases, the wear resistance of the sample decreased, and higher weight loss

due to wear.

. The surface morphologies of the worn composites indicate the following:

1. At low loads, fly ash particles support the load by acting as a particulate

reinforcement and prevents sugarcane fiber- matrix have direct contact with the

counterpart thus helps in preventing the damages caused due to sliding action.

Abrasion wear mechanism becomes dominant under this condition.

2. Higher applied load results in stresses which exceed fracture stress of fly ash

particles, these particles lose their capacity to sustain the load. In addition the hard

fly ash particles create scars on the surface of the steel counter face which in turn

causes higher wear rate of the composite. The worn out particles also act as third

body abrasives, initiate friction and could penetrate the opposing surfaces in a

contact zone which lead micro ploughing action at the interface.

6.3.3 Most Optimum Composition – Which and Why?

Observing the results obtained from all the tests conducted (Impact, Hardness and Wear)

following conclusion can be drawn regarding the most optimum composition:

42

1. In Impact test, the strength of the sample decreased with increase in fly ash,

whereas when we increased the fiber content strength of the sample increased.

Hence it can be said that, the sample with 3g of fiber, and 30% of fly ash by

weight, showed the highest Strength.

2. In the Rockwell tests, the increase in both fiber and fly ash content, helped in

the hardness of the sample. Hence, the sample with 3g fiber and 60% of fly ash

by weight, was the hardest sample.

3. The Wear Tests showed results favoring higher Fiber content, but increase in

fly ash after certain limit lead to increase in wear. Also, in low load conditions,

50% by weight of fly ash Sample showed most optimum results, both in low

and high fiber content. In high load conditions, 30% by weight of fly ash was

the most optimum sample in 1.5g fiber content, and 60% by weight of fly ash

had the least wear in case of 3g of fiber content.

Looking at the results, we can say that, the optimum composition can be decided as per the

application it will be used for.

In the case where high speed and low weight material is required, like in automobile sector, 30%

by weight of fly ash sample, will be most optimum. It will have high strength and good wear

resistance as well.

In 60% by weight of fly ash sample with 3g of fiber can be used where weight of the sample is not

a constrain, as increasing in the fly ash content will lead to increase in the weight of the sample.

But this increase in fly ash will result in higher hardness but lower impact strength. It will find

applications where high loads are applied and the material is used for wear purpose only.

In 50% by weight of fly ash sample is good with both 1.5g and 3g sample. With moderate hardness

and moderate impact strength as compared to 30% and 60% samples. This has lighter weight than

the 60% by weight of fly ash sample, and higher wear resistance than the 30% sample in case of

higher loads. Hence we can say that, it can be taken as the optimum sample, provided the

applications it is used for doesn’t require high strength.

43

7. APPLICATIONS OF THE MATERIAL

The high wear resistance, good hardness and impact strength of the composite can be

used in various application .Also the property of the fly ash to resist compression is

significant in development of the application of the composite.

7.1 Coupling

Good torsional strength, compression resistance and the ability to resist shear helps

it in coupling 2 different shafts of varying diameters. The hardness of the composite

is found to be in between that of a steel and aluminum. This property can effectively

be used in joining two shafts made of aluminum and steel which otherwise would

eat into each other.

7.2 Plunger

The addition of fly ash makes the composite wear resistant and can be used in

making plunger head. Also the light weight of the composite is another important

property that helps us make the plunger lighter in comparison with traditional

plungers.

7.3 Others

Other fields where there might be future scope for the application of the composites

are in the field of Prosthetic Limbs. The composite can take huge amount of

compression load with good wear resistance hence there is good scope for is use in

the prosthetic medicine.

44

8. SCOPE FOR FUTURE WORK

1. In the present investigation a hand-lay-up technique was used to fabricate the composite.

However there exists other manufacturing process for polymer matrix composite. They

could be tried and analyzed, so that a final conclusion can be drawn there from. However

the results provided in this thesis can act as a base for the utilization of this fiber.

2. From this work it is found that chemical modification of the fiber with alkali significantly

improves the mechanical performance of the composite. Other chemical modification

methods such as silane treatment, acetylation treatment, acrylation treatment isocynates

treatment, Permanganate treatment, Maleated coupling agents could be tried and a final

conclusion can be drawn thereafter.

3. This work can be further extended to other particle size and types of particle like glass bead

etc., to study the effect of particle size and type of particles on wear behavior of the composite.

4. More compositions of the fiber, fly ash and epoxy can be tried to observe the behavior of

the composite more closely. Instead of adding the fiber and fly ash with respect to weight,

they can be added by percentage of volume and the results for the same can be studied.

45

REFERENCES

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2. www.Wikipedia.com

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Department of Mechanical Engineering National Institute of Technology Rourkela -

769 008 (India)

4. Mechanical Properties of Epoxy Resin – Fly Ash Composite 2Department of Materials

& Metallurgical Effect of Fly Ash Content on Friction and Dry Sliding Wear Behavior

of Glass

5. Fiber Reinforced Polymer Composites - A Taguchi Approachgineering, I.I.T. Roorkee

(Uttaranchal), INDIA

6. Experimental Evaluation of Aluminium-Fly Ash Composite Material to Increase the

Mechanical &Wear Behaviour by Stir Casting Method1: PG Scholar, Dept of Mech,

Mokambigai college of Engineering Professor, Dept of Mech, Mokambigai college of

Engineering

7. Chand N. SEM observations of fractured fly-polyester composites. J Mat Sci Lett

1988;7:

8. 36–8.Bijwe, J., Logani, C.M. and Tewari, U.S., 1989, “Influence of fillers and fibre

reinforcement on abrasive wear resistance of some polymeric composites”, In:

Proceeding of the International Conference on Wear of Materials, Denver, CO, USA,

April 8–14, pp. 75–92.

9. Khuri, A.I. and Cornell, J.A., 1987, “Response Surfaces. Designs and Analyses”, Vol.

81 of Statistics, Textbooks and Monographs, Marcel Dekker, Inc. ASQC, New York.

10. Barkoula, N.M. and Karger-Kocsis, J., 2002, “Review-processes and influencing

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