CHAPTER 1

1.1 COMPOSITES:

INTRODUCTION

Composite materials are microscopic mixture of two or more

different materials, one typically being the continuous phase (matrix), and the

other being the discontinuous phase (reinforcement). A clear definition is,

Loose terms like “materials composed of two or more distinctly identifiable

constituents”. The main advantages of composite materials are their high

strength and stiffness, combined with low density, when compared with bulk

materials, allowing for a weight reduction in the finished part.

The composite materials derived from natural, renewable sources have

received significant interest in recent years due to increased environmental

awareness, concern about the depletion of non-renewable resources. The

primary advantages of natural fibers over synthetic fibers have been their low

cost, light weight, high specific strength, and biodegradability show in fig 1.1

Figure. 1.1 Composite material 1

1.1.1 NEED OF COMPOSITE MATERIAL:

There is unabated thirst for new material with improved desired

properties. All the desired properties are difficult to find in a single material.

For example, a material which needs high fatigue life may not be cost

effective.

The life of the desired properties depending upon the requirement of the

application is given below,

1. Strength

2. Stiffness

3. Toughness

4. High corrosion resistance

5. High wear resistance

6. High chemical resistance

7. Reduced weight

8. High fatigue life

9. Thermal& electrical insulation or conductivity

10. Energy dissipation

11. Reduced cost

The list of desired properties are in-exhaustive. It should be noted that

the most important characteristics of composite material is that their

properties are satisfied, that is one can design the required properties.

2

1.1.2 TYPES OF COMPOSITES

Particle-reinforced

(i) Large – particle

(ii) Dispersion - strengthened

Fiber - reinforced

(i) Continuous

(ii) Discontinuous

(a) Aligned

(b) Randomly oriented

Structural

(i) Laminates

(ii) Sandwich panels

Particulate composite

Particulate composites are composed of particle of one or more

material is suspended in a matrix of another material to make the material

stronger.

Fiber reinforced composite

Fiber reinforced composite are the long fiber of one material is

embedded in the matrix of other material which turns out to be extremely

strong.

3

Structural composite

Structural composite are layer of two or more different material

are bonded together by sandwiching two layers of strong.

1.1.3 APPLICATION OF COMPOSITE:

Piping for chilled water will need much less insulation or even none

in some cases.

Low mass skips and hoisting ropes.

Low mass and high capacity breathing apparatus in cylinders

Corrosion resistant air handling equipment.

Slurry transport.

Ventilation ducting.

Thermal insulation cladding.

Hydro power piping.

Corrosive fluid handling and storage.

Corrosion resistant cable trays and gratings.

Blast protection.

Water hydraulics.

Air actuators.

Chemical resistant piping and tanks for platinum refining.

Insulation cladding for chilled water transport.

Ventilation ducting.

The coal mining industry makes extensive use of GRP composite

pipes for fresh water, acid water and slurries. GRP replaced mild

steel and wood incapable of handling corrosion associated with

4

sulfuric acid. Successful installations can be found at Eastern

Associated Coal, Consolidated Coal, North American Coal, Carbon

Fuel and many others.

1.2 FIBER

Fibers are the principal constituents in a fiber-reinforced composite

material. They occupy the largest volume fraction in a composite laminate

and share the major portion of the load acting on a composite structure.

Proper selection of the fiber type, fiber volume fraction, fiber length, and fiber

orientation is very important, since it influences the following characteristics

of a composite laminate:

(i) Density

(ii) Tensile strength and modulus

(iii) Compressive strength and modulus

(iv) Fatigue strength as well as fatigue failure mechanisms

Fibers that make up fabrics used in every- day life can be best

understood as the building blocks of textile and clothing goods. The

durability and success of fabrics used in clothing and home furnishings

depend on the fiber used. Fibers resemble a fine, hair-like structure that is

able to with- stand the rigorous manufacturing required from design to

distribution (Cohen & John- son, 2010). For thousands of years individual-

also and families have been using natural fibers for clothing, cording, home

furnish- INS, and much more

5

If the fibers used in a composite are very long and unbroken or cut then

it forms a continuous fiber composite. A composite, thus formed using

continuous fiber is called as fibrous composite.

The fibers are chopped into small pieces when used in fabricating a

composite. A composite with short fibers as reinforcements is called as short

fiber composite show in fig 1.2.

Figure. 1.2 Fiber

1.2.1 TYPES OF FIBERS

The fiber is classified into two types as follows,

• Synthetic fiber

• Natural fiber

6

1.2.1.1 Synthetic Fiber:

Synthetic fibers made from cellulose and manufactured from

chemicals derived from petroleum. These are made from synthesized

polymers or small molecules. The main raw materials are petroleum based

chemicals or petrochemicals. Their main properties are heat sensitive,

resistant to most chemicals, low moisture absorbency, easy to wash and

maintain, flame resistant. They are more expensive but can supply the world‟s

demand.

The synthetic fiber include that is various fibers as follow,

a. Glass fiber

b. Carbon fiber

c. Boron fiber

d. Ceramic fiber

e. Silicon carbide

f. Aramid fiber

g. Quartz and silica

1.2.1.2 Natural Fibers:

Example of natural fiber is jute, flax, sisal, hemp, hemi, cotton fiber,

coconut fiber (coir), and banana fiber (abaca). All these fibers are growth in

agricultural plants in various parts of the world and are commonly used for

making ropes, carpet backing, bags, and so on. The components of natural

fibers are cellulose micro fibrils dispersed in an amorphous matrix of lignin

7

and hemicellulose. Depending on the type of the natural fiber, the cellulose

contents is in the range of 60-80 wt.% and the lignin content is in the range of

5-20 wt.%. In addition, the moisture content in natural fibers can be up to

20%.

1. Plant fiber:

Seed fiber (Cotton)

Leaf fiber (Sisal, Pineapple)

Bast fiber (Flax, Ramie, Hemp)

Fruit fiber (Coir)

Stalk fiber (Rice)

2. Animal fiber:

Animal hair

Silk fiber

3. Mineral fiber:

Amosite , Crocidolite, Tremolite, Actinolite, Anthophylite,

Chrysolite

1.2.2 Classification of Natural Fibers

Fibers are a class of hair-like material that are continuous

filaments or are in discrete elongated pieces, similar to pieces of thread.

8

They can be spun into filaments, thread, or rope. They can be used as a

component of composites materials. They can also be matted into sheets to

make products such as paper or felt. Fibers are of two types: natural fiber

and manmade or synthetic fiber. Figure 1 shows the classification of natural

fibers show in fig 1.3.

Figure. 1.3 Classification of natural fiber

1.2.3 Applications of Natural Fiber Composites

The natural fiber composites can be very cost effective material for

following applications:

Building and construction industry: panels for partition and false

ceiling, partition buildings which can be used in times of natural calamities

such as floods, cyclones, earthquakes, etc.

Storage devices: post-boxes, grain storage silos, bio-gas containers, etc.

Furniture: chair, table, shower, bath units, etc.

Electric devices: electrical appliances, pipes, etc.

Everyday applications: lampshades, suitcases, helmets, etc.

9

Transportation: automobile and railway coach interior, boat, etc.

The reasons for the application of natural fibers in the automotive

industry include:

Low density: which may lead to a weight reduction of 10 to 30%?

Acceptable mechanical properties, good acoustic properties.

Favorable processing properties, for instance low wear on tools, etc.

Options for new production technologies and materials.

Properties

Chemical analysis of palm fiber shows high cellulose content as

seen from Table 1. The hemi- cellulose content is quite low when

compared with other natural fibers. Cellulose content is responsible for

long fiber chain that ranges (28-53) % for palm fibers.

Table No:1.1

FIBER

CHEMICAL PROPERTIES

HEMI CELLULOSE

%

CELLULOSE

%

LIGNIN %

WAX

%

PALM LEAF

STALK

PALM LEAF

SHEATH

PALM

PETIDE

40-52 40-43 - -

28 25 45 -

30 14 28 -

PALM FRUIT 53 12 21 0.8

PINE APPLE LEAF 70-83 - 5-12.7 -

10

Physical properties

The Physical properties of natural fibers in comparison with

palm fibers were presented in the

Table No:1.2

Physical properties

Fiber

Density

(g/cm3)

Elongation

(%)

Tensile

strength

(MPa)

Young’s

modulus

(GPa)

2.50-

Palm leaf stalk 1-1.2 2-4.50 97-196 5.40

Palm leaf sheath 1.20-1.30 2.84 220 4.8

Palm petiole 0.7-1.55 25 248 3.24

Palm fruit 1.09 28 423 6.-8.

Coir 1.15-1.2 30 175 4.-6.

Pineapple leaf 0.80-1.60 14.5 144 400-627

3.3.1. Fiber density.

Fiber Vs Density

2

1.5

1

0.5

0

1.2 1.3

1.55

1.09 1.2

1.6 palm leaf stalk

palm leaf sheath

palm petiole

palm fruit

Coir

Pineapple leaf

11

Tensile strength

Figure 4 shows the tensile strength of palm fibers and few

natural fibers. The tensile behavior of the palm fibers increases with

increase in gauge lengths from 10 mm to 40 mm. As the gauge

length increases the deviation from the mean value for various

samples increases, which was expected for any natural fiber

characterization. The variation in Young‟s modulus was rather high

which is due to artifacts.

Fiber Vs Tensile strength

500

450

400

350

300

250

200

150

100

50

0

196

220

248

Fiber

423

175

144

palm leaf stalk

palm leaf sheath

palm petiole

palm fruit

Coir

Pineapple leaf

12

1.3 RESIN:

Composites are a combination of fiber reinforcement and a

resin matrix. The resin system holds everything together, and transfers

mechanical loads through the fibers to the rest of the structure. In addition

to binding the composite structure together, it protects from impact,

abrasion, corrosion, other environmental factors and rough handling.

Resin systems come in a variety of chemical families, each designed and

designated to serve industries providing certain advantages like economic,

structural performance,resistance to various factors, legislation

compliance, etc. Only the most common resins of the below. Those are

Polyester (orthophthalic and isophthalic), vinyl ester, epoxy, and phenolic.

Fibermax Composites carries only epoxy resin systems thermoses family

and the ones mostly used in composite construction are described show in

fig 1.4

Figure. 1.4 Resin with hardener

13

1.3.1 TYPES OF RESIN

1.3.1.1 Polyesters:

Unsaturated polyester resins are the simplest, most economical

resin systems that are easiest to prepare and show good performance.

Millions of tons of this material is used annually around the world.They

are manufactured by the condensation polymerization of various idols

(alcohols) and dibasic acids (e.g. malefic anhydride or numeric acid) to

give esters, a very viscous liquid that is then dissolved in styrene, a

reactive monomer. Styrene lowers the viscosity to a level suitable for

impregnation or lamination. Applications include transportation markets

(large body parts for automobiles, trucks, trailers, buses), marine (small

and large boat hulls and other marine equipment), building (panels,

bathtub and shower shells), appliances etc.

1.3.1.2 Orthophthalic:

Is also referred to as Roth or General Purpose Polyester

(GP) was the original polyester developed. It has the lowest cost and is

still very widely used in FRP industry . It is commonly used in

applications where high mechanical properties, corrosion resistance, and

thermal stability are not required. Although the upper temperature limit is

only 50oC, it performs satisfactory in water and sea water. It is normally

not recommended for use in contact with chemicals.

14

1.3.1.3 Isophthalic:

Often referred to as ISO, it is improved polyester. It has a slightly

higher cost, improved strength, thermal stability(55oC) and mild resistance

to corrosion conditions. Improved resistance to water permeation has

prompted its use as a gel barrier coat in marine applications. Improved

chemical resistance has led them to extensive use in underground

petroleum tanks (in gas stations) with satisfactory service life. They are

also used in salts and mild acids.

1.3.1.4 Vinylester:

Even further improved polyester, it is biphenyl chlorinated, or a

combination of polyester and epoxy. Its curing, handling and processing

characteristics are those of polyester, and it exhibits higher test results in

corrosion temperature resistance and strength and has higher cost.

Modifications of the molecule have produced even higher properties.

1.3.1.5 Phenolic:

Phenolic resin is a reaction of phenol and formaldehyde. It can be

cured via heat and pressure, without the use of catalysts or curing agents.

It is one of the oldest thermosetting resins available and sells at a very

reasonable cost. Cured phenolic resins are fire resistant without the use of

mineral fillers or fire retardant additives. Phenolic composites have

excellent high-temperature properties and if properly formulated and

cured, they can form carbon to carbon composites with outstanding

temperature resistance. Phenolics are also unique in their chemical

resistance. The use of phenolic resins in composites is growing, primarily

15

due to regulative legislation on flame spread, smoke generation, and

smoke toxicity. It is used extensively in automobiles, appliances,

electronics, and as an industrial adhesive both in higher and lower

temperature applications.

1.3.1.6 Epoxy :

Epoxy resins are a broad family of materials. The most common ones are

prepared from the reaction of bis-phenol A and epichlorohydrin and contain a

reactive functional group in their molecular structure. Epoxy resin systems

show extremely high three dimensional crosslink density which results to the

best mechanical performance characteristics of all the resins. The most

demanding strength/weight applications use epoxy almost exclusively. It has

excellent strength and hardness, very good chemical heat and electrical

resistance. Also, often heat curing is required.) Epoxy systems are used in

applications like aerospace, defense, marine, sports equipment, adhesives,

sealants, coatings, architectural, flooring and many others .More information

about epoxies and Fibermax Composites systems.

1.3.1.7 Gel coats

Gel coats are prepared from a base resin and additives. The base resin

can be polyester, vinyl ester, phenolic or epoxy. Additives are thyrotrophic

agents, fillers, pigments and other. The gel coat, as the name implies, has a gel

texture. This makes the gel coat capable to “stay” on vertical surfaces of

molds without draping. It is placed f irst in the mold, so it becomes the outer

surface.

16

1.3.2 APPLICATION

It is applicable for joining the slabs.

It is mixed with the paint for painting.

Resins are used in reinforced composite material for joining

purpose.

There also used for connecting pipe lines.

1.3.3 Properties:

Epoxy resins are stronger than polyester resin and vinyl ester

resin. Epoxy resin having a matrix chain linkage structure so it provides high

bonding strength.

• Some of the most important properties include:

• Water and chemical resistance

• Electrical stability

• Thermal stability

• Toughness

• Low volatiles during manufacture

• Low shrinkage

Features

• MeetsUL94V-0 approval

• Low shrinkage

• Good chemical and water resistance

17

• Non-toxic

• Free of abrasive fillers, low wear on dispensing machinery

Typical Properties:

Liquid Properties: BaseMaterial

Epoxy

Density Part A-Resin(g/ml) 2.25

Density Part B-Hardener(g/ml) 0.94

Part A Viscosity (mPa 23°C) 200000

Part B Viscosity (mPa 23°C) 58

Mix Ratio (Weight) 17.31:1

Mix Ratio (Volume) 7.23:1

Usable Life(20°C) 90mins Gel Time(23°C)5hours

Cured System: Thermal Conductivity(W/mK) 1.26

Cured Density (g/ml) 2.09

Mixed System Viscosity (mPa 23°C) 16700

Temperature Range(°C) -40to+130

Max Temperature Range (Short Term °C / 30 Mins)

(Application and Geometry Dependent) +150

Dielectric Strength(kV/mm) 10

Volume Resistivity (ohm-cm) 1015

Shore Hardness D80

Colour (Mixed System) White

Flame Retardency Yes 18

Tensile Strength(MPa) 82

Compressive Strength(MPa) 120

Deflection Temperature(°C) 60

1.3.4 HARDENER

A substance mixed with paint or other protective covering to make the

finish hardener or more durable. A chemical used to raise the melting point of

an emulsion show in fig 1.5

Figure. 1.5 Hardener

19

CHAPTER 3

WORKING METHODOLOGY

3.1 PREPARATION OF PALM FIBER:

The palm fibers are easily available in all places. The palm tree

were extracted by either retting in water and/or mechanical processing or hand

picking methods are used. The fiber were cleaned with water after soaking for

two weeks. The fiber were further dried in natural sunlight to remove

moisture content and long uniform fiber were obtained. Then the fiber is

separate in the equal dimensions for producing a composite material. The

palm fibers were available plenty from INDIA fibers . The fibers were

further dried in natural sunlight to remove moisture content and long

uniform fibers were obtained (Fig. 3.1).

Palm leaf stalk fiber Palm fruit fiber

Palm leaf sheath fiber Palm petiole fiber

Figure. 3.1 Fiber extraction

25

3.2 PREPARATION OF RESIN:

When in Resin pack form, the resin and hardener are mixed by

removing the clip and moving the contents around inside the pack until

thoroughly mixed. To remove the clip, remove both end caps, grip each

end of the pack and pull apart gently. By using the removed clip, take

special care to push unmixed material from the corners of the pack.

Mixing normally takes from two to four minutes depending on the skill of

the operator and the size of the pack. Both the resin and hardener are

evacuated prior to packing so the system is ready for use immediately after

mixing. The corner may be cut from the pack so that it may be used as a

simple dispenser show in fig 3.2.

Figure. 3.2 Preparation of resin

26

3.3 MOULD BOX:

In our project the molding box is manually prepared .The mould box

is made in the natural wood . This type of mould is prepared for medium size

jobs and its smooth surface show in fig 3.3 .

Figure. 3.3 Molding box

Dimension of Molding Box :

Length : 45 cm

Breath : 40 cm

Height : 3 cm

27

3.4 WORKING:

The mounding box is manually prepared by using sheet metal. And

the wax is coated bottom side .The resin is mixed with the hardener due to the

increasing the hardness properties of resin. The palm is fiber is collected

manually and it is cut required size. The wax is used for easily removing the

composite material from the mould box.

Inside the mould box the resin and fiber are pasted alter natively like

a layer .The wax is pasted before the first layer and also after the last layer .It

takes 24hr for complete the work in atmosphere .After completion of work the

job is includes the test of temperature, hardness and impact.

Mold preparation:

The composite were manufactured in a metal mold of 900mm X

450mm X 10mm. The fabrication of the composite material was carried

out through the hand-layup technique. The top and bottom plate surface of the

mold and the walls were coated with remover and allowed to dry. The top and

bottom plates are to be covered and press the fiber after the epoxy resin is

applied.

Product Description

ER2074 is a flame retardant, thermally conductive , two part potting

and encapsulating compound. The flame retardant technology used is of a

„clean‟ type leading to relatively low toxicity fumes and low smoke

emission.

28

Fiber density

The fiber density is calculated by using pycnometer having to line as

density comparing element, the density of palm fiber is(1-1.2 g/cm3). The

investigated palm fiber was found to have an average density of (0.7-1.55

g/cm3) which is significantly lower than wield used synthetic fibers such as

E-glass fiber(2.5 g/cm3) and carbon fiber (1.4-1.8 g/cm3).

Tensile strength of fiber

The tensile test was conducted using UTM as per the ASTM standard

for all fibers. The fibers with gauge length of 20mm, 30mm, 40mm and

50mm are tested. A constant cross head speed of 0.1mm/min was used for the

testing.

Fiber reinforcement composite:

Fiber reinforced composite material consist of fibers of high strength

and modules embedded in or bonded with distinct interfaces (boundaries)

between them. Common fiber reinforced composites are composed of fibers

and a matrix. Fibers are the reinforcement and the main source of strength

while matrix glues all the fibers together in shape and transfers stresses

between the reinforcing fibers. Sometimes, filler might be added to smooth

the manufacturing process, impact special properties to the composites, and or

reduce the product cost. The principal fibers in commercial use are various

types of glass and carbon as well as Kevlar 49. Other fibers, such as boron,

silicon carbide, and aluminum oxide, are used in limited quantities.

29

Fiber orientation in each layer as well as the stacking sequence of

various layers in a composite laminate can be controlled to generate a wide

range of physical and mechanical properties for the composite laminate.

3.5 CHARACTERISTICS OF PALM FIBER:

Palm fibers are a composite material designed by nature. The

fibers are basically a rigid, crystalline cellulose micro fibril-reinforced

amorphous lignin and/or with hemi cellulosic matrix. Most plant fibers are

composed of cellulose, hemicelluloses, lignin, waxes, and some water-

soluble compounds. The percentage composition of each of these

components varies for different fibers. Generally, the fiber contains 60-80

% cellulose, 5-20% lignin and up to 20% moisture. During the biological

synthesis of plant cell walls, polysaccharides such as cellulose. This

lignification‟s process causes a stiffening of cell walls and the carbohydrate

is protected from chemical and physical damage show in fig 3.4.

Figure .3.4 Palm fiber

30

CHAPTER 4

TESTING METHODS

4.1 HARDNESS TEST:

Hardness is the property of a material that enables it to resist plastic

deformation, usually by penetration. However, the term hardness may also

refer to resistance to bending, scratching, abrasion or cutting.

Measurement of Hardness:

Hardness is not an intrinsic material property dictated by precise

definitions in terms of fundamental units of mass, length and time. A hardness

property value is the result of a defined measurement procedure.

Hardness of materials has probably long been assessed by resistance to

scratching or cutting. An example would be material B scratches material C,

but not material A. Alternatively, material A scratches material B slightly and

scratches material C heavily. Relative hardness of minerals can be assessed by

reference to the Moh's Scale that ranks the ability of materials to resist

scratching by another material. Similar methods of relative hardness

assessment are still commonly used today. An example is the file test where a

file tempered to a desired hardness is rubbed on the test material surface. If

the file slides without biting or marking the surface, the test material would be

considered harder than the file. If the file bites or marks the surface, the test

material would be considered softer than the file.

The above relative hardness tests are limited in practical use and do

not provide accurate numeric data or scales particularly for modern day

metals and materials. The usual method to achieve a hardness value is to

31

measure the depth or area of an indentation left by an indenter of a specific

shape, with a specific force applied for a specific time. There are three

principal standard test methods for expressing the relationship between

hardness and the size of the impression, these being Brinell, Vickers, and

Rockwell. For practical and calibration reasons, each of these methods is

divided into a range of scales, defined by a combination of applied load and

indenter geometry.

Hardness Test Methods:

Rockwell Hardness Test

Rockwell Superficial Hardness Test

Brinell Hardness Test

Vickers Hardness Test

Microhardness Test

Moh's Hardness Test

Scleroscope and other hardness test methods

4.1.1 Rockwell Hardness Test

The Rockwell hardness test method consists of indenting the test

material with a diamond cone or hardened steel ball indenter. The

indenter is forced into the test material under a preliminary minor load F0

usually 10 kgf. When equilibrium has been reached, an indicating device,

which follows the movements of the indenter and so responds to changes

in depth of penetration of the indenter is set to a datum position. While

the preliminary minor load is still applied an additional major load is

applied with resulting increase in penetration. When equilibrium has

again been reach, the additional major load is removed but the

32

preliminary minor load is still maintained. Removal of the additional

major load allows a partial recovery, so reducing the depth of penetration

The permanent increase in depth of penetration, resulting from the

application and removal of the additional major load is used to calculate

the Rockwell hardness number.

HR = E - e

F0 = preliminary minor load in kgf

F1 = additional major load in kgf

F = total load in kgf

e = permanent increase in depth of penetration due to major load F1

measured in units of 0.002 mm

E = a constant depending on form of indenter: 100 units for diamond

indenter, 130 units for steel ball indenter

HR = Rockwell hardness number

D = diameter of steel ball

33

Diagram of Rock Well Hardness Testing Machine

Figure. 4.1 Rockwell Hardness test

CALCULATION:

Table No:4.1

Specimen Indenter Load RHN Average

Composite

material 1/16

100 65

100 75

100 67

67.3

34

4.1.2 The Brinell Hardness Test

The Brinell hardness test method consists of indenting the test

material with a 10 mm diameter hardened steel or carbide ball subjected

to a load of 3000 kg. For softer materials the load can be reduced to 1500

kg or 500 kg to avoid excessive indentation. The full load is normally

applied for 10 to 15 seconds in the case of iron and steel and for at least

30 seconds in the case of other metals. The diameter of the indentation

left in the test material is measured with a low powered microscope. The

Brinell harness number is calculated by dividing the load applied by the

surface area of the indentation.

The diameter of the impression is the average of two readings at right

angles and the use of a Brinell hardness number table can simplify the

determination of the Brinell hardness. A well structured Brinell hardness

number reveals the test conditions, and looks like this, "75 HB

10/500/30" which means that a Brinell Hardness of 75 was obtained

using a 10mm diameter hardened steel with a 500 kilogram load applied

for a period of 30 seconds. On tests of extremely hard metals a tungsten

carbide ball is substituted for the steel ball. Compared to the other

hardness test methods, the Brinell ball makes the deepest and widest

indentation, so the test averages the hardness over a wider amount of

material, which will more accurately account for multiple grain structures

and any irregularities in the uniformity of the material. This method is

the best for achieving the bulk or macro-hardness of a material,

particularly those materials with heterogeneous structures.

35

Diagram of Brinell Hardness Testing Machine

Figure. 4.2 Brinell hardness test

Table No:4.2

Specimen Load Diameter of

Specimen

Area

In mm^2

BHN

Composite 100

100

100

1.3 0.676 147.84

36

CALCULATION:

BHN= P/A

A= (πD)/2 (D- (D^2-d^2))

D=1.5mm

d=1.3

BHN=56 Kgf

4.1.3 Vickers Hardness Test

The Vickers hardness test method consists of indenting the test

material with a diamond indenter, in the form of a right pyramid with a

square base and an angle of 136 degrees between opposite faces

subjected to a load of 1 to 100 kgf. The full load is normally applied for

10 to 15 seconds. The two diagonals of the indentation left in the surface

of the material after removal of the load are measured using a microscope

and their average calculated. The area of the sloping surface of the

indentation is calculated. The Vickers hardness is the quotient obtained

by dividing the kgf load by the square mm area of indentation.

F = Load in kgf d = Arithmetic mean of the two diagonals, d1 and d2 in

mm

HV = Vickers hardness

37

When the mean diagonal of the indentation has been determined

the Vickers hardness may be calculated from the formula, but is more

convenient to use conversion tables. The Vickers hardness should be

reported like 800 HV/10, which means a Vickers hardness of 800, was

obtained using a 10 kgf force. Several different loading settings give

practically identical hardness numbers on uniform material, which is

much better than the arbitrary changing of scale with the other hardness

testing methods. The advantages of the Vickers hardness test are that

extremely accurate readings can be taken, and just one type of indenter is

used for all types of metals and surface treatments. Although thoroughly

adaptable and very precise for testing the softest and hardest of materials,

under varying loads, the Vickers machine is a floor standing unit that is

more expensive than the Brinell or Rockwell machines.

There is now a trend towards reporting Vickers hardness in SI units

(MPa or GPa) particularly in academic papers. Unfortunately, this can

cause confusion. Vickers hardness (e.g. HV/30) value should normally be

expressed as a number only (without the units kgf/mm2). Rigorous

application of SI is a problem. Most Vickers hardness testing machines

use forces of 1, 2, 5, 10, 30, 50 and 100 kgf and tables for calculating

HV. SI would involve reporting force in newtons (compare 700 HV/30 to

HV/294 N = 6.87 GPa) which is practically meaningless and messy to

engineers and technicians. To convert a Vickers hardness number the

force applied needs converting from kgf to newtons and the area needs

converting form mm2 to m2 to give results in pascals using the formula

above.

38

4.2 IMPACT TEST:

An impact test is a technique for determining the behavior of

material subjected to shock loading in bending , tension and torsion. The test

designed to determine how a specimen of a known material will respond to a

suddenly applied stress .The test ascertains whether the material is to tough or

brittle. Impact test is also known as ASTM E23. The impact test is a method

for evaluating the toughness ,impact strength , and notch sensitivity of

engineering materials. They are basically two types of impact test ,pendulum

and drop weight show in fig 4.3.

Figure. 4.3 Impact test

39

CALCULATION:

1. Charpy

Table No:4.3

S.No Energy stored in

pendulum chamber

before striking the

specimen

(J)

Energy forced in

pendulum

(J)

Energy

absorbed by

the specimen

(J)

Impact

strength

(J/mm^2)

1 300 180 120 1.2

Material = composite

Size of the specimen = 10mm×10mm=100mm^2

Length of the specimen = 75mm

Breath of the specimen = 10mm

Thickness of the specimen = 10mm

Formula:

I = K/A

A = (d-d1)×b

I = 1.2 J/mm^2

40

2. Izod

Table No:4.4

S.No Energy stored in

pendulum chamber

before striking the

specimen

(J)

Energy forced in

pendulum

(J)

Energy

absorbed by

the specimen

(J)

Impact

strength

(J/mm^2)

1 164 152 12 0.12

CALCULATION:

Material = composite

Size of the specimen = 10mm×10mm=100mm^2

Length of the specimen = 75mm

Breath of the specimen = 10mm

Thickness of the specimen = 10mm

Formula:

I = K/A

A = (d-d1)×b

I = 0.12 J/mm^2

41

4.3 TEMPERATURE TEST:

Table No:4.5

S.No Area of specimen

mm^2

Minimum

Temperature

C

Maximum

Temperature

C

1 100 160 250

4.4 DEFLECTION TEST:

The deflection distance of a member under a load is directly

related to the slope of the deflected shape of the member under that load and

can be calculated by integrating the function that mathematically describes the

slope of the member under that load.

Deflection can be calculated by standard formula (will only give the

deflection of common beam configurations and load cases at discrete

locations), or by methods such as virtual work, direct

integration, Castiglione‟s method, Macaulay's method or the direct stiffness

method, amongst others show in fig :4.4

42

UTM MACHINE

Figure. 4.4 Deflection test

Calculation:

Table No:4.6

S.No Length of specimen

Energy absorbed by

mm the specimen Kg

1 52 77

43

CHAPTER 5

COMPARISION

Tensile Testing

The tensile test specimens were prepared according to

ASTMD 638. For testing the specimen was mounted in the grips of the

Instron universal tester with 10 mm gauge length. The stress strain

plotted during the test for the determination of ultimate tensile

strength and elastic modulus.

The tensile strength of palm fibers and few natural fibers. The

tensile behavior of the palm fibers increases with increase in gauge

lengths from 10 mm to 40 mm. As the gauge length increases the

deviation from the mean value for various samples increases,

which was expected for any natural fiber characterization. The

variation in Young‟s modulus was rather high which is due to artifacts.

Tensile strength, also known as Ultimate Tensile Strength (UTS),

44

FIBER COMBINATION vs PERCENTAGE

ELONGATION

13

12.5

12

11.5

11

10.5

10

9.5

palm coir

FIBER COMBINATION

Figure 1 Comparison of effect of fiber combination on percentage elongation

FIBER COMBINATION vs ULTIMATE STRESS

(N/mm2)

176

174

172

170

168

166

164

palm coir

FIBER COMBINATION

Figure 2 Comparison of effect of fiber combination on ultimate stress.

Flexural Properties

Figures 3 shows the flexural strength of palm based composite

and the coir based composite. From the results of flexural test, the palm

matrix composite shows better flexural property than coir matrix

composite.

45

FIBER COMBINATION vs FLEXURAL STRENGTH

N/mm2

124 123 122 121 120 119 118 117 116 115

palm coir

FIBER COMBINATION

Figure 3 Comparison of effect of fiber combination on flexural strength.

Impact Properties

The impact responses of both composites were presented in Figure

4. The Palm based composite posses higher impact strength that leads to

the higher toughness in the material. 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.

46

FIBER COMBINATION vs IMPACT STRENGTH

8.1

8

7.9

7.8

7.7

7.6

7.5

7.4

7.3

7.2

palm coir

FIBER COMBINATION

Figure 4 Comparison of effect of fiber combination on Impact length.

Wear Properties

The figur represents the effect of fiber combination on the

weight loss of the specimen. It was observed that palm specimen

holding superior wear resistance on comparison with coir specimen.

Also the weight loss on coir based composite was higher than palm

based composites.

Wear can also be defined as a process where interaction

between two surfaces or bounding faces of solids within the working

environment results in dimensional loss of one solid, with or without

any actual decoupling and loss of material. Aspects of the working

environment which affect wear include loads and features such as

unidirectional sliding, reciprocating, rolling, and impact loads, speed,

temperature.

47

Rate of Weight loss due to wear

3

2.5

2

1.5

1

0.5

0

0.7 0.5

0.89

1.45

2.6 2.4

palm

coir

90 180 270 360

Time(sec)

Figure 5 Comparison of effect of fiber combination on rate of weight loss due to wear.

Moisture absorption Test

Figure 6 shows the comparison of rate of absorption of

moisture content between the two com- posites. It was observed that

Palm fiber composites absorbed less moisture on comparing with

coir fiber composites and holds a better result that they can be used in

areas where the require- ment is dry.

48

Rate of absorbtion of moisture content

0.2

0.18

0.16

0.14

0.12

0.1

0.08

0.06

0.04

0.02

0

7.3 15 22.3 30 37.3 45

palm

coir

49

COMPOSITION:

CALCULATION

Volume of mould = Area x Thickness

=40 x 45 x 1.4 c.m

=2520 c.m3

F=30% R =60% P=10%

Volume of fiber = 1716 X30/100 =514.8 c.m3

Volume of resin =1716 X60/100 =1029.6c.m3

Weight:

Volume of Powder = 1716 X10/100 =171.6c.m3

Weight of fiber = 200g

Weight of Resin

= 2 Kg

Weight of power

= 70g

Total weight = 2.270Kg

50

6. COST ESTIMATION

RESIN - 1500

HARDNER - 500

MOLDING BOX - 200

FIBER,BRUSH,WAX - 500

REPORT - 1200

TRANSPORT - 1000

TOTAL - 4900

51

7. CONCLUSION:

In our project contains 60% of resin 30% fiber and 10% of neem

powder . It is with stand up to 75kg of load . So it suitable for alternative of

slab in kitchen and shelf and also a coir applications.

52

REFRENCES:

[1] Wallenberger, F. T. & Weston, N. (2004) Natural. Fibers, Plastics

and Composites Natural,. Mate- rials Source Book from

C.H.I.P.S. Texas

[2] Satyanarayana, K. G., K. Sukumaran, P. S. Mukherjee, C.

Pavithran and S. G. K. Pillai. (1990), Natural Fiber–Polymer

Composites, J. Cement and Concrete Composites, 12(2) pp. .

[3] Satyanarayana, K.G., Sukumaran, K. Kulkarni, A.G. , Pillai,

S.G.K. andRohatgi, P.K. (1986). Fabri- cation and Properties of

Natural Fiber-reinforced Polyester Composites , Composties , 17:

[4] Gowda, T. M. Naidu, A. C. B. Chhaya, R. (1999) Some

Mechanical Properties of Untreated Jute Fabric-Reinforced

Polyester Composites, Journal of Composites Part A: Applied

Science and Manu- facturing, 30(3), pp. .

[5] Sastra, H, Siregar, J, Sapuan, S and Hamdan, M (2006),'Tensile

properties of Arenga pinnata fiber- reinforced epoxy composites,

Polymer-Plastics Technology and Engineering, vol. 45, no. 1, pp.

[6] Kazuya Okubo, Toru Fujii, & Yuzo Yamamoto. (2004).

Development of bamboo-based polymer composites and their

mechanical properties, Composites Part A: Applied Science

and Manufac- turing, 35 (3), 2004, .

[7] Antich, A. Vázquez, I. Mondragon and C. Bernal (2006).

Mechanical behavior of high impact poly- styrene rein forced with

short sisal fibers, Composites Part A, 37, 2006, .

53