Transcript Mechanical and Tribological Behaviour of Nano Fly Ash Reinforced

Mechanical and Tribological
Behaviour of Nano Fly Ash
Reinforced Hybrid Composites
Dr.S.K.Acharya,Professor
Raghavendra Gujjala,PhD Scholar
Mechanical Engg Department
NIT Rourkela-769008
CONTENTS
 Introduction

Bio Fiber Composite

Background/Origin of the work

Nano Fly Ash

Experimental Aspects

Results And Discussion

Conclusions
What are composite materials ??
Metals & Alloys
SteelCord
tyres
Composites
Polymers
Metal
matrix
composites
Ceramics &
Glasses
Carbon fibre reinforced plastic
Glass fibre reinforced plastic
Introduction

Composite material is a multiphase material
formed from a combination
of two or more materials that differ in composition or form, which are
bonded together, but retaining their identities and properties. The outcome
of this composition is that the newly formed material has superior
properties over the individual components.

Composite material consists of two or more different materials, combining
together through a interface, to form a new material. This new material can
offer better properties which can not be offered by either of the constituent
materials separately.

Composites are comprised of two or more separate material, that when
combined lead to improved properties over the individual components.
Introduction
Contd..

Composites have higher strength than conventional
materials due to aligned fibers carrying the load.

Composites are lighter than traditional materials. They
can be designed to minimum weight without sacrificing
strength.
Why a Composite?

It reduces the weight of the components by 30% in comparison
to conventional material such as metal, plastic or ceramic.

The stiffness or strength needs to be doubled.

The number of sub-components has to be reduced.

The cost may be reduced.

The fatigue life or operating temperature should be increased.

A component with a zero coefficient of thermal expansion may
be obtained.
Why Bio-Fiber Composites ?
Natural Fibers
Advantages of Natural fiber
Reinforcement
1. Environmental reasons:
Renewable resource of raw material
Thermally recyclable, biodegradable,
Low energy consumption
2. Excellent specific strength &
high modulus
3. Health & safety: less abrasive,
safe manufacturing processes
4. Lower cost & reduced density
of products
Bottlenecks
1. Variability
2. Hydro-philicity (moisture)
3. Weak interface
CONSTITUENTS OF BIO- FIBRE COMPOSITE
+
Fiber
Flax
=
Resin
Composite Material
Hemp
Kenaf
Natural Fibers
Sisal
Coir
NATURAL FIBERS
Jute
Bamboo
Banana
Sugarcane
They are
- low-cost
- low density fibers
- high specific strength and modulus
- low priced
- recyclable
- biodegradable
- nonabrasive
- easily available
and above all are
ECO-FRIENDLY
Natural Fibers: Applications
11
Advantage of Natural Fiber over man made fiber
Natural fiber composites are likely to be environmentally superior to glass
fiber composites, in most cases for the following reasons:
1.
Natural fiber production has lower environmentally impacts compared to
glass fiber production.
2.
Natural fiber composites have higher fiber content for equivalent
performance, reducing more polluting base polymer content
3.
The light weight natural fiber composites improve fuel efficiency and
reduce emission in the use phase of the component, especially in auto
applications.
4.
Moreover, natural fibers are non-uniform with irregular cross sections
which make their structures quite unique and much different with manmade
fibers such
as glass
fibers,
carbon
fibers
etc.
Background/Origin of the work
Polymer composites filled with fibers and/or solid lubricants have been
widely accepted as tribo-materials and used on the components supposed to
run without any external lubricants. The former mainly improves the
mechanical strength and wear resistance of polymers, while the latter
improves friction characteristics and contributes to the control of wear.
Tribological properties of polymer composites can also be greatly enhanced
with the addition of nano particles, such as nano-Al2O3/polyimide, nanoZnO/polytetrafluoroethylene(PTFE) , and nano-TiO2/epoxy . One of the
distinct advantages of nano composites over micro composites lies in that
the performance improvement is often achieved at relatively low
concentration of the nano fillers, which is beneficial to the mechanical
properties, processability, and esthetic appearance of the end products.
The term filler is very broad and encompasses a very wide
range of materials which plays an important role for the
improvement in performance of polymers and their composites.
Filler materials are used to reduce the material cost, to improve the
mechanical properties to some extent and in some cases to improve
processability. Besides, it also increases properties like abrasion
resistance, hardness and reduces shrinkages. Therefore a judicious
selection of matrix and the reinforcing phase can lead to a
composite with combination of strength and modulus comparable
or even better than conventional metallic materials. The physical
and mechanical properties can further be modified by addition of a
solid filler phase to the matrix body during the composite
preparation.
Jute, the so-called golden fiber from eastern India and
Bangladesh is one of the most common agro-fibers having
high tensile modulus and low elongation at break. If the low
density of this fiber is taken in to consideration, then its
specific stiffness and strength are comparable to the
respective quantities of glass fibers. The fiber has a high
aspect ratio, high strength to weight ratio, is low in energy
conversion, and has good insulation properties. The jute fiber
composites can be very cost-effective material especially for
building & construction industry, packing, automobile &
railway coach interiors and storage devices.
The main chemical constituents of Jute are
cellulose-61-71%
hemicellulose-13-20%
lignin-12-13%
Lignin
- acts as a binder for the cellulose
fibers
- behaves as an energy storage
system
Cellulose - high tensile strength of composite
materials.
Objective of the work
1.To explore the possibility of making composites
with Nano Fly Ash as reinforcement in polymer
base.
2.Solid Particle Erosion wear behaviour of the
composite.
3. Some Value added novel applications of Jute based
composites are also suggested. This would certainly
in a long way will improve the uses of Fly Ash in
high priority areas, and would also ensure
international market for cheaper substitution.
Introduction to Nanocomposites
• Particulate composites:
– Matrix
– Particulate Phase
• Reinforcing particles have at least one dimension (i.e. length, width, or
thickness) on the nanometer scale
Why small?
Surface area:
5 x 5 x 6 = 150
125 x (1 x 1 x 6) = 750 = 5 x
150
In proceeding from a mm to nm scale the specific
surface area increases by 3 orders of magnitude
EXPERIMENTAL ASPECTS
Materials Required





Jute fiber.
E-Glass fiber.
Flyash
Epoxy resin: LY-556 and
Hardener HY-951
E-Glass
ADVANTAGES
 High strength
 Low cost
 High chemical resistance
 Good insulating properties
DRAW BACKS
 Low elastic modulus.
 Poor adhesion to polymer.
 Low fatigue strength
EPOXY
Epoxy resin (Araldite LY 556) having properties :•
Excellent Mechanical Properties
•
Good Fatigue Resistance
•
Low Shrinkage
•
Negligible shrinkage.
Hardener
In the present work Hardener (araldite) HY 951 is used. This has
viscosity of 10-20 poise at 25 °c. the hardener is taken 10
volume of polymer .
%
of
Fly ash

Fly ash, also known as flue-ash, is one of the
residues generated in combustion, and comprises
the fine particles that rise with the flue gases.
Ash which does not rise is termed bottom ash. In
an industrial context, fly ash usually refers to ash
produced during combustion of coal.
Chemical composition of fly ash
SiO2
Al2O3 Fe2O3 TiO2
CaO MgO Na2O
K2O
Loss on ignition
48.32
31.2
1
1.35
3.5
8.23
2.56
2.1
1.2
Manufacturing technique used
Ingredients used for composite Preparation: Fiber:- Woven Jute Mats and glass fiber (layered stacking
sequence)
Filler :- Fly Ash
Polymer:- Araldite LY 556 (CIBA GEIGY Ltd.)
Hardener :- HY951
Mould used for casting:Per- pex sheet mould of dimension
150x60x6mm is used
Method: - Sl.no
1
Symbol
Stacking sequence
Hand lay-up technique.
L1
GGGG
2
L2
JJJJ
3
L3
JGGJ
4
L4
GJJG
5
L5
JGJG
J-Jute ply, G-Glass ply.
composites samples
Name
Fly ash Filler content
GGGG
0g
0g
JJJJ
0g
0g
JGGJ
2g
4g
GJJG
2g
4g
JGJG
2g
4g
Erosion Test:-
ASTM G 76
Erosion
test rig
Details of erosion test rig. (1) Sand hopper. (2) Conveyor belt system for sand
flow. (3) Pressure transducer. (4) Particle-air mixing chamber. (5) Nozzle. (6) X–
Y and θ axes assembly. (7) Sample holder
Test parameters
 Erodent:  Erodent size (µm): Impingement angle (α0):-
Silica sand
200 ± 50
30, 45, 60, 90
 Impact velocity (m/s):-
70
 Erodent feed rate (g/min):-
4
 Test temperature: -
RT
 Nozzle to sample distance (mm):-
10
 Nozzle diameter
3
RESULTS AND DISCUSSIONS
SEM micrographs of fresh fly ash SEM micrographs of fly ash after
ball milling for 15 hours
XRD patterns of fly ash before
ball mill
XRD patterns of fly ash after ball
mill ball-milled for 15 h,
250
194.3
Flexural Strength Mpa
200
184.82
182.23
180.3
165.89
152.23
150
135.6
123.23
105.2
100.23
100
133.05
87.1
72.18
50
38.23
0
composite Samples
Flexural results of the composites
Tensile Strength Mpa
140
116.22
120
115.35
96.28
100
78.34
80
68.23
85.23
73.46
59.23
60
51.94
40
20
96.28
93.78
89.56
18.22
0
composite Samples
Tensile results of the composites
86.57
80
68.23
Tensile Strength Mpa
70
60
51.94
62.35
62.1
JJJJ 12g FA
Composite Sample
JJJJ 2g N FA
56.23
50
40
30
20
10
0
JJJJ
JJJJ 6g FA
JJJJ 4g N FA
140
123.23
Flexural Strength Mpa
120
100.23
100
90
82
80
72.18
60
40
20
0
JJJJ
JJJJ 6g FA
JJJJ 12g FA
Composite Sample
JJJJ 2g N FA
JJJJ 4g N FA
7
Erosion wear g/g
6
5
4
3
2
1
GGGG
JJJJ
JJJJ+2g FA
JJJJ+4g FA
0
0
10
20
30
40
50
60
70
80
Impingement angles
Erosion Wear Of Composites
90
100
The hybrid composite shows enhanced properties due to the
addition of Nano fillers in comparison to micro fillers.
The Erosion behavior of jute changes from semi brittle to brittle
due to addition of Nano fly ash.
•M.G.
Lines, J. Alloys Compd., doi:10.1016/j.jallcom.2006.02.082 (2007).
•Guozhong
Cao, 2004, Nanostructures and Nanomaterials- Synthesis, properties
and Applications, Imperial College Press, USA.
•Baraton
M.I., 2003, Synthesis, functionalization and surface treatment of
Nanoparticles, American Scientific publication, USA..
•Carl
C Koch, 2006, Nanostructured materials processing, properties and
applications, William Andrew Inc.- NY, USA.
•Kamar
Shah Ariffin, EBS 425/3 – Mineral Perindustrian.
•Kumar
V, Abraham Zacharia K, Sharma P. Fly ash utilization: indian scenario &
case studies. http://www.tifac.org.in/news/flyindia.htm as on 15 April 2007.
•Matsunaga
T, Kim JK, Hardcastle S, Rohatgi PK. Crystallinity and selected
properties of fly ash particles. Mater Sci Eng-A 2002; 325:333–43.