1

Project Report

On

SETTING UP OF ELECTROPLATING UNIT

FOR FABRICATION OF AGRICULTURAL

TOOLS

Submitted in Partial Fulfilment of the requirement for the award of degree of

Bachelor Engineering

In

Mechanical Engineering

BY

Kumar Saheb Manoj Kumar Rajput Apoorva Kumar

1PI10ME061 1PI10ME065 1PI10ME024

Under the guidance of

Dr. C. S. RAMESH

Professor

Department of Mechanical Engineering

PES Institute of Technology

2

PEOPLES EDUCATION SOCIETY

I N S T I T U T E O F T E C H N O L O G Y

100 Feet Ring Road, BSK III Stage, Bangalore - 560 085.

Tel : 26721983

DEPARTMENT OF MECHANICAL ENGINEERING

C E R T I F I C A T E

Certified that the mini project entitled “Setting up of electroplating unit for the

fabrication of agricultural tools” is a bonafide work carried out by Kumar Saheb

(1PI10ME061), Manoj Kumar Rajput (1PI10ME065) and Apoorva Kumar

(1PI10ME024) in partial fulfillment for the award of degree of Bachelor of Engineering

in Mechanical engineering of the Visveswaraya Technological University, Belgaum

during the year 2013 - 2014. It is certified that all corrections/suggestions indicated for

Internal Assessment have been incorporated in the report deposited in the

departmental library. The project report has been approved as it satisfies the academic

requirements in respect of project work prescribed for the Bachelor of Engineering

Degree.

Dr C.S Ramesh Dr K.S Sridhar

Professor, HOD,

Dept of Mech Engg, Dept of Mech Engg,

Pesit,Bangalore Pesit,Bangalore

Signature of the examiners

(Examiner 1) (Examiner 2)

3

DECLRATION

I hereby declare that the project work entitled “SETTING UP OF

ELECTROPLATING UNIT FOR FABRICATION OF

AGRICULTURAL TOOLS” submitted to PES Institute of

Technology, is a record of an original work done by us under

the guidance of Dr. C. S. Ramesh Professor, PES Institute of

Technology, Bangalore, and this project work has not

performed the basis for award of any Degree or Diploma/

Associate ship/ Fellowship and similar project if any.

Kumar Saheb Manoj Kumar Rajput Apoorva Kumar

(1PI10ME061) (IPI10ME065) (1PI10ME024)

4

ACKNOWLEDGEMENT

The satisfaction and euphoria that accompany the successful completion

of any task would be incomplete without the mention of the people who

made it possible, whose constant guidance and encouragement crowned

out effort with success.

We express our deep sense of gratitude to my

guide Dr. C.S Ramesh, Professor, P.E.S. Institute of Technology

Bangalore for his untiring and valuable guidance with constant

encouragement at every stage of this project work. We are grateful to Dr.

K.S. Sridhar, Professor& Head of the Department of Mechanical

Engineering, P.E.S. Institute of technology for giving me the consent to

carry out the dissertation work. We also express my sincere gratitude to

Dr. K.N. Balasubramanya Murthy, Principal & Director, P.E.S. Institute of

technology, Bangalore for permitting to carry out the dissertation work.

We

sincerely thank Dr. K.T. Kashayp, Professor, Department Mechanical

Engineering, P.E.S Institute of technology for his constant support in

carrying out project work. I sincerely thank Dr. Rajesh Mathivanan N,

Associate Professor, Department Mechanical Engineering, P.E.S Institute

of technology for his constant support and valuable advice

We are very grateful to all the teaching, non-teaching, and administrative

staff of Department of Mechanical Engineering, P.E.S. Institute of

Technology for their kind co-operation during this work. Finally, we thank

to almighty, Our Parents, friends for their help and support throughout our

course and all who have helped me directly and indirectly during this

course of project

5

ABSTRACT

Low carbon steel with manganese as a major alloying element is the most

popular material for fabrication of harvester blades. During harvesting,

these blades tend to get corroded and also get worn out quickly due to the

abrasive and erosive nature of the hard particles of soil. This leads to huge

problems of either getting the worn harvester blades replaced by a new

set of blades resulting in uncalled increased farming investments. In

recent years, surface engineering methods offer solutions to the address

the above issues in farming.

In the light of the above, this work focuses on nickel-silicon carbide

composite electroplating of harvester blades. Nickel electroplating is

commercially proven technique with it unique advantages being low

temperature process and easily the most economical one. Nickel coatings

offer excellent corrosion resistance even under harsh environment during

farming. SiC has been used to enhance hardness of the blade.

Erosive wear of the coated and uncoated harvester blade material will be

characterized using air jet erosive wear test rig. The effect of standoff

distance (50 mm,40mm,30mm,20mm) and test duration time (5,10,15,20

minutes),Vickers hardness value of both coated and uncoated harvester

blade material is reported.

6

TABLE OF CONTENTS

Cover page..............................................................................................1

Certificate …………………………………………………………………..…2

Declaration .............................................................................................3

Acknowledgements... .............................................................................4

Abstract…………….................................................................................5

Table of Contents…………………………………………………….…. .....6

Chapter 1: Introduction .........................................................................8

1.1: Aim of the Project

1.2: Present scenario

Chapter 2: Brief Literature survey…….………………..........................9

2.1: Advantage of Composite coating over base alloy coating.

2.2: Air Jet erosion test over MMC’s

Chapter 3: The Combined harvester ………………………………… 13

3.1: Functions and working

3.2: Parameters affecting combined harvester blades

Chapter 4: Experimental Procedure...................................................20

4.1: Chemical composition test

4.1.1: Principal of the test

7

4.1.2: Result of the test

4.2: Hardness test before the electroplating

4.2.1: Principal of the test

4.2.2: Result of the test

4.3: The electroplating process

4.3.1: The coating process

4.3.2: Why Nickel as base metal for electroplating?

4.3.3: Why SiC used as reinforcement?

4.3.4: Electroplating experimental procedure

4.4: Hardness test after the electroplating

4.5: Air jet erosive Wear test

4.5.1: Air jet tester details

4.5.2: Test condition and parameter

4.5.3: Observations and Results

4.5.3.1: Effect of varying stand of distance

4.5.3.2: Effect of varying test duration

Chapter 5: Conclusion and Future work...........................................47

Chapter 6: References........................................................................48

8

CHAPTER 1

Introduction

1.1 Aim of the project

The objective is to improve the wear and corrosion resistance of Combine Harvester

Blades with the help of Electroplating process.

1.2 Present scenario

Being an agrarian country, the agricultural sector plays a very important role in the

economy of developing nation like India. Thus keeping this thing in mind, in the present

study we are looking for very important problem faced by the farmers in the agricultural

sector today. The problem is related with the blades of combine harvester which worn

out quickly owing to the high pressure dusty environment that it has to work into, which

adds to uncalled cost and expenditure to the farmers as the blades has to be replaced

Periodically.

Several attempts has been done to maximize the life of the blades via

thermal spray and arc coating but without any considerable success. Thus the over

plan of the project is to increase the wear and corrosion resistance via Ni/SiC

electroplating over the blades to check for the extent of success, we would be

conducting hardness and air jet erosion test before and after the fabrication

9

Chapter 2

Brief Literature survey

2.1 Advantage of Composite coating over base alloy coating

Coatings are used in both aqueous and high temperature applications. Electric power

generation, and waste incineration involve severe conditions and thick coatings have

proved effective. Diesel and gas turbine engines are subjects of the high temperature

corrosion and highly beneficial coatings have been developed. Some nuclear power

systems also rely on coatings. Factors that must be taken into account include

substrate compatibility, adhesion, porosity, the possibility of repair or recoating,

interdiffusion, the effect of thermal cycling, resistance to wear and corrosion, and not

at last the cost.

Advances in materials performance often require the development of

composite systems. Coated materials could be one form to use. The abrasion and

corrosion resistance of components can be greatly increased by protective coatings

and this is a growing industry of considerable economic importance. Both

measurements of electrochemical corrosion and friction coefficient show a better

resistance of nano-structured composite coating compared with pure nickel coating.

The nano-composite coating show a bigger polarisation resistance and reduced

corrosion current density compared with pure nickel coating in moving conditions. The

friction coefficient of nano-composite coating is smaller compared with pure nickel

coating.

Deposition of electrochemical composite coatings (ECC) is not a newly

developed technique [1], but has been in continuous development since the 1970s [2–

9]. The steady interest is explained by easy maintainability and low cost of ECC

manufacture as well as by a possibility of changing the properties and adapting them

to many applications. Due to their high wear resistance and the low cost of ceramic

powder, Ni–SiC composites have been investigated to the greatest extent and

10

successfully commercialised for the protection of friction parts The most recent works

on the Ni–SiC system are developed on the modulated current in order to obtain SiC

gradient distribution [8] or by-layers with different SiC content [9].

Figure 1: (A) SEM of Ni + SiC composite coating (B) TEM image inside of a nickel composite coating.

11

2.1 Air Jet erosion over MMC’S

Metal matrix composites (MMC’s) are presently the most preferred innovative

materials due to their excellent strength, higher wear resistance, better thermal

conductivity and low coefficient of thermal expansion. It has been nearly three

decades, that these exotic materials are mainly processed by two well established

techniques namely the powder and liquid metallurgy. Homogeneity in the distribution

and high volume fractions of reinforcements in the matrix alloy are the characteristics

features of the powder metallurgical processing technique. However, the liquid

metallurgy processing technique possesses unique features such as mass production

of large and complex shaped composite castings. A blend of the above two processes

will positively bring out enhanced homogeneity, greater volume incorporation of

reinforcements, leading to production of light weight large structures with improved

mechanical and tribological properties of the composites [10]. It has been re-ported

that increased content of hard reinforcement in the soft matrix alloy has resulted in

effective decrease in wear rates of the composites [11]. Majority of the metal matrix

composite materials systems studied are reinforced with ceramics possessing high

hardness and strength either continuous in the form of fibre or discontinuous in the

form of whisker, platelets or particulate reinforcements embedded in a ductile metallic

matrix [12]. Most of the researchers have focused their attention on 9

Processing and characterization of mechanical and adhesive wear behaviour of

MMC’s [13,14,15]. Currently MMC’s are being explored as the candidate materials for

components subjected to hard solid particle erosion. Merger information is available

as regards the assessment of solid particle erosion wear of MMC’s although

researchers have reported on erosive wear behaviour of polymer based composites

[16,17]. Decrease in the angle of impact from 90˚ to 20˚ has resulted in significant

increase in erosion wear loss and ductility [18]. The mass loss of the target material

subjected to sand particle erosion tests is directly proportional to kinetic energy and is

inversely to the hardness of the target material [19]. Metal matrix composites with

silicon carbide as the reinforcement possesses the maximum erosion wear resistance

its mass fraction ranging from 60 to 75 Weight% [20]. Interesting work on erosive wear

of polymer based composites has been reported. Factors such as impingement angle,

12

impact velocity, erodent size and amount of reinforcement are the major factors

affecting the erosion rate of composites [21,17]. It has been reported that glass and

carbon fibre reinforced composites do exhibit semi-ductile erosion characteristics with

the peak erosion wear occurring at 60˚ impingement angle [22,23]. Hybridization of

the reinforcements with use of discontinuous fibres and hard particulates in processing

of MMC’s leads to improved hardness, strength and wear resistance. However, no

information is available as regards the erosive wear of hybrid MMC’s with hard

particulate and discontinuous fibre reinforcements. In the light of the above, this work

focuses on novel processing of hybrid MMC’s and assessing its erosive wear

behaviour.

13

Chapter 3

The Combined harvester

Figure 2: A combine harvester in a field of cut barley in summer

The combine harvester, or simply combine, is a machine that harvests grain crops.

The name derives from its combining three separate operations comprising harvesting

reaping, threshing, and winnowing into a single process. Among the crops harvested

with a combine are wheat, oats, rye,barley, corn (maize), soybeans and flax (linseed).

The waste straw left behind on the field is the remaining dried stems and leaves of the

crop with limited nutrients which is either chopped and spread on the field or baled for

feed and bedding for livestock.

Combine harvesters are one of the most economically important labour saving

inventions, enabling a small fraction of the population to be engaged in agriculture.

14

3.1 How does it work?

The crops we grow in our fields, such as wheat, barley, and rye, are only partly edible.

We can use the seeds at the top of each plant (known as the grain) to make products

like bread and cereal, but the rest of the plant (the chaff) is inedible and has to be

discarded.

Before modern-day machines were developed, agricultural workers had to

harvest crops by carrying out a series of laborious operations one after another. First

they had to cut down the plants with a long-handled cutting tool such as a scythe.

Next, they had to separate the edible grain from the inedible chaff by beating the cut

stalks—an operation known as threshing. Finally, they had to clean any remaining

debris away from the seeds to make them suitable for use in a mill. All this took a lot

of time and a lot of people.

Thankfully, modern combine harvesters do the whole job

automatically: you simply drive them through a field of growing crops and they cut,

thresh, and clean the grains all by themselves using rotating blades, wheels, sieves,

and elevators. The grain collects in a tank inside the combine harvester (which is

periodically emptied into tractors that drive alongside), while the chaff spurts from a

big exit pipe at the back and falls back down onto the field.

Figure 3: Wheat crop

15

Figure 4: different parts of the harvester.

1. Cereal crops are gathered in by the header at the front, which has a pair of

sharp pincers called crop dividers at either end. Generally speaking, the wider

the header, the faster and more efficiently a harvester can cut a field. Different

headers are used for cutting different crops; the header is

often hydraulically powered and can be raised, lowered, and angled in different

ways from the cab. The header can be removed and towed behind the

harvester lengthwise so it can fit down narrow lanes.

2. A slowly rotating wheel called the reel (or pickup reel) pushes the crops down

toward the cutter. The reel has horizontal bars called bats and vertical teeth or

tines to grip the plant stalks.

3. The cutter bar runs the entire length of the header underneath the reel. Its

teeth (sometimes called mowing fingers) open and close repeatedly to cut off

16

the crops at their base, a bit like a giant electric hedge cutter sweeping along

at ground level.

Figure 5: Close-up of the cutter on a John Deere combine harvester. Left: Looking

from the front; Right: looking down from the cab toward the incoming crops.

4. Behind the cutter bar, the cut crops are fed toward the centre by spinning augurs

(screws) and travel up a conveyor to the processing mechanism inside the main part

of the combine.

5. A threshing drum beats the cut crops to break and shake the grains away from

their stalks.

6. The grains fall through sieves into a collecting tank below.

7. The chaff (unwanted material) passes along conveyors called straw

walkers toward the back of the machine. More grain falls through into the tank.

8. When the grain tank is full, a tractor with a trailer on the back pulls alongside the

combine. The grain is carried up from the tank by an elevator and shoots out of a side

pipe (sometimes called the unloader) into the trailer.

17

9. The unwanted straw chaff tumbles from the back of the machine. Some combines

have a rotating spreader mechanism that throws the straw over a wide area.

Sometimes the straw is baled up by a baling machine and used for animal bedding.

3.2: Parameters affecting combine harvester blades

We shall study the various impact forces taking place during the various operation of

the combine but before that we will pictorially understand the operations.

Figure 6: Combine stray elevator.

In this operation the blades are almost to near contact with the soil and small straw

particles continuously hit the blades. If the ph. of the soil is high it will cause wear and

corrosion. High air pressure environment is also created which adds to the losses.

18

Figure 7: Threshing and separation

Figure 8: wear in the blades

19

The impact on the blades include the soil and dusty hitting the blades at various angles

which will be studied in the air jet erosion test.

20

CHAPTER 4

EXPERIMENTAL PROCEDURE

After the literature survey and data analysis, the actual project was started. The

whole project was divided into various phases in series. The First step in the analysis

was to bring the actual worn out non-working harvester blade and do the chemical

composition test over it.

Figure 9: Profile view of the Experimental blades

21

Figure 10: Top view of the experimental blades

The blades clearly showed the corrosion over the cutting surface.

4.1: Chemical composition test

This test was performed using optical emission spectrometry

Figure 11: Optical emission spectrometry

22

4.1.1: Principle of the test

Optical emission spectrometry involves applying electrical energy in the form of spark

generated between an electrode and a metal sample, whereby the vaporized atoms

are brought to a high energy state within a so-called “discharge plasma”.

These excited

atoms and ions in the discharge plasma create a unique emission spectrum specific

to each element. Thus, a single element generates numerous characteristic emission

spectral lines.

Therefore, the light generated by the discharge can be said to be a

collection of the spectral lines generated by the elements in the sample. This light is

split by a diffraction grating to extract the emission spectrum for the target elements.

The intensity of each emission spectrum depends on the concentration of the element

in the sample. Detectors (photomultiplier tubes) measure the presence or absence of

the spectrum extracted for each element and the intensity of the spectrum to perform

qualitative and quantitative analysis of the elements.

23

Figure 12 : Spectral lines

4.1.2 : Result of the test

Result of composition test in percent by weight

EElements Percent weight

Carbon 0.261

Silicon 0.28

Manganese 1.19

Phosphorous 0.012

Sulphur 0.009

Chromium 0.32

Nickel 0.23

Molybdenum 0.07

24

4.2 : Hardness test before the electroplating

Hardness is defined as the resistance of metal to plastic deformation, usually by an

indentation. However this term can also be referred to abrasion, scratching or cutting.

The addition of hard reinforcement increases the hardness of the composites and

similarly softer reinforcement’s decreases hardness. The type and extent of

incorporation of the reinforcements has greater influence on the hardness of the

composite. Hardness also depends upon nature of reinforcements and quantity of

reinforcements. Incorporation of particles, whiskers, or fibers in to MMC causes a

significant increase in the hardness of the material [61, 62]. The coating with Ni [63]

and Cu [64] also leads to good quality interface. Alberto Borrego et al. [65] have

reported that on extrusion the hardness of material improves. Ramesh and M. Safiulla

[66] have reported that in both cast and extruded conditions, the micro hardness of

Al6061 composites increases with increased content of reinforcements. Extruded

composites possess higher micro hardness when compared with cast one.

The method employed to determine the hardness was the micro Vickers hardness test

The Vickers hardness test was developed in 1921 by Robert L. Smith and George

E. Sandland at Vickers Ltd as an alternative to the Brinell method to measure

the hardness of materials. The Vickers test is often easier to use than other hardness

tests since the required calculations are independent of the size of the indenter, and

the indenter can be used for all materials irrespective of hardness.

25

Figure 13: Vickers hardness tester

4.2.1: Principle

The basic principle, as with all common measures of hardness, is to observe the

questioned material's ability to resist plastic deformation from a standard source. The

Vickers test can be used for all metals and has one of the widest scales among

hardness tests. The unit of hardness given by the test is known as the Vickers

Pyramid Number (HV) or Diamond Pyramid Hardness (DPH). The hardness

number can be converted into units of Pascal’s, but should not be confused with a

pressure, which also has units of Pascal’s. The hardness number is determined by the

load over the surface area of the indentation and not the area normal to the force, and

is therefore not a pressure.

26

Figure14 : Vicker’s test sceme

It was decided that the indenter shape should be capable of producing geometrically

similar impressions, irrespective of size; the impression should have well-defined

points of measurement; and the indenter should have high resistance to self-

deformation. A diamond in the form of a square-based pyramid satisfied these

conditions. It had been established that the ideal size of a Brinell impression was 3/8

of the ball diameter. As two tangents to the circle at the ends of a chord 3d/8 long

intersect at 136°, it was decided to use this as the included angle of the indenter, giving

an angle to the horizontal plane of 22° on each side. The angle was varied

experimentally and it was found that the hardness value obtained on a homogeneous

27

piece of material remained constant, irrespective of load. Accordingly, loads of various

magnitudes are applied to a flat surface, depending on the hardness of the material to

be measured. The HV number is then determined by the ratio F/A, where F is the force

applied to the diamond in kilograms-force and is the surface area of the resulting

indentation in square millimetres. A can be determined by the formula.

Which can be approximated by evaluating the sine term to give

Where d is the average length of the diagonal left by the indenter in millimetres.

Hence,

,

Where F is in kgf and d is in millimetres.

The corresponding units of HV are then kilograms-force per square

millimetre (kgf/mm²). To calculate Vickers hardness number using SI units

one needs to convert the force applied from kilogram-force to newton’s by

multiplying by 9.806 65 (standard gravity) and convert mm to m. To do the

calculation directly, the following equation can be used:

Where F is in kgf and d is in millimetres.

Vickers hardness numbers are reported as xxxHVyy, e.g. 440HV30,

or xxxHVyy/zz if duration of force differs from 10 s to 15 s, e.g.

440Hv30/20, where:

440 is the hardness number,

HV gives the hardness scale (Vickers),

30 indicates the load used in kgf.

28

20 indicates the loading time if it differs from 10 s to 15 s

Vickers values are generally independent of the test force: they will

come out the same for 500 gf and 50 kgf, as long as the force is at least

200 gf.

For thin samples indentation depth can be an issue due to substrate

effects. As a general rule of thumb the sample thickness should be kept

greater than 2.5 times the indent diameter. Alternatively indent depth

can be calculated according to:

5.2.2 : Hardness test result

Trial 1 478 HV

Trial 2 486 HV

Trial 3 482 HV

Average value 482 HV

5.3 : The electroplating process

Electroplating is a process that uses electrical current to reduce dissolved

metal cations so that they form a coherent metal coating on an electrode. The term is

also used for electrical oxidation of anions onto a solid subtrate, as in the formation

silver chloride on silver wire to make silver/silver-chloride electrodes. Electroplating is

primarily used to change the surface properties of an object (e.g. abrasion and wear

resistance, corrosion protection,lubricity, aesthetic qualities, etc.), but may also be

used to build up thickness on undersized parts or to form objects by electroforming.

29

Figure 15 : Electroplating setup

5.3.1: The coating process

Plating is the application of a surface finish to another material; it provides the surfaces

of manufactured parts with a number of desirable physical, chemical, and appearance

qualities. Nearly all manufactured or fabricated products made of metal or having

metal components have some type of surface finishing. Plating increases sturdiness,

prevents corrosion, provides hardness, or gives an attractive finish to an object. One

of the popular coating method is Electroplating

Electroplating is inexpensive, reliable,

efficient, and applicable to a wide variety of shapes and sizes. However, traditional

electroplating technologies often result in uneven surface finishes, and have inherent

pollution problems. Electroplating is used to change the surface properties of a metal

part by adding a metal coating by the action of electric current; it is also called "electro

deposition,". The object to be coated receives a negative charge and is immersed into

a solution that contains a salt of the metal to be deposited. The metallic ions of the salt

carry a positive charge and are attracted to the object. Surface pre-treatment by

chemical or mechanical means is important for electroplating, as the successful

adhesion of the surface coating depends on removing contaminants and films from

the substrate. In addition, the geometric shape and contour of the object affects the

30

thickness of the deposited layer. Objects with sharp corners and features will have

thicker deposits on the outside corners and thinner ones in the recessed areas,

because the current flows more densely to prominent points than to less accessible

areas. This characteristic of electroplating limits applications with uneven surfaces or

that have depressions or hidden holes. Some metals used in electroplating are

aluminium, brass, bronze, cadmium, copper, chromium, iron, lead, nickel, tin, and zinc,

as well as precious metals such as gold, platinum, and silver. Different types of

coatings can be achieved through control of parameters such as voltage, amperage,

temperature, residence times, and purity of the bath solutions. Applications of

electroplating are numerous because it is an inexpensive and simple method; it is used

in all aspects of electronics, optics, and the automobile industry where, for example,

chrome plating is used to enhance the corrosion resistance of metal parts .

Below is a chart that shows the diversity of electroplating metals and the associated

applications:

31

4.3.2: Why Nickel chosen as a base element for electroplating?

Nickel electroplating is a commercially important and versatile surface-finishing

process. Its commercial importance may be judged from the amount of nickel in the

form of metal and salts consumed annually for electroplating, now roughly 100,000

metric tons worldwide, as well as its versatility from its many current applications. The

applications of nickel electroplating fall into three main categories: decorative,

functional, and electroforming.

In decorative applications, electroplated nickel is most often applied in combination

with electrodeposited chromium. The thin layer of chromium was first specified to

prevent the nickel from tarnishing. It was originally deposited on top of a relatively

thick, single layer of nickel that had been polished and buffed to a mirror-bright finish.

Today decorative nickel coatings are mirror bright as deposited and do not require

polishing prior to chromium plating. Multi-layered nickel coatings outperform single-

layer ones of equal thickness and are widely specified to protect materials exposed to

severely corrosive conditions. The corrosion performance of decorative, electroplated

nickel plus chromium coatings has been further improved by the development of

processes by which the porosity of chromium can be varied and controlled on a

microscopic scale (micro discontinuous chromium). Modern multi-layered nickel

coatings in combination with micro discontinuous chromium are capable of protecting

steel, zinc, copper, aluminium, and many other materials from corrosion for extended

periods of time. The complexity of modern-day nickel plus chromium coatings is more

than offset by the greatly improved corrosion resistance that has been achieved

without significantly increasing coating thickness and costs.

There are many functional applications where decoration is not the issue. Instead,

nickel and nickel alloys with matte or dull finishes are deposited on surfaces to improve

corrosion and wear resistance or modify magnetic and other properties. The properties

of nickel electrodeposits produced under different conditions of operation are of

particular interest in this connection. Electroforming is electroplating applied to the

fabrication of products of various kinds. Nickel is deposited onto a mandrel and then

32

removed from it to create a part made entirely of nickel. A variation of this is electro

fabrication where the deposit is not separated from the substrate and where fabrication

may involve electrodeposition through masks rather than the use of traditional

mandrels. The many current applications of nickel electroplating are the result of

developments and improvements that have been made almost since the day the

process was discovered. This is evident in the following retrospective on the

development of nickel electroplating solutions as well as in subsequent sections that

deal with basics, decorative electroplating, functional applications and deposit

properties, nickel electroforming, nickel anode materials, quality control, and pollution

prevention.

The amount of nickel deposited at the cathode and the amount dissolved at the anode

are directly proportional to the product of the current and time and may be calculated

from the expression q ,where m is the amount of nickel deposited at the cathode (or

dissolved at the anode) in grams, I is the current that flows through the plating tank in

amperes, t is the time that the current flows in hours, and a is the current efficiency

ratio (see Chapter 1 for the definition of current efficiency). The proportionality constant

(1.095) in grams per ampere hour equals M/nF, where M is the atomic weight of nickel

(58.69), n is the number of electrons in the electrochemical reaction (2), and F is

Faraday’s constant, equal to 26.799 A-h (more commonly given as 96,500 C).

m = 1.095xaxt …….[q]

4.3.3: Why Silicon Carbide as reinforcement material?

Silicon Carbide is the only chemical compound of carbon and silicon. It was originally

produced by a high temperature electro-chemical reaction of sand and carbon. Silicon

carbide is an excellent abrasive and has been produced and made into grinding wheels

and other abrasive products for over one hundred years. Today the material has been

developed into a high quality technical grade ceramic with very good mechanical

properties. It is used in abrasives, refractories, ceramics, and numerous high-performance

applications. The material can also be made an electrical conductor and has applications

in resistance heating, flame igniters and electronic components. Structural and wear

applications are constantly developing. Carbon fibre has been described as a fibre

33

containing at least 90% carbon obtained by the controlled pyrolysis of appropriate fibres.

Carbon fibre composites are ideally suited to applications where strength, stiffness, lower

weight, and outstanding fatigue characteristics are critical requirements. They also can be

used in the occasion where high temperature, chemical inertness and high damping are

important.

Figure 16: Properties of silicon Carbide.

5.3.4: Electroplating procedure

An empty fish aquarium was used as an electroplating bath. It was checked for any

leakage by pouring ordinary water. The list of chemicals was decided as per project

plan was bought from the lab. An agitator fan was fixed to the bottom surface of the

bath in order to mix the electrolytic solution properly for uniform coating. A ac to dc

current supplier was brought as in electroplating, the type of current used is direct

current, again for uniform coating. The blade is polished to remove the corrosion layer

from the surface of the cutting blade, it is then washed properly with acetone to remove

any type of foreign particles and impurities. Firstly base Ni coating is done which is

followed by SiC coating via electroplating.

34

Chemicals Value

Nickel sulfamate 120 g/L

Ferrous sulphate 1 g/L

Dimethyl formamide 1 L

Boric Acid 25 g/L

BN powder 5-20 g/L

Table 2: List of chemical that is to be used.

Figure 17: The Electroplating bath

35

Figure 18: setting up of agitator

Figure 19: Mounted cut specimen of uncoated blade to be used air jet erosion,

chemical composition and hardness test.

36

Figure 20: Masking of the blade after treating it with acetone

Figure 21: preparation of required chemical mixture

37

Figure 22: electrolytic mixture poured into the bath

Figure 22: Final electroplating setup.

38

Figure 23: Picture after Ni electroplating

Figure 24: Picture after Sic composite coating.

39

4.4: Hardness test after the coating

Figure 25: Specification of the wicker’s hardness tester used

Hardness value before electroplating: 482HV

Hardness value after electroplating: 638HV

Percentage increase = 32.36

0

100

200

300

400

500

600

700

blue = before coating ; orange =after coating

hardness before and after the electroplating

Series 1 Series 2 Column1

40

4.5: The Air Jet erosion test

The Air Jet Erosion Test is used to test the erosion resistance of solid materials

to a stream of gas containing abrasive particulate.

The test is performed by propelling a stream of abrasive particulate gas through

a small nozzle of known orifice diameter toward the test sample.

Material loss, in this case, is achieved via the impingement of small abrasive

particles upon the surface of the test sample.

Materials such as metals, ceramics, minerals, polymers, composites,

abrasives, and coatings can be tested with this instrument.

The test specimen, temperature, angle of incidence of the jet stream, abrasive

particulate speed and flux density, can be varied to best simulate actual

conditions.

Special adapters are available to test various geometries and components for

user-specified testing applications. The instrument can be configured to test as

per ASTM G76 specifications

41

Figure 26: Air jet erosion tester as per ASTM 76 standard

42

4.5.1: TEST CONDITION AND PARAMETERS

1. Erodent material: Silica sand

2. Erodent size [μm]: 300

3. Particle velocity [m/s]: 30

4. Erodent feed rate [g/m]: 2

5. Impact angle [degrees]: 90

6. Test temperature: Room temperature

7. Test time [minutes]: 5,10,15,20

8. Sample size [mm]: random

9. Nozzle inner diameter [mm]: 1.5

10. Standoff distance [mm]:50, 40, 30, 20

11. System pressure [bar] : 1.4

Note: - Weight loss of the blade specimen before and after electroplating were

recorded using a precision micro balance of accuracy 0.1 mg.

43

Fig 27: setup of specimen on air jet tester before testing

Figure 28: specimen after air jet action

44

4.5.2: Observation and result

45

46

Study of air jet erosion before and after the electroplating on the blade specimen is the

last stage of our undertaken project but surely the most important one. An air jet

erosion test machine was used to assess the erosion wear behaviour. As stated earlier

the study is performed by varying two very important parameters of air jet erosion

testing i.e. duration and stand of distance of abrasive sand particles over the

specimen. We shall take up their result and discussion separately in the next section.

Looking into the various result one thing which is

very clear is that in all the case the losses after the coating is considerably less. An

average of 40% less losses is seen which proves that coating adopted by us is very

useful for combine harvester blades. The blades come contact with the components

which are eccentrically mounted over the central shaft of the harvester, hence the

distance of impact keep changing. This parameter is studied with stand of distance

which is the distance between the surface of the specimen and the tip of the nozzle. It

can be seen that with increasing time the wear losses decreases in all the cases. Since

an angle of 90 has been used there has been high losses in both the cases as with 90

degree the specimen is in direct contact with the specimen i.e the nozzle is directly

over the specimen .We can also observe a linear drop in the losses with time in both

before and after the fabrication.

Now if we make a comparison of the various stand-off

distance, it is expected that with decreasing SOD the wear loss should increase but

does not follow completely. Before the electroplating the loss was highest for 50 mmm

sod followed by 20, 30, and 40. This is because we had used the same sample for all

the sod and started with 20mm sod which gave considerable losses owing to the less

distance, so more impact. With 50 mm sod it should give the least loss but it gives the

highest loss because by this time the specimen becomes worn out and loses all its

toughness thus with higher sod also it is able to give the highest loses. Now studying

effect for before the fabrication the loses are same for 20 and 50 sod with 30 and 40

being in the intermediate range. Here also the reason can be accounted for the same

reason as stated above.

47

CHAPTER 5

CONCLUSION AND FUTURE WORKS

The project was undertaken with a mission to develop a better material for a harvester

blades. Which was achieved successfully with the use of Ni-SiC composite coating

over the blade. This was proved through hardness and air jet erosion test before and

after the electroplating. There was a 32.36% increase in the hardness and Air jet

erosion showed around 40 % less wear and erosion loses for all the cases after the

fabrication. Thus through this project we have proven the above used combination of

electroplating very much useful and superior for the harvester blades currently being

used in the agricultural sector.

The future works that can be undertaken

can be study of the above coated blade for more parameter changes in the air jet

erosion test like taking different grain size, various pressure of the air from the nozzle,

different angle of orientation. Coating combination can also be varied to check for

cheaper coating.

48

CHAPER 6

REFRENCES

[1] N. Guglielmi, J. Electrochem. Soc. 8 (119) (1972) 1009–1012.

[2] L. Benea, Composite Electrodeposition—Theory and Practice, Porto Franco,

Romania,ISBN 973 557 490 X, (1998), 173 pp.

[3] S.W. Watson, J. Electrochem. Soc. 140 (1993) 2235.

[4] G. Maurin, A. Lavanant, J. Appl. Electrochem. 25 (1995) 1113–1121.

[5] L. Benea, G. Carac, Metal. New Mater. Res. 2 (1997) 1–19.

[6] L. Benea, in: P.M. Natishan, H.S. Isaacs, M. Janik-Czachor, V.A. Macagno, P.

Marcus, M. Seo (Eds.), Proceeding volume Passivity and Its Breakdown, 1997, ISBN

1-56677-179-X.

[7] L. Benea, Mater. Manufact. Processes 14 (2) (1999) 231–242.

[8] L. Orlowskaja, N. Pereine, M. Kurtinaitiene, S. Surviliene, Surf. Coat. Technol. 111

(1999) 234–239.

[9] S.K. Kim, H.J. Yoo, Surf. Coat. Technol. 108109 (1998) 564–569.

[10] Ramesh.C.S, Harsha.R.Gudi, Nirupama Mohan and Adarsh.H, Development of

innovative Al6061-SiC composite by hybrid technique. Editors- Proceedings of STLE

Conference May 6-10, 2012, St. Louis, USA, 2012.

[11] C.S. Ramesh and Mir Safiulla, Wear behaviour of hot extruded Al6061 based

composites, Wear Vol. 263, (2007) 629-635.

[12] C.S. Ramesh and T.B. Prasad, Dry sliding friction and wear behaviour of

hypereutectic Al-Si-Carbon fibre metal matrix composite, Tribology Vol. 1 No. 4, (2007)

197-202.

[13] C.S. Ramesh, R. Keshavamurthy, S. Pramod and Praveennath G. Koppad,

Abrasive wear beha-vior of Ni–P coated Si3N4 reinforced Al6061 composites, Journal

of Materials Processing Tech-nology Vol. 211, (2011) 1423–1431.

49

[14] R.K. Uyyuru, M.K. Surappa, and S. Brusethaug, Tribological behavior of Al–Si–

SiCp compo-sites/automobile brake pad system under dry sliding conditions,

Tribology International Vol. 40, (2007) 365–373.

[15] Ranjit Bauri and M.K. Surappa, Sliding wear behavior of Al–Li–SiCp composites,

Wear Vol. 265, (2008) 1756–1766.

[16] Tamer Sinmazcelik, Sinan Fidan and Volkan Gunay, Residual mechanical

properties of car-bon/polyphenylenesulphide composites after solid particle erosion,

Materials and Design Vol. 29, (2008) 1419–1426.

[17] S.S. Mahapatra and Amar Patnaik, Study on mechanical and erosion wear

behavior of hybrid composites using Taguchi experimental design, Materials and

Design Vol. 30, (2009) 2791–2801.

[18] Brian E. MacMillin, Christopher D. Roll and Paul Funkenbusch, Erosion and

surface structure development of metal–diamond particulate composites, Wear Vol.

269, (2010) 875–883.

[19] R.J.K. Wood and A.J. Speyer, Erosion–corrosion of candidate HVOF aluminium-

based marine coatings, Wear Vol. 256, (2004) 545–556.

[20]] Z. Huang, Z.Z. Li and X. Yuan, The effect of reinforcing particles on the erosive

wear behavior of particles reinforced silicone matrix composite coating, Wear Vol. 249,

(2001) 1046–1050.

[21] A.P. Harsha and Avinash A. Thakre, Investigation on solid particle erosion

behaviour of polye-therimide and its composites, Wear Vol.262, (2007) 807–818.

[22] S.S. Mahapatra, Amar Patnaik and Alok Satapathy, Taguchi method applied to

parametric ap-praisal of erosion behaviour of GF-reinforced polyester composites,

Wear Vol. 265, (2008) 214–222.

[23] A.P. Harsha and Deepak Kumar Bhaskar, Solid particle erosion behaviour of

ferrous and non-ferrous materials and correlation of erosion data with erosion models,

Materials and Design Vol. 29, (2008) 1745–1754.

50