the study of conductivity of different alloys composition

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THE STUDY OF CONDUCTIVITY OF DIFFERENT ALLOYS COMPOSITION

‘;

AMIR LUQMAN BIN AZMI PUAT

AHMAD FAHMI IRSYAD BIN ARZEMI

FINAL YEAR PROJECT

(DIPLOMA IN NON DESTRUCTIVE TESTING)

TATI UNIVERSITY COLLEGE

2013/2014



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1.0 Introduction

As a student in a course of Non Destructive Testing at TATIUC, we have to do an assignment in

subject Final Year Project . The assignment about study of conductivity of different alloys

composition . We need to examine about what is correct conductivity for each alloy by using

Eddy Current Testing.

In eddy current inspection a magnetic field is produced by an alternating current flowing

through the test coil. When the energised coil is brought close to, or placed in contact with, a

conductive material, eddy currents are induced in the material. The induced eddy currents

produce a magnetic field that opposes the field produced by the coil. The net effect is to cause a

change in the impedance of the test coil. This change in impedance can be detected with a high

degree of accuracy by the instrument circuits.

Conductivity

Conductivity defines a material's ability to conduct electricity. Electric current can flow easily

through a material with high conductivity. Conductivity is measured in Siemen’s per meter and

is often represented using the Greek letter σ. A material such as metal has a high conductivity,

while rubber has a very low conductivity. A semiconductor's conductivity is intermediate.

Factors such as temperature have a large effect on conductivity. Resistivity is the reciprocal of

conductivity so that a material with high conductivity has low resistivity, and a material with

high resistance is, by definition, a poor conductor.

Alloys

Alloys are found very often in nature and are defined as a mixture of two or more materials, out

of which at least one has to be a metal. Alloys can be combination of various metallic and non

metallic components and also a mixture of different metals. No matter what these

combninations and mixtures are, each component present in an alloy is known to have its own



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specific set or properties. these combinantions of metals with each other as well as non-metallic

components, can go up to any number and types of alloys

Sample of copper alloys

IACS

IACS stands for the International Annealed Copper Standard. This is a measurement scale whichcompares the conductivity of materials to that of annealed copper. The readings are expressed as

percent IACS. Since some materials are better conductors that copper, readings over 100% are

sometimes encountered.



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1.1 Objectives

To measure conductivity on different composition of copper alloys.

To identify the signal characteristic of different copper alloys using absolute probe.

To measure the percentage of composition of each different alloys.



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2.0 Material & Methods

2.1 Material

a) Sample of Alloys

i) Brass ( copper , zinc )

- A yellowish alloy of copper and zinc, sometimes including small amounts of other

metals, but usually 67 percent copper and 33 percent zinc.

ii) Bronze ( copper , tin , aluminium )

- any of various alloys consisting essentially of copper and tin, the tin content not

exceeding 11 percent.



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iii) Constantan ( copper , nickel )

- An alloy of 45 percent nickel and 55 percent copper, used chiefly in electrical

instruments because of its constant resistance under variations of temperature.

iv) Copper tungsten ( copper , tungsten )

- Alloy with 75% of tungsten, is widely used in chip carriers, substrates, flanges and

frames for power semiconductor devices



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v) beryllium copper ( copper , beryllium )

vi) Gunmetal (copper, tin and zinc)

- An alloy of copper (88%), tin (8%), and zinc (4%). Originally used chiefly for making

guns, gunmetal was eventually superseded by steel. Gunmetal casts and machines well

and is resistant to corrosion from steam and salt water,[3] and is used to make steam and

hydraulic castings, valves, and gears, and also statues

b) Eddy Current Instruments

i) Absolute probe – These probes normally consist of a single coil (or winding) that

can respond to all changes in the area being inspected. They can be used to detect

gradual changes such as metallurgy variations, heat treatment and shape as well

as sudden changes such as cracks.

ii) Conductivity probe – The conductivity probe can be used to measure either

solution conductivity or total ion concentration of aqueous samples being

investigated in the field or in the laboratory. Conductivity is one of the easiest

environmental tests of aquatic samples. Even though it does not tell you specific

ions that are present, it does quickly determine the total concentration of ions in a

sample. It can be used to perform a wide variety of tests or planned experiments

to determine the changes in or levels of total dissolved ions or salinity.



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iii) Calibration block

Eddy current set

2.2 Methods

Eddy Current Calibration Process

Basic Absolute Probe Settings

Step Task

1 Connect Absolute Probe to instrument and switch on.

2 Set the parameters as above (guide only).

3 Balance probe in air.

4 Place probe on slots and edges. Using the phase control, rotate the signal

to obtain a vertical signal amplitude.

5 Increase the % Full Screen Height (FSH) of the signal to >100% FSH by

using the gain control



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6 Now that the instrument has been set up, place the probe on the area to be

inspected, noting the % FSH of the signal amplitude.

Set the parameter ( mode, frequency, probe, gain) in the eddy current machine.

Perform calibration on the calibration block. Make sure the signal in eddy current screen is 90.

Place the inspection probe (coil) on the component surface. Read the conductivity values. The

process of finding the copper alloys conductivity is done base on try and error. Repeat the step on

another copper alloys. Record all the data.

Signal characteristic

Place the inspection probe on the component surface and identify the signal characteristic on the

screen. Take some photo to record the signal. After that, sketch the signal again into a proper sketch

to make the result clearer. Repeat the step on the other copper alloys. This procedure should be

done for 2 – 3 times to take the average for better result and reduce error. Record all the data and

analysis.

Measure percentage of composition copper alloys



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This experiment can be done at the chemical lab. The sample will be send to the chemical lab for

comfirmation about the percentage of composition in the copper alloys.



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2.3 Flow chart , Block diagram & Design of this project.

Measure frequency for calibration block

Set the parameter ( mode, frequency, probe,

Perform measurement of conductivity by

using pen probe

Analysis each signal characteristic

Carry out the signal into the proper sketch

Record all the data that have been taken

Troubleshooting the problem

Presentation of the project and finish report

Start

End



3 Expected Result

From this project, we can measure the actual conductivity on different composition of

copper alloys and identify the signal by using absolute probe. We can define the factor

affecting conductivity.



4 Gantt Chart

Week

Task

1 2 3 4 5 6 7 8 9 10 11 12 13 14

Calculate frequency for copper

Produce the calibration block

Measure conductivity of the

copper alloys

Carry out the data that can becollect

Identify the signal characteristics

Draw the proper sketch

Confirmation for composition on

copper alloys

Final year project report



5 Conclusion

As a conclusion, we can study about the factor affecting conductivity. Copper is one of the

good conductor. After that, we can use the signal characteristic as a references in copper

alloys.

the study of conductivity of different alloys composition

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