material testing lab manual

MATERIAL TESTING LAB

MANUAL

Prepared by

Venkatraman Narasiman.,B.E.,M.E.,MISTE, (PhD).,

Lecturer in mechanical engg,

Wollega university,

Nekemtee,Ethiopia.

Dr.Temesgen.,PhD

Dean of Engineering science and technology

Wollega university,

Nekemtee,Ethiopia.

Tadesse beyenee.,MSc..,

Head of the department in mechanical Engineering,

Wollega university,

Nekemtee,Ethiopia.

Acknowledgement

I wish to express my thanks to Dr. Eba Mijena, president, Wollega university, Nekemtee, Ethiopa for the encouragement to prepare this lab manual. I wish to express my thanks to Dr.Dungana,Acadamic Vice president,Wollega university,Nekemtee,Ethiopa for the encouragement to prepare this lab manual. I also wish to thank Dr.Temesgen, Dean, College of engineering and technology, Wollega university, Nekemtee, Ethiopia for his valuables ideas for quality. I also wish to thank Mr. Tadesse beyene, Head of department, Mechanical Engineering Department, Wollega university,Nekemtee,Ethiopa. Working under their guidance is of immense pleasure and very worthful in the context of knowledge. I also wish to thank Mr. Abera, Lab technician, Mechanical Engineering Department, Wollega university,Nekemtee, Ethiopa who helped me during the lab activity. I am very thankful to my parents, friends and colleagues for their encouragement and support in building up this lab manual which is more help full for our students.

My family, I love them dearly.

Content

Note :

Atleast minimum of 5 experiments should be conducted for each semester.

S.N Topic Page number

1 Safety Guideline 1-3

2 Impact test machine 5-8

3 Rockwell hardness number 9-12

4 Torsion test 13-16

5 Creep test 17-20

6 Vickers hardness test 21-24

7 Brinell hardness test 25-28

Wollega University Material Testing Lab Manual

Prepared by Venkatraman Narasiman, Dep. Of Mechanical Engg. Page 1

MATERIAL TESTING LAB

Safety Guidelines 1. Read through the procedures of each laboratory activity before you start the lab so that

you are familiar with them.

2. Know how to locate and use all safety equipment in the laboratory, including the fume

hood, emergency shower, first aid kit, fire blanket, fire extinguisher, and eyewash. Also

be sure to locate the nearest exit in case of an emergency.

3. Avoid dangerous behavior in the laboratory.

4. Always conduct your experiments with adult supervision.

5. Wear safety goggles when handling all hazardous chemicals, working with an open

flame, or when otherwise instructed.

6. Wear an apron or a smock to protect your clothing in the laboratory when using

chemicals.

7. Tie back long hair, and secure any loose-fitting clothing.

8. Never eat or drink in the laboratory.

9. Wash your hands before and after each activity in the lab.

10. Keep the work area free of any unnecessary items.

11. Wash all utensils thoroughly before and after each use.

12. Never smell or taste any chemicals unless instructed to do so by your teacher and the

experiment instructions.

13. Do not experiment or mix chemicals on your own. Many chemicals in the lab are

explosive or dangerous.

14. When using scissors or a scalpel, cut away from yourself and others.

15. When heating substances in a test tube, always point the mouth of the test tube away from

yourself and others.

16. Clearly label all containers with the names of the materials you are using.

17. Report all accidents to the teacher immediately, including breakage of materials, chemical

spills, and injury.

18. Do not pick up broken glass with your hands. Sweep up broken glass with a broom, and

dispose of the glass in a container labeled for glass disposal.

19. Never return unused chemicals to their original containers. Follow your teacher’s

instructions for the proper disposal and cleanup of all materials.

20. Clean up your equipment and work area before leaving the lab.



21. Be certain that all Bunsen burners, gas outlets, and water faucets are turned off before

leaving the lab.

Handling of chemicals 1. Respect all chemicals and be cautious when handling them, especially those you know

very little about.

2. Corrosive and toxic chemicals must be handled in the fame hood.

3. Laboratory coats and safety glasses must be worn.

4. Never use your mouth to pipette dangerous liquids- Use a rubber safety bulb for all

pipetting purposes.

5. Do not carry bottles containing corrosive liquids (concentrated acids, bromine etc) by

their necks. There are baskets specially made for that purpose.

6. Do not pour or dispose of hazardous materials in the sink. Labeled residual bottles should

be used and kept in the fume cupboard.

7. Compressed gas cylinders must be properly strapped and not left standing on their own.

Eye Safety 1. Wear your laboratory safety goggles when you are working with chemicals, open flame,

or any substances that may be harmful to your eyes.

2. Know how to use the emergency eyewash system. If chemicals get into your eyes, flush

them out with plenty of water for 15 minutes. Inform your teacher.

Clothing Protection 1. Wear your laboratory apron. It will help to protect your clothing from stains or damage.

Glassware Safety 1. Check glassware for chips or cracks. Broken, cracked, or chipped glassware should be

disposed of properly.

2. Do not force glass tubing into rubber stoppers. Follow your teacher’s instructions.

2. Clean all glassware and air-dry them rather than drying with a towel.

Sharp objects 1. Be careful when using knives, scalpels, or scissors.

2. Always cut in the direction away from your body and from others who are nearby.

3. Inform your teacher immediately if you or your partner is cut.

Heating Safety 1. Turn off heat sources when they are not in use.



2. Point test tubes away from yourself and others when heating substances in them.

3. Use the proper procedures when lighting a Bunsen burner.

4. To avoid burns, do not handle heated glassware or materials directly. Use tongs, test-tube

holders, or heat-resistant gloves or mitts.

5. For heating, use glassware that is meant to be used for that purpose.

6. When heating flasks or beakers over the laboratory burner, use a ring-stand setup with a

square of wire gauze.

7. Use a water bath to heat solids.

8. When heating with a laboratory burner, gently move the test tube over the hottest part of

the flame.

9. Do not pour hot liquids into plastic containers.

Fire/Explosion Safety 1. Tie back long hair and roll up long sleeves when working near an open flame. Confine

loose clothing.

2. Do not reach across an open flame.

3. Know the location and proper use of fire blankets and fire extinguishers

Electrical Safety 1. Be careful when using electrical equipment.

2. Check all electrical equipment for worn cords or loose plugs before using.

3. Keep your work area dry.

4. Do not overload electric circuits.

5. Be sure that any electrical cords are not in a place where someone can trip over them.

Poison 1. Do not mix any chemicals unless directed to do so in a procedure or by your teacher.

2. Inform your teacher immediately if you spill chemicals or get any chemicals on your skin

or in your eyes.

3. Never taste any chemicals or substances unless directed to do so by your teacher.

4. Keep your hands away from your face when working with chemicals.

5. Wash your hands with soap and water after handling chemicals.



ExpErimEnts



Figure.1 Impact test machine



Ex.No.1 Impact test machine Date :

Group: ID.No : Batch :

Aim:

To determine the impact strength using IZOD method.

Apparatus required:

Impact test machine Vernier caliper Scale Specimen

Formula:

Impact strength = Energy absorbed/Cross section area

Where cross section area = pie/4 D2

Specification:

Pendulum impact testing machine = DIN50115

Specimen cross section = 10 x 10 mm

Specimen cross section notch -= 10 x 5 mm and 10 x 8 mm

Hammer impact speed = 3.8m./s

Capacity to perform work = 25Nm



Tabular column

S.N Material

Energy absorbed by force(A) in

Joule

Energy spend to break the specimen (B)

in Joule

Energy absorbed by specimen(A-

B)

Impact strength in

J/mm2

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25



Procedure:

1. Rise the pendulum weight and lock it.

2. Release the trigger and allow the pendulum to swing

3. This actuates the point to move.

4. Note down the frictional energy absorbed by bearings.

5. Raise the pendulum weight again and lock it.

6. The notch should face the direction of blow.

7. Release the trigger and allow the pendulum to swing which it strikes the specimen

at its mid-point.

8. Note down the energy spent in breaking the specimen.

9. Tabulate the observation.

Result:

Thus the impact strength using IZOD method has been determined.



Figure.2 Rockwell hardness machine



Ex.No.2 Rockwell hardness test Date :


Aim:

To determine the Rockwell hardness number by using Rockwell hardness testing machine.

Apparatus required:

1. Indenter

2. Rockwell hardness test machine

3. Specimen

4. Emery paper.

Specification:



Tabular column

S.N Material Scale Load RHN RHN ( Mean)

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25



Procedure:

1. Clean the surface of the specimen with emery paper

2. Place the specimen on the machine plateform.

3. Rise the plateform until the smaller needle in the dial gauge reads against the red

mark.

4. The load is applied on the specimen until the longer point comes to rest,then the

load applied lever is released.

5. Thus gives the direct reading of Rockwell hardness number in corresponding

scale.

6. The same procedure is repeated for each specimen and average value is

calculated.

Result:

Thus the Rockwell hardness number has been determined by using Rockwell hardness testing machine.



Figure.3 Torsion test machine



Ex.No.3 Torsion Test Date :


Aim:

To determine the torque for the given specimen along with Modulus of rigidity and shear stress.

Apparatus required:

1. Torsion Testing machine 2. Specimen 3. vernier caliper.

Formula:

1. Modulus of rigidity = TL/JQ

Where, T=Torque in NMM

L= Length of specimen

J= Polar moment of inertia

Q= angle of twist in radian

2. Shear stress = TR/JQ

Where, T=Torque in Nmm

R= Radius of specimen

J= Polar moment of inertia

Q= angle of twist in radian

Specification:



Tabular column

S.N Number of rotation

Angle of twist

(Degree)

Angle of twist

(radian) Torque MOR SS

1 2 3 4 5 6 7 8 9

10 11 12 13 14 15 16 17 18 19 20

Graph:

Time in seconds

Elongation in mm

Y

X



Procedure:

1. Measure the diameter ansd length of rod

2. The rod is fitted into the grips of the machine.

3. Set the point on the torque measuring scale.

4. The handle of the machine is rotated in one direction.

5. The torque and angle of twist is note for every 5 degree increment of twist.

6. Now the torque and angle of twist is noted for same increments

7. Finally the angle of twist is made to zero and rod is taken out.

Result:

Thus the torque for the given specimen is indentified along with Modulus of rigidity and shear stress.



Figure .4 Creep test machine



Ex.No.4 Creep test Date :


Aim:

To determine the creep point in the plastic material.

Apparatus required:

1. Creep machine 2. dial gauge 3. stop watch 4. weight 5. Specimen 6. Thermometer.

Formula:

Elasticity = change in length / original length

Specification:

Length = 700mm

Width = 350mm

Height = 510mm

Weight = 23Kg

Sample 1= Lead

Sample 2 = Plastic

Thermometer measurement range = 1 C to 300 C.

Dial gauge = 0 to 10 mm.



Tabular column

S.N Time (sec) Change in length (mm) Elasticity (mm) Temperature

in C

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25



Procedure:

1. Locate the sample specimen in the holder.

2. Insert the thermometer in the climatic chamber.

3. Locate the dial gauge and set to zero above the coolant chamber which

touches the beam of the specimen.

4. Release the lock net and apply the load as per the required needs.

5. Observe the time taken and change in length which takes places in the

experiment with the help of stopwatch.

Result:

Thus the creep point has been indentified for the corresponding material.



Figure .5 Vickers teswt machine



Aim:

To determine the Vickers hardness number for the corresponding specimen.

Apparatus required:

1. Vickers hardness testing machine

2. Specimen

3. Diamond shape indendor.

Formula:

VH = 1.854F/d2

Where, d = distance between two diagonals, F = force/Load

Specification:

Load = 1,2,3,5,10,15,20,30 and 50Kgf.

Height of specimen = 200mm

Sweep of machine = 150mm

Weight = 90Kg

Width =600mm

Depth = 280mm

Height = 850mm

Maximum weight of specimen = 100Kg

Connnected laod = 0.1KVA,220V,50 HZ,single phase.

Ex.No.5 Vickers hardness test Date :




Tabular column

S.N Load Indentor VHN

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25



Procedure:

1. Insert the main cables in the sockets and actuate the switch.

2. Turn the rotationg head through handle to make the axis of objective lens

aligned with axis of test anvil.

3. Now the lamp of projecting device lights ups.

4. Select the load by rotating the knob in clockwise direction.

5. Insert the indender applicable to test required in the indenter holder of the

machine.

6. The specimen is placed above the table.

7. Now raise the table and observe the image through the optic system.

8. Calculate the d through the optic system.

Result:

Thus the Vickers hardness number for the corresponding specimen has been determined.



Figure. 6 Brinell hardness machine



Ex.No.6 Brinell hardness test Date :


Aim:

To determine the Brinell hardness number for the corresponding specimen.

Apparatus required:

1. Brinell hardness testing machine 2. Specimen 3. Ball shape indenter.

Formula:

BH = 2F/PieD(D-D-d)

Where d = distance between two diagonals, F = force/Load

Specification:

Load = 1,2,3,5,10,15,20,30 and 50Kgf.

Height of specimen = 200mm

Sweep of machine = 150mm

Weight = 90Kg

Width =600mm

Depth = 280mm

Height = 850mm

Maximum weight of specimen = 100Kg

Connnected laod = 0.1KVA,220V,50 HZ,single phase



Tabular column

S.N Load Indentor VHN

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25



Procedure:

1. Insert the main cables in the sockets and actuate the switch.

2. Turn the rotationg head through handle to make the axis of objective lens

aligned with axis of test anvil.

3. Now the lamp of projecting device lights ups.

4. Select the load by rotating the knob in clockwise direction.

5. Insert the indender applicable to test required in the indenter holder of the

machine.

6. The specimen is placed above the table.

7. Now raise the table and observe the image through the optic system.

8. Calculate the d through the optic system.

Result:

Thus the brinell hardness number for the corresponding specimen has been determined