Powder Metallurgy Practical
Content
INTRODUCTION
POWDER METALLURGY
Powder metallurgy may be defined as
“The art and science of producing metal powders and using them to make
serviceable objects”.
It may also be defined as:
“Powder metallurgy is the material processing techniques used to consolidate
particulate i.e. powders both metals and non-metals.”
An other words,
Powder metallurgy is the process of molding metal parts from
metal powders to precise shape through the application of high pressure. Compaction of
the metal powders is followed by a high temperature sintering operation in an atmosphere
controlled furnace in which the cold welded metal compact is bound into strong
homogenous structure. Physical properties of the sintered compact are similar to those of
the parent metal. Sintering is usually accomplished at about 80% of the melting point.
The major application of Powder metallurgy to day may be grouped into five
areas.
1)
Alloying of essentially non-alloy able metal.
2)
Combining metal & non-metallic materials.
3)
Utilizing metals with melting point too high for casting.
4)
Fabrication of metals for unique structure properties.
5)
Economical production of precision parts.
PRACTICAL No:1
Object:
To study the effect of compaction pressure on the density of the compact powder.
Introduction:
The compaction of particles into prescribed shape require a full
understanding of the consolidation process of the optimum mechanical properties of the
compact are to be achieved. The compaction mechanisms vary depending.
For example: where the particles are of brittle or a ductile material. Compaction pressure
density relationship play an important role in the choice of processing values and these
must be determined. The subsequent sintering operation and the resulting density strength
relationship will also be very important as these established the final properties of the
particles.
Equipment:
1. paper boat
2. physical balance
3. compression machine
4. Mould with base plunge & plunger
5. Iron powder, Aluminum powder.
6. Cotton wool.
7. Zinc stearate suspension in acetone as a lubricant.
8. Muffled furnace for sintering capable of controlling temperature up to 1250 0C
9. Mounting resin.
10. Polishing machine and metallurgical microscope.
Procedure:
The experiment involves the preparation of number of compacts of
powdered material by compaction in simple mould followed by mechanical testing and
metallographic examination of the compact in the green and sintered conditions. Carried
out the following procedures.
1. Calculate the volume of the pallet produced by the mould, if the plunger is
inserted to the mark position.
2. Using the density of the powdered material provided. Calculate the mass
required in order to fill the parallel volume of the mold determined theoretical
volume of 50,56,62,67 & 72% of the pallet volume.
3. Weight out the required amount of powder for each of the above and for 72%
volume in readiness to charge the pallet mould.
4. Using a cotton wool to lubricate the pallet mould, base plunge and with the Zinc
stearate suspension in acetone. Allow evaporation of the acetone prior to
charging the mould with powder.
Note:
The pellet mold, base plunge and plunger must be wiped cleaned
and lubricant prior to the introduction of new charge.
5. Place the pellet, moulds assembling charge with powder in the press and
compact the charge to the marked position on the plunger. Record the load
required.
6. Eject the pellet from the mould and carefully measure its diameter and
thickness (N.B). The high porosity sample will be friable at the edge.
7. Repeat 4,5,6 for each charge taking care to the clean and lubricant the mould
plunger and base each time.
8. Compress four samples of 72% volume filled with iron powder sinter two
sample in muffle furnace at 1100 0C for 3 hours and cooled them.
9. Compress sintered and un-sintered samples on the edge record the load when
cracking is first evident in the place of specimen.
10. Mount sintered and un-sintered sample one of each in cooled setting resin or in
mounting press with bakelite powder.
11. Polish the finer grades with diamond wheel and to study the microstructure.
12. Observe the micro-structure.
PRACTICAL No:2
Object:
To study the effect of sintering on the strength of powder compact to compare the
microstructure of sintered and un-sintered compacts.
Introduction:
The compaction of particles into prescribed shape require a full
understanding of the consolidation process of the optimum mechanical properties of the
compact are to be achieved. The compaction mechanisms vary depending.
For example: where the particles are of brittle or a ductile material. Compaction pressure
density relationship play an important role in the choice of processing values and these
must be determined. The subsequent sintering operation and the resulting density strength
relationship will also be very important as these established the final properties of the
particles.
Equipment:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
paper boat
physical balance
compression machine
Mould with base plunge & plunger
Iron powder, Aluminum powder.
Cotton wool.
Zinc separate suspension in acetone as a lubricant.
Muffled furnace for sintering capable of controlling temperature up to 1250 0F
Mounting resin.
Polishing machine and metallurgical microscope.
Procedure:
The experiment involves the preparation of number of compacts of
powdered material by compaction in simple mould followed by mechanical testing and
metallographic examination of the compact in the green and sintered conditions. Carried
out the following procedures.
5. Calculate the volume of the pallet produced by the mould, if the plunger is
inserted to the mark position.
6. Using the density of the powdered material provided. Calculate the mass
required in order to fill the parallel volume of the mold determined theoretical
volume of 50,56,62,67 & 72% of the pallet volume.
7. Weight out the required amount of powder for each of the above and for 72%
volume in readiness to charge the pallet mould.
8. Using a cotton wool to lubricate the pallet mould, base plunge and with the Zinc
separate suspension in acetone. Allow evaporation of the acetone prior to
charging the mould with powder.
Note: The pellet mold, base plunge and plunger must be wiped cleaned and lubricant
prior to the introduction of new charge.
13. Place the pellet, moulds assembling charge with powder in the press and
compact the charge to the marked position on the plunger. Record the load
required.
14. Eject the pellet from the mould and carefully measure its diameter and
thickness (N.B). The high porosity sample will be friable at the edge.
15. Repeat 4, 5, 6 for each charge taking care to the clean and lubricant the mould
plunger and base each time.
16. Compress four samples of 72% volume filled with iron powder sinter two
sample in muffle furnace at 1100 0C for 3 hours and cooled them.
17. Compress sintered and un-sintered samples on the edge record the load when
cracking is first evident in the place of specimen.
18. Mount sintered and un-sintered sample one of each in cooled setting resin or in
mounting press with bake light powder.
19. Polish the finer grades with diamond wheel and to study the microstructure.
Observe the micro-structure.
PRACTICAL NO: 4
Object:
To determine the hardness of mild steel compact by using Rockwell hardness
tester.
Equipment:
Rockwell testing machine, Mild steel, Compact indenter (steel ball 1/6” dia) and load
100kg.
Procedure:
The specimen is placed on the object table under the indenter of machine. The
specimen is brought in touch with indenter by turning the wheel of machine until small
pointer (needle) on the dial stands approximately at the red dash. This shows that the
initial load of 10kg has been applied. Then set the big pointer at zero position. The major
load of 90 kg is then applied by pushing back the crank handle. This moves the needle in
to antilock-wise direction and when it comes to the rest position. The crank handle is pull
forward again. By doing so, the major load is removed but not the minor load. The dial
reading then gives the Rockwell hardness number directly. Repeat the above procedure to
get different readings at different position and take the mean.
Result:
The hardness of mild steel compact is RHB 70.
PRACTICAL NO: 5
Object:
To study the micro-structure of mild steel powder compact by using metallurgical
microscope.
Equipment:1.
2.
3.
4.
5.
Sample of mild steel compact.
Grinding machine.
Polishing machine.
Nital solution.
Optical metallurgical microscope.
Procedure:1. Grind the sample on 200,300 mesh emery paper by using grinding machine.
2. Do the intermediate polishing on 600,700 and 1000 mesh emery paper using
grinding machine.
3. Polish the compact using Al2O3 powder polish may be carried out on polishing
machine by polishing cloth.
4. Etch the sample in 50% Nital solution for few seconds.
5. Dry the steel sample and check the micro-structure.
PRACTICAL NO: 6
Object:To study the micro-structure of 50% M.S and 50% Zn) Powder compact by using
metallurgical microscope.
Equipment:1.
2.
3.
4.
5.
50% Mild steel and 50% Zinc compact..
Grinding machine.
Polishing machine.
Nital solution.
Optical metallurgical microscope.
Procedure:
1. Grind the sample on 200,300 mesh emery paper by using grinding machine.
2. Do the intermediate polishing on 600,700 and 1000 mesh emery paper using
grinding machine.
3. Polish the compact using Al2O3 powder polish may be carried out on polishing
machine by polishing cloth.
4. Etch the sample in 50% Nital solution for few seconds.
5. Dry the steel sample and investigate the micro-structure by using metallurgical
microscope.
PRACTICAL NO: 7
Object:
To prepare the sample of Zinc steel powder (50% M.S and 50%ZN).
Equipment:1. Mild steel powder.
2. Mounting machine.
3. Zinc powder.
Procedure:1.
2.
3.
4.
5.
6.
7.
8.
9.
Take a little quantity of mild steel and zinc powder (50% M.S and 50% Zn).
Switch the mounting machine.
Mix the powder of Mild steel and Zinc and pour it into mounting machine.
Set the mounting machine at a temperature of 1850C and pressure of 40 KN.
Heating time of the machine is 15 minutes.
Cooling time of mounting machine is 4 minutes.
Eject the compact from the mounting machine.
Sinter the sample at temperature of 3000C.
Take hardness and observe microstructure.
Result:
The compact of 50% Mild steel and 50% zinc powder has been prepared.
PRACTICAL NO: 8
Object:
To determine the hardness of mild steel. Zinc compact by Rockwell hardness
testing machine.
Equipment:Rockwell tester, Mild steel and zinc compact indenter steel ball (dia 1/6”) load (100kg).
Procedure:The specimen is placed on the object table under the indenter of the machine. The
specimen is brought in touch with the indenter by turning the wheel of machine, until
small pointer (needle) on dial stands approximately at the red dash. This shows that the
initial load of 10kg has been applied. Then set the big pointer at zero position. The major
load of 90 kg is then applied by pushing back the crank handle. This moves the needle in
to antilock-wise direction and when it comes to the rest position. The crank handle is pull
forward again. By doing so, the major load is removed but not the minor load. The dial
reading then gives the Rockwell hardness number directly. Repeat the above procedure to
get different readings at different position and take the mean.
Result:
The hardness of 50% Mild steel and 50% Zinc compact is RHB 70.
PRACTICAL NO: 9
Object:
To prepare the compact of 75% of M.S and 25% Zinc powder by using M.S and
Zn alloy.
Equipment:1. Mild powder.
2. Zinc powder.
3. Mounting machine.
Procedure:1. Pour 75% Mild steel and 25% Zinc powder in the mounting machine.
2. Switch on the mounting machine.
3. Set the mounting machine at a temperature of 1850C and pressure is 40 KN.
4. Heating time of the machine is 15 minutes.
5. Cooling time of mounting machine is 4 minutes.
6. After cooling eject the sample from the mounting machine..
7. Sinter the sample at temperature of 4000C.
8. Take out the sample from the furnace.
Result:The compact of 75% Mild steel and 25 % Zn powder has been prepared.
PRACTICAL NO: 10
Object:
To determine the hardness of 75% mild steel and 25% Zinc compact by using
Rockwell hardness tester.
Equipment:Rockwell testing machine, 75% Mild steel and25% zinc compact indenter steel ball (1/6”
dia) and load (100kg).
Procedure:The specimen is placed on the object table under the indenter of the machine. The
specimen is brought in touch with the indenter by turning the wheel of machine, until
small pointer (needle) on the dial, stands approximately at the red dash. This shows that
the initial load of 10kg has been applied. Then set the big pointer at zero position. The
major load of 90 kg is then applied by pushing back the crank handle. This moves the
needle in the antilock-wise direction and when it comes to the rest, the crank handle is
pull forward again. By doing so, the major load is removed but not the minor load. The
dial reading then gives the Rockwell hardness number directly. Repeat the above
procedure to get different readings at different position and take the mean.
Result:
The hardness of 75% Mild steel and 25% Zinc compact is RHB 60.
PRACTICAL NO: 11
Object:
To prepare the sample of Aluminum and Iron powder (50% Al and 50%Fe)
Equipment:Aluminum and Iron powder mounting machine.
Procedure:10. Take a little quantity of Aluminum and Iron powder (50%Al and 50% Fe)
11. Switch the mounting machine.
12. Mix the powder of Al and Fe and pour into the mounting machine.
13. Set the mounting machine at a temperature of 1800C and pressure of 40 KN.
14. Heating time of the machine is 15 minutes.
15. Cooling time of mounting machine is 4 minutes.
16. Eject the compact from the mounting machine.
17. Sinter the sample at temperature of 3000C.
18. Take hardness and observe micro-structure.
Result:
The compact of 50% Al and 50% Fe powder has been prepared.
PRACTICAL NO: 12
Object:
To determine the hardness of Al and Iron compact by using Rockwell hardness
testing machine.
Equipment:Rockwell testing machine, Aluminum and Iron compact indenter (steel ball 1/6” dia) and
load (100kg).
Procedure:The specimen is placed on the object table under the indenter of the machine. The
specimen is brought in touch with the indenter by turning the wheel of machine, until
small pointer (needle) on the dial, stands approximately at the red dash. This shows that
the initial load of 10kg has been applied. Then set the big pointer at zero position. The
major load of 90 kg is then applied by pushing back the crank handle. This moves the
needle in the antilock-wise direction and when it comes to the rest, the crank handle is
pull forward again. By doing so, the major load is removed but not the minor load. The
dial reading then gives the Rockwell hardness number directly. Repeat the above
procedure to get different readings at different position and take the mean.
Result:
The hardness of 50% Al and 50% Fe compact is RHB 60.
PRACTICAL NO: 13
Object:To study the micro-structure of 50% Al and 50% Fe) Powder compact by using
metallurgical microscope.
Equipment:6. 50% Al and 50% Fe compact..
7. Grinding machine.
8. Polishing machine.
9. Nital solution.
10. Optical metallurgical microscope.
Procedure:
6. Grind the sample on 200,300 and 500 mesh emery paper by using grinding
machine.
7. Do the intermediate polishing on 600,700 and 1000 mesh emery paper using
grinding machine.
8. Polish the compact using Al2O3 powder polishing may be carried out on the
polishing.
9. Etch the sample is 50% Nital solution for few seconds.
10. Dry the steel sample and investigate the micro-structure by using metallurgical
microscope.
POWDER METALLURGY
Powder metallurgy may be defined as
“The art and science of producing metal powders and using them to make
serviceable objects”.
It may also be defined as:
“Powder metallurgy is the material processing techniques used to consolidate
particulate i.e. powders both metals and non-metals.”
An other words,
Powder metallurgy is the process of molding metal parts from
metal powders to precise shape through the application of high pressure. Compaction of
the metal powders is followed by a high temperature sintering operation in an atmosphere
controlled furnace in which the cold welded metal compact is bound into strong
homogenous structure. Physical properties of the sintered compact are similar to those of
the parent metal. Sintering is usually accomplished at about 80% of the melting point.
The major application of Powder metallurgy to day may be grouped into five
areas.
1)
Alloying of essentially non-alloy able metal.
2)
Combining metal & non-metallic materials.
3)
Utilizing metals with melting point too high for casting.
4)
Fabrication of metals for unique structure properties.
5)
Economical production of precision parts.
PRACTICAL No:1
Object:
To study the effect of compaction pressure on the density of the compact powder.
Introduction:
The compaction of particles into prescribed shape require a full
understanding of the consolidation process of the optimum mechanical properties of the
compact are to be achieved. The compaction mechanisms vary depending.
For example: where the particles are of brittle or a ductile material. Compaction pressure
density relationship play an important role in the choice of processing values and these
must be determined. The subsequent sintering operation and the resulting density strength
relationship will also be very important as these established the final properties of the
particles.
Equipment:
1. paper boat
2. physical balance
3. compression machine
4. Mould with base plunge & plunger
5. Iron powder, Aluminum powder.
6. Cotton wool.
7. Zinc stearate suspension in acetone as a lubricant.
8. Muffled furnace for sintering capable of controlling temperature up to 1250 0C
9. Mounting resin.
10. Polishing machine and metallurgical microscope.
Procedure:
The experiment involves the preparation of number of compacts of
powdered material by compaction in simple mould followed by mechanical testing and
metallographic examination of the compact in the green and sintered conditions. Carried
out the following procedures.
1. Calculate the volume of the pallet produced by the mould, if the plunger is
inserted to the mark position.
2. Using the density of the powdered material provided. Calculate the mass
required in order to fill the parallel volume of the mold determined theoretical
volume of 50,56,62,67 & 72% of the pallet volume.
3. Weight out the required amount of powder for each of the above and for 72%
volume in readiness to charge the pallet mould.
4. Using a cotton wool to lubricate the pallet mould, base plunge and with the Zinc
stearate suspension in acetone. Allow evaporation of the acetone prior to
charging the mould with powder.
Note:
The pellet mold, base plunge and plunger must be wiped cleaned
and lubricant prior to the introduction of new charge.
5. Place the pellet, moulds assembling charge with powder in the press and
compact the charge to the marked position on the plunger. Record the load
required.
6. Eject the pellet from the mould and carefully measure its diameter and
thickness (N.B). The high porosity sample will be friable at the edge.
7. Repeat 4,5,6 for each charge taking care to the clean and lubricant the mould
plunger and base each time.
8. Compress four samples of 72% volume filled with iron powder sinter two
sample in muffle furnace at 1100 0C for 3 hours and cooled them.
9. Compress sintered and un-sintered samples on the edge record the load when
cracking is first evident in the place of specimen.
10. Mount sintered and un-sintered sample one of each in cooled setting resin or in
mounting press with bakelite powder.
11. Polish the finer grades with diamond wheel and to study the microstructure.
12. Observe the micro-structure.
PRACTICAL No:2
Object:
To study the effect of sintering on the strength of powder compact to compare the
microstructure of sintered and un-sintered compacts.
Introduction:
The compaction of particles into prescribed shape require a full
understanding of the consolidation process of the optimum mechanical properties of the
compact are to be achieved. The compaction mechanisms vary depending.
For example: where the particles are of brittle or a ductile material. Compaction pressure
density relationship play an important role in the choice of processing values and these
must be determined. The subsequent sintering operation and the resulting density strength
relationship will also be very important as these established the final properties of the
particles.
Equipment:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
paper boat
physical balance
compression machine
Mould with base plunge & plunger
Iron powder, Aluminum powder.
Cotton wool.
Zinc separate suspension in acetone as a lubricant.
Muffled furnace for sintering capable of controlling temperature up to 1250 0F
Mounting resin.
Polishing machine and metallurgical microscope.
Procedure:
The experiment involves the preparation of number of compacts of
powdered material by compaction in simple mould followed by mechanical testing and
metallographic examination of the compact in the green and sintered conditions. Carried
out the following procedures.
5. Calculate the volume of the pallet produced by the mould, if the plunger is
inserted to the mark position.
6. Using the density of the powdered material provided. Calculate the mass
required in order to fill the parallel volume of the mold determined theoretical
volume of 50,56,62,67 & 72% of the pallet volume.
7. Weight out the required amount of powder for each of the above and for 72%
volume in readiness to charge the pallet mould.
8. Using a cotton wool to lubricate the pallet mould, base plunge and with the Zinc
separate suspension in acetone. Allow evaporation of the acetone prior to
charging the mould with powder.
Note: The pellet mold, base plunge and plunger must be wiped cleaned and lubricant
prior to the introduction of new charge.
13. Place the pellet, moulds assembling charge with powder in the press and
compact the charge to the marked position on the plunger. Record the load
required.
14. Eject the pellet from the mould and carefully measure its diameter and
thickness (N.B). The high porosity sample will be friable at the edge.
15. Repeat 4, 5, 6 for each charge taking care to the clean and lubricant the mould
plunger and base each time.
16. Compress four samples of 72% volume filled with iron powder sinter two
sample in muffle furnace at 1100 0C for 3 hours and cooled them.
17. Compress sintered and un-sintered samples on the edge record the load when
cracking is first evident in the place of specimen.
18. Mount sintered and un-sintered sample one of each in cooled setting resin or in
mounting press with bake light powder.
19. Polish the finer grades with diamond wheel and to study the microstructure.
Observe the micro-structure.
PRACTICAL NO: 4
Object:
To determine the hardness of mild steel compact by using Rockwell hardness
tester.
Equipment:
Rockwell testing machine, Mild steel, Compact indenter (steel ball 1/6” dia) and load
100kg.
Procedure:
The specimen is placed on the object table under the indenter of machine. The
specimen is brought in touch with indenter by turning the wheel of machine until small
pointer (needle) on the dial stands approximately at the red dash. This shows that the
initial load of 10kg has been applied. Then set the big pointer at zero position. The major
load of 90 kg is then applied by pushing back the crank handle. This moves the needle in
to antilock-wise direction and when it comes to the rest position. The crank handle is pull
forward again. By doing so, the major load is removed but not the minor load. The dial
reading then gives the Rockwell hardness number directly. Repeat the above procedure to
get different readings at different position and take the mean.
Result:
The hardness of mild steel compact is RHB 70.
PRACTICAL NO: 5
Object:
To study the micro-structure of mild steel powder compact by using metallurgical
microscope.
Equipment:1.
2.
3.
4.
5.
Sample of mild steel compact.
Grinding machine.
Polishing machine.
Nital solution.
Optical metallurgical microscope.
Procedure:1. Grind the sample on 200,300 mesh emery paper by using grinding machine.
2. Do the intermediate polishing on 600,700 and 1000 mesh emery paper using
grinding machine.
3. Polish the compact using Al2O3 powder polish may be carried out on polishing
machine by polishing cloth.
4. Etch the sample in 50% Nital solution for few seconds.
5. Dry the steel sample and check the micro-structure.
PRACTICAL NO: 6
Object:To study the micro-structure of 50% M.S and 50% Zn) Powder compact by using
metallurgical microscope.
Equipment:1.
2.
3.
4.
5.
50% Mild steel and 50% Zinc compact..
Grinding machine.
Polishing machine.
Nital solution.
Optical metallurgical microscope.
Procedure:
1. Grind the sample on 200,300 mesh emery paper by using grinding machine.
2. Do the intermediate polishing on 600,700 and 1000 mesh emery paper using
grinding machine.
3. Polish the compact using Al2O3 powder polish may be carried out on polishing
machine by polishing cloth.
4. Etch the sample in 50% Nital solution for few seconds.
5. Dry the steel sample and investigate the micro-structure by using metallurgical
microscope.
PRACTICAL NO: 7
Object:
To prepare the sample of Zinc steel powder (50% M.S and 50%ZN).
Equipment:1. Mild steel powder.
2. Mounting machine.
3. Zinc powder.
Procedure:1.
2.
3.
4.
5.
6.
7.
8.
9.
Take a little quantity of mild steel and zinc powder (50% M.S and 50% Zn).
Switch the mounting machine.
Mix the powder of Mild steel and Zinc and pour it into mounting machine.
Set the mounting machine at a temperature of 1850C and pressure of 40 KN.
Heating time of the machine is 15 minutes.
Cooling time of mounting machine is 4 minutes.
Eject the compact from the mounting machine.
Sinter the sample at temperature of 3000C.
Take hardness and observe microstructure.
Result:
The compact of 50% Mild steel and 50% zinc powder has been prepared.
PRACTICAL NO: 8
Object:
To determine the hardness of mild steel. Zinc compact by Rockwell hardness
testing machine.
Equipment:Rockwell tester, Mild steel and zinc compact indenter steel ball (dia 1/6”) load (100kg).
Procedure:The specimen is placed on the object table under the indenter of the machine. The
specimen is brought in touch with the indenter by turning the wheel of machine, until
small pointer (needle) on dial stands approximately at the red dash. This shows that the
initial load of 10kg has been applied. Then set the big pointer at zero position. The major
load of 90 kg is then applied by pushing back the crank handle. This moves the needle in
to antilock-wise direction and when it comes to the rest position. The crank handle is pull
forward again. By doing so, the major load is removed but not the minor load. The dial
reading then gives the Rockwell hardness number directly. Repeat the above procedure to
get different readings at different position and take the mean.
Result:
The hardness of 50% Mild steel and 50% Zinc compact is RHB 70.
PRACTICAL NO: 9
Object:
To prepare the compact of 75% of M.S and 25% Zinc powder by using M.S and
Zn alloy.
Equipment:1. Mild powder.
2. Zinc powder.
3. Mounting machine.
Procedure:1. Pour 75% Mild steel and 25% Zinc powder in the mounting machine.
2. Switch on the mounting machine.
3. Set the mounting machine at a temperature of 1850C and pressure is 40 KN.
4. Heating time of the machine is 15 minutes.
5. Cooling time of mounting machine is 4 minutes.
6. After cooling eject the sample from the mounting machine..
7. Sinter the sample at temperature of 4000C.
8. Take out the sample from the furnace.
Result:The compact of 75% Mild steel and 25 % Zn powder has been prepared.
PRACTICAL NO: 10
Object:
To determine the hardness of 75% mild steel and 25% Zinc compact by using
Rockwell hardness tester.
Equipment:Rockwell testing machine, 75% Mild steel and25% zinc compact indenter steel ball (1/6”
dia) and load (100kg).
Procedure:The specimen is placed on the object table under the indenter of the machine. The
specimen is brought in touch with the indenter by turning the wheel of machine, until
small pointer (needle) on the dial, stands approximately at the red dash. This shows that
the initial load of 10kg has been applied. Then set the big pointer at zero position. The
major load of 90 kg is then applied by pushing back the crank handle. This moves the
needle in the antilock-wise direction and when it comes to the rest, the crank handle is
pull forward again. By doing so, the major load is removed but not the minor load. The
dial reading then gives the Rockwell hardness number directly. Repeat the above
procedure to get different readings at different position and take the mean.
Result:
The hardness of 75% Mild steel and 25% Zinc compact is RHB 60.
PRACTICAL NO: 11
Object:
To prepare the sample of Aluminum and Iron powder (50% Al and 50%Fe)
Equipment:Aluminum and Iron powder mounting machine.
Procedure:10. Take a little quantity of Aluminum and Iron powder (50%Al and 50% Fe)
11. Switch the mounting machine.
12. Mix the powder of Al and Fe and pour into the mounting machine.
13. Set the mounting machine at a temperature of 1800C and pressure of 40 KN.
14. Heating time of the machine is 15 minutes.
15. Cooling time of mounting machine is 4 minutes.
16. Eject the compact from the mounting machine.
17. Sinter the sample at temperature of 3000C.
18. Take hardness and observe micro-structure.
Result:
The compact of 50% Al and 50% Fe powder has been prepared.
PRACTICAL NO: 12
Object:
To determine the hardness of Al and Iron compact by using Rockwell hardness
testing machine.
Equipment:Rockwell testing machine, Aluminum and Iron compact indenter (steel ball 1/6” dia) and
load (100kg).
Procedure:The specimen is placed on the object table under the indenter of the machine. The
specimen is brought in touch with the indenter by turning the wheel of machine, until
small pointer (needle) on the dial, stands approximately at the red dash. This shows that
the initial load of 10kg has been applied. Then set the big pointer at zero position. The
major load of 90 kg is then applied by pushing back the crank handle. This moves the
needle in the antilock-wise direction and when it comes to the rest, the crank handle is
pull forward again. By doing so, the major load is removed but not the minor load. The
dial reading then gives the Rockwell hardness number directly. Repeat the above
procedure to get different readings at different position and take the mean.
Result:
The hardness of 50% Al and 50% Fe compact is RHB 60.
PRACTICAL NO: 13
Object:To study the micro-structure of 50% Al and 50% Fe) Powder compact by using
metallurgical microscope.
Equipment:6. 50% Al and 50% Fe compact..
7. Grinding machine.
8. Polishing machine.
9. Nital solution.
10. Optical metallurgical microscope.
Procedure:
6. Grind the sample on 200,300 and 500 mesh emery paper by using grinding
machine.
7. Do the intermediate polishing on 600,700 and 1000 mesh emery paper using
grinding machine.
8. Polish the compact using Al2O3 powder polishing may be carried out on the
polishing.
9. Etch the sample is 50% Nital solution for few seconds.
10. Dry the steel sample and investigate the micro-structure by using metallurgical
microscope.
