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1. LECTURE NO.
13
AS 211 – CHEMISTRY FOR TECHNOLOGISTS
BACHELOR OF TECHNOLOGY
UNIT 2
INORGANIC
INDUSTRIAL
MATERIALS

2. AS 211 – CHEMISTRY FOR TECHNOLOGISTS
BACHELOR OF TECHNOLOGY
LECTURE
NO.
13
1. Define Abrsasives
2. Determine the types of abrasives and their
chemical compositions
3. Determine the common uses of abrasives
4. Discuss the properties of abrasives
LESSON
OBJECTIVES
AS 211 - CHEMISTRY FOR TECHNOLOGISTS
BACHELOR OF TECHNOLOGY Preparedby:
ALVIN Z. GRULLA, LPT
ChemistryInstructor

3. What are
Abrasives?

4. ABRASIVES
Abrasives are hard
substances, often a
mineral, used for
grinding, shaping,
and polishing other
materials.
AS 211 - CHEMISTRY FOR TECHNOLOGISTS
BACHELOR OF TECHNOLOGY Preparedby:
ALVIN Z. GRULLA, LPT
ChemistryInstructor

5. ABRASIVES
Abrasives are
primarily used in
metalworking
because their grains
can penetrate even
the hardest metals
and alloys.
AS 211 - CHEMISTRY FOR TECHNOLOGISTS
BACHELOR OF TECHNOLOGY Preparedby:
ALVIN Z. GRULLA, LPT
ChemistryInstructor

6. What are types of
abrasives and their
composition?

7. TYPES OF ABRASIVES
There are two types of
abrasives:
1. Natural Abrasives
2. Synthetic Abrasives
AS 211 - CHEMISTRY FOR TECHNOLOGISTS
BACHELOR OF TECHNOLOGY Preparedby:
ALVIN Z. GRULLA, LPT
ChemistryInstructor

8. TYPES OF ABRASIVES
Natural Abrasives are those
that are obtained from nature
and occur as minerals or rocks
in the crust of the earth.
They can be:
a. Non-siliceous abrasives
b. Siliceous abrasives
AS 211 - CHEMISTRY FOR TECHNOLOGISTS
BACHELOR OF TECHNOLOGY Preparedby:
ALVIN Z. GRULLA, LPT
ChemistryInstructor

9. TYPES OF ABRASIVES
Non-siliceous abrasives
are natural abrasives that
does not contain silica
such as:
a. Diamond (C)
b. Corundum (Al2O3)
c. Emery (Al2O3)
AS 211 - CHEMISTRY FOR TECHNOLOGISTS
BACHELOR OF TECHNOLOGY Preparedby:
ALVIN Z. GRULLA, LPT
ChemistryInstructor
Diamond
Corundum
Emery

10. TYPES OF ABRASIVES
Siliceous abrasives are
natural abrasives that contain
silica such as:
a. Quartz (SiO2)
b. Garnet (X3Y2(SiO4)3
c. Pumice (primarily SiO2)
AS 211 - CHEMISTRY FOR TECHNOLOGISTS
BACHELOR OF TECHNOLOGY Preparedby:
ALVIN Z. GRULLA, LPT
ChemistryInstructor
Quartz
Garnet
Pumice

11. TYPES OF ABRASIVES
Talc
AS 211 - CHEMISTRY FOR TECHNOLOGISTS
BACHELOR OF TECHNOLOGY Preparedby:
ALVIN Z. GRULLA, LPT
ChemistryInstructor
Sandstone Limestone
Mg3Si4O10(OH)2 Quartz and Feldspar (silicates) CaCO3

12. TYPES OF ABRASIVES
Synthetic Abrasives are
manufactured to have well defined
and controlled properties of
hardness, roughness, and type of
structure.
a. Carborundum (Silicon carbide)
b. Alundum (Aluminum oxide)
c. Norbide (Boron carbide)
d. Borazon (CBN, Cubic Boron Nitride)
AS 211 - CHEMISTRY FOR TECHNOLOGISTS
BACHELOR OF TECHNOLOGY Preparedby:
ALVIN Z. GRULLA, LPT
ChemistryInstructor
Carborundum
Alundum
Norbide
Borazon

13. What are common
uses of Abrasives?

14. USES OF ABRASIVES
The following are the
common uses of abrasives:
1. Grinding
2. Polishing
3. Buffing
4. Drilling
5. Cutting
6. Sanding
AS 211 - CHEMISTRY FOR TECHNOLOGISTS
BACHELOR OF TECHNOLOGY Preparedby:
ALVIN Z. GRULLA, LPT
ChemistryInstructor

15. USES OF ABRASIVES
Grinding
An abrasive machining
process that removes very
fine quantities of
deformed surface from a
workpiece for a smoother
finish before polishing.
AS 211 - CHEMISTRY FOR TECHNOLOGISTS
BACHELOR OF TECHNOLOGY Preparedby:
ALVIN Z. GRULLA, LPT
ChemistryInstructor

16. USES OF ABRASIVES
Polishing
Surface enhancement by
means of metal removal
using an abrasive belt,
grinding wheel, and other
abrasive media.
It removes large amounts
of metal from a particular
surface.
AS 211 - CHEMISTRY FOR TECHNOLOGISTS
BACHELOR OF TECHNOLOGY Preparedby:
ALVIN Z. GRULLA, LPT
ChemistryInstructor

17. USES OF ABRASIVES
Buffing
The processing of metal
surface to give a specific
or desired finish. It is a
less harsh process which
leads to smoother,
brighter finish.
Bright mirror finishes are
actually buffed.
AS 211 - CHEMISTRY FOR TECHNOLOGISTS
BACHELOR OF TECHNOLOGY Preparedby:
ALVIN Z. GRULLA, LPT
ChemistryInstructor

18. USES OF ABRASIVES
Drilling
A cutting process that
uses a drill bit to cut or
enlarge a hole in solid
materials.
AS 211 - CHEMISTRY FOR TECHNOLOGISTS
BACHELOR OF TECHNOLOGY Preparedby:
ALVIN Z. GRULLA, LPT
ChemistryInstructor

19. USES OF ABRASIVES
Cutting
The separation of a
physical object into two
portions though the
application of an acutely
directed force.
AS 211 - CHEMISTRY FOR TECHNOLOGISTS
BACHELOR OF TECHNOLOGY Preparedby:
ALVIN Z. GRULLA, LPT
ChemistryInstructor

20. USES OF ABRASIVES
Sanding
A process of smoothing
surfaces using sandpaper.
AS 211 - CHEMISTRY FOR TECHNOLOGISTS
BACHELOR OF TECHNOLOGY Preparedby:
ALVIN Z. GRULLA, LPT
ChemistryInstructor

21. What are important
properties of
Abrasives?

22. PROPERTIES OF
ABRASIVES
The following are some of the
important properties of
abrasives.
1. Hardness
2. Toughness
3. Resistance to Attrition
AS 211 - CHEMISTRY FOR TECHNOLOGISTS
BACHELOR OF TECHNOLOGY Preparedby:
ALVIN Z. GRULLA, LPT
ChemistryInstructor

23. PROPERTIES OF
ABRASIVES
Hardness
The most important property
of an abrasive.
Defined as the resistance of a
material to localized
deformation.
The abrasive should be harder
than the material to which it
will be used.
AS 211 - CHEMISTRY FOR TECHNOLOGISTS
BACHELOR OF TECHNOLOGY Preparedby:
ALVIN Z. GRULLA, LPT
ChemistryInstructor

24. PROPERTIES OF
ABRASIVES
Mohs Scale of Hardness
A rough measure of the
resistance of a smooth
surface to scratching or
abrasion.
Devised by German
mineralogist Friedrich
Mohs in 1812.
AS 211 - CHEMISTRY FOR TECHNOLOGISTS
BACHELOR OF TECHNOLOGY Preparedby:
ALVIN Z. GRULLA, LPT
ChemistryInstructor

25. PROPERTIES OF
ABRASIVES
AS 211 - CHEMISTRY FOR TECHNOLOGISTS
BACHELOR OF TECHNOLOGY Preparedby:
ALVIN Z. GRULLA, LPT
ChemistryInstructor

26. PROPERTIES OF
ABRASIVES
Toughness refers to the
resistance of a material to
fracture
AS 211 - CHEMISTRY FOR TECHNOLOGISTS
BACHELOR OF TECHNOLOGY Preparedby:
ALVIN Z. GRULLA, LPT
ChemistryInstructor

27. PROPERTIES OF
ABRASIVES
Resistance to Attrition
is the resistance from
wearing away of a surface
typically by friction of
abrasion.
AS 211 - CHEMISTRY FOR TECHNOLOGISTS
BACHELOR OF TECHNOLOGY Preparedby:
ALVIN Z. GRULLA, LPT
ChemistryInstructor

28. VIDEOS

29. NEXT LESSON
CEMENT