All credit goes to the creators, my colleagues.

1. CERAMIC PROCESSES
AND PARTICALE
PRODUCTION

2. Processing of ceramics
❖Operation in sequence
• Crushing and grinding raw materials into fine
particles.
• Mixing with additives
• Shaping, drying and firing the material
• Finishing operations: grinding, lapping, tumbling and
other machining operations
Next, we will consider above operations one by one………….

3. crushing????
Step 01):Crushing raw materials into fine particles
The first step in processing ceramics is the crushing of the raw
materials. Crushing generally is done in a ball mill either dry or wet.

4. Step 02):Mixing with additives
The ground particles are then mixed with additives. The functions of
which are one or more of the following:
• Binder – to bind particles
• Lubricant – to aid mould release and reduce particle
friction
• Wetting agent – to improve mixing
• Plasticizer – to make the mix more plastic and
formable
• Deflocculent – to make ceramic water suspension
more uniform
• Other agents – to control forming and sintering

5. Step 03):Shaping, drying and firing the material
Shaping
The three basic shaping processes for ceramics are casting, plastic
forming, and pressing.
1)Casting
▪ Also Known as slip casting or drain casting
▪ Slip: a suspension of colloidal ceramic particles in an
immiscible liquid (e.g. water)
▪ Similar to “Slush Casting” process

6. 2) Plastic forming
▪ Also known as soft, wet, or hydro plastic forming
▪ Methods: Extrusion, Injection Moulding, Jiggering
▪ Tends to orient the layered structure of clay along the direction
of material flow and cause anisotropic behaviour of the material
▪ Extrusion: clay mixture containing 20% to 30% water forced
through a die-opening by screw-type equipment

7. Continue…………

8. 03) pressing
The common basic pressing processes for ceramics.
1) Dry Pressing
❖Similar to powder metal compaction
❖Use to make simple shapes
❖Mixture: 4% to 12% moisture and organic or inorganic binders (stearic acid,
wax, starch, etc.)
❖Pressing pressure: 35 MPa to 200 MPa

9. 02)Wet pressing
❖Part is formed in a mould while under high pressure in a
hydraulic or mechanical press
❖Use to make complex shapes
❖Mixture: 10% to 15% moisture and binders

10. 03) lsostatic Pressing
❖Used extensively in powder metallurgy
❖isostatic pressing also is used for ceramics in order to obtain a uniform
density distribution throughout the part during compaction.
04) jiggering
❖jiggering is a motion in which the clay bat is formed by means of templates
or rollers.
❖The jiggering process is confined to axisymmetric parts and has limited
dimensional accuracy.
❖The operation is automated for improved productivity.

11. 05) Injection Molding
❖Injection molding is used extensively for the precision forming of ceramics in
high-technology applications.
❖The injection-molding process can produce thin sections [typically less than 10
to 15 mm thick].
❖Thicker sections require careful control of the materials used and of the
processing parameters in order to avoid defects, such as internal voids and
cracks-especially those due to shrinkage.
06) Hot Pressing
❖In this process the pressure and the heat are applied simultaneously.
❖thereby reducing porosity and making the part denser and stronger.
❖Graphite commonly is used as a punch and die material, and protective
atmospheres usually are employed during pressing.

12. Drying
❖To give the part proper strength and hardness.
❖Tendency to crack or warp.
❖Shrinkage of wet clay caused by removal of water during drying.
Shrinkage may be as much as 20% by volume.

13. Firing
❖Involves heating the part to an elevated temperature in a
controlled environment.
❖Purposes:
1. Develop a strong bond between the oxide particles
2. Reduce porosity
3. Improve hardness

14. Step 03):Finishing operations: grinding, lapping, tumbling and
other machining operations
Because firing causes dimensional changes, additional operations may be performed
to (a) give the ceramic part its final shape.
(b) improve its surface finish and dimensional tolerances.
(c) remove any surface flaws.
What are the finishing operations.
I. Grinding (using a diamond wheel)
2. Lapping and honing
3. Ultrasonic machining
4. Drilling (using a diamond-coated drill)
5. Electrical-discharge machining
6. Laser- beam machining
7.Abrasive water-jet cutting
8.Tumbling (to remove sharp edges and grinding marks).