Manufacturing Processes Powders metallurgy, Ceramics, Glasses

Powders, Glasses 

Manufacturing Processes 

© Pearson Pearson 

& GNU Su-Jin Su Jin Kim 


Powders metallurgy, metallurgy, 

Ceramics, Glasses

Contents 

Powder Metallurgy(분말야금) 

1. Powder production 

2. Blending or mixing 

3. Compaction 

4. Sintering 

Ceramic 

1. Mixing particles with additives 

2. Shaping 

3. Drying & Firing 

Glass 

1. Plate, Tubing 

2. Blowing, Pressing 




& GNU Su-Jin Su Jin Kim

Powder Metallurgy Usage 





PM1: http://www.youtube.com/watch?v=n_FW7Q2xO5o 

http://www.hmptech.com

Powder Metallurgy 

1. Powder production 

2. Blending or mixing 

3. Compaction 

4. Sintering 

5. Finishing operations 





PM2: http://www.youtube.com/watch?v=iQIsk44JUYs&feature=related 

http://www.youtube.com/watch?v=1Mjsi2F2MrY

Powder Production 

Atomization (입자화) 

• Liquid‐metal stream is broken into powder by water jet. 

Reduction (환원) 

• Metallic oxides are reduced to the metallic state. 





Particle size and shape 

• Particle size is measured and controlled by screening. 

• Particle shape is expressed by aspect ratio or shape 

factor. 

• Size and shape of particles affect the processing 

characteristics of the powder. 





Blending metal powders 

• Blending (mixing) powders is the second step, and the 

purposes are: 

1. to impart physical and mechanical properties and 

characteristics to the P/M part 

2. obtain uniformity from part to part 

3. lubricants are mixed to improve flow characteristics 

4. binders are used for sufficient green strength 





Compaction(압축) of metal powders 

• Powders are pressed into shapes using dies and presses. 

• Obtain the required shape, density and particle‐to‐ 

particle contact. 





Compaction of metal powders 

• The density after compaction 

depends on: 

1. compaction pressure 

2. powder composition 

3. hardness of the powder 

• Higher the density, higher 

the strength and 

elastic modulus of the part. 





Pressure distribution in powder 

compaction 

• Pressure distribution along length of the compact. 

p 

x 

 

μ : powder‐wall friction coef. 

k : the inter‐particle friction coef. 

x/D : length‐to‐diameter ratio 





p 

0 

e 

4kx 

D

Isostatic pressing 

• Powders are subjected to hydrostatic pressure in order 

to to achieve uniform compaction. 

• In cold isostatic pressing (CIP), metal powder is placed 

in a flexible rubber mold. 





Isostatic pressing 

• In hot isostatic pressing (HIP), a container is made of 

high‐melting point sheet metal and the pressurizing 

medium is an inert gas. 





Sintering 

• Sintering (소결) is where compacted metal powder is 

heated to below its melting point for the bonding of the 

individual metal particles. 

• Sintered density increases with temperature and time. 





Metal Injection Molding (MIM) 

1. Mixing: metal + polymer 

2. Injection monding 

3. Debinding 

4. Sintering 

• Ceramic Injection Molding (CIM) 

1. Mixing: ceramic + polymer 

… 





MIM: http://www.youtube.com/watch?v=BxJaq-WpIIc&feature=related

Design for Powder Metallurgy 

1. Simple & uniform shape 

2. Easy ejection from die 

3. Large tolerance reduce cost 

4. Avoid sharp radius 





Economics of Powder Metallurgy 

• The cost depends on method of powder production, its 

quality and quantity purchased. 

• Due to high cost of punches, dies and equipment for 

P/M processing, production volume must be high. 





Ceramic usage 



Pottery 



Aerospace 

Memory 

Medical

Ceramic usage 





Electric resistance 

Wear resistance 

Art 

High temperature

Ceramics 

• Ceramics are compounds of metallic and non‐metallic 

elements. 

• Bonding between atoms can be covalent and ionic. 

• Various types of ceramics are: 

1. Oxide ceramics O: Alumina Al2O3, Zirconia ZrO2 2. Carbides C: Tungstem carbides WC, Silicon carbide SiC 

3. Nitrides N: Cubic boron nitride cBN, Titanium nitride TiN, Sialon, Cermets 

4. Silica SiO 2 

5. Nanophase ceramic 





General properties of ceramics 

• Ceramics are brittle, have high compressive strength and 

hardness at elevated temperatures, high elastic modulus, 

low toughness, low density, low thermal expansion, and low 

thermal and electrical conductivity. 

1. Mechanical properties 

• Sensitivity to cracks, impurities and porosity 

• Strength in tension is lower than compressive strength. 

2. Physical properties 

• Low specific gravity and have high melting temperatures. 





Ceramic process 

1. Crushing raw materials into very fine particles 

2. Mixing particles with additives 

3. Shaping 

4. Drying 

5. Baking in fire 

6. Finishing 





Knife: http://www.youtube.com/watch?v=JFnT5INymiY&feature=related 

Toilet: http://www.youtube.com/watch?v=vaUFN-q3_mk&feature=related

Diamond 

• Has a covalently bonded structure and is the hardest 

substance. 

• It is brittle and decompose in air at about 973 K. 

• Applications include cutting tools, window of laser. 





Glass 

• Glass is an amorphous solid with the structure of a liquid. 

• All glasses contain at least 50% silica SiO2. • They are resistant to chemical attacks and ranked by their 

resistance to acid, alkali or water corrosion. 





Mechanical properties 

• Consider to be linearly elastic and brittle. 

• Bulk formed glass has low strength(

Float method 

1. Molten glass from the furnace is fed into a bath of 

molten tin. 

2. The glass floats on the tin bath an then moves over 

rollers and is cut to glass plates. 





Plate glass: http://www.youtube.com/watch?v=j4RzW2_vbHI

Glass tubing 

Air is blown through the mandrel to make the tube 





Glass Blowing 

Glass bottle is made by blowing 





Bottle: http://www.youtube.com/watch?v=NVKcISj2LfA&feature=related

Glass Pressing 

Glass vessel is made by pressing. 





Block: http://www.youtube.com/watch?v=pEd2Oni88uY

Graphite 

• Graphite is a layered structure of carbon C. 

• It is brittle, electrical thermal conductor, has resistance 

to chemical thermal shock. 

• Low frictional properties allow it to be a solid lubricant, 

abrasive but a poor lubricant in a vacuum. 

• Special structure : Graphite fiber and Carbon nano tube.

Manufacturing Processes Powders metallurgy, Ceramics, Glasses

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