© pearson & gnu su-jin kim powders, glasses manufacturing processes powders metallurgy(...

© Pearson & GNU Su-Jin Kim© Pearson & GNU Su-Jin Kim

Powders, GlassesPowders, GlassesManufacturing ProcessesManufacturing Processes

Manufacturing Processes Manufacturing Processes

Powders metallurgy(Powders metallurgy( 분말금속분말금속 ))Ceramics(Ceramics( 세라믹세라믹 ))

Glasses(Glasses( 유리유리 ))

Associate Professor Su-Jin Kim

School of Mechanical EngineeringGyeongsang National University



Contents

Powder Metallurgy( 분말야금 )1. Powder production2. Blending or mixing3. Compaction4. Sintering

Ceramic1. Mixing particles with additives2. Shaping3. Drying & Firing

Glass1. Plate, Tubing2. Blowing, Pressing



Powder Metallurgy Usage

http://www.hmptech.com

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



Powder Metallurgy

1. Powder production2. Blending or mixing( 혼합 )3. Compaction( 압축 )4. Sintering( 소결 )5. Finishing operations( 마무리가공 )

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

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



Powder ProductionAtomization ( 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 ( 혼합 )

• 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 part3. lubricants are mixed to improve flow characteristics4. 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 pressure2. powder composition3. hardness of the powder

• Higher the density, higher the strength and elastic modulus of the part.



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 + polymer2. Injection monding3. Debinding4. 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 shape2. Easy ejection from die3. Large tolerance reduce cost4. 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.

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