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© 2012 Su-Jin Kim GNU© 2012 Su-Jin Kim GNU

Expendable Mold CastingProcess ( 소모성 주형 주조 공정 )

1. Sand casting2. Shell mold casting3. Plaster mold casting4. Investment casting (lost wax casting)5. Lost foam casting

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© 2012 Su-Jin Kim GNU© 2012 Su-Jin Kim GNU

Sand casting ( 사형주조 )

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© 2012 Su-Jin Kim GNU© 2012 Su-Jin Kim GNU

Sand casting

http://www.youtube.com/watch?v=rgL2Jn5mk1A Manualhttp://ma.gnu.ac.kr/vod/casting/casting_tap.wmv Tap

• Use expendable sand molds• Low production rate(1–20 pieces/hour-mold)• Low cost, Recycle sand• Small quantity production• Complex entire parts at one time

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© 2012 Su-Jin Kim GNU© 2012 Su-Jin Kim GNU

Shell mold casting ( 셸주조 )

• Fine sand mixed with a resin is heated by the pattern and hardened into a shell around the pattern

• Can produce castings with close dimensional tolerances, good surface finish and low cost.

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© 2012 Su-Jin Kim GNU© 2012 Su-Jin Kim GNU

Plaster mold casting ( 석고주형 주조 ) • Plaster is mixed with water and poured over the

pattern.• Accurate, good surface and low melting point alloy

http://www.youtube.com/watch?v=xPSI1wUOBnk&p=9B6D9EAE75875D9D

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© 2012 Su-Jin Kim GNU© 2012 Su-Jin Kim GNU

Investment casting ( 인베스트먼트 주조 , lost wax casting)• A wax pattern is coated by ceramic slurry that hardens

into the mold.• One pattern creates one part, which increases

production time and labor costs.• Complex geometries, good surface and high melting

point alloy.

SME: http://www.youtube.com/watch?v=PIneaDTZ16g

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© 2012 Su-Jin Kim GNU© 2012 Su-Jin Kim GNU

Investment casting (lost wax casting)• Wax pattern Mold Pouring

Coin: http://www.youtube.com/watch?v=4Yvm6fUXf1UAerospace: http://www.youtube.com/watch?v=f7FXtnXVqzY

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© 2012 Su-Jin Kim GNU© 2012 Su-Jin Kim GNU

Lost foam casting ( 소실모형주조 )

• Polystyrene patterns evaporate with molten metal to form a cavity for the casting.

Molding ( 금형 ) Patterns

Compact in sand

Coating

Casting Shakeout Manhole cover

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