Forming

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Metal Forming Operations

Rolling: makes sheet metal(hot or cold)Forging: makes strong solid parts(hot or cold)KalpakjianKalpakjian1

Wire drawing: Makes strong small dia. wire(hot or cold)

Extrusion:makes complex cross-sections from soft metals and plastics(hot)

KalpakjianKalpakjianwww.capalex.com2

Bending: (2D)Bend sheet metal about single axis(hot or cold)Deep drawing (3D)Makes cups from sheet metal,for mass production.(cold)KalpakjianKalpakjian3

Spinning:Makes cups from sheet metal,for lower production.(cold)

Roll forming (Hot):Moves bulk metal, makes I-beamsKalpakjianKalpakjian

KalpakjianRoll forming (Cold):Bends sheetmetal into complex cross-sections4

Shearing:Cut or punch sheetmetal(hot or cold)Kalpakjian5

ASM Metals Handbook Vol.9BrallaFormingOriented flowlines decrease fracture risk from grain boundaries, improve strength along flow direction.(Directional properties).Especially seen in:ForgingRollingDrawingCracks tend to start where grain boundaries intersect surface. Forging minimizes these.6

Thread-rolling for bolts: Rolled threads stronger than machined (and less expensive)

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Directional Properties in RollingOriented flowlines:Less ductility when bent in one directionMore ductility when bent in the other

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Slab Production: Hot Rollingwww.labware.com www.falckacciai.it

www.beautifuliron.comColor & Temp9

Progressive Hot Rolling: smaller, uniform grainsKalpakjian10Hot Working:Forging

Paul Berenson, www.paulb.comT.Green, WIT www.smeedwerkunica.nlOpen Die Forging11

Hydraulic pressMechanical press with an eccentric drive: fasterSlow but high forceand low costForging Presses

KalpakjianErie Press12Forging PressesKnuckle-joint pressScrew pressGravity drop hammer:Simplest

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Forging: Closed Die ForgingKalpakjian14

Forging: Heat LossMetal near die surfaces are coolest, flow less

www.lft.uni-erlangen.de www.freedomalloysusa.com 15

KalpakjianUpset Forging (hot or cold)Bolt manufacture16

Roll Forming (hot):I-beams

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Lunchtime on a Crossbeam, Unknown, www.buffalogames.com

www.civil.ubc.ca17

Extrusion (hot or cold):Typ.: Alum., soft metalsWith special lubes: steels~Any cross-sectionInexpensive diesGood finish

T.Green, WIT en.wikipedia.org 18

Extrusion:Hollow cross-sections: Use MandrelsKalpakjianwww.abra.net.au 19

Mannesmann Process: Piercing (Hot) Seamless pipe, tubeKalpakjian20Cold-Working (vs. Hot):Products: Better tolerances Much better surface finish Elongated (and smaller) grains Turns inexpensive alloys into stronger but less ductile products Sheetmetal lends itself to cold working, not hot working

Processes: Higher processing forces Larger and stronger machinery Less ductility available Lower energy use

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Cold Rolling: Sheetmetal production

Kalpakjianwww.nzsteel.co.nz

finance.pipex.com22

Cold Rolling: Sheetmetal production

Cluster rolls support smaller contacting rollswww.sendzimir.com

www.elgiloy.com23

Cold Rolling: Sheetmetal production

Residual Stresses may lead to warping after bar is machinedLarge reductionSmall reductionKalpakjian24Roll Forming of Sheetmetal (cold)

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www.cometroll.com www.safeair-dowco.com 25

Roll Forming of sheetmetal www.mortonbuildings.com 26Punching & Blanking of Sheetmetal

Punching (Scrap)Blanking (Saved: a blank)PunchDieStripper plateT.Green, WIT 27

Punching ofSheetmetalKalpakjian28

Blanking of Sheetmetal: Efficient Nesting of BlanksKalpakjian29Sheetmetal: Bending

KalpakjianSpringback:30

Sheetmetal: Minimum Bend RadiusKalpakjianTight radius bends (folds) require metal with ~40% ductility31

KalpakjianBending of SheetmetalUse notches to avoid tearing and wrinkling in right-angle bends32Press Brakes:For lower production volumes10-30 foot long50-3000 tons

Bending of Sheetmetal

www.loomismetals.com 33

Bending:Press-Brake OperationsKalpakjian34

For large quantities, forging and die casting are more economical. Sand casting is the more economical process for fewer than about 20,000 pieces.Relative Unit Costs of a Small Connecting RodKalpakjian35

Deep Drawing (cold, for sheetmetal)- Punch draws blank into die Metal is supported on both sides to avoid wrinkling Hold-down pressure (blankholder force) is primary process variable if too high: tearing if too low: wrinkling

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www.endo-mfg.co.jp36Deep DrawingDraw beads may be used to control metal flow

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www.dissco.co.nzSpinningIdeal for Lower production volumes Large parts Inexpensive tooling

www.traditional-building.com

www.ashfordmetalspinning.co.uk38Spinning videos39Cost comparison: manufacturing a round sheet-metal container by spinning and deep drawing. For small quantities, spinning is more economical.

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Finite Element SimulationsPredict and minimize tearing and wrinkling locations

nsmwww.eng.ohio-state.edu

www.esi-group.comtmku209.ctw.utwente.nl41

Progressive Stamping DiesCommon method to handle complex partswww.nissin-precision.com 42Tube-drawingDOM: Drawn Over Mandrel TubingSeamlessThin wall, tight tolerance, strong

Kalpakjianwww.twmetals.com MalickyFloating plug43

Bicycles: Butted DOM tubingIncreased wall thickness at endsReinforces high stress pointsmaterials.npl.co.uk

www.torelli.com44

Diego Rivera, Detroit Industry, Detroit Institute of Art45References

Kalpakjian: http://www.nd.edu/~manufact/index3.htm

Bralla: James G. Bralla, Design for Manufacturing Handbook, McGraw-Hill, 2nd Edition. In: www.rose-hulman.edu/~stienstr

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