Metal Forming OperationsRolling: makes sheet metal(hot or cold)Forging: makes strong solid parts(hot or cold)KalpakjianKalpakjian

Wire drawing: Makes strong small dia. wire(hot or cold)Extrusion:makes complex cross-sections from soft metals and plastics(hot)KalpakjianKalpakjianwww.capalex.com

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

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

Roll forming (Hot):Moves bulk metal, makes I-beamsKalpakjianKalpakjianKalpakjianRoll forming (Cold):Bends sheetmetal into complex cross-sections

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

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.

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

Kalpakjian

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

Kalpakjian

Slab Production: Hot Rollingwww.labware.com www.falckacciai.it www.beautifuliron.comColor & Temp

Progressive Hot Rolling: smaller, uniform grainsKalpakjian

Hot Working:ForgingPaul Berenson, www.paulb.comT.Green, WIT www.smeedwerkunica.nlOpen Die Forging

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

Forging PressesKalpakjian

Forging: Closed Die ForgingKalpakjian

Forging: Heat LossMetal near die surfaces are coolest, flow lesswww.lft.uni-erlangen.de www.freedomalloysusa.com

KalpakjianUpset Forging (hot or cold)Bolt manufacture

Roll Forming (hot):I-beams

KalpakjianLunchtime on a Crossbeam, Unknown, www.buffalogames.com www.civil.ubc.ca

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

T.Green, WIT en.wikipedia.org

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

Mannesmann Process: Piercing (Hot) Seamless pipe, tubeKalpakjian

Cold-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

Cold Rolling: Sheetmetal productionKalpakjianwww.nzsteel.co.nz finance.pipex.com

Cold Rolling: Sheetmetal production

Cluster rolls support smaller contacting rollswww.sendzimir.comwww.elgiloy.com

Cold Rolling: Sheetmetal production

Residual Stresses may lead to warping after bar is machinedLarge reductionSmall reductionKalpakjian

Roll Forming of Sheetmetal (cold)Kalpakjianwww.cometroll.com www.safeair-dowco.com

Roll Forming of sheetmetal www.mortonbuildings.com

Punching & Blanking of SheetmetalPunching (Scrap)Blanking (Saved: a blank)PunchDieStripper plateT.Green, WIT

Punching ofSheetmetalKalpakjian

Blanking of Sheetmetal: Efficient Nesting of BlanksKalpakjian

Sheetmetal: BendingKalpakjianSpringback:

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

KalpakjianBending of SheetmetalUse notches to avoid tearing and wrinkling in right-angle bends

Press Brakes:For lower production volumes10-30 foot long50-3000 tons

Bending of Sheetmetalwww.loomismetals.com

Bending:Press-Brake OperationsKalpakjian

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 RodKalpakjian

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

Kalpakjianwww.endo-mfg.co.jp

Deep DrawingDraw beads may be used to control metal flowKalpakjian

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

www.traditional-building.comwww.ashfordmetalspinning.co.uk

Spinning videos

Cost comparison: manufacturing a round sheet-metal container by spinning and deep drawing. For small quantities, spinning is more economical. Kalpakjian

Finite Element SimulationsPredict and minimize tearing and wrinkling locations

nsmwww.eng.ohio-state.edu www.esi-group.comtmku209.ctw.utwente.nl

Progressive Stamping DiesCommon method to handle complex partswww.nissin-precision.com

Tube-drawingDOM: Drawn Over Mandrel TubingSeamlessThin wall, tight tolerance, strongKalpakjianwww.twmetals.com MalickyFloating plug

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

Diego Rivera, Detroit Industry, Detroit Institute of Art

References

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