Metal Forming Operations Rolling makes sheet metal hot

Metal Forming Operations Rolling: makes sheet metal (hot or cold) Kalpakjian Forging: makes strong solid parts (hot or cold) Kalpakjian

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

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

Spinning: Makes “cups” from sheet metal, for lower production. (cold) Kalpakjian Roll forming (Hot): Roll forming (Cold): Moves bulk metal, makes I-beams Bends sheetmetal into complex cross-sections Kalpakjian

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

Forming Oriented flowlines decrease fracture risk from grain boundaries, improve strength along flow direction. (Directional properties). Especially seen in: -Forging -Rolling -Drawing ASM Metals Handbook Vol. 9 Cracks tend to start where grain boundaries intersect surface. Forging minimizes these. Bralla

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

Directional Properties in Rolling Oriented flowlines: -Less ductility when bent in one direction -More ductility when bent in the other Kalpakjian

Slab Production: Hot Rolling Color & Temp www. labware. com www. falckacciai. it www. beautifuliron. com

Progressive Hot Rolling: smaller, uniform grains Kalpakjian

Hot Working: Forging www. smeedwerkunica. nl Open Die Forging Paul Berenson, www. paulb. com T. Green, WIT

Forging Presses Kalpakjian Hydraulic press Slow but high force and low cost Mechanical press with an eccentric drive: faster Erie Press

Forging Presses Knuckle-joint press Screw press Gravity drop hammer: Simplest Kalpakjian

Forging: Closed Die Forging Kalpakjian

Forging: Heat Loss Metal near die surfaces are coolest, flow less www. lft. unierlangen. de www. freedomalloysusa. com

Upset Forging (hot or cold) Bolt manufacture Kalpakjian

Roll Forming (hot): I-beams Kalpakjian www. civil. ubc. ca Lunchtime on a Crossbeam, Unknown, www. buffalogames. com

Extrusion (hot or cold): Typ. : Alum. , soft metals With special lubes: steels ~Any cross-section Inexpensive dies Good finish en. wikipedia. org T. Green, WIT

Extrusion: Hollow cross-sections: Use Mandrels Kalpakjian www. abra. net. au

Mannesmann Process: Piercing (Hot) Seamless pipe, tube Kalpakjian

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 production finance. pipex. com www. nzsteel. co. nz Kalpakjian

Cold Rolling: Sheetmetal production Cluster rolls support smaller contacting rolls www. sendzimir. com www. elgiloy. com

Cold Rolling: Sheetmetal production Residual Stresses may lead to warping after bar is machined Kalpakjian Large reduction Small reduction

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

Roll Forming of sheetmetal www. mortonbuildings. com

Punching & Blanking of Sheetmetal Punch Stripper plate Die T. Green, WIT Punching (Scrap) Blanking (Saved: a “blank”)

Punching of Sheetmetal Kalpakjian

Blanking of Sheetmetal: Efficient Nesting of Blanks Kalpakjian

Sheetmetal: Bending Springback: Kalpakjian

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

Bending of Sheetmetal Use notches to avoid tearing and wrinkling in right-angle bends Kalpakjian

Bending of Sheetmetal Press Brakes: For lower production volumes 10 -30 foot long 50 -3000 tons www. loomismetals. com

Bending: Press-Brake Operations Kalpakjian

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

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 www. endo-mfg. co. jp Kalpakjian

Deep Drawing “Draw beads” may be used to control metal flow Kalpakjian

Spinning Ideal for • Lower production volumes • Large parts • Inexpensive tooling www. dissco. nz www. ashfordmetalspinning. co. uk www. traditional-building. com

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 Simulations Predict and minimize tearing and wrinkling locations www. esi-group. com nsmwww. eng. ohio-state. edu tmku 209. ctw. utwente. nl

Progressive Stamping Dies Common method to handle complex parts www. nissin-precision. com

Tube-drawing DOM: Drawn Over Mandrel Tubing Seamless Thin wall, tight tolerance, strong Malicky www. twmetals. com “Floating plug” Kalpakjian

Bicycles: Butted DOM tubing Increased wall thickness at ends Reinforces high stress points www. torelli. com materials. npl. co. uk

Diego Rivera, Detroit Industry, Detroit Institute of Art

References Kalpakjian: http: //www. nd. edu/~manufact/index 3. htm Bralla: James G. Bralla, Design for Manufacturing Handbook, Mc. Graw. Hill, 2 nd Edition. In: www. rose-hulman. edu/~stienstr