Metal Forming 1

Fundamentals of Metal Forming Processes Amr Shehata Fayed, Ph.D. Assistant Professor of Mechanical Engineering Materials Engineering Department Faculty of Engineering Zagazig University

Dr. Amr Shehata Fayed

Forming and Shaping

Forming: means changing the shape of an existing solid body.

Shaping: usually involves molding and casting.

Ex. The metal body for a car (sheet metal forming)

Ex. The white ceramic insulator for a spark plug of a car body for a car (clay molding, drying and firing)

Dr. Amr Shehata Fayed

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Metal Forming Processes

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Metal Forming includes a large group of manufacturing processes in which plastic deformation is used to change the shape of metal work-pieces. Deformation results from the use of a tool, usually a die in metal forming, which applies stresses that exceed the yield strength of the metal.

Dr. Amr Shehata Fayed

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(a) (b) (c)

(d)

(e)

(f)

(g)

(h)

Hammer forging two connecting rods; (a) bar stock; after (b) fullering, (c) “rolling”, (d) blocking, (e) finishing, (f) trimming; (g) the flash; (h) the forging dies. Dr. Amr Shehata Fayed

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Metal Forming Processes Sheet Metal-working:

Bulk Deformation:

 Also called “Press-working”.

 Compressive deformation force.

 Cold working processes.

 Significant deformations.

 Use set of punch and die.

 Massive shape changes.

 Performed on metal sheets,

 Starting work shapes include

strips and coils.

billets and rectangular bars.

 Surface area / volume is small.

 Surface area / volume is large. Dr. Amr Shehata Fayed

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Metal Forming Processes Sheet Metalworking Bending operations

Bulk Deformation Surface Area / Volume is small

Surface Area / Volume is large

Shearing processes

Forging Extrusion

Deep or Cup drawing Dr. Amr Shehata Fayed

Rolling

Wire and Bar drawing 6

Bulk Deformation Processes Rolling: A compressive deformation process in which the thickness of slab or plate is reduced by two opposing tools “rolls”. They rotate to draw the work piece into the gap between them and squeeze it.

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Bulk Deformation Processes Forging: The work-piece is compressed between two opposing dies so that the die shapes are imparted to work. It is traditionally hot working process however many types of forging are performed cold.

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Bulk Deformation Processes Extrusion: A compressive deformation process in which the work metal is forced to flow through a die opening to produce a desired cross-sectional shape.

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Bulk Deformation Processes Drawing: The work metal is being pulled through a die opening to reduce the diameter of a wire or a bar. See Fig. Wire Drawing.

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Examples of Precision Cold Forged Products

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Precision Hot Forging of Complex Shapes

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Precision Hot Forging of Complex Shapes

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Sheet Metalworking Processes Bending: It involves straining of metal sheet or plate to take an angle along a (usually) straight axis.

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Sheet Metalworking Processes Drawing: (Cup or deep drawing) Forming of a flat metal sheet into a hollow or concave shape, such as cup, by stretching the metal. A blank holder is used to hold down the blank while the punch pushes into the sheet metal.

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Sheet Metalworking Processes Shearing: It involves cutting rather than forming of a metal. A shearing operation cuts the work using a punch and die.

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Importance of Metal Forming in Manufacturing Engineering • • • • •

Net Shape or Close to Net Shape High Production Rate High Profit Margin Low Scrap Rate Improving Material Properties

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Applications and Products of Metal forming in Macro Scale • • • •

Automotive Aerospace Appliance Cookware

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Current Issues of Metal Forming Industry • • • • •

Lack of Experienced Metal Forming Engineer Short Product Life Cycle New Metallic Materials Developing New Hybrid Process High Accuracy and Small Feature Products

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Skills Needed for Metal Forming Engineering • • • • • • •

Mechanics Material Science Manufacturing Process Design and Control Machinery Computer Skills FEA

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Students Need • To know the current and future needs of metal forming industry. • To be taught on a series of classes to meet challenges of current and future metal forming industry.

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Homework • Is metal forming the most cost effective manufacturing process? • Why metal forming is the best process for mass production? • According to your imagination, what is the best process to make beverage can?

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