Forging of Metals

1
Forging of Metals

• Chapter 14

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Introduction

• A metal is shaped by compressive forces
• Oldest metal working process 4000BC
• Can be performed with a hammer and anvil
• Typical forged products
• Bolts
• Rivets
• Connecting rods
• Gears

3
Lading-gear components for the C5A and C5B
transport aircraft, made by forging.

• Steps involved in forging a bevel gear with a
  shaft.

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Outline of Forging and Related Operations
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Grain Structure

• Parts have good strength
• High toughness
• Forgings require additional heat treating

• Fig A part made by three different procedures,
  showing grain flow (a) casting (b) machining (c)
  forging

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Open-Die Forging

• Is the simplest forging process
• Sizes can very from very small parts to very
  large parts

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Open-Die Forging

• Upsetting or flat-die forging a solid workpiece
  is placed between flat dies and is compressed
• Barreling
• caused by frictional forces at the die-workpiece
  interfaces
• Can be minimized if a lubricant is used
• Thermal effects caused by barreling can be
  minimized by using heated dies

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Open-Die Forging

• Forging force

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Impression-Die Closed-Die Forging

• The workpiece acquires the shape of the die
  cavities while being forged between the two
  shaped dies

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Impression-Die Closed-Die Forging

• The blank to be forged is prepared by
• Cutting from a bar stock
• Preformed blank
• Casting
• Preformed blank from prior forging

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Impression-Die Closed-Die Forging

• Fullering edging are used to distribute the
  material
• Fullering material is distributed away from an
  area
• Edging material is gathered into an area
• Blocking rough shaping of the part
• Impression dies give the part its final shape

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Precision Forging

• Used for economic reasons
• The part formed is close to the final dimensions
• Less machining is needed
• Higher capacity equipment is needed
• Aluminum and Magnesium alloys work well in the
  process

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Coining

• Closed-die forging process
• Used for minting coins, medallions, jewelry
• Lubricants can not be used in coining
• Can be used to improve surface finish

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THE END