ME383 Modern Manufacturing Practices

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ME 383Modern Manufacturing Practices
Lecture Note 4 Forging Dr. Y.B. Guo Mechanical
Engineering The University of Alabama
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Todays Lecture

• Overview of Metal Forming
• Introduction of Forging
• Mechanics of Forging
• Quality of Forged Parts
• Forging Equipment and Tooling
• Process Capability

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Overview of Metal Forming

• Example

Forging
Rolling
Extrusion
Drawing
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Overview of Metal Forming

• Example

Bending
Deep drawing
Shearing
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Overview of Metal Forming

• Metal Forming
• Shape changes by plastic deformation in dies
• A large group of manufacturing processes
• Applied compressive stresses in bulk forming
• Applied tensile stresses in sheet-metal forming

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Overview of Metal Forming

• Classification by Size and Shape
• Bulk deformation small surface-to-volume ratio
• Sheet-metal forming large surface-to-volume
  ratio

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Overview of Metal Forming

• Classification by Working Temp.
• Cold working
• Warm working
• Hot working

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Introduction of Forging

• Forging Process
• Compressive deformation
• Part taking the shape of dies
• Forging Operation Types

Open Die
Closed Die w. flash
Closed-Die flashless
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Introduction of Forging

• Typical Products
• Crankshafts, gears, hand tools, connecting rods,
  

Landing-gear component
Connecting rod
Bevel gear
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Mechanics of Forging Open Die Forging

• Homogeneous Deformation
• Forging without friction
• Forging Force, etc. (cylinder)

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Mechanics of Forging Open Die Forging

• Actual Deformation (barreling)
• Friction
• Non-uniform heat transfer

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Mechanics of Forging Open Die Forging

• Forging Force, etc. (cylinder)

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Mechanics of Forging Open Die Forging

• Example
  , Find F

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Mechanics of Forging Closed Die Forging

• Forging Force

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Quality of Forged Parts

• Forgeability capability to undergo deformation
  by forging without cracking
• Strengthened Part
• End Grains

forging
machining
casting
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Quality of Forged Parts

• Web Buckling (insufficient filling matl)
• Internal Cracks (excess filling matl)

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Forging Equipment and Tooling

• Presses applying gradual pressure

(c)
Screw Press
Hydraulic Press
Mechanical Press
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Forging Equipment and Tooling

• Hydraulic Presses up to 82,000 tons

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Forging Equipment and Tooling

• Hammer applying impact load

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Design for Forging

• Forging Dies Parting Line, Draft, Webs, Ribs,
  Fillet, Corner Radii, and Flash

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Process Capability

• Discrete Part
• Structural Parts favorable characteritics such
  as strength, toughness, etc.
• Near Net Shape or Net Shape
• Tolerance
• 0.5 1 of dim.
• Hot forging 6mm
• Precision forging 0.25 mm (0.01 in)

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End

• Questions ?