1. BULK DEFORMATION PROCESSES IN METALWORKING
Rolling
Forging
Extrusion
SME Video
In-class Assignment 01
In-class Assignment 02
©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e

2. Bulk Deformation Significant shape change Cylindrical bars and billets
Rectangular billets and slabs
Processes stresses cause plastic flow
Cold, warm, and hot working operations
Near net shape or net shape processes
Little or no subsequent machining
Little or no waste
©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e

3. Rolled Products Made of Steel
The rolling process (specifically, flat rolling)
Flat rolling products and shape rolling (I beams) products
©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e

4. Diagram of Flat Rolling
Rolling mill for hot flat rolling
(photo courtesy of Bethlehem Steel)
©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e

5. Rolling Mills 2‑high rolling mill 3‑high rolling mill
four‑high rolling mill
tandem rolling mill
cluster mill
©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e

6. Rolling Thread rolling with flat dies
Ring rolling used to reduce the wall thickness and increase the diameter of a ring
©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e

7. Roll Piercing
Typical variation in pressure along the contact length in flat rolling
©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e

8. Forging Impression‑die forging Open‑die forging Flashless forging
©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e

9. Open-Die Forging Open-die forging with no friction
Open-die forging with friction
barreling
©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e

10. Several Open-Die Forging Operations
fullering
edging
cogging
©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e

11. Forging Flashless forging Impression-die forging
©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e

12. Forging Metal grain flow - hot forged with machining
Metal grain flow - machined complete
Conventional forging
Precision forging
©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e

13. Coining Operation
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14. Drop Hammer Details Types: Mechanical press Hydraulic press
Screw press
©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e

15. Conventional Impression-Die in Forging
©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e

16. Upset Forging
An upset forging operation to form a head on a bolt or similar hardware item
©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e

17. Heading (Upset Forging)
Examples of heading (upset forging) operations
(a) heading a nail using open dies
(b) round head formed by punch
(c) and (d) two common head styles for screws formed by die
(e) carriage bolt head formed by punch and die
©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e

18. Swaging
In radial forging, the workpiece rotates while the dies remain in a fixed
(a) Reduction
(b) Tapering
(c) Groove on a tube
(d) Pointing of a tube
(e) Neck on a gas cylinder
©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e

19. Roll Forging
©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e

20. Orbital Forging and Hubbing
Note that the excess material formed by the penetration of the hub must be machined away
©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e

21. Direct Extrusion Forward extrusion Extra portion known as butt
Separate from extrudate
©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e

22. Hollow and Semi-Hollow Shapes
(a) Direct extrusion for hollow or semi‑hollow cross sections
©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e

23. Indirect Extrusion backward extrusion reverse extrusion
Hot versus cold extrusion
(a) Definition of die angle
(b) Effect of die angle on ram force
©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e

24. Complex Cross Section A complex extruded cross section for a heat sink
(photo courtesy of Aluminum Company of America)
©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e

25. Examples of Impact Extrusion
(a) Forward
(b) Backward
(c) Combination of forward and backward
©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e

26. Extrusion Process Hydrostatic extrusion Defects in extrusion
Centerburst
Piping
Surface cracking
©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e

27. SME Video
©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e

28. In-class Assignment 1 of 2
The strength coefficient and strain-hardening exponent of a certain test metal are 40,000 lb/in2 and 0.19, respectively. A cylindrical specimen of the metal with starting diameter = 2.5 in and length = 3.0 in is compressed to a length of 1.5 in.
Determine the flow stress at this compressed length and the average flow stress that the metal has experienced during deformation.
©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e

29. In-class Assignment 2 of 2
Determine the value of the strain-hardening exponent for a metal that will cause the average flow stress to be 3/4 of the final flow stress after deformation.
©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e

30. Production Scheduling Machine-Machine Diagrams
©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e

31. Time Permitting Content
©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e

32. Wire and Bar Drawing Bar, rod, or wire
Wire drawing - small diameter stock
Bar drawing - large diameter bar and rod stock
Preparation of work material
Annealing
Cleaning
Pointing
©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e

33. Wire and Bar Drawing Hydraulically operated draw drawing bench
Single‑draft operation
Continuous drawing of wire
©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e

34. Tube Drawing Tube drawing with no mandrel (tube sinking)
©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e

35. Sample Extrusion Cross Sections
©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e