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

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

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

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

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

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

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

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

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

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

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

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

Coining Operation ©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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