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NEEP 541 – Hardening II. Fall 2002 Jake Blanchard. Outline. Hardening. Hardening by Impenetrable Obstacles. Some barriers cannot be cut by a dislocation Precipitation hardening creates very hard carbides that connot be sheared The dislocation must bow around them.
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NEEP 541 – Hardening II Fall 2002 Jake Blanchard
Outline • Hardening
Hardening by Impenetrable Obstacles • Some barriers cannot be cut by a dislocation • Precipitation hardening creates very hard carbides that connot be sheared • The dislocation must bow around them
Loop Hardening • Forces between loops and edge dislocations can impede motion of a dislocation • As before: • Experiments indicate:
Summary • Source Hardening – increase stress to start Frank-Read source • Friction hardening – increase stress required to move dislocations • Long range – forces from other dislocations • Short range - obstacles
Summary • Short range – obstacles • Depleted zones • Impenetrable obstacles • loops