Introduction and Outline

In the previous Chapter, we explored basic mechanical behavior with the aide of a powerful, but limited, atomistic model. In this chapter, we'll continue our investigation of plasticity, focusing mainly on the origins of plasticity in crystalline solids (i.e., metals, ceramics). We won't outline this chapter in detail now, but instead allow you to explore some historical anomalies in plasticity theory from the early 20th Century. Yes, this is some time ago, but the ideas are still relevant and instructional today. Proceed to the next section to investigate.

We'll forgo the outline for this chapter en lieu of our exploration on the next page, but the chapter's outcomes are below.

Outcomes

• Describe the basic mechanisms behind plasticity (dislocation motion, slip systems).
• Assess edge dislocations with respect to:
  • Dislocation characteristics.
  • Burger’s vector
  • Slip direction.
  • Dislocation motion.
• Relate slip behavior to crystal structure.
• Understand (and apply this understanding) the mechanisms at work behind the four strengthening behaviors in metals that we covered in class.
• Evaluate how thermal treatments can yield recovery in dislocation-dense crystals.