This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: Homework 8 PART A. Definitions and Nomenclature (10 points-1 point each) 1. Steels whose compositions are to the left of the eutectoid are referred to as hypoeutectoid alloys. 2. A critical nucleus is a newly formed phase, which can reduce its Gibbs free energy by either growing or dissolving. 3. Two phases with same crystal structure and atomic spacings meet at a coherent interface. 4. The Body Centered Cubic (BCC) phase of iron is called ferrite. 5. A steel microstructure consisting of spherical carbides distributed in ferrite is called bainite . 6. When dislocations are present at an interface to relieve strain the interface is said to be a partially, or semi-coherent interface . 7. When nucleation occurs at random sites in the parent phase, the nucleation process is said to be homogeneous nucleation . 8. The process by which powders are densified at elevated temperature to form nearly fully dense microstructure is sintering. 9. A two phase microstructure with alternate lamellar microstructure in steels is referred to as pearlite . 10. The only phase which can produce martensite as a result of a rapid quench is austenite . PART B. Circle the appropriate response. (10 points-each 1 point) 1.1....
View Full Document
- Fall '08
- Entropy, Austenite, homogeneous nucleation, pearlite