Materials Engineering – Day 9 Phases and Phase Diagram. Preliminary Discussion Concept of the Phase Phase Diagram – start with Copper Nickel. What phase or phases are present? What is the chemical composition of each phase present? How much (relative amounts) of each phase is present?
Al, surrounded by a mixture of Al and CuAl2.
Al and CuAl2 mixture.
The darker area is Fe with small amount of interstitial carbon.
The lighter standout areas are the compound cementite,
Fe3C. (Iron carbide.)
BLOCK DISLOCATIONS! INCREASE STRENGTH.
The symbol a stands for a solid consisting of Ni dissolved in Cu or visca-versa.
1. Liquid and a
2. CL = 32% Ni and Ca = 43% Ni
3. Use the Lever Rule!
Once we know how to answer the three major questions, let’s move on to a more complicated binary system.
Let’s work on this one together, using the handout.