{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

Lecture15

# Lecture15 - Chapter 9 Phase Diagrams ISSUES TO ADDRESS When...

This preview shows pages 1–6. Sign up to view the full content.

Chapter 9 - 1 ISSUES TO ADDRESS... When we combine two elements... what equilibrium state do we get? In particular, if we specify... --a composition (e.g., wt% Cu - wt% Ni), and --a temperature ( T ) then... How many phases do we get? What is the composition of each phase? How much of each phase do we get? Chapter 9: Phase Diagrams Phase B Phase A Nickel atom Copper atom

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Chapter 9 - 2 Components : The elements or compounds which are present in the mixture (e.g., Al and Cu) Phases : The physically and chemically distinct material regions that result (e.g., α and β ). Aluminum- Copper Alloy Components and Phases α (darker phase) β (lighter phase) Adapted from chapter-opening photograph, Chapter 9, Callister 3e.
Chapter 9 - 3 A phase diagram - graphical representation of the combinations of temperature, pressure, composition, or other variables for which specific phases exist at equilibrium.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Chapter 9 - 4 Phase Equilibria: Solubility Limit Introduction Solutions – solid solutions, single phase Mixtures – more than one phase Solubility Limit : Max concentration for which only a single phase solution occurs. Question: What is the solubility limit at 20°C ? Answer: 65 wt% sugar . If C o < 65 wt% sugar: syrup If C o > 65 wt% sugar: syrup + sugar. 65 Sucrose/Water Phase Diagram Pure Sugar Temperature (°C) 0 20 40 60 80 100 =Composition (wt% sugar) L (liquid solution i.e., syrup) Solubility Limit L (liquid) + S (solid sugar) 20 40 60 80 100 Pure Water Adapted from Fig. 9.1, Callister 7e.
Chapter 9 - 5 Effect of T & Composition ( C o ) Changing T can change # of phases: Adapted from Fig. 9.1, Callister 7e.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}