{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

09-3 (1)

# 09-3 (1) - E45 Lecture Chapter 10 Chapter 10 Phase Diagrams...

This preview shows pages 1–10. Sign up to view the full content.

Chapter 10 - E45 Lecture 9/25/09

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

View Full Document
Chapter 10 - 2 ISSUES TO ADDRESS... When we combine two elements... what is the resulting equilibrium state? In particular, if we specify... -- the composition (e.g., wt% Cu - wt% Ni), and -- the temperature (T ) then... How many phases form? What is the composition of each phase? What is the amount of each phase? Chapter 10: Phase Diagrams Phase B Phase A Nickel atom Copper atom Phase = physically and chemically distinct material
Chapter 10 - 3 Phase Equilibria: Solubility Limit Solution – solid, liquid, or gas solutions, single phase Mixture – more than one phase

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

View Full Document
Chapter 10 - 4 Phase Equilibria: Solubility Limit Solution – solid, liquid, or gas solutions, single phase Mixture – more than one phase Solubility Limit : Maximum concentration for which only a single phase solution exists. Sugar/Water Phase Diagram Sugar Temperature (°C) 0 20 40 60 80 100 C = Composition (wt% sugar) L (liquid solution i.e., syrup) Solubility Limit L (liquid) + S (solid sugar) 20 40 60 80 100 Water Adapted from Fig. 10.1, Callister & Rethwisch 3e.
Chapter 10 - 5 Phase Equilibria: Solubility Limit Solution – solid, liquid, or gas solutions, single phase Mixture – more than one phase Question: What is the solubility limit for sugar in water at 20°C ? Answer: 65 wt% sugar . At 20°C, if C < 65 wt% sugar: syrup At 20°C, if C > 65 wt% sugar: syrup + sugar 65 Solubility Limit : Maximum concentration for which only a single phase solution exists. Sugar/Water Phase Diagram Sugar Temperature (°C) 0 20 40 60 80 100 C = Composition (wt% sugar) L (liquid solution i.e., syrup) Solubility Limit L (liquid) + S (solid sugar) 20 40 60 80 100 Water Adapted from Fig. 10.1, Callister & Rethwisch 3e.

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

View Full Document
Chapter 10 - 6 Components : The elements or compounds which are present in the alloy (e.g., Al and Cu) Phases : The physically and chemically distinct material regions that form (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, Materials Science & Engineering: An Introduction, 3e.
Chapter 10 - 7 70 80 100 60 40 20 0 Temperature (°C) C = Composition (wt% sugar) L ( liquid solution i.e., syrup) 20 100 40 60 80 0 L (liquid) + S (solid sugar) Effect of Temperature & Composition Altering T can change # of phases: path A to B . Altering C can change # of phases: path B to D . water- sugar system Adapted from Fig. 10.1, Callister & Rethwisch 3e. D (100°C,C = 90) 2 phases B (100°C,C = 70) 1 phase A (20°C,C = 70) 2 phases

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

View Full Document
Chapter 10 - 8 Criteria for Solid Solubility Crystal Structure electroneg r (nm) Ni FCC 1.9 0.1246 Cu FCC 1.8 0.1278 Both have the same crystal structure (FCC) and have similar electronegativities and atomic radii ( W. Hume – Rothery rules ) suggesting high mutual solubility. Simple system (e.g., Ni-Cu solution) Ni and Cu are totally soluble in one another for all proportions.
Chapter 10 - 9 Phase Diagrams Indicate phases as a function of T, C, and P.

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 ]}

### Page1 / 40

09-3 (1) - E45 Lecture Chapter 10 Chapter 10 Phase Diagrams...

This preview shows document pages 1 - 10. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online