lecture 10 - ME 330 Engineering Materials Lecture 10...

Info iconThis preview shows pages 1–9. Sign up to view the full content.

View Full Document Right Arrow Icon
Lecture 10 Iron-Carbon Phase Diagram Stephen D. Downing Mechanical Science and Engineering © 2001 - 2010 University of Illinois Board of Trustees, All Rights Reserved ME 330 Engineering Materials
Background image of page 1

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

View Full Document Right Arrow Icon
ME 330 - Lecture 10 © 2010 Stephen Downing, University of Illinois at Urbana-Champaign, All Rights Reserved 1 of 43 This Lecture . .. ± Phase Diagram Review ± Intermediate compounds ± Steel Microstructures ± Calculating Compositions ± Heat Treatment ± Cast Iron
Background image of page 2
ME 330 - Lecture 10 © 2010 Stephen Downing, University of Illinois at Urbana-Champaign, All Rights Reserved 2 of 43 Next Lecture . .. ± Hardenability ± Reaction kinetics … what happens when time is introduced to solidification ± TTT curves ± CCT curve ± Hardenability and Jominy end quench test ± Surface hardening treatments Please read chapter 10 Please read chapter 10
Background image of page 3

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

View Full Document Right Arrow Icon
ME 330 - Lecture 10 © 2010 Stephen Downing, University of Illinois at Urbana-Champaign, All Rights Reserved 3 of 43 Gibb’s Phase Rule ± Describes conditions for phase equilibria ± P : number of phases present ± F : degrees of freedom (state variables that can be changed without changing the phases present) ± C : number of components in the system ± N : number of noncompositional variables (T, p) not held constant ± Constant pressure or temperature process, N = 1 ± Constant pressure and temperature process, N = 0 ± Will use to understand changing variables in phase diagrams N C F P + = +
Background image of page 4
ME 330 - Lecture 10 © 2010 Stephen Downing, University of Illinois at Urbana-Champaign, All Rights Reserved 4 of 43 Binary Eutectic Phase Diagram ± Liquidus ± Solidus ± Eutectic isotherm - horizontal solidus ± Solvus - solid solubility limit ± Eutectic point - liquid solidifies isothermally to a two-phase solid ± Regions of importance ± Rules ± In each field, only one or two phases in equilibrium ± At points, 3 phases can be in equilibrium ± Single phase regions always separated by a two phase region with both single phases present 20 40 60 80 0% A 80 60 40 20 100% B 100 0 Composition (%A) Temperature α α+β α +L β +L β L E
Background image of page 5

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

View Full Document Right Arrow Icon
ME 330 - Lecture 10 © 2010 Stephen Downing, University of Illinois at Urbana-Champaign, All Rights Reserved 5 of 43 Solubility Limits ± Below eutectic isotherm, limited concentration of A can dissolve in B and vice versa (limited solubility) ± In α+β region, both solid solutions coexist in equilibrium ± Maximum solubility of A in B shown at point D ± Maximum solubility of B in A shown at point F α α+β α +L β +L β L E 20 40 60 80 0% A 80 60 40 20 100% B 100 0 D 12% F 92% Composition (%A) Temperature
Background image of page 6
ME 330 - Lecture 10 © 2010 Stephen Downing, University of Illinois at Urbana-Champaign, All Rights Reserved 6 of 43 ± Three phases present ± Look at Phase Rule: ± ± Invariant point - cannot change temperature without losing a phase ± Reaction: L ⇒α + β ± Isothermal, similar to pure metal solidification ± Lowest melting point of all compositions Eutectic Point 0 1 3 2 1 P C F = + = + = T E t T L L+ α + β (F = 0) α + β C E α α+β α +L β +L β L 20 40 60 80 0% A 80 60 40 20 100% B 100 0 E D 12% F 92% Composition (%A) Temperature
Background image of page 7

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

View Full Document Right Arrow Icon
ME 330 - Lecture 10
Background image of page 8
Image of page 9
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

Page1 / 45

lecture 10 - ME 330 Engineering Materials Lecture 10...

This preview shows document pages 1 - 9. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online