3Phase Diagram - Chapter 9 Phase Diagrams Why Study Phase...

Info icon This preview shows pages 1–8. Sign up to view the full content.

View Full Document Right Arrow Icon
Chapter 9 - 1 Why Study Phase Diagram? Because there is a strong correlation between microstructures and mechanical properties and the development of microstructures of an alloy is related to the characteristic of its phase diagram Provide valuable information about melting, casting, crystallization and other phenomena Chapter 9: Phase Diagrams
Image of page 1

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

View Full Document Right Arrow Icon
Chapter 9 - 2 Components : Pure metal and or compound of which alloy is composed (e.g. Cu and Zn) System : a specific body of material under consideration or a series of alloys consisting of the same component ( e.g. iron-carbon system) Solvent : represent the element or compound that is present in the greatest amount Solute : an element or compound present in a minor concentration Phase : a homogeneous portion of a system that is uniform physical and chemical characteristics Definitions
Image of page 2
Chapter 9 - 3 Solubility Limit Question: What is the solubility limit for sugar in water at 20ºC ? Answer: 65 wt% sugar . At 20ºC, if C < 65 wt% sugar: syrup At 20ºC, if C > 65 wt% sugar: syrup + sugar 65 Solubility Limit : Maximum concentration of solute atoms that may dissolve in the solvent to form a solid solution Solubility limit depend on temp. Sugar/Water Phase Diagram Sugar Temperature (ºC) 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. 9.1, Callister & Rethwisch 8e. Solution – solid, liquid, or gas solutions, single phase Mixture – more than one phase
Image of page 3

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

View Full Document Right Arrow Icon
Chapter 9 - 4 70 80 100 60 40 20 0 Temperature (ºC) 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. 9.1, Callister & Rethwisch 8e. D (100ºC, C = 90) 2 phases B (100ºC, C = 70) 1 phase A (20ºC, C = 70) 2 phases
Image of page 4
Chapter 9 - 5 Phases Phase : A homogeneous portion of a system that is uniform physical and chemical characteristics Every pure material is considered to be a phase If more than one phase is present in a system each will have its own distinct properties and a boundary separating the phases will exist . Eg. – sugar water solution When two separate phases exists they are physically dissimilar but identical in chemical make up e. Ice – water : solid – liquid Single phase is termed homogeneous Two or more phase : heterogeneous
Image of page 5

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

View Full Document Right Arrow Icon
Chapter 9 - Microstructure Physical properties in particular mechanical behaviour of material depend on microstructure. In metal alloy microstructure is characterized by the number of phases present, their proportion and the manner in which they are distributed or arrange The microstructure of an alloy depends on alloying elements present, their concentrations and their heat treatment of the alloy 6
Image of page 6
Chapter 9 - Phase Equilibria Free energy is a function of the internal energy of a system and the readomness of disorder of the atoms A system is at equilibrium if its free energy is at a minimum
Image of page 7

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

View Full Document Right Arrow Icon
Image of page 8
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern