Homework Solutions- ch09 (1).docx - 9.11 Is it possible to have a copper–silver alloy that at equilibrium consists of a β phase of composition 92 wt

Homework Solutions- ch09 (1).docx - 9.11 Is it possible to...

This preview shows page 1 - 4 out of 12 pages.

9.11 Is it possible to have a copper–silver alloy that, at equilibrium, consists of a β phase of composition 92 wt% Ag–8 wt% Cu and also a liquid phase of composition 76 wt% Ag–24 wt% Cu? If so, what will be the approximate temperature of the alloy? If this is not possible, explain why. Solution It is possible to have a Cu-Ag alloy, which at equilibrium consists of a phase of composition 92 wt% Ag-8 wt% Cu and a liquid phase of composition 77 wt% Ag-23 wt% Cu. From Figure 9.7 a horizontal tie line can be constructed across the + L phase region at about 800 C which intersects the L ( + L ) phase boundary at 76 wt% Ag, and also the ( + L )– phase boundary at 92 wt% Ag.
Image of page 1

Subscribe to view the full document.

9.14 A 50 wt% Ni–50 wt% Cu alloy is slowly cooled from 1400°C (2550°F) to 1200°C (2190°F). (a) At what temperature does the first solid phase form? (b) What is the composition of this solid phase? (c) At what temperature does the liquid solidify? (d) What is the composition of this last remaining liquid phase? Solution Shown below is the Cu-Ni phase diagram (Figure 10.3a) and a vertical line constructed at a composition of 50 wt% Ni-50 wt% Cu. (a) The first solid phase forms at the temperature at which a vertical line at this composition intersects the L –( + L ) phase boundary--i.e., at about 1320 C. (b) The composition of this solid phase corresponds to the intersection with the L –( + L ) phase boundary, of a tie line constructed across the + L phase region at 1320 C--i.e., C = 62 wt% Ni-38 wt% Cu. (c) Complete solidification of the alloy occurs at the intersection of this same vertical line at 50 wt% Ni with the ( + L )– phase boundary--i.e., at about 1270 C. (d) The composition of the last liquid phase remaining prior to complete solidification corresponds to the intersection with the L ( + L ) boundary, of the tie line constructed across the + L phase region at 1270 C--i.e., C L is about 37 wt% Ni-63 wt% Cu.
Image of page 2
9.44 For a 52 wt% Zn–48 wt% Cu alloy, make schematic sketches of the microstructure that would be
Image of page 3

Subscribe to view the full document.

Image of page 4
  • Spring '08
  • YC

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

Ask Expert Tutors You can ask 0 bonus questions You can ask 0 questions (0 expire soon) You can ask 0 questions (will expire )
Answers in as fast as 15 minutes