ENGR 240 - 10.29.07

ENGR 240 - 10.29.07 - D another layer of the α forms with...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
ENGR 240 – October 29, 2007 Equilibrium Solidification o Slow cooling o Solidification according to what is shown on phase diagram A) liquid phase 50% – 50% B) α + L; 50-50% liquid comp.; 22-88% α comp. C) α + L; 70-30% liquid comp.; 27-73% α comp. D) α + L; 88-12% liquid comp.; 50-50% α comp. E) α phase only, 50-50% Non-equilibrium solidification o Composition of phases are not as they appear on the phase diagram o Solid state diffusion cannot keep up with changes in composition that are shown on the phase diagram A) same as before B) same as before because solidification has just started C) α is forming at this temperature and can be read off of the regular tie line but does not give you the average concentration Concentration of α in terms of antimony is greater than the composition at point C and less then the concentration at B
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: D) another layer of the α forms with a different concentration and composition E) same as before because it is below the dotted line o Called “coring” or microsegregation Can be bad because results in a variation in the mechanical properties and the melting point • Outer regions that froze last melt first Composition cen be evend out by heating it up to a temperature below the melting point • Increases diffusion to create homogeneous grains o Type of annealing homogenization Mechanical Properties of binary Isomorphous alloys o As you add a second component you strain the atomic structure Creates a higher resistance to slip %EL decreases as tensile strength increases Weird stuff in BISystems o Under certain temperature and pressure, you can have solid immiscibility...
View Full Document

This note was uploaded on 04/07/2008 for the course ENGR 240 taught by Professor Gross during the Fall '07 term at Bucknell.

Ask a homework question - tutors are online