Question

(a) The phase diagram of the binary system, neodymium-scandium ( Nd-Sc ) is given below. There are two polymorphs in the solid state: alpha which is hexagonal close packed (HCP) and beta which is body-centered cubic (BCC).

Identify all phases present at points 1, 2, and 3.


Point 1:
Liquid
Vapor
beta-phase
Sc-rich beta -phase
Nd-rich beta-phase
alpha-phase
Sc-rich alpha-phase
Nd-rich alpha-phase

Point 2:
Liquid
Vapor
beta-phase
alpha-phase

Point 3:
Liquid
Vapor
beta-phase
Sc-rich beta -phase
Nd-rich beta-phase
alpha-phase
Sc-rich alpha-phase
Nd-rich alpha-phase

(b) Are there any examples of a three-phase equilibrium in this phase diagram?
i)Yes, there is a eutectic at 700 degrees C and 60 at. % Sc.
ii)Yes, there is a eutectoid at 800 degrees C and 22 at. % Sc.
iii)Yes, there is a peritectic at 800 degrees C and 22 at. % Sc.
iv)No, there are no three-phase equilibrium points in this diagram.


(c) At point 3, calculate the phase fraction of the phase richest in Nd

Answer 1

(a)
Point 1: Liquid, beta-phase
Point 2: alpha-phase
Point 3: Sc-rich alpha-phase, Nd-rich alpha-phase

(b)
iv)No, there are no three-phase equilibrium points in this diagram.

(c)
0.2631

Answer 2

Thank you

Answer 3

thank you bery much

Answer 4

how you clacula the number c?

Answer 5

@an apply the lever rule.