(1)
How many triple points are there in the pure iron pressure-temperature equilibrium phase
diagram? What phases are in equilibrium at each of the triple points? [10 Points]
(2)
Consider an alloy containing 70 wt % Ni and 30 wt % Cu
(a) At 1350C make a phase analysis assuming equilibrium conditions. In the phase analysis
include the following:
(i) What phases are present?
(ii) What is the chemical composition of each phase?
(iii) What amount of each phase is present?
(b) Make a similar phase analysis at 1500°C.
(c) Sketch the microstructure of the alloy at each of these temperatures by using circular
microscopic fields.
(3)
A Pb-Sn alloy contains 40 wt % and 60 wt % at 50°C. What is the average composition of Pb
and Sn in this alloy?
(4)
Consider the Cu-Zn phase diagram.
(a) What is the maximum solid solubility in weight percent of Zn in Cu in the terminal solid
solution ?
(b) Identify the intermediate phases in the Cu-Zn phase diagram.
(c) Identify the three-phase invariant reactions in the Cu-Zn diagram.
(i) Determine the composition and temperature coordinates of the invariant reactions.
(ii) Write the equations for the invariant reactions.
(iii) Name the invariant reactions.
(5)
Consider the aluminum-nickel (Al-Ni) phase diagram. For this phase diagram:
(a) Determine the coordinates of the composition and temperature of the invariant reactions.
(b) Write the equations for the three-phase invariant reactions and name them.
(c) Label the two-phase regions in the phase diagram.