Practice Problems of Eutectic Binary Phase System
Tuesday, 14 May 2024
12:35 PM
Callister's Materials Book 7th Edition: 9.11
A lead–tin alloy of composition 30 wt% Sn–70 wt% Pb is slowly heated from a temperature of 150oC.
(a) At what temperature does the first liquid phase form?
(b) What is the composition of this liquid phase?
(c) At what temperature does complete melting of the alloy occur?
(d) What is the composition of the last solid remaining prior to complete melting?
Callister's Materials Book 7th Edition: 9.31
For 2.8 kg of a lead-tin alloy, is it possible to have the masses of primary 𝛽 and total 𝛽 of 2.21 kg and 2.53 kg,
respectively, at 180oC? Why or why not?
Callister's Materials Book 7th Edition: 9.32
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Callister's Materials Book 7th Edition: 9.32
For a lead-tin alloy of composition 80 wt% Sn-20 wt% Pb and 180oC do the following:
(a) Determine the mass fraction of 𝛼 and 𝛽 phases.
(b) Determine the mass fractions of primary 𝛽 and eutectic microconstituents.
(c) Determine the mass fraction of eutectic 𝛽.
Callister's Materials Book 7th Edition: 9.33
The microstructure of a copper–silver alloy at 775oC consists of primary and eutectic structures. If the mass
fractions of these two microconstituents are 0.73 and 0.27, respectively, determine the composition of the alloy.
Callister's Materials Book 7th Edition: 9.34
Consider the hypothetical eutectic phase diagram for metals A and B, which is similar to that for the lead–tin
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Consider the hypothetical eutectic phase diagram for metals A and B, which is similar to that for the lead–tin
system. Assume that: (l) 𝛼 and 𝛽 phases exist at the A and B extremities of the phase diagram, respectively;
(2) the eutectic composition is 36 wt% A–64 wt% B; and (3) the composition of the 𝛼 phase at the eutectic
temperature is 88 wt% A–12 wt% B. Determine the composition of an alloy that will yield primary 𝛽 and total
𝛽 mass fractions of 0.367 and 0.768, respectively.
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