.For a solder containing 70%Pb 30%Sn determine: a. If the alloy is hypo- or hypereutectic b. the composition of the first solid to form during solidification c. the amount and composition of each phase at 1840 C d. the amount and composition of each phase at 1820 C e. the amount and composition of each phase at 500 C f. the eutectic composition and temperature ( 35 points)

Question in proper order:

Consider a solder containing 70%Pb 30%Sn, determine:

a. If the alloy is hypo- or hypereutectic

b. the composition of the first solid to form during solidification

c. the amount and composition of each phase at 1840 C

d. the amount and composition of each phase at 1820 C

e. the amount and composition of each phase at 500 C f. the eutectic composition and temperature ( 35 points)

Answer and explanation:

The Phase Diagram of Pb-Sn Alloy is given in the attached image

a. Pb-Sn alloy will have eutectic composition between 61.9% and 97.5% Sn, so the Pb-70%Sn alloy will have eutectic composition as it has 70%Sn