Question

Materials science

Consider the graph below for a Pb-35% Sn alloy. Is the alloy hypoeutectic or hypereutectic: The alloy is -select 400 300 Liquidus Solidus Liquidus Solidus α+L 200 -B 19 183 61.9 97.5 Solvus - Solvus 100 + Pb 40 20 60 80 Sn Weight percent tin Enter your answers below with whole numbers. The composition of the first solid to form, Cf, during solidification C % Sn The amounts (%a, %2) and compositions (Ca, C2) of each phase at 184 °C % Sn Ca C2 % Sn %a %2 The amounts and compositions of each phase at 182 °C % Sn Ca % Sn C2 %a %2 Temperature C) The amounts and compositions of each phase at 182 °C Ca % Sn C2 % Sn %α- % | % ounts and compositions of each microconstituent at 182 °C: Ca % Sn C2= % Sn | % |% The amounts and compositions of each phase at 25°C: %α- %2 = Ca % Sn C2 % Sn %α- % %2

Answer 1

​​​​​​ANSWER: Consider the graph for a Pb-35% Sn alloy:

(a.) The alloy is hypoeutectic .

(b.) The composition of the first solid to form, C_f , during solidification:

C_f = 14% Sn

(c.) The amount and compositions of each phase at 184°C:

C_$\alpha$ = 19% Sn

C_{2 =} 62% Sn

%$\alpha$​​​​​​ = [(62 - 35)/(62 -19)]×100%

%$\alpha$ = 63%

%2 = 37%

(d.) The amount and compositions of each phase at 182°C:

C$\alpha$ = 19% Sn

C₂ = 98% Sn

%$\alpha$ = [(98 - 35)/(98 - 19)]×100%

%$\alpha$ = 80%

%2 = 20%

(e.) The amount and compositions of each microconstituent at 182°C:

C$\alpha$ = 19% Sn

C2 = 62% Sn

%$\alpha$ = 63%

%2 = 37%

(f.) The amount and compositions of each phase at 25°C:

C$\alpha$ = 2% Sn

C2 = 100% Sn

%$\alpha$ = [(100 - 35)/(100 - 2)]×100%

%$\alpha$ = 66%

%2 = 34%