Below find a phase diagram for Buffalo numb Bu containing a

Below find a phase diagram for Buffalo numb (Bu) containing a second element (X). You have been handed a homogeneous sample of Bu which contains 0.4% X. You have been asked to heat the material above its melting point, so it becomes a homogeneous liquid of the same composition. Then, you cool the material slowly through the liquid-solid phase field. What is the composition of the first solid to form? A: 0.10%X, B: 0.16% X, C: 0.22%X, D: 0.4%X 2. What is the composition of the liquid phase (liquids) and the solid phase (solidus) at 320 degree C? A: 0.16X. 0.40X: B: 0.40X, 0.60X; C: 0.24X. 0.60X: D: 0.24X. 0.40X

Solution

(1)

steps to identify the first solid to form:

- identify the point on the on the constant composition line (0.4%x) which will intersect the liquidus line.

- draw a horinzontal line from that point towards temperature axis.

- identfy the point where that horizontal line touches the solidus line (in figure that is indicated as red dot).

- match the composition at that point on the X-axis.

option A,C, and D are wrong.

therefore, option A is correct.

(2)

steps to identify the liquid phase and solid phase at 320⁰ C.

- draw a horizontal line from 320⁰ C which will passes through solid and liquid phase.

- identify the intersection points on the solidus line and liquidus line.

- match the corresponding % composotion of the both liquidus and solidus.

therefore, option A,B,and D are wrong.

option C is correct

solidus at 0.24%x and liquidus at 0.6%x.