Phase Diagrams QCAA Engineering Unit 4

Which rule is used to calculate the percentages of solid and liquid in a lead-tin alloy?

• Lever rule

• Inverse lever rule

• Phase rule

• Equilibrium rule

What does the term "isomorphous" imply in a binary isomorphous system?

• A. The metals form a single new solid alloy.

• B. The metals form multiple solid phases.

• C. The metals are not soluble in each other.

• D. The metals form a liquid solution.

At what temperature does a 60 wt % Ni-copper alloy start to solidify according to the phase diagram?

• A. 1350°C

• B. 1310°C

• C. 1270°C

• D. 1240°C

Which line represents the boundary between the solid solution (S) and the liquid + solid (L + S) phases in the copper/nickel phase diagram?

• Solidus line

• Liquidus line

• Cooling curve

• Phase boundary line

What does the liquidus line indicate in a phase diagram?

• The temperature at which solidification starts for a particular alloy composition.

• The temperature at which solidification ends for a particular alloy composition.

• The temperature at which the mixture is completely solid.

• The temperature at which the mixture is completely gaseous.

What is the state of the mixture below the solidus line?

• Completely solid

• Completely liquid

• Partially solid and partially liquid

• Completely gaseous

What is the state of the mixture in the region labeled "liquid (L)" in the phase diagram?

• Completely solid

• Completely liquid

• Partially solid and partially liquid

• Completely gaseous

What is the composition of point A in the phase diagram?

• 60 wt% Ni and 40 wt% Cu

• 70 wt% Ni and 30 wt% Cu

• 35 wt% Ni and 65 wt% Cu

• 95 wt% Cu and 5 wt% Ni

What is the composition of point B in the phase diagram?

• 60 wt% Ni and 40 wt% Cu

• 70 wt% Ni and 30 wt% Cu

• 35 wt% Ni and 65 wt% Cu

• 95 wt% Cu and 5 wt% Ni

In the phase diagram, what is the solvent at point b?

• Nickel

• Copper

• Lead

• Tin