Lead-Tin Phase Diagram QCAA Engineering Unit 4

What does the inverse lever rule help to calculate in the context of the lead-tin phase diagram?

• Percentages of solid and liquid

• Melting points of components

• Electrical conductivity

• Thermal expansion coefficients

Which of the following is NOT a key feature to be identified in the lead-tin thermal-equilibrium phase diagram?

• Electrical resistance

• Components

• Phases

• Key features

What is the inverse lever rule used to determine?

• A) The balance of mechanical forces

• B) The proportions of two phases in a two-phase region of a phase diagram

• C) The length of a mechanical lever

• D) The overall composition of a phase diagram

In the lever rule, what acts like a lever?

• A) The balance point

• B) The overall composition

• C) The tie line in a phase diagram

• D) The segments on either side

What is the inverse lever rule sometimes referred to as?

• A) The balance rule

• B) The fulcrum rule

• C) The lever rule

• D) The phase rule

• A) The balance point

• B) The fulcrum

• C) The tie line

• D) The segments

What is done after determining the length of the tie line from the overall alloy composition to the phase boundary for the other phase?

• A) The length is multiplied by 100

• B) The length is divided by the total tie line length

• C) The length is added to the total tie line length

• D) The length is subtracted from the total tie line length

What does the vertical axis in the phase diagram represent?

At 20 wt% Bi and a temperature of 180 degrees, what phases are present in the alloy?

• Alpha

• Alpha + L

• L

• Beta + alpha

What is the first step in determining the mass fractions of phases present in an alloy?

• Draw a tie line from to liquidus and solidus at the specified temperature

• Read the C_L and C_alpha from the x axis

• From liquidus drop vertical to obtain Liquid phase composition

• From solidus line drop vertical to obtain Solid phase composition