# 8.6: Questions


## Quick questions

You should be able to answer these questions without too much difficulty after studying this TLP. If not, then you should go through it again!

1. Where α and β are solid phases, which of the following describes a eutectic transformation?
 a $$\alpha + liquid \rightarrow \beta$$ b $$\alpha \rightarrow \beta$$ c $$liquid \rightarrow \beta + \alpha$$ d $$liquid \rightarrow \beta + alpha$$

C
The eutectic transformation is from a single liquid phase to two solid phases. Eutectic composition alloys are often used in solders, for example Bi 44wt.%Sn – see the phase diagram

Where α and β are solid phases, which of the following describes a peritectic transformation?

 a $$\alpha + liquid \rightarrow \beta$$ b $$\alpha \rightarrow \beta$$ c $$liquid \rightarrow \beta + \alpha$$ d $$liquid \rightarrow \beta + alpha$$

A

Which of the following alloying additions stabilises the austenite phase of steel? (You may select more than one)

1. Carbon - C
2. Nickel - Ni
3. Cerium - Ce
4. Silicon - Si

The answers is a. and b. Carbon, Nickel and Manganese (Mn) are γ - stabilisers.

What differences in appearance might you expect between annealing and deformation twins?

 a Annealing twins are smaller than deformation twins b Deformation twins are smaller than annealing twins c Deformation twins have flat sides, annealing twins are lens-shaped d Annealing twins have flat sides, deformation twins are lens-shaped e There are no differences