Above is the binary phase diagram for Pt$-$g:

a$.$ How many eutectics are there in the phase diagram?

b$.$ How many peritectics?

c$.$ How many pure phase transitions, e$.$g$.$ melting?

d$.$ Suppose you start at $T_p$ and you cool to room temperature $($bottom line$)$ the

composition $C_1,$ what phases would be present?

e$.$ If you had a composition with composition $c_1$ could you treat this composition to have

the transformation known as "solid$-$state precipitation" $($yes$/$no$)?$

f$.$ Show $($with an arrow on the diagram$)$ where a composition is that can undergo solid$-$

state precipitations and where it crosses the solvus.

In solid$-$state precipitation kinetics, a precipitate may be treated as an isolated

particle or not$-$isolated particle. When several precipitate particles are located within

the same matrix grain, it is possible for coarsening to occur. Coarsening is driven by

the Gibbs$-$Thomson affect that shows that free energy varies across a curved surface. That

means the $$ particle in the $$ matrix with radius $r_2$ is more easily dissolved than the $$

particle with radius $r_1,$ where $r_1$ is larger than $r_2.$ Insert the correct word

$($increase$/$decrease$)$ in the sentence to make this a true statement.

g$.$ Mass conservation means that, if one particle grows then another particle must

h$.$ The mechanism for coarsening is diffusion, hence the kinetics when the

temperature is reduced.

i$.$ The average size increases with time, while the number of particles

j$.$ Is coarsening good or bad for properties? Explain.