Engineering Materials

A $60wt\%Pb-40wt\%Mg$ alloy is slowly cooled from $700C$ to $400C.($a$)$ At what temperature

does the first solid phase form? $($b$)$ What is the composition of this solid phase? $($c$)$ At what

temperature does the liquid solidify? $($d$)$ What is the composition of this last remaining liquid

phase?

$A40wt\%Sn-60wt\%Pb$ alloy is heated to a temperature within the $+$ liquid phase region. If the

mass fraction of each phase is $0\mathrm{.}5,$ estimate $($a$)$ the temperature of the alloy, and $($b$)$ the

compositions of the two phases.

A magnesium$-$lead alloy of mass $10$ kg consists of a solid $$ phase that has a composition that is

just slightly below the solubility limit at $200C.($a$)$ What mass of lead is in the alloy? $($b$)$ If the

alloy is heated to $350C$ how much more lead may be dissolved in the $$ phase without

exceeding the solubility limit of this phase?

The microstructure of an iron$-$carbon alloy consists of proeutectoid ferrite and pearlite; the

mass fractions of these microconstituents are $0\mathrm{.}22$ and $0\mathrm{.}78,$ respectively. Determine the

concentration of carbon in this alloy.

Compute the maximum mass fraction of proeutectoid cementite possible for a hypereutectoid

iron$-$carbon alloy.

Is it possible to have an iron$-$carbon alloy for which the mass fractions of total cementite and

proeutectoid ferrite are $0\mathrm{.}055$ and $0\mathrm{.}37,$ respectively? Why or why not?