Here is an example. You can correct the calculation yourself.

The following questions come from: the foundation of material science-single component phase diagram and solidification of pure crystal.

essay question

① It is known that liquid pure nickel nucleates uniformly at1.013×105pa (1ATM), and the supercooling degree is 3 19℃. Assuming that the critical nucleation radius is 1nm, the melting point of pure nickel is 1726K, heat of fusion Lm= 18075J/mol, and the molar volume V=6.6cm3/mol, the liquid-solid interface energy and critical nucleation work of pure nickel are calculated.

(2) If homogeneous nucleation occurs at 2045K, the atmospheric pressure must be increased to the known volume change during solidification △ V =-0.26 cm3/mol (1j = 9.87×106 cm3 pa).

Test answer

(1) Due to [*]

Because of solidification, [*]

therefore

[*]

(2) In order to uniformly nucleate at 1726K, the undercooling of 3 19℃ is required, so the pressure must be increased to raise the solidification temperature of pure nickel from 1726K to 2045K.

[*]

Integral of the above formula:

[*]

That is, when p =116366×105+13×105 =116367×105 (.