# Chapter 12 : Heat Treatment¶

### Example 12.1 page no : 304¶

In [1]:
import math

# Variables
n_bcc = 1./2;
n_fcc = 1./4;
r_fcc = 1.26;			#in Angstorm
r_bcc = 1.24;			#in Angstorm

# Calculations
a_bcc = 4.*r_bcc/math.sqrt(3);			#in Angstorm
a_fcc = 2.*math.sqrt(2)*r_fcc;			#in Angstorm
v_fcc = a_fcc**3;
v_bcc = a_bcc**3;
v = 100*((n_fcc*v_fcc)-(n_bcc*v_bcc))/(n_fcc*v_fcc);

# Results
print "Percentage change in volume  =  %.3f"%v
Percentage change in volume  =  -3.764

### Example 12.3 pageno : 317¶

In [3]:
# Variables
e = 51.;			#Young modulous in GPa
v = 0.22;			#poisson ratio

# Calculations
g = e/(2*(1-v));			#shear modulous in GPa
b = 2*10.**-10;
ue = (1./2)*g*10**9*b**2*10**12;			#in J/m**3

# Results
print "Change in free energy during recrysatllization (in J/m**3)  =  %.1f J/m**3"%ue
Change in free energy during recrysatllization (in J/m**3)  =  653.8 J/m**3

### Example 12.5 pageno : 329¶

In [4]:
# Variables
g = 41.*10**9;			#in N/m**2
b = 0.64*10**-9;			#in m
l = 20.*10**-6;			#in m

# Calculations
t = g*b/l;			#in N/m**2
T = t*10.**-6;			#in MPa

# Results
print "Contribution of these particles (in MPa)  =  %.3f MPa"%T
Contribution of these particles (in MPa)  =  1.312 MPa