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{
"metadata": {
"name": ""
},
"nbformat": 3,
"nbformat_minor": 0,
"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"Chapter 10 :Phase Transformation In Metals"
]
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 10.1 Page no 318"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"Hf=-1.16*10**9 # in J/m**3 latent heat of fusion\n",
"Y=0.132 # in J/m**2 Surface energy\n",
"Tm=1064.0+273.0 # in K Melting point of gold\n",
"\n",
"import math\n",
"T=Tm-230.0 # in K 230 is supercooling value\n",
"r=-2*Y*Tm/(Hf*(Tm-T))\n",
"G=16*math.pi*Y**3*Tm**2/(3*Hf**2*(Tm-T)**2)\n",
"\n",
"a=0.413*10**-9 # in m Unit Cell edge length\n",
"u_c=4*math.pi*r**3/(3*a**3)\n",
"n=4 #In FCC . no of atoms in per unit cell\n",
"U_c=int(u_c)*n\n",
"\n",
"print\"(a)Critical Radius is \",round(r/10**-9,2),\"nm\"\n",
"print\"Activation free energy is \",round(G,21),\"J\"\n",
"print\"(b)Total no. of atoms per critical nucleus are \",U_c\n",
"\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"(a)Critical Radius is 1.32 nm\n",
"Activation free energy is 9.68e-19 J\n",
"(b)Total no. of atoms per critical nucleus are 548\n"
]
}
],
"prompt_number": 11
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 10.2 Page no 335"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"n=5.0\n",
"y=0.3\n",
"t=100.0 #in min\n",
"\n",
"k=-math.log(1-y)/t**n\n",
"thalf=(-math.log(1-0.5)/k)**(1/n)\n",
"rate=1/thalf\n",
"\n",
"print\"Rate is \",rate,\"min**-1\"\n",
"\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Rate is 0.00875567087531 min**-1\n"
]
}
],
"prompt_number": 13
},
{
"cell_type": "code",
"collapsed": false,
"input": [],
"language": "python",
"metadata": {},
"outputs": []
}
],
"metadata": {}
}
]
}
|
