{ "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "# Aliatges binaris: Llei de la palanca" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "Quan tenim un aliatge a la zona de coexistència de fases, podem fàcilment conèixer la composició de la fase sòlida $C_{\\alpha}$ i de la fase líquida $C_{L}$ buscant la intersecció de la isoterma amb les línies *liquidus* i *solidus* :" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "![](img/LleiPalanca.png)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "Una mica més complicat és calcular quin percentatge de l'aliatge el tindrem en fase sòlida i en fase líquida. Fent una mica d'àlgebra arribem a la llei de la palanca, on $W_{\\alpha}$ és el percentatge en fase $\\alpha$ (sòlid) i $W_{L}$ el percentatge en fase líquida:" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "$W_{\\alpha} \\cdot C_{\\alpha} + (1-W_{\\alpha}) \\cdot C_{L} = C_{0}$" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "$W_{\\alpha} \\cdot C_{\\alpha} + C_{L}-W_{\\alpha} \\cdot C_{L} = C_{0}$" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "$W_{\\alpha} \\cdot C_{\\alpha} -W_{\\alpha} \\cdot C_{L} = C_{0} - C_{L}$" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "$W_{\\alpha} (C_{\\alpha} -C_{L}) = C_{0} - C_{L}$" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "$W_{\\alpha} = \\frac{C_{0}-C_{L}}{C_{\\alpha}-C_{L}}$ " ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "Fent un càlcul anàlog per $W_{L}$:" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "$W_{L} = \\frac{C_{\\alpha}-C_{0}}{C_{\\alpha}-C_{L}}$" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Exemple: aliatge Ni-Cu" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "Si tenim un aliatge amb un 53% de Ni, a $1300$ $^{0}C$ tindrem coexistència de dos fases: una fase líquida amb un 45% de Ni i una sòlida amb un 58% de Ni " ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "![](img/CuNi.png)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "Calculem quin percentatge tindrem a cada fase:" ] }, { "cell_type": "code", "execution_count": 4, "metadata": {}, "outputs": [], "source": [ "C0=0.53\n", "CL=0.45\n", "Calfa=0.58" ] }, { "cell_type": "code", "execution_count": 13, "metadata": {}, "outputs": [ { "data": { "text/plain": [ "0.6153846153846158" ] }, "execution_count": 13, "metadata": {}, "output_type": "execute_result" } ], "source": [ "Walfa=(C0-CL)/(Calfa-CL)\n", "Walfa" ] }, { "cell_type": "code", "execution_count": 12, "metadata": { "scrolled": true }, "outputs": [ { "data": { "text/plain": [ "0.38461538461538425" ] }, "execution_count": 12, "metadata": {}, "output_type": "execute_result" } ], "source": [ "WL=(Calfa-C0)/(Calfa-CL)\n", "WL" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "Es a dir, tindrem un 61,5 % en fase sòlida i un 38,5 % en fase líquida" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "### Crèdits" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "Imatges estretes de [https://sites.google.com/site/federubiotecindbachillerato/home/2o-bachillerato/materiales/4-diagramas-de-equilibrio](https://sites.google.com/site/federubiotecindbachillerato/home/2o-bachillerato/materiales/4-diagramas-de-equilibrio)" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [] } ], "metadata": { "kernelspec": { "display_name": "Python 3", "language": "python", "name": "python3" }, "language_info": { "codemirror_mode": { "name": "ipython", "version": 3 }, "file_extension": ".py", "mimetype": "text/x-python", "name": "python", "nbconvert_exporter": "python", "pygments_lexer": "ipython3", "version": "3.7.3" } }, "nbformat": 4, "nbformat_minor": 4 }