Developing a Thermodynamic Database for Lead-Based Alloys

Iina Vaajamo

Developing a Thermodynamic Database for Lead-Based Alloys

Julkaisun otsikon käännös: Termodynaamisen lyijyseostietokannan kehittäminen

Iina Vaajamo

Tutkimustuotos: Doctoral Thesis › Collection of Articles

Abstrakti

Kehittyneet termodynaamiset tietokannat ja laskentaohjelmistot yhdessä CALPHAD-metodin kanssa mahdollistavat erilaisten ilmiöiden, kuten faasimuutosten ja kemiallisten reaktioiden, tarkastelun matemaattisesti termodynaamisen laskennan avulla. Tällaiset laskennat vaativat yhteinäisiä ja luotettavia termodynaamisia tietokantoja, kuten MTOX (metalli-sulfidi-oksidi-fluoridi) tietokanta, joka sisältää termodynaamisia ainearvoja systeemeistä, jotka liittyvät metallien valmistusprosesseihin. Näissä prosesseissa lyijyä pidetään usein epäpuhtautena, joka tulee prosessiin primäärisistä ja sekundäärisistä raaka-aineista. Lyijyn ja sen metalliseosten termodynamiikan syvällisempi tuntemus edesauttaa sulatus-, raffinointi- ja kuonanpuhdistusprosessien kehittämistä, joissa lyijy usein esiintyy komponenttina. Tässä väitöskirjassa tutkittiin sulan lyijyn ja kiinteän metallifolion (Ni, Fe, Cu, Fe-Ni) keskinäistä liukoisuutta isotermisellä tasapainotustekniikalla. Kokeet toteutettiin kvartsiampullissa korkeissa lämpötiloissa. Näytteiden kemialliset koostumukset analysoitiin ICP-spektrometrillä ja EPMA:lla. Systeemeistä tehtiin kirjallisuustutkimukset tavoitteena etsiä kaikki julkaistu kokeellinen tieto aina 1900-luvun alusta tähän päivään asti. Kirjallisuudesta löytynyt kokeellinen tieto analysoitiin kriittisesti ja valittu kokeellinen tieto käytettiin yhdessä omista kokeista saatujen tulosten kanssa systeemien liuosfaasien termodynaamisten parametriarvojen optimoimiseen CALPHAD-menetelmällä. Liuosfaasien kuvaamiseen käytettiin yksinkertaista korvausliuosmallia. Puhtaiden alkuaineiden ominaisuuksille käytettiin SGTE:n Unary-tietokantaa. Systeemit sovitettiin käyttäen MTDATA-laskentaohjelmistoa ja pienimmän neliösumman menetelmää. Tässä työssä saatu kokeellinen tieto mahdollisti systeemien tarkempien termodynaamisten kuvausten määrittämisen. Erityisesti lyijyn liukoisuutta kiinteään metalliin monotektistä matalemmissa lämpötiloissa ei ole mitattu näin suurella tarkkuudella aikaisemmin. Kyseisten metallien liukoisuudet sulaan metalliin ovat suhteellisen hyvin tunnettuja ja tässä työssä saadut tulokset ovat yhdenmukaisia kirjallisuudessa ilmoitettujen tulosten kanssa. Systeemien Ni-Pb, Fe-Pb, Cu-Pb ja Fe-Ni-Pb termodynaamisia kuvauksia on parannettu/luotu. Yhdenmukaisuus laskettujen faasitasapainojen ja kriittisesti valittujen kokeellisten pisteiden välillä on hyvä. Työssä saatuja sovituksia voidaan käyttää yhdessä MTOX-tietokannan kanssa laskettaessa monikomponenttisysteemien termodynaamisia ominaisuuksia ja faasitasapainoja, sekä ratkaista materiaalitekniikkaan ja metallurgiaan liittyviä ongelmia.

Julkaisun otsikon käännös	Termodynaamisen lyijyseostietokannan kehittäminen
Alkuperäiskieli	Englanti
Pätevyys	Tohtorintutkinto
Myöntävä instituutio	Aalto-yliopisto
Valvoja/neuvonantaja	Taskinen, Pekka, Vastuuprofessori Taskinen, Pekka, Ohjaaja
Kustantaja	Aalto University
Painoksen ISBN	978-952-60-5401-8
Sähköinen ISBN	978-952-60-5402-5
Tila	Julkaistu - 2013
OKM-julkaisutyyppi	G5 Artikkeliväitöskirja

Tutkimusalat

termodynamiikka
CALPHAD
tasapainotuskoe
liukoisuus
MTOX
tietokanta
lyijy

Pääsy asiakirjaan

http://urn.fi/URN:ISBN:978-952-60-5402-5

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@phdthesis{98475f0205e74d6587b13b2ef76fec66,

title = "Developing a Thermodynamic Database for Lead-Based Alloys",

abstract = "The availability of advanced thermodynamic databases and software and the CALPHAD method allow different phenomena, i.e. phase transformations, and chemical reactions, to be evaluated mathematically by means of thermodynamic calculations. These calculations require internally consistent and reliable thermodynamic databases, such as the MTOX (metal-oxide-sulphide-fluoride) database. MTOX covers the thermodynamic data of the systems related to metal smelting and refining processes, where lead is often considered as an impurity coming from the primary and secondary raw materials. Better knowledge of the thermodynamic behaviour of lead and its alloys can help in developing the smelting, refining and slag cleaning processes where lead often exists as a component. In this thesis, the mutual solubilities of molten lead and solid metallic foils (Ni, Fe, Cu, Fe-Ni) were measured by means of an isothermal equilibration technique at elevated temperatures, in specially formed quartz ampoules. The chemical compositions of the saturated metals were analysed with an ICP spectrometer and by EPMA. Literature surveys of the experimental data of the respective systems were performed with the aim of covering all the published data from the early 20th century until today. The critically evaluated and selected experimental literature data together with the data obtained from my own experiments were used to optimize the thermodynamic interaction parameters of the solution phases with the CALPHAD method. These phases were described in terms of a simple substitutional solution model. For the pure elements the SGTE Unary data were used. The systems were assessed with MTDATA software and the experimental data were fitted by a least square method. The new experimental data obtained within this thesis enabled the determination of more accurate thermodynamic description of the present systems. In particular, the lead solid solubility in the solid metals, below the monotectic temperature, had not been determined experimentally before with this accuracy. The metal solubilities in molten lead of these systems are rather well known and are in agreement with the results obtained in this thesis. The thermodynamic description of the Ni-Pb, Fe-Pb, Cu-Pb and Fe-Ni-Pb systems have been improved/established. The overall agreement of the calculated phase diagrams with the critically selected experimental data is good. The thermodynamic assessment of these lead-alloy systems can be used together with the MTOX database to calculate the thermodynamic properties and phase equilibria of multicomponent systems and consequently, to solve practical problems related to materials engineering and metallurgy.",

keywords = "thermodynamics, CALPHAD, equilibration experiment, solubility, MTOX, database, lead, termodynamiikka, CALPHAD, tasapainotuskoe, liukoisuus, MTOX, tietokanta, lyijy, thermodynamics, CALPHAD, equilibration experiment, solubility, MTOX, database, lead",

author = "Iina Vaajamo",

year = "2013",

language = "English",

isbn = "978-952-60-5401-8",

series = "Aalto University publication series DOCTORAL DISSERTATIONS",

publisher = "Aalto University",

number = "173",

address = "Finland",

school = "Aalto University",

}

TY - BOOK

T1 - Developing a Thermodynamic Database for Lead-Based Alloys

AU - Vaajamo, Iina

PY - 2013

Y1 - 2013

N2 - The availability of advanced thermodynamic databases and software and the CALPHAD method allow different phenomena, i.e. phase transformations, and chemical reactions, to be evaluated mathematically by means of thermodynamic calculations. These calculations require internally consistent and reliable thermodynamic databases, such as the MTOX (metal-oxide-sulphide-fluoride) database. MTOX covers the thermodynamic data of the systems related to metal smelting and refining processes, where lead is often considered as an impurity coming from the primary and secondary raw materials. Better knowledge of the thermodynamic behaviour of lead and its alloys can help in developing the smelting, refining and slag cleaning processes where lead often exists as a component. In this thesis, the mutual solubilities of molten lead and solid metallic foils (Ni, Fe, Cu, Fe-Ni) were measured by means of an isothermal equilibration technique at elevated temperatures, in specially formed quartz ampoules. The chemical compositions of the saturated metals were analysed with an ICP spectrometer and by EPMA. Literature surveys of the experimental data of the respective systems were performed with the aim of covering all the published data from the early 20th century until today. The critically evaluated and selected experimental literature data together with the data obtained from my own experiments were used to optimize the thermodynamic interaction parameters of the solution phases with the CALPHAD method. These phases were described in terms of a simple substitutional solution model. For the pure elements the SGTE Unary data were used. The systems were assessed with MTDATA software and the experimental data were fitted by a least square method. The new experimental data obtained within this thesis enabled the determination of more accurate thermodynamic description of the present systems. In particular, the lead solid solubility in the solid metals, below the monotectic temperature, had not been determined experimentally before with this accuracy. The metal solubilities in molten lead of these systems are rather well known and are in agreement with the results obtained in this thesis. The thermodynamic description of the Ni-Pb, Fe-Pb, Cu-Pb and Fe-Ni-Pb systems have been improved/established. The overall agreement of the calculated phase diagrams with the critically selected experimental data is good. The thermodynamic assessment of these lead-alloy systems can be used together with the MTOX database to calculate the thermodynamic properties and phase equilibria of multicomponent systems and consequently, to solve practical problems related to materials engineering and metallurgy.

AB - The availability of advanced thermodynamic databases and software and the CALPHAD method allow different phenomena, i.e. phase transformations, and chemical reactions, to be evaluated mathematically by means of thermodynamic calculations. These calculations require internally consistent and reliable thermodynamic databases, such as the MTOX (metal-oxide-sulphide-fluoride) database. MTOX covers the thermodynamic data of the systems related to metal smelting and refining processes, where lead is often considered as an impurity coming from the primary and secondary raw materials. Better knowledge of the thermodynamic behaviour of lead and its alloys can help in developing the smelting, refining and slag cleaning processes where lead often exists as a component. In this thesis, the mutual solubilities of molten lead and solid metallic foils (Ni, Fe, Cu, Fe-Ni) were measured by means of an isothermal equilibration technique at elevated temperatures, in specially formed quartz ampoules. The chemical compositions of the saturated metals were analysed with an ICP spectrometer and by EPMA. Literature surveys of the experimental data of the respective systems were performed with the aim of covering all the published data from the early 20th century until today. The critically evaluated and selected experimental literature data together with the data obtained from my own experiments were used to optimize the thermodynamic interaction parameters of the solution phases with the CALPHAD method. These phases were described in terms of a simple substitutional solution model. For the pure elements the SGTE Unary data were used. The systems were assessed with MTDATA software and the experimental data were fitted by a least square method. The new experimental data obtained within this thesis enabled the determination of more accurate thermodynamic description of the present systems. In particular, the lead solid solubility in the solid metals, below the monotectic temperature, had not been determined experimentally before with this accuracy. The metal solubilities in molten lead of these systems are rather well known and are in agreement with the results obtained in this thesis. The thermodynamic description of the Ni-Pb, Fe-Pb, Cu-Pb and Fe-Ni-Pb systems have been improved/established. The overall agreement of the calculated phase diagrams with the critically selected experimental data is good. The thermodynamic assessment of these lead-alloy systems can be used together with the MTOX database to calculate the thermodynamic properties and phase equilibria of multicomponent systems and consequently, to solve practical problems related to materials engineering and metallurgy.

KW - thermodynamics

KW - CALPHAD

KW - equilibration experiment

KW - solubility

KW - MTOX

KW - database

KW - lead

KW - termodynamiikka

KW - CALPHAD

KW - tasapainotuskoe

KW - liukoisuus

KW - MTOX

KW - tietokanta

KW - lyijy

KW - thermodynamics

KW - CALPHAD

KW - equilibration experiment

KW - solubility

KW - MTOX

KW - database

KW - lead

M3 - Doctoral Thesis

SN - 978-952-60-5401-8

T3 - Aalto University publication series DOCTORAL DISSERTATIONS

PB - Aalto University

ER -

Developing a Thermodynamic Database for Lead-Based Alloys

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