TY - CHAP

T1 - Thermodynamic description of reactions between Mg and CaO

AU - Schmid-Fetzer, Rainer

AU - Kozlov, Artem

AU - Wiese, Björn

AU - Mendis, Chamini L.

AU - Tolnai, Domonkos

AU - Kainer, Karl U.

AU - Hort, Norbert

N1 - Conference code: 145

PY - 2016

Y1 - 2016

N2 - CaO is considered as possible replacement for cover gases such as SF6 during melting and casting of Mg alloys. Such CaO additions to molten Mg increase the ignition resistance by forming a protective oxide layer. The actual reactions between liquid Mg and CaO are not well understood. An approach based on chemical reaction equations cannot capture the "CaO dissolution" process. This work presents the development of a consistent thermodynamic description of the ternary Mg-Ca-O alloy system. To that end a revision of the thermodynamic data of key oxides, CaO and MgO, has been performed based on original experimental work so far not considered in thermodynamic databases or tabulations. The formation of a liquid Mg-Ca-[O] alloy during the reaction is predicted from the thermodynamic calculations at melting temperatures; solidification simulations are also performed. These predictions from thermodynamic simulations are validated by experimental data using in situ synchrotron radiation diffraction.

AB - CaO is considered as possible replacement for cover gases such as SF6 during melting and casting of Mg alloys. Such CaO additions to molten Mg increase the ignition resistance by forming a protective oxide layer. The actual reactions between liquid Mg and CaO are not well understood. An approach based on chemical reaction equations cannot capture the "CaO dissolution" process. This work presents the development of a consistent thermodynamic description of the ternary Mg-Ca-O alloy system. To that end a revision of the thermodynamic data of key oxides, CaO and MgO, has been performed based on original experimental work so far not considered in thermodynamic databases or tabulations. The formation of a liquid Mg-Ca-[O] alloy during the reaction is predicted from the thermodynamic calculations at melting temperatures; solidification simulations are also performed. These predictions from thermodynamic simulations are validated by experimental data using in situ synchrotron radiation diffraction.

KW - CaO

KW - In situ XRD

KW - Magnesium alloys

KW - Thermodynamic evaluation

KW - Engineering

UR - http://www.scopus.com/inward/record.url?scp=84975079876&partnerID=8YFLogxK

U2 - 10.1002/9781119274803.ch15

DO - 10.1002/9781119274803.ch15

M3 - Article in conference proceedings

AN - SCOPUS:84975079876

T3 - Magnesium Technology

SP - 67

EP - 72

BT - Magnesium Technology 2016 - Held During TMS 2016

A2 - Singh, Alok

A2 - Solanki, Kiran

A2 - Manuel, Michele Viola

A2 - Neelameggham, Neale R.

PB - The Minerals, Metals & Materials Society

T2 - 145th Annual Meeting and Exhibition of Magnesium Technology - TMS 2016

Y2 - 14 February 2016 through 18 February 2016

ER -