TTMG5: ThermoTech Mg-based Alloys Database

Database name (acronym):

TT Mg-based Alloys Database (TTMG)

Database owner:

ThermoTech

Database version:

5.1

TTMG5 is a comprehensive database for Mg-alloys that can be used for all major types of commercial Mg-alloys ranging from pure Mg to complex commercial alloys.

Included Elements (17)

Al

Ca

Ce

Cu

Fe

Gd

La

Mg

Mn

Nd

Sc

Si

Sn

Sr

Y

Zn

Zr

      

Included Phases

The FCC_A1, DHCP, DIAMOND_A4, BCT_A5 and Alpha_Zr are always rejected by default; while, if it is necessary for some systems with higher-contents of Fe/La/Nd/Si/Sn/Zr, they can be restored in the TDB Module in Console Mode. The nomenclature surrounding the various intermetallic phases can differ depending on which reference text is used as a basis.

Liquid

HCP_A3

(Mg-dominant)

Mg17Al12

Mg2Ca

Mg2Cu

MgCu2

Mg5Gd

Mg3RE_D03

Mg12RE

Mg41RE5

Mg2Si

Mg2Sn

Mg17Sr2

Mg24Y5

MgZn

MgZn2

Mg2Zn3

Phi-AlMgZn

Q-Al7Cu3Mg6

T-AlCuMgZn

T-MgCeZn

I-MgYZn

W-MgYZn

X-MgYZn

Z-MgYZn

A12Fe

A13Fe

A15Fe2

Al4(Ca,Sr)

Ca2Sn

A14Mn

A18Mn5

Al11Mn4

A12Zr

A13Zr

Al2RE

Al3RE_D019

Al11RE3_alpha

Ca2Mg5Zn13

Ca2Mg6Zn3

Alpha_Zr

(Zr-rich HCP_A3)

BCC_A2

(pure-Fe_alpha)

CBCC_A12

(pure-Mn_alpha)

CUB_A3

(pure-Mn_beta)

FCC_A1

(pure-Al,Ca,Ce,Cu,Sr and pure-La_beta)

DHCP

(pure-La/Nd)

DIAMOND_A4

(pure-Si)

BCT_A5

(pure-Sn)

Assessed Systems

All phases have been critically assessed and treated by some appropriate thermodynamic models (e.g. the Sublattice Model for solid solutions and liquid mixture phases), which are applicable to various grades of multicomponent Mg-alloys over a wide temperature-pressure-composition range. The Liquid and HCP-A3 phases are modeled as substitutional mixing phases, with the HCP-A3 phase corresponding to the Mg-rich solid solution. From TTMg4 to TTMg5, Sn-bearing phases Mg2Sn and Ca2Sn have been added. New assessments of the Mg-Zn-(Ca,Ce,Y) ternaries are included, which means inclusion of new ternary phases as listed. Also certain Al-rich phases (Al6Mn, AlMSi_alpha, Al8FeMg3Si6 and Al5Cu2Mg8Si6) have been removed as they would never be formed in Mg-alloys.

Validations

TTMG is a sister database to TTAl and helps provides new insight into phase equilibria behaviour in complex Mg-alloys. Like TTAl it is well suited for use in the modelling of non-equilibrium solidification processes. As part of a validation process of the database, extensive comparison has been made between the simulated results and available experimental data for Mg-alloys. The database performs at accuracy close to the level expected of the experiments.

The database can be used for predictions of all types of equilibria, solvus, solidus and liquidus relations, etc. Using the SCHEIL module in the Thermo‑Calc software, it is also possible to make solidification simulations which provide effective predictions for non-equilibrium micro-segregation, fs vs T plots, heat evolution, etc, of multicomponent Mg-alloys in conditions that are well away from those associated with equilibrium. For more complex modeling, the calculations provide critical information which otherwise can only be found by the use of expensive experimental techniques.

Limits

The TTMG database has been developed primarily for performing various types of calculations of multicomponent Mg-based alloys; but please also note that it is not aimed at calculating complete binary/ternary/quaternary phase diagrams.

As in the spirit of the CALPHAD method, predictions can be made for multicomponent systems by extrapolation into multicomponent space of data critically evaluated and assessed based on binary, ternary and in some cases higher order systems. However, critical calculations must always be verified by equilibrium experimental data; it is the user's responsibility to verify the calculations but Thermo‑Calc Software AB is interested to know about any significant deviations in order to improve any future release.