COST 507 - Repositório Aberto da Universidade do Porto

Thermodynamic evaluations for high­strength, hot­strength
and wrought aluminium alloys
D3
Tatjana Jantzen, Suzana G Fries, Iñaki Hurtado, Michel H. G. Jacobs
and Philip J. Spencer
Lehrstuhl fur Theoretische Hüttenkunde, RWTH Aachen, Kopernukusstr.16,
D­52074 Aachen, Germany
Abstract
In this work, thermodynamic evaluations of the binary system Cu­Si and the
ternary systems Al­Cu­Mg, Al­Cu­Si, Al­Cu­Zn, Cu­Mg­Si, Cu­Mg­Y and Cu­
Mg­Ni are presented. The results of the calculations are compared with
published experimental data and with experimental data which have become
available during the progress of the COST Action 507.
1 Introduction
High­strength, hot­strength and wrought aluminium alloys are of considerable
technological importance. For their design and development a knowledge of the
phase constitution, which influences the mechanical and physical properties of
the alloys and thus their suitability for particular applications, is essential.
LTH has been concerned with the thermodynamic evaluation of systems based
on Al­Cu­Mg­Si­Zn (Ni,Y),which is one of the key systems in COST 507
Round 2.
The binary sub­systems have already been evaluated in the first round of COST
507. The thermodynamic assessment of the ternary systems, on which
calculations in more complex systems are based, has been the major aim of the
work in the second round.
Particular attention has been given to the modelling of phases such as the Laves
and the Τ phase, since it is essential that the models used are compatible for the
description of the extensions of the phases into all the different subsystems in
which they appear.
2 Data Assessment
A significant number of all the binary and ternary sub­systems of the Al­Cu­
Mg­Si­Zn system, on which calculations in more complex systems are based,
have already been evaluated in the first round of the COST­507 Project.
2.1 The Cu-Si system
In view of experimental data and the necessity to describe ternary systems into
which several of the binary phases extend, the Cu­Si system was re­evaluated.
­ 73 ­