ENCYCLOPÉDIE DE LA RECHERCHE SUR L’ALUMINIUM AU QUÉBEC 2013 | Page 23

PRODUCTION DE L’ALUMINIUM
ALUMINIUM PRODUCTION

21

La susceptibilité de fissuration à chaud des alliages
d’aluminium de type 356 SUSCEPTIBILITÉ DE FISSURATION À CHAUD DES
LA et 319

ALLIAGES D’ALUMINIUM DE TYPE 356 ET 319

Hot tearing susceptibility of 356- and 319- typeHOT TEARING SUSCEPTIBILITY OF
Al
alloys
356- AND 319- TYPE Al ALLOYS
1er nom1, 2e Larouche1, nom3
Mousa Javidani1, Daniel nom2 et 3eX. Grant Chen2
1-Aluminum Research Center- REGAL, Laval1
1 Affiliation University
2- Aluminum Research Center- 2 Affiliation 2
REGAL, Université du Québec à Chicoutimi
3

Affiliation 3

Introduction
Common Al-base Alloys Used in Cylinder Head
β (Mg2Si)

σ

 Thermal fatigue failure  = Casting Defects  (in defect-limited specimens, initiation
of fatigue crack can be greatly delayed)

319-type alloy

β +Q (Al5Cu2Mg8Si6)

 One the major casting defects
356-type alloy

θ (Al2Cu)
Q (Al5Cu2Mg8Si6 )
ε

Introduction

 About 2 Kg of the as-received 1050 Al alloy and
Controlled amounts (Si, Cu, Mg, Fe) were melted at
~740℃.

Fraction Liquid (%)

Effect of different elements (Cu, Mg and Fe) on solidification interval :
1

Fraction Liquid (%)

319-0.7Fe
319-0.1Fe

0,8

356-0.1Fe

∆T=90

356

0,6

0,4

∆T=81

356-0.5Cu

 The pouring temperature was about 735℃.

∆T=95

319

0,8

356-0.7Fe

0,6

319-0.3Mg

1

 A cast iron ring mold with the design presented in
Figure 1 was used in this study.
 The corresponding chemical compositions of the
alloys are presented in table 1.

∆T=40

 In order to apply the most sever hot tearing
situation, the lowest possible mold temperature
(based on flowability of the alloys) was selected for
each alloy.

0,4

0,2

0,2

0

0

505

525

545

565

585

Temperature (ºC)

605

 Hot Tearing:
 Macro-Scale Parameters (e.g. Shrinkage, Strain Rate, Lack of Feeding, …)
 Micro-Scale Parameters (e.g., Structure Coherency, Crack Nucleation, …)

Research Methodology

General Idea:
 Solidification interval (∆T)  = Hot tearing susceptibility

505

525

545 565 585
Temperature (ºC)

 To ensure consistency, at least five iterations (of ring
test) were carried out for each alloy.

605

 Hot Tearing

 Hot Tearing is an irreversible failure (crack), occurs in the semisolid state during
solidification; (it is because of inadequate compensation of solidification shrinkage by
melt flow in the presence of thermal stresses).

Table 1: chemical composition of the alloys (wt.%)
Alloy No. ()M