ENCYCLOPÉDIE DE LA RECHERCHE SUR L’ALUMINIUM AU QUÉBEC 2013 | Page 41

NOUVEAUX PRODUITS ET MATÉRIAUX À BASE D'ALUMINIUM
NEW ALUMINIUM BASED PRODUCTS AND MATERIALS

39

Effect of precipitation treatment on properties of
EFFET elevated temperature
AA3004 alloy atDU TRAITEMENT PAR PRÉCIPITATION SUR LES PROPRIÉTÉS DE
L’ALLIAGE AA3004 POUR DES APPLICATIONS À TEMPÉRATURE ÉLEVÉE
(Effet du traitement de précipitation sur les
EFFECT à température élevée)
propriétés des alliages AA3004 OF PRECIPITATION TREATMENT ON THE PROPERTIES
OF AA3004 ALLOY FOR APPLICATIONS AT ELEVATED TEMPERATURE

Kun Liu, X.-Grant Chen
NSERC/Rio Tinto Alcan Industrial Research Chair
in Metallurgy of Aluminum Transformation, UQAC

Results

Introduction

1). Microstructures of AA3004 alloy at as-cast condition

The characters of dispersoids precipitated during
the heat treatment, such as size, density and
distribution,
play
a
significant
role
in
strengthening 3XXX alloys, especially for the
applications at elevated temperature. In present
work, various precipitation treatments have been
performed on AA3004 alloy. It is found that the
α-Al(MnFeSi) dispersoids are fine and uniformly
distributed when treated at 375oC for 48 hours
and the yield strength (YS) at 300oC in
compression tests can reach as high as 72.5
MPa.

α-Al(MnFe)Si

Mg2Si
Al6(MnFe)

Al6(MnFe)

The microstructure
of AA 3004 at ascast condition is
composed
of
dominant Al6(FeMn)
and low volume of
(b)and
Mg2Si
α-Al(MnFeSi)
intermetallics,
as
confirmed by DSC.

Fig. 1 As-cast microstructure of AA 3004 alloy
Mg2Si

α-Al(MnFe)Si

Al6(MnFe)

Objective
To investigate the precipitation treatment on
the characters of dispersoids in AA 3004 alloy
and develop the optimal precipitation treatment.

Experimental

Fig. 2 DSC heating curve and its first derivate
performed at 10K/min of AA 3004 alloy at as-cast condition

Table 1 Chemical composition of AA3004 alloy
Mn

Mg

Fe

Si

1.2

1.1

0.61

0.29

Temperature (oC)
350
375
425
450
480

Cu

Ti

0.01 0.005

2). Properties of AA 3004 alloy after precipitation treatments

Al
(a)

Bal.

(c)

(b)

Table 2 Precipitation treatments in this work
Time (hour)
4, 8, 12, 24, 48, 72
4, 8, 12, 24, 48, 72
4, 8, 12, 24, 48, 72
4, 8, 12, 24, 48, 72
4, 8, 12

Fig. 3 Properties of 3004 alloy after precipitation treatment: (a) EC, (b) HV, and (c) YS
(a)

(b)

(c)

(d)

Properties test:
The Electric Conductivity (EC) and VickersHardness (HV) are measured at room
temperature.
The compression test is performed at 300 oC
with a strain rate of 0.001/s.

Fig. 4 Etched microstructures of AA 3004:
(a) as-cast, (b) 350 oC@48h, (c) 375 oC@48h, and (d) 425 oC@48h
The fine and uniformly distributed α-Al(MnFeSi) dispersoids after 375oC@48h
result in the higher EC and YS, indicating the possible applications of AA3004
alloy at elevated temperature.

Kun Liu
X.-Grant Chen
Chaire industrielle
de recherche
CRSNG/Rio Tinto Alcan
sur les nouvelles avenues en
métallurgie de la
transformation de l’aluminium
(CIMTAL),
Université du Québec
à Chicoutimi

Conclusions
As-cast microstructure of AA3004 alloy consists of dominant Al6(MnFe) with low volume of Mg2Si and α-Al(MnFe)Si intermetallics.
During the heat treatment, EC and HV rapidly increase to a peak. After the peak, EC keeps a plateau while HV begins to decrease with
increasing the treatment time. When heat-treated for 48 hours, YS gradually increases to a peak (72.5 Mpa) at 375 oC, then rapidly drops with
increasing temperature. Fine and uniformly distributed α-Al(MnFeSi) dispersoids were observed in the samples treated at 375 oC for 48 hours.
The precipitation treatment can be recommended as 375oC@24-48h.

Journée des étudiants – REGAL

Les caractéristiques des dispersoïdes précipités pendant le traitement thermique,
The characters of dispersoids precipitated during the heat treatment, such as
Palais des congrès de Montréal, QC, Canada, 22 octobre size,
comme la taille, la densité et la distribution, jouent un rôle considérable dans le 2013 density and distribution, play a significant role in strengthening the non heatdurcissement de l'alliage 3XXX thermiquement non traitable, particulièrement à
treatable 3XXX alloy, especially at elevated temperature. In the present work,
température élevée. Dans ce travail, l'effet du traitement par précipitation sur les
the effect of the precipitation treatment on the materials properties has been
propriétés des matériaux a été étudié. Les résultats montrent une augmentation
studied. Results show that the precipitation of Mn and the formation of α-Al(MnFe)
rapide de la conductivité électrique (CE) et de la Dureté – Vickers (HV), atteignant
Si dispersoids results in a rapid increase of Electric Conductivity (EC) and
une valeur maximale (pic) au cours du traitement. Au-delà du pic, la conductivité
Vickers-Hardness (HV) leading to a peak during the treatment. After the peak, EC
électrique suit un plateau tandis que la dureté Vic