Effect of CeLa addition on the microstructures and mechanical properties of Al-Cu-Mn-Mg-Fe alloy

    Effect of CeLa addition on the microstructures and mechanical properties of Al-Cu-Mn-Mg-Fe alloy Jiandi Du, Dongyan Ding, Zhou Xu, Junchao Zhang, Wenlong Zhang, Yongjin Gao, Guozhen Chen, Weigao Chen, Xiaohua You, Renzong Chen, Yuanwei Huang, Jinsong Tang PII: DOI: Reference:

S1044-5803(16)30893-2 doi: 10.1016/j.matchar.2016.11.010 MTL 8450

To appear in:

Materials Characterization

Received date: Revised date: Accepted date:

31 March 2016 1 November 2016 11 November 2016

Please cite this article as: Du Jiandi, Ding Dongyan, Xu Zhou, Zhang Junchao, Zhang Wenlong, Gao Yongjin, Chen Guozhen, Chen Weigao, You Xiaohua, Chen Renzong, Huang Yuanwei, Tang Jinsong, Effect of CeLa addition on the microstructures and mechanical properties of Al-Cu-Mn-Mg-Fe alloy, Materials Characterization (2016), doi: 10.1016/j.matchar.2016.11.010

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ACCEPTED MANUSCRIPT Effect of CeLa addition on the microstructures and mechanical properties of Al-Cu-Mn-Mg-Fe alloy

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Jiandi Dua, Dongyan Dinga*, Zhou Xua, Junchao Zhanga, Wenlong Zhanga , Yongjin Gaob, Guozhen Chenb, Weigao Chenb, Xiaohua Youb, Renzong Chenc, Yuanwei Huangc, Jinsong Tangc School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China

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Huafon NLM Al Co., Ltd, Shanghai 201506, China

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Shanghai Huafon Materials Technology Institute, Shanghai 201203, China

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Abstract

Development of high strength lithium battery shell alloy is highly desired for new energy automobile industry.

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The microstructures and mechanical properties of Al-Cu-Mn-Mg-Fe alloy with different CeLa additions were investigated through optical microscopy (OM), X-ray diffraction (XRD), scanning electron microscopy (SEM),

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transmission electron microscopy (TEM), Rietveld refinement and tensile testing. Experimental results indicate that Al8Cu4Ce and Al6Cu6La phases formed due to CeLa addition. Addition of 0.25 wt.% CeLa could promote

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the formation of denser precipitation of Al20Cu2Mn3 and Al6(Mn, Fe) phases, which improved the mechanical properties of the alloy at room temperature. However, up to 0.50 wt.% CeLa addition could promote the formation of coarse Al8Cu4Ce phase, Al6Cu6La phase and Al6(Mn, Fe) phase, which resulted in weakened mechanical properties. Keywords: Al-Cu-Mn-Mg-Fe alloy; CeLa addition; Microstructure; Rietveld analysis; Mechanical properties

Corresponding Author. Tel.: +86 21 34202741. E-mail address: [email protected] (D. Ding). 1

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1. Introduction

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Due to a desirable combination of low cost, high specific strength and good corrosion property, aluminum

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alloys have been extensively utilized in aerospace, automobile and electronic industries, such as fuselage [1,2], engine block [3,4] and Li battery shell [5]. Traditionally, 3003 alloy was selected as a lithium battery shell alloy. In order to get a battery shell with a higher specific strength as well as low cost, it is highly desired that a thinner

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but stronger shell alloy should be provided. However, when the 3003 aluminum alloy was employed as a thin

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battery shell, the pressure resistance was low as expansion deformation may occur during the charging or discharging process or in a high temperature environment such as in the car. When Cu was added to the 3003

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alloy, the strength improved significantly. As a result, Al-Cu-Mn-Mg-Fe alloys have been considered as a

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promising candidate material for battery shell [5-9].

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It is well known that addition of rare earth (RE) in aluminum alloys has a lot of benefits, such as refining grain size [10-13], inhibiting recrystallization [14-19] and affecting the precipitation response [20, 21]. Recently,

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addition of RE elements to modify the microstructures and mechanical properties of various aluminum alloys has been extensively investigated. Huang et al. investigated the effect of La addition on the microstructure and mechanical property of as-cast ADC12 alloy [22]. It was found that the eutectic Si crystals presented a granular distribution and the alloy possessed the best mechanical property with the addition of 0.3 wt.% La. Voncina et al. reported the influence of Ce addition on the morphology of α-(Al)-Al2Cu eutectic in Al-Si-Cu alloy [23], and found that Al2Cu was coarse due to partial dissolution of Ce in Al2Cu. Zhang et al. studied the influence of Ce addition on the microstructure of Al-Cu-Mn-Mg alloys, and concluded that high melting point Al8Cu4Ce and Al20Cu2Mn3 could form with addition of 0.36% Ce in the alloy. Tensile strength of Al-Cu-Mn-Mg alloy with Ce addition was also enhanced [9].

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ACCEPTED MANUSCRIPT To date, the effect of CeLa addition on the microstructures and mechanical properties of Al-Cu-Mn-Mg-Fe alloy has been rarely reported. Therefore, the purpose of the present work is to evaluate the effect of CeLa

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addition on the microstructure and mechanical properties of Al-Cu-Mn-Mg-Fe alloy.

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2. Materials and methods

Chemical composition of the experimental alloys was analyzed through inductively coupled plasma-optical

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emission spectroscopy (ICP-OES). Corresponding results are shown in Table 1. Homogenization treatment of the ingots was conducted at 590°C for 8 hours. Then, the homogenized ingots with a thickness of 40 mm were at

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preheated at 500°C and hot rolled for 8 passes to 3 mm thick plates (about 30% reduction per pass). Then the

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hot rolled plates were stress-relief annealing at 300°C for 2 hours, and cold rolled for 9 passes (about 20%

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reduction per pass) to 0.45 mm sheets. The sheets were finally annealed at 150°C for 24 hours.

Cu

Mn

Mg

Fe

Ce

La

Al

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Table 1 Chemical compositions of the experimental alloys (wt.%).

Alloy

1.48

1.33

0.74

0.53

0

0

Bal.

Al-Cu-Mn-Mg-Fe-0.25 CeLa

1.49

1.34

0.75

0.54

0.14

0.13

Bal.

Al-Cu-Mn-Mg-Fe-0.50 CeLa

1.46

1.32

0.72

0.52

0.25

0.24

Bal.

Al-Cu-Mn-Mg-Fe

Phase analyses of the alloys were performed with an X-ray diffractometer (XRD, Rigaku D/max 2500). Grain structure of the alloys was observed using optical microscopy under polarized light after preparing samples according to standard metallographic procedures. The microstructure and second-phase particles of the alloys were investigated with scanning electron microscope (SEM, JSM-7600F) and transmission electron microscope (TEM, JEM-2100F) operated at an accelerating voltage of 200 kV. TEM samples of 3 mm in diameter and about

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spectroscopy (EDS).

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X-ray diffraction for Rietveld analysis were conducted with an X-Ray diffractometer (Cu Kα radiation, Rigaku, SmartLab) using the standard 2θ-θ mode (step scanning) with 2θ ranging from 10°to 90°with step of

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0.02°and the counting time of per step was 5 s. The operated voltage and current were 40 kV and 30 mA, respectively. The particle size and phase fraction were calculated by the Rietveld method using the General

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Structure Analysis System (GSAS) software [24-26]. The background of XRD pattern was refined by the Chebyschev polynomial function (tenth grade), and the peak profile was analyzed by a modified pseudo-Voigt

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function [27-29]. Preferred orientation of α-Al along [311], [220], [200] and [111] planes was taken into account in terms of the March-Dollase functions. The parameters (scale factor, zero shifts, cell parameters, background,

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preferred orientation and peak profile) were refined for all the detected phases. The Lorentizian particle-size value was used to determine particle size (P) by the following equation [30]: (1)

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P = 18000Kλ / (πLX)

where K is the Scherrer constant and its value is 1. λ is the Cu Kα radiation wavelength of 1.5406 Å. LX is the Lorentizian particle size. The unit of P is Å. Tensile testing of five parallel specimens was performed with Zwick universal tension machine at room temperature. The tensile testing was conducted according to the ASTM standard of E8/E8M-13a. The specimens were taken in the longitudinal direction (RD) and transverse direction (TD) from alloy plates and the tensile speed was 1 mm/min. 3. Results and discussion 3.1. Microstructure

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ACCEPTED MANUSCRIPT Fig. 1 shows longitudinal section microstructure of the Al-Cu-Mn-Mg-Fe alloys with different CeLa addition. The grains elongated along the rolling direction, due to the effect of stress during the rolling process. It could be

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the grain size of the CeLa-free alloy and 0.50 wt.% CeLa alloy was coarse.

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observed that the grains existed as slender fibrous grains for the alloy with 0.25 wt.% CeLa addition. Whereas,

(c) 0.50 wt.%.

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Fig. 1. Longitudinal section microstructure of the Al-Cu-Mn-Mg-Fe alloy with different CeLa addition. (a) 0, (b) 0.25 wt.%,

Fig. 2 shows XRD pattern of the Al-Cu-Mn-Mg-Fe alloys with different CeLa addition. It is clearly observed that all alloys mainly consist of α-Al matrix, Al2CuMg phase, Al6Mn phase or Al6(Mn, Fe) phase and Al7Cu2Fe phase. In comparison with the CeLa-free alloy, two kinds of new phases of Al8Cu4Ce and Al6Cu6La could be found in the CeLa-containing alloys. The diffraction peaks corresponding to Al8Cu4Ce and Al6Cu6La enhanced with the increase of CeLa content, suggesting that the quantity of these two phases increased. The crystal structure of the Al6Cu6La phase is cubic structure of NaZn13 type, and its lattice spacing a is 1.1949 nm [31]. There exists a strong interaction between La and Cu atoms according to the results of the calculated enthalpies

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ACCEPTED MANUSCRIPT of solution at infinite dilution, ΔHAB [32, 33], which indicates that rare earth La and Cu atoms have good chemical affinity. Generally, as the atomic radius of Al is much smaller than those of Ce and La atoms, the Ce

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and La elements hardly dissolve in the α-Al [34]. On the other hand, as Cu and Ce, La atoms have chemical

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affinity [35, 36], the Al8Cu4Ce and Al6Cu6La could form when CeLa was added to the Cu-containing Al alloys. As the new emerging phases, Al8Cu4Ce and Al6Cu6La precipitates could be expected to have an important effect

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on the mechanical properties of the corresponding alloys.

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Fig. 2. XRD patterns of the Al-Cu-Mn-Mg-Fe alloys with different CeLa addition.

Microstructures of the alloys with different CeLa contents are shown in Fig. 3. It could be observed that large quantity of grey irregular shape phases existed in the alloys with different CeLa content. According to the EDS analysis in Fig. 3d and Fig. 4, the grey particles were enriched with Al, Mn and Fe elements and the atomic ratio of Al and (Fe + Mn) was close to 7:1. This phase could be defined as Al6(Mn, Fe), which is the most common phase in 3003 aluminum alloy [37]. The Al6(Mn, Fe) particles could transform to α-Al(Mn, Fe)Si during the heat treatment, and the quantity of α-Al(Mn, Fe)Si increased with increase of the homogenization temperature and time [38, 39]. With the addition of CeLa, some white particles composed of Al, Cu, Ce and La were observed (Fig. 3). From the experimental results of XRD (Fig. 2) and EDS (Fig. 3e), it could be determined that

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these white particles were Al8Cu4Ce phase and Al6Cu6La phase.

Fig. 3. Backscattered electron SEM micrographs of the Al-Cu-Mn-Mg-Fe alloy with different CeLa addition. (a) 0, (b)

0.25 wt.%, (c) 0.50 wt.%, (d) EDS analysis of a precipitate corresponding to region A, (e) EDS analysis of a precipitate

corresponding to region B.

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Fig. 4. SEM image, and EDS mapping of Al, Mn, Fe, Cu, Ce, La elements for Al-Cu-Mn-Mg-Fe alloy with 0.5

wt.% CeLa addition. As shown in Fig 3, the area of grey Al6(Mn, Fe) phases (with a size bigger than 1 m) in the Al-Cu-Mn-Mg-Fe alloy decreased when 0.25 wt.% CeLa was added to alloy. To better analyze the effect of

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ACCEPTED MANUSCRIPT CeLa addition on the size of Al6(Mn, Fe) particles, 4 images containing around 630 particles for each alloy were randomly selected. The size distribution of the grey Al6(Mn, Fe) phases was statistical analysis using Image Pro

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Plus (IPP) software. Compared to the CeLa-free alloy (Fig. 5a), much more smaller particles formed after 0.25

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wt.% CeLa addition (Fig. 5b). Statistical analysis indicated that the quantity percentage of the particles less than 10 m 2 for the alloys with 0, 0.25 wt.% CeLa and 0.50 wt.% CeLa addition was 63.94%, 74.60% and 64.51%, respectively. Some very large particles such as those bigger than 70 m 2 occurred in the CeLa-free alloy and

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0.50 wt.% CeLa alloys. This indicates that the second phase of Al6(Mn, Fe) could be greatly refined by 0.25

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wt.% CeLa addition.

Fig. 5. Size distribution of Al6(Mn, Fe) phase in the Al-Cu-Mn-Mg-Fe alloys with different CeLa additions. (a) 0, (b) 0.25 wt.%, (c) 0.50 wt.%

Fig. 6 shows the Rietveld refinement results obtained according to the XRD patterns of the Al-Cu-Mn-Mg-Fe alloys with different CeLa addition. It could be found that the Rietveld refinement demonstrated a good fitting. 9

ACCEPTED MANUSCRIPT Table 2 shows the Rietveld refinement results including particle size, volume fraction and the numerical criteria of the Al6( Mn. Fe) particle in the alloys. It could be found that the goodness-of-fit (χ2) values and

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figures-of-merit (Rp, Rwp) values were relatively low, which suggests good fitting results according to the

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recommended numerical criteria of χ2 less than 4 and Rwp less than 20% [40]. The calculated particle sizes of the

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Al6( Mn. Fe) were greatly smaller than those observed in the SEM images of Fig. 3, but it was similar to the sizes

Fig. 6. Rietveld refinement of X-ray diffraction patterns of the Al-Cu-Mn-Mg-Fe alloy with different CeLa addition. (a) 0, (b) 0.25 wt.%, (c) 0.50 wt.%. The observed diffraction intensity is displayed as crosses in black, with the calculated values drawn as a red curve. The blue curve at the bottom shows the difference between the observed data and the calculated data. The short vertical lines show the position of different phases’ Bragg reflections of the calculated pattern.

Table 2 Rietveld refinement results of the Al6( Mn. Fe) particle in the Al-Cu-Mn-Mg-Fe alloy with different CeLa addition. Alloy

Al-Cu-Mn-Mg-Fe

Particle size

Volume fraction

Number density

(nm )

(vol.%)

(10-2)

155.14

4.16

2.68

Rp (%)

Rwp (%)

χ2

3.25

4.45

1.89

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13.01

9.39

3.29

4.75

1.32

Al-Cu-Mn-Mg-Fe-0.50 wt.% CeLa

164.72

5.48

3.33

3.78

5.25

1.71

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Al-Cu-Mn-Mg-Fe-0.25 wt.% CeLa

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reflected by the TEM bright field images of Fig. 7a. This indicated that the Al6(Mn, Fe) phases observed using

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the SEM were multi-crystalline phase rather than single crystalline phase [41]. In our experiment, number density of the Al6( Mn. Fe) was calculated according to the as-fitted particle size and volume fraction. It was

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shown that the Al6(Mn, Fe) phase of the alloys with 0.25 wt.% CeLa addition had the largest number density.

Fig. 7. TEM images showing precipitates in the Al-Cu-Mn-Mg-Fe alloy with different CeLa addition. (a) 0, (b) 0.25 wt.%, 11

ACCEPTED MANUSCRIPT (c) 0.50 wt.%, (d)-(f) EDS analysis of the precipitates S, T and A, respectively.

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In addition to the formation of CeLa-rich phase in the Al-Cu-Mn-Mg-Fe alloy with CeLa addition, large

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quantity of rod-like phases and plate-like phases existed in the investigated alloys (Fig. 7). According to EDS

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analysis, Al20Cu2Mn3 (T) phase appear as rod-like particle, which is consistent with a former report [42-44]. The size of the Al20Cu2Mn3 phase ranged from tens of nanometers to hundreds of nanometers. The plate-like particle

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was defined as Al2CuMg (S) phases. The shape of Al2CuMg was quite different from needle-like Al2CuMg, which formed after solution and aging treatment [45, 46]. Therefore, the Al2CuMg here should form in the

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casting process.

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In order to better clarify the influence of CeLa addition on the Al20Cu2Mn3 phase, statistical analysis and

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Rietveld refinement of the XRD data were performed. The number and size distribution of Al20Cu2Mn3 phase were counted by Image Pro Plus software with images from 10 randomly visual fields of the TEM for each alloy.

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As shown in Table 3, mean areas of the Al20Cu2Mn3 phase in the three kinds of alloys are close. Compared to the CeLa-free alloy, there was a significant increase of the number density and area fraction of the Al20Cu2Mn3

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phase in the 0.25 wt.% CeLa alloy. The number density and area fraction of the Al20Cu2Mn3 phase decreased when 0.50 wt.% CeLa were added to the alloy.

Table 3 Statistical analysis results of Al20Cu2Mn3 phase in the alloys. Mean area (10-2m2)

Number density (m2)

Area Fraction (%)

Al-Cu-Mn-Mg-Fe

2.07±1.42

1.07

2.22

Al-Cu-Mn-Mg-Fe-0.25 wt.% CeLa

2.24±1.45

4.46

9.98

Al-Cu-Mn-Mg-Fe-0.50 wt.% CeLa

1.92±1.34

1.62

3.12

Alloy

Table 4 shows Rietveld refinement results of the Al20Cu2Mn3 and Al2CuMg phases in the Al-Cu-Mn-Mg-Fe 12

ACCEPTED MANUSCRIPT alloys with different CeLa addition. There was a little difference in the particle size between the Rietveld refinement results and the TEM statistical analysis results. As TEM analysis is not a reliable technique for

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measuring the phase fractions, there was a large difference between the Rietveld refinement and the TEM

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statistical analysis results. However, the same changing tendency of the number density of the Al20Cu2Mn3 was obtained by the two kinds of analysis methods. The Al20Cu2Mn3 phase in the 0.25 wt.% CeLa-containing alloys had the largest phase fraction and number density. This proved that 0.25 wt.% addition to the alloy could

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promote the formation of Al20Cu2Mn3 phase and result in a higher quantity of Al20Cu2Mn3 phase than the

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CeLa-free alloy.

Table 4 Rietveld refinement results of the Al-Cu-Mn-Mg-Fe alloy with different CeLa addition.

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Particle sizes (nm)

Number density (10-2)

Al20Cu2Mn3

Al2CuMg

Al20Cu2Mn3

Al2CuMg

Al20Cu2Mn3

0.45

11.73

90.2

160.8

0.50

7.29

Al-Cu-Mn-Mg-Fe-0.25 wt.% CeLa

0.11

20.08

87.2

149.6

0.13

13.42

Al-Cu-Mn-Mg-Fe-0.50 wt.% CeLa

0.10

13.85

105.6

155.2

0.09

8.92

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Al2CuMg

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Al-Cu-Mn-Mg-Fe

According to Darken Gurry theory [47-49], the element electronegativity and size factor could act as a parameter, which was defined as the interaction intensity (W) between alloy elements. Thus, it could be used to characterize the formation trend of alloy compounds as a qualitative method. When the W value increased, the interaction of the alloying elements will be enhanced. As a result, the formation trend of these alloy elements was stronger. The interaction intensity (W) could be defined as [50]: W= [(RA - RB) / (0.15 * RA)] 2 + [(NA - NB) / 0.4] 2

(2)

where RA and RB are the atomic radius of A and B atom, NA and NB are the electronegativity of A and B atom. Equation 1 was used to calculate the interaction strength and the results are listed as follows: WAl-Cu = 1.01, 13

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W(Al-X)-RE = WAl-X + WX-RE + 8.8

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Thus, the results are as follows: W(Al-Cu)-Ce = 4.07, W(Al-Cu)-La = 5.78, W(Al-Mg)-Ce = -6.05, W(Al-Mg)-La = -7.22, W(Al-Mn)-Ce = 0.61, W(Al-Mn)-La = -0.85. It is obvious that the rare earth element of Ce and La increase the interaction between Al and Cu element. Thus, new phases of Al6Cu6La and Al8Cu4Ce could be found after

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addition of CeLa to the alloy. The additions of rare earth reduce the interaction between Al and Mg element.

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Thus, the quantity of Al2CuMg decreased in the rare earth containing alloy. The formation of Al6Cu6La and Al8Cu4Ce consumed Cu in the alloy. Thus, low-Cu phase of Al20Cu2Mn3 tended to form with a higher quantity

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than those of the high-Cu phase of Al2Cu or Al2CuMg phase [51]. Hence the quantity of Al20Cu2Mn3 phase

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significantly increased with the addition of CeLa. However, with extra CeLa addition, a large amount of Cu

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element will be consumed. This results in a decrease of Al20Cu2Mn3 and Al2CuMg phases in the 0.50 wt.% CeLa alloy, which is consistent with the Rietveld refinement results shown in Fig. 6 and Table 4.

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Table 5 Atomic radius and electronegativity of the alloying elements [9, 31]

Al

Cu

Mn

Mg

Ce

La

atomic radius (nm)

0.143

0.128

0.132

0.160

0.182

0.187

electronegativity

1.610

1.900

1.550

1.310

1.120

1.110

3.2. Mechanical properties

Tensile testing results of longitudinal direction and transverse direction of the three kinds of alloys are shown in Table 6. Compared to the CeLa-free alloy, the yield strength and tensile strength of the 0.25 wt.% CeLa alloy along longitudinal direction increased by 6.64 % and 9.47 %, respectively. The elongation of the alloy also

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Similar change was found with the mechanical properties along transverse direction. The strength and

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elongation along the longitudinal direction were better than those along the transverse direction.

Table 6 Mechanical properties of the Al-Cu-Mn-Mg-Fe alloys with different CeLa addition.

σ0.2 (MPa)

σb (MPa)

δ (%)

RD

241±1.4

285±2.6

3.1±0.2

TD

223±2.5

263±1.4

1.7±0.1

RD

257±1.4

312±2.0

4.2±0.2

TD

241±1.5

307±2.3

3.6±0.2

RD

247±2.6

297±3.0

3.1±0.1

TD

232±1.9

275±2.1

2.3±0.2

Rolling direction

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Al-Cu-Mn-Mg-Fe

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Al-Cu-Mn-Mg-Fe-0.50 wt.% CeLa

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Fig. 8 shows SEM images of the fracture surfaces of the tensile specimen along longitudinal direction. Large quantity of sub-micron dimples formed on the fracture surfaces of the specimens, and some large dimples with particles and tear ridges could be also observed. The coarse phases in Fig. 8a and 8c presented a brittle fracture behavior by showing some cracks on the surface of the particles. According to EDS analysis, the coarse particles mainly consisted of Al6(Mn, Fe), which was reported as a brittle compound and could shear when it underwent deformation [52, 53]. The above analysis indicated that the alloys presented a macroscopically ductile fracture with locally brittle fracture [54, 55]. The Al6(Mn, Fe) with larger size significantly deteriorate the mechanical properties of the alloy. However, the role of the Al20Cu2Mn3 was just the opposite. In addition to the effect of pinning dislocation [56], twin reaction could happen with the Al20Cu2Mn3 during deformation process [57]. It

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wt.% CeLa-addition alloy presented the highest mechanical properties.

Fig. 8. Fracture surfaces of Al-Cu-Mn-Mg-Fe alloy with different CeLa addition. (a) 0, (b) 0.25 wt.%, (c) 0.50 wt.%, (d)

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EDS analysis of a precipitates.

4. Conclusions

(1) Major role of rare earth CeLa in the Al–Cu–Mn–Mg-Fe alloy is to form the Al8Cu4Ce phase and Al6Cu6La phase, which also suppressed the formation of Al2CuMg phase. (2) The Al6Mn or Al6(Mn, Fe) phase refined and denser precipitation of Al20Cu2Mn3 could form with 0.25 wt.% CeLa addition in Al-Cu-Mn-Mg-Fe alloy. Therefore, mechanical property of the alloys with 0.25 wt.% CeLa was improved at room temperature. (3) Extra addition of CeLa (0.50 wt.%) promoted the formation of coarse Al8Cu4Ce phase, Al6Cu6La phase

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temperature.

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Acknowledgments

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This work was supported by Shanghai Excellent Technical Leader Project (No. 15XD1524600) and China

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National Major Scientific Instruments Equipment Development Project (No. 2012YQ15000105).

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ACCEPTED MANUSCRIPT Highlights

• Lithium battery shell alloys of Al-Cu-Mn-Mg-Fe with different CeLa addition were fabricated through

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• Al8Cu4Ce and Al6Cu6La phases formed after CeLa addition.

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casting and rolling.

• Addition of 0.25 wt.% CeLa to the Al-Cu-Mn-Mg-Fe alloy promoted formation of denser precipitates of Al20Cu2Mn3 and Al6(Mn, Fe).

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• Mechanical properties of the alloy was improved after 0.25 wt.% CeLa addition.

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