Microstructure and Mechanical Properties of AlSi10Mg Alloy Manufactured by Laser Powder Bed Fusion Under Nitrogen and Argon Atmosphere

doi:10.1007/s40195-021-01354-7

Abstract

Abstract:

In order to study the effect of gas atmosphere on forming performance of laser powder bed fusion (LPBF), AlSi10Mg alloy was prepared by direct forming and in situ laser remelting under the shielding gas of argon and nitrogen in this study, and its microstructure and properties were characterized and tested, respectively. The results show that the forming performance of AlSi10Mg under nitrogen atmosphere is better than that of argon. Moreover, in situ laser remelting method can effectively enhance the relative density and mechanical properties of AlSi10Mg, in which the densification is increased to 99.5%. In terms of mechanical properties, after in situ remelting, ultimate tensile strength under argon protection increased from 444.85 ± 8.73 to 489.45 ± 3.20 MPa, and that under nitrogen protection increased from 459.21 ± 13.77 to 500.14 ± 5.15 MPa. In addition, the elongation is nearly doubled and the micro-Vickers hardness is increased by 20%. The research results provide a new regulation control method for the customization of AlSi10Mg properties fabricated by LPBF.

Key words: In situ laser remelting, Laser powder bed fusion, AlSi10Mg alloy, Mechanical properties, Shielding gas

Yunmian Xiao, Yongqiang Yang, Shibiao Wu, Jie Chen, Di Wang, Changhui Song. Microstructure and Mechanical Properties of AlSi10Mg Alloy Manufactured by Laser Powder Bed Fusion Under Nitrogen and Argon Atmosphere[J]. Acta Metallurgica Sinica (English Letters), 2022, 35(3): 486-500.

Figures/Tables 15

Fig. 1 a SEM images of AlSi10Mg powder, b particle size distribution of AlSi10Mg powder used

Table 1 Chemical composition of the used AlSi10Mg alloy powder and ISO 3522 standard AlSi10Mg powder (wt%)

Powder	Al	Si	Mg	Fe	Mn	Zn	Others
AlSi10Mg	Bal	10.15	0.35	0.16	0.20	0.043	< 0.10
ISO 3522 [17]	Bal	9-11	0.20-0.45	< 0.55	< 0.45	< 0.1	-

Fig. 2 a Schematic of the experimental SLM equipment, b scanning strategy of “S-cross Orthogonal inter-layer stagger,” c schematic diagram of SLM remelting process

Table 2 SLM processing parameters used for four batches of AlSi10Mg alloy

	Laser power (W)	Scanning speed (mm/s)	Scanning space (μm)	Layer thickness (μm)	Atmosphere
SLM	220	1100	80	30	Argon or nitrogen
SLM remelting	200	1200	80	-	Argon or nitrogen

Fig. 3 a Bulk and tensile test samples (8 mm height for each items) fabricated by SLRM-Ar, SLRM-N2, SLM-N2 and SLM-Ar in turn, b relative density of SLM and SLRM parts

Fig. 4 a XRD patterns of AlSi10Mg SLM and SLRM samples in argon/nitrogen atmosphere, b small range of 2θ (38°-39°)

Fig. 5 OM images of the SLM AlSi10Mg alloys. Scanning track, molten pool morphology, and grain size details of the alloy from a-c SLM-Ar built, d-f SLM-N2 built

Fig. 6 OM and SEM images of the SLMed AlSi10Mg alloys. Scanning track and molten pool morphology details of the alloy from a-c SLRM-Ar built, d-f SLRM-N2 built

Fig. 7 Cross section of AlSi10Mg melt pool depth, H is melt pool depth of single track, and h is distance of melt pool between previous layer and remelting layer. a SLM-Ar build, b SLM-N2 build, c SLRM-Ar build, d SLRM-N2 build

Fig. 8 a Growth refinement mechanism of eutectic Si in the SLM prepared samples. Strengthening schematic of in situ laser remelting, finer grain growth diagram of remelting and resolidification b under argon atmosphere, c under nitrogen atmosphere

Fig. 9 EDS mapping results of AlSi10Mg alloy: a SLM-Ar, b SLM-N2, c SLRM-Ar, d SLRM-N2

Fig. 10 a Tensile stress-strain curve at room temperature of the as-built AlSi10Mg alloy and macroscopic fracture morphology in argon and nitrogen atmosphere; b microhardness test of the as-built sample

Table 3 Summary of average tensile properties of four batches AlSi10Mg samples fabricated by different process parameters

Samples	Ultimate tensile strength (MPa)	Yield strength (MPa)	Elongation (%)	Elastic modulus (GPa)
SLM-Ar	444.85 ± 8.73	341.49 ± 9.97	2.55 ± 0.27	76.37 ± 10.16
SLM-N₂	459.21 ± 13.77	346.18 ± 10.45	2.88 ± 0.29	75.84 ± 9.38
SLRM-Ar	489.45 ± 3.20	323.75 ± 2.28	4.51 ± 0.22	72.92 ± 3.99
SLRM-N₂	500.14 ± 5.15	324.91 ± 4.82	5.13 ± 0.27	70.21 ± 1.44
AM as-built	452 ± 1	264 ± 4	8.6 ± 1.0	Ref. [29]
Gravity Cast-T6	330 ± 13	268 ± 6	3.8 ± 1.5

Fig. 11 Fracture morphologies of AlSi10Mg alloy fabricated by SLM: a-c in the argon atmosphere, d-f in the nitrogen atmosphere

Fig. 12 Fracture morphologies of AlSi10Mg alloy fabricated by SLRM: a-c in the argon atmosphere, d-f in the nitrogen atmosphere

References 45

[1]	J.H. Martin, B.D. Yahata, J.M. Hundley, J.A. Mayer, T.A. Schaedler, T.M. Pollock, Nature 549, 365 (2017)
[2]	S. Dadbakhsh, R. Mertens, L. Hao, J. Van Humbeeck, J.P. Kruth, Adv. Eng. Mater. 21, 1801244(2019)
[3]	K.G. Prashanth, R. Damodaram, S. Scudino, Z. Wang, K. Prasad Rao, J. Eckert, Mater. Des. 57, 632 (2014). DOI URL
[4]	U. Tradowsky, J. White, R.M. Ward, N. Read, W. Reimers, M.M. Attallah, Mater. Des. 105, 212 (2016) DOI URL
[5]	N.T. Aboulkhair, N.M. Everitt, I. Ashcroft, C. Tuck, Addit. Manuf. 1-4, 77(2014)
[6]	L.N. Carter, C. Martin, P.J. Withers, M.M. Attallah, J. Alloys Compd. 615(2014).
[7]	N. Read, W. Wang, K. Essa, M.M. Attallah, Mater. Des. 65, 417 (2015) DOI URL
[8]	H.H. Wu, J.F. Li, Z.Y. Wei, P. Wei, Rapid Prototyp. J. 26, 871 (2020) DOI URL
[9]	L. Thijs, K. Kempen, J.-P. Kruth, J. Van Humbeeck, Acta Mater. 61, 1809 (2013) DOI URL
[10]	E. Yasa, J. Deckers, J.P. Kruth, Rapid Prototyp. J. 17, 312 (2011) DOI URL
[11]	A.G. Demir, B. Previtali, Int. J. Adv. Manuf. Technol. 93, 2697 (2017) DOI URL
[12]	J. Vaithilingam, R.D. Goodridge, R.J.M. Hague, S.D.R. Christie, S. Edmondson, J. Mater. Process. Technol. 232, 1 (2016) DOI URL
[13]	S. Traore, M. Schneider, I. Koutiri, F. Coste, R. Fabbro, C. Charpentier, P. Lefebvre, P. Peyre, J. Mater. Process. Technol. 288, 116851 (2021). DOI URL
[14]	X.J. Wang, L.C. Zhang, M.H. Fang, T.B. Sercombe, Mater. Sci. Eng. A 597, 370 (2014)
[15]	M.A. Balbaa, A. Ghasemi, E. Fereiduni, M.A. Elbestawi, S.D. Jadhav, J.P. Kruth, Addit. Manuf. 37, 101630(2021).
[16]	ASTM B213-17, Standard Test Methods for Flow Rate of Metal Powders Using the Hall Flowmeter Funnel, ASTM International. ASTM International, West Conshohocken, PA(2017).
[17]	ISO 3522:2007, Specifies the Chemical Composition Limits for Aluminium Casting Alloys and Mechanical Properties of Separately Cast Test Bars for These Alloys (2007).
[18]	Y. Bai, Y. Yang, Z. Xiao, M. Zhang, D. Wang, Mater. Des. 140, 257 (2018) DOI URL
[19]	A.B. Spierings, M. Schneider, R. Eggenberger, Rapid Prototyp. J. 17, 380 (2011) DOI URL
[20]	ASTM E112-13, Standard Test Methods for Determining Average Grain Size. ASTM International, West Conshohocken, PA (2013).
[21]	ISO 6892-1:2019, Metallic Materials—Tensile Testing—Part 1:Method of Test at Room Temperature (2019).
[22]	G.E. Jauncey, Proc. Natl. Acad. Sci. USA 10, 57 (1924)
[23]	D. Carluccio, M.J. Bermingham, Y. Zhang, D.H. StJohn, K. Yang, P.A. Rometsch, X. Wu, M.S. Dargusch, J. Manuf, J. Manuf. Processes 35, 715 (2018)
[24]	T. Gustmann, H. Schwab, U. Kuhn, S. Pauly, Mater. Des. 153, 129 (2018) DOI URL
[25]	J. Chen, W. Hou, X. Wang, S. Chu, Z. Yang, Chin. J. Aeronaut. 33, 2043 (2020)
[26]	C. Weingarten, D. Buchbinder, N. Pirch, W. Meiners, K. Wissenbach, R. Poprawe, J. Mater. Process. Technol. 221, 112 (2015) DOI URL
[27]	E. Sjölander, S. Seifeddine, J. Mater. Process. Technol. 210, 1249 (2010) DOI URL
[28]	C.A. Biffi, J. Fiocchi, A. Tuissi, J. Alloys Compd. 755, 100 (2018) DOI URL
[29]	L. Girelli, M. Tocci, M. Gelfi, A. Pola, Mater. Sci. Eng. A 739, 317 (2019)
[30]	Q. Yan, B. Song, Y.S. Shi, J. Mater. Sci. Technol. 41, 199 (2020) DOI URL
[31]	Q.Y. Tan, J.Q. Zhang, N. Mo, Z.Q. Fan, Y. Yin, M. Bermingham, Y.G. Liu, H. Huang, M.X. Zhang, Addit. Manuf. 32, 101034(2020).
[32]	N. Kang, P. Coddet, L. Dembinski, H. Liao, C. Coddet, J. Alloys Compd. 691, 316 (2017) DOI URL
[33]	L.F. Wang, J. Sun, X.L. Yu, Y. Shi, X.G. Zhu, L.Y. Cheng, H.H. Liang, B. Yan, L.J. Guo, Mater. Sci. Eng. A 734, 299 (2018)
[34]	T. Kurzynowski, K. Gruber, W. Stopyra, B. Kuźnicka, E. Chlebus, Mater. Sci. Eng. A 718, 64 (2018)
[35]	W. Kurz, B. Giovanola, R. Trivedi, Acta Metall. 34, 823 (1986) DOI URL
[36]	M. Zimmermann, M. Carrard, W. Kurz, Acta Metall. 37, 3305 (1989) DOI URL
[37]	G. Vastola, G. Zhang, Q.X. Pei, Y.W. Zhang, Addit. Manuf. 7, 57 (2015)
[38]	W. Kurz, C. Bezençon, M. Gäumann, Sci. Technol. Adv. Mater. 2, 185 (2001) DOI URL
[39]	F.M. Faubert, G.S. Springer, J. Chem. Phys. 57, 2333 (1972) DOI URL
[40]	D. Gu, H. Wang, G. Zhang, Metall. Mater. Trans. A 45, 464 (2013)
[41]	C. Gao, Z. Wang, Z. Xiao, D. You, K. Wong, A.H. Akbarzadeh, J. Mater. Process. Technol. 281, 116618(2020).
[42]	N. Takata, M. Liu, H. Kodaira, A. Suzuki, M. Kobashi, Addit. Manuf. 33, 101152(2020).
[43]	J. Suryawanshi, K.G. Prashanth, S. Scudino, J. Eckert, O. Prakash, U. Ramamurty, Acta Mater. 115, 285 (2016) DOI URL
[44]	T.H. Park, M.S. Baek, H. Hyer, Y. Sohn, K.A. Lee, Mater. Charact. 176, 111113(2021).
[45]	M.J. Paul, Q. Liu, J.P. Best, X. Li, J.J. Kruzic, U. Ramamurty, B. Gludovatz, Acta Mater. 211, 116869(2021).