Role of inclination angle on columnar-to-equiaxed transition in the eutectic Al-5Mg-2Si alloy fabricated by laser powder bed fusion

Abstract

In this study, the effect of inclination angles relative to the building direction in the additively manufactured eutectic Al-5Mg-2Si alloy was investigated through the laser powder bed fusion (LPBF). The microstructures and mechanical properties of the Al-5Mg-2Si alloy manufactured with different inclination angles (0°, 30°, 45°, 60° and 90°) were reported and discussed. It is found that the “semicircular” melt pool (MP) in the load bearing face of 0° sample was eventually transformed into “stripe-like” MP in the 90° sample, accompanied by an increased fraction of melt pool boundaries (MPBs). Moreover, the microstructural analysis revealed that the columnar-to-equiaxed transition (CET) of the α-Al grains and eutectic Mg₂Si was completed in the 90° sample, which were significantly refined with the average size of 9.5 µm and 0.44 µm, respectively. It is also found that the 90° sample exhibited good combination of strength and elongation (i. e. yield strength (YS) of 393 MPa, ultimate tensile strength (UTS) of 483 MPa and elongation (El) of 8.1%). The anisotropic mechanical properties were highly associated with the refined microstructures, thermal stress, and density of MPBs. Additionally, the CET driven by inclination angles were attributed to the variation of thermal conditions inside the local MPs.

Keywords

additive manufacturing / aluminium alloys / columnar-to-equiaxed transition / anisotropy / mechanical property

References

[1] HerzogD, SeydaV, WyciskE, et al. . Additive manufacturing of metals [J]. Acta Materialia, 2016, 117: 371-392

[2] ZagadeP, GauthamB P, DeA, et al. . Analytical estimation of fusion zone dimensions and cooling rates in part scale laser powder bed fusion [J]. Additive Manufacturing, 2021, 46: 102222

[3] ZhouL-B, ShuJ-G, SunJ-S, et al. . Effects of tantalum addition on microstructure and properties of titanium alloy fabricated by laser powder bed fusion [J]. Journal of Central South University, 2021, 28(4): 1111-1128

[4] BiJ, ChenY-B, ChenX, et al. . Densification, microstructural features and tensile properties of selective laser melted AlMgSiScZr alloy from single track to block specimen [J]. Journal of Central South University, 2021, 28(4): 1129-1143

[5] WangJ-Y, ZouJ-P, YangH-L, et al. . Exceptional strength-ductility synergy of additively manufactured CoCrNi medium-entropy alloy achieved by lattice defects in heterogeneous microstructures [J]. Journal of Materials Science & Technology, 2022, 12761-70

[6] WangJ-Y, ZouJ-P, YangH-L, et al. . High strength and ductility of an additively manufactured CrCoNi medium-entropy alloy achieved by minor Mo doping [J]. Materials Science and Engineering: A, 2022, 843: 143129

[7] LiuX-H, ZhaoC-C, ZhouX, et al. . Microstructure of selective laser melted AlSi₁₀Mg alloy [J]. Materials & Design, 2019, 168107677

[8] MartinJ H, YahataB D, HundleyJ M, et al. . 3D printing of high-strength aluminium alloys [J]. Nature, 2017, 549365-369

[9] TanQ-Y, YinY, PrasadA, et al. . Demonstrating the roles of solute and nucleant in grain refinement of additively manufactured aluminium alloys [J]. Additive Manufacturing, 2022, 49: 102516

[10] LiM-J, LianJ, CaoL-F, et al. . Effect of platform temperature on microstructure and corrosion resistance of selective laser melted Al-Mg-Sc alloy plate [J]. Journal of Central South University, 2022, 29(3): 999-1014

[11] ZhuZ-G, NgF L, SeetH L, et al. . Superior mechanical properties of a selective-laser-melted AlZnMgCuScZr alloy enabled by a tunable hierarchical microstructure and dual-nanoprecipitation [J]. Materials Today, 2022, 5290-101

[12] ZhangJ-L, GaoJ-B, SongB, et al. . A novel crack-free Ti-modified Al-Cu-Mg alloy designed for selective laser melting [J]. Additive Manufacturing, 2021, 38: 101829

[13] XiaoF, WangS-B, WangY-X, et al. . Niobium nanoparticle-enabled grain refinement of a crack-free high strength Al-Zn-Mg-Cu alloy manufactured by selective laser melting [J]. Journal of Alloys and Compounds, 2022, 900163427

[14] GaoC, WuW, ShiJ, et al. . Simultaneous enhancement of strength, ductility, and hardness of TiN/AlSi₁₀Mg nanocomposites via selective laser melting [J]. Additive Manufacturing, 2020, 34101378

[15] LiX P, JiG, ChenZ, et al. . Selective laser melting of nano-TiB₂ decorated AlSi₁₀Mg alloy with high fracture strength and ductility [J]. Acta Materialia, 2017, 129183-193

[16] DavidS A, VitekJ M. Correlation between solidification parameters and weld microstructures [J]. International Materials Reviews, 1989, 34(1): 213-245

[17] YangK V, ShiY-J, PalmF, et al. . Columnar to equiaxed transition in Al-Mg (-Sc) -Zr alloys produced by selective laser melting [J]. Scripta Materialia, 2018, 145: 113-117

[18] BiJ, LeiZ-L, ChenY-B, et al. . Microstructure, tensile properties and thermal stability of AlMgSiScZr alloy printed by laser powder bed fusion [J]. Journal of Materials Science & Technology, 2021, 69: 200-211

[19] KotadiaH R, GibbonsG, DasA, et al. . A review of laser powder bed fusion additive manufacturing of aluminium alloys: Microstructure and properties [J]. Additive Manufacturing, 2021, 46: 102155

[20] TanQ-Y, ZhangJ-Q, MoN, et al. . A novel method to 3D-print fine-grained AlSi₁₀Mg alloy with isotropic properties via inoculation with LaB₆ nanoparticles [J]. Additive Manufacturing, 2020, 32101034

[21] LvH-Y, PengP, FengT, et al. . High-performance co-continuous Al-Ce-Mg alloy with in situ nano-network structure fabricated by laser powder bed fusion [J]. Additive Manufacturing, 2022, 60103218

[22] QiX, TakataN, SuzukiA, et al. . Laser powder bed fusion of a near-eutectic Al - Fe binary alloy: Processing and microstructure [J]. Additive Manufacturing, 2020, 35101308

[23] WangJ-Y, GaoJ-B, YangH-L, et al. . High-strength Al - 5Mg₂ Si-2Mg-2Fe alloy with extremely high Fe content for green industrial application through additive manufacturing [J]. Virtual and Physical Prototyping, 2023, 18(1): 2235587

[24] YangF-P, WangJ-Y, WenT, et al. . Manipulating microstructure and mechanical properties of laser powder bed fusion processed hypo-eutectic Al-13.3Mg₂Si alloy via annealing [J]. Journal of Alloys and Compounds, 2023, 967171805

[25] JiS, WatsonD, FanZ, et al. . Development of a super ductile diecast Al - Mg - Si alloy [J]. Materials Science and Engineering: A, 2012, 556824-833

[26] YangH-L, ZhangY-Y, WangJ-Y, et al. . Additive manufacturing of a high strength Al-5Mg₂Si-2Mg alloy: Microstructure and mechanical properties [J]. Journal of Materials Science & Technology, 2021, 91215-223

[27] YangF-P, WangJ-Y, WenT, et al. . Double-peak age strengthening of an Al-Mg-Si-Zn alloy processed by laser powder bed fusion [J]. Journal of Materials Science & Technology, 2024, 192: 82-94

[28] WangJ-Y, YangF-P, YangH-L, et al. . Effect of heat treatment on the microstructure and mechanical properties of an Al-5Mg₂Si-2Mg alloy processed by laser powder bed fusion [J]. Journal of Alloys and Compounds, 2022, 920: 165944

[29] YangF-P, WangJ-Y, WenT, et al. . Microstructure and mechanical properties of pseudo binary eutectic Al-Mg₂Si alloy processed by laser powder bed fusion [J]. Journal of Materials Research and Technology, 2023, 242187-2199

[30] YangF-P, WangJ-Y, WenT, et al. . Microstructure and mechanical properties of pseudo binary eutectic Al-Mg₂Si alloy processed by laser powder bed fusion [J]. Journal of Materials Research and Technology, 2023, 24: 2187-2199

[31] YangK V, RometschP, DaviesC H J, et al. . Effect of heat treatment on the microstructure and anisotropy in mechanical properties of A357 alloy produced by selective laser melting [J]. Materials & Design, 2018, 154: 275-290

[32] WangC G, ZhuJ X, WangG W, et al. . Effect of building orientation and heat treatment on the anisotropic tensile properties of AlSi₁₀Mg fabricated by selective laser melting [J]. Journal of Alloys and Compounds, 2022, 895: 162665

[33] LiX-F, YiD-H, WuX-Y, et al. . Effect of construction angles on microstructure and mechanical properties of AlSi₁₀Mg alloy fabricated by selective laser melting [J]. Journal of Alloys and Compounds, 2021, 881160459

[34] FengZ, TanH, FangY-B, et al. . Selective laser melting of TiB₂/AlSi₁₀Mg composite: Processability, microstructure and fracture behavior [J]. Journal of Materials Processing Technology, 2022, 299117386

[35] XiaoY K, BianZ Y, WuY, et al. . Effect of nano-TiB₂ particles on the anisotropy in an AlSi₁₀Mg alloy processed by selective laser melting [J]. Journal of Alloys and Compounds, 2019, 798644-655

[36] ChenS-Q, TanQ-Y, GaoW-Q, et al. . Effect of heat treatment on the anisotropy in mechanical properties of selective laser melted AlSi₁₀Mg [J]. Materials Science and Engineering: A, 2022, 858: 144130

[37] WuJ, WangX Q, WangW, et al. . Microstructure and strength of selectively laser melted AlSi₁₀Mg [J]. Acta Materialia, 2016, 117311-320

[38] TakataN, LiuM-L, KodairaH, et al. . Anomalous strengthening by supersaturated solid solutions of selectively laser melted Al-Si-based alloys [J]. Additive Manufacturing, 2020, 33: 101152

[39] XiongZ H, LiuS L, LiS F, et al. . Role of melt pool boundary condition in determining the mechanical properties of selective laser melting AlSi₁₀Mg alloy [J]. Materials Science and Engineering: A, 2019, 740–741148-156

[40] LiY-L, GuD-D. Parametric analysis of thermal behavior during selective laser melting additive manufacturing of aluminum alloy powder [J]. Materials & Design, 2014, 63: 856-867

[41] ZhangS-Y, LinX, WangL-L, et al. . Strengthening mechanisms in selective laser-melted Inconel718 superalloy [J]. Materials Science and Engineering A, 2021, 812: 141145

[42] DongZ-C, OuyangP-X, ZhangS-T, et al. . Effect of building direction on anisotropy of mechanical properties of GH4169 alloy fabricated by laser powder bed fusion [J]. Materials Science and Engineering A, 2023, 862144430

[43] SanjariM, HadadzadehA, PirgaziH, et al. . Selective laser melted stainless steel CX: Role of built orientation on microstructure and micro-mechanical properties [J]. Materials Science and Engineering A, 2020, 786139365

[44] CzerwinskiF. The growth of quaternary divorced eutectic in Al-Ce-Si-Mg alloys [J]. Metallurgical and Materials Transactions A, 2023, 54(2): 391-398

[45] DelahayeJ, TchuindjangJ T, Lecomte-BeckersJ, et al. . Influence of Si precipitates on fracture mechanisms of AlSi₁₀Mg parts processed by Selective Laser Melting [J]. Acta Materialia, 2019, 175160-170

[46] XieZ-Y, DaiY, OuX-Q, et al. . Effects of selective laser melting build orientations on the microstructure and tensile performance of Ti-6Al-4V alloy [J]. Materials Science and Engineering: A, 2020, 776: 139001

[47] EastonM, StjohnD. Grain refinement of aluminum alloys: Part I. the nucleant and solute paradigms—A review of the literature [J]. Metallurgical and Materials Transactions A, 1999, 30(6): 1613-1623

[48] HadadzadehA, AmirkhizB S, LiJ, et al. . Columnar to equiaxed transition during direct metal laser sintering of AlSi₁₀Mg alloy: Effect of building direction [J]. Additive Manufacturing, 2018, 23121-131

[49] YadollahiA, ShamsaeiN, ThompsonS M, et al. . Effects of process time interval and heat treatment on the mechanical and microstructural properties of direct laser deposited 316L stainless steel [J]. Materials Science and Engineering A, 2015, 644: 171-183

[50] FleischerR L. Substitutional solution hardening [J]. Acta Metallurgica, 1963, 11(3): 203-209

[51] JiangF-Q, TangL, YeH-Q, et al. . The role of TiH₂ on microstructure and mechanical properties of Al-Zn-Mg-Cu alloy fabricated by laser powder bed fusion [J]. Materials Science and Engineering A, 2023, 869: 144819

[52] HansenN. Hall-Petch relation and boundary strengthening [J]. Scripta Materialia, 2004, 51(8): 801-806

[53] KempfA, HilgenbergK. Influence of sub-cell structure on the mechanical properties of AlSi₁₀Mg manufactured by laser powder bed fusion [J]. Materials Science and Engineering A, 2020, 776138976

[54] HadadzadehA, AmirkhizB S, MohammadiM. Contribution of Mg₂Si precipitates to the strength of direct metal laser sintered AlSi₁₀Mg [J]. Materials Science and Engineering A, 2019, 739295-300

[55] HeJ Y, WangH, HuangH L, et al. . A precipitation-hardened high-entropy alloy with outstanding tensile properties [J]. Acta Materialia, 2016, 102: 187-196

[56] MaK-K, WenH-M, HuT, et al. . Mechanical behavior and strengthening mechanisms in ultrafine grain precipitation-strengthened aluminum alloy [J]. Acta Materialia, 2014, 62: 141-155

[57] DengD-Y, PengR l, BrodinH, et al. . Microstructure and mechanical properties of Inconel 718 produced by selective laser melting: Sample orientation dependence and effects of post heat treatments [J]. Materials Science and Engineering A, 2018, 713: 294-306

[58] OtaniY, TakataN, SuzukiA, et al. . Microstructural origin of amisotropic tensile ductility of Al-Si alloy manufactured by laler powder bed fusion [J]. Scripta Materialia, 2023, 226: 115259

[59] WangM, SongB, WeiQ-S, et al. . Effects of annealing on the microstructure and mechanical properties of selective laser melted AlSi₇Mg alloy [J]. Materials Science and Engineering: A, 2019, 739463-472

[60] BosioF, PhutelaC, GhisiN, et al. . Tuning the microstructure and mechanical properties of AlSi₁₀Mg alloy via in situ heat-treatments in laser powder bed fusion [J]. Materials Science and Engineering: A, 2023, 879145268