Excellent strength–ductility balance of Sc-Zr-modified Al–Mg alloy by tuning bimodal microstructure via hatch spacing in laser powder bed fusion

被引：39

作者：

Ekubaru Y. ^{[1
,2
]}

Gokcekaya O. ^{[1
,2
]}

Ishimoto T. ^{[1
,2
,3
]}

Sato K. ^{[4
]}

Manabe K. ^{[1
]}

Wang P. ^{[5
]}

Nakano T. ^{[1
,2
]}

机构：

[1] Division of Materials and Manufacturing Science, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, 565-0871, Osaka

[2] Anisotropic Design and Additive Manufacturing Research Center, Osaka University, 2-1, Yamadaoka, Suita, 565-0871, Osaka

[3] Aluninium Research Center, University of Toyama, 3190, Gofuku, Toyama

[4] Research Center for Ultra-High Voltage Electron Microscopy and Division of Materials and Manufacturing Science, Graduate School of Engineering, Osaka University, Ibaraki

[5] Singapore Institute of Manufacturing Technology, A*STAR

来源：

Materials and Design | 2022年 / 221卷

基金：

日本科学技术振兴机构;

关键词：

Hatch spacing; Laser powder bed fusion; Melt pool; Precipitation; Scalmalloy; Ultrafine grain;

D O I：

10.1016/j.matdes.2022.110976

中图分类号：

学科分类号：

摘要：

The bimodal microstructure, which comprises ultrafine grains (UFGs) forming along the melt pool boundary and relatively coarse grains inside the melt pool, is a characteristic of the Sc-Zr-modified Al–Mg-based alloy (Scalmalloy) microstructure manufactured using laser powder bed fusion (LPBF). Focusing on this microstructural feature, we investigated the improvement in the mechanical properties of LPBF-fabricated Scalmalloy by tailoring the volume fraction of UFGs. Our approach was to decrease the laser hatch spacing (d) from 0.1 to 0.04 mm, while the volume fraction of UFGs increased from 34.6 ± 0.6 % (d = 0.1 mm) to 59.5 ± 0.5 % (d = 0.06 mm). The tensile yield stress increased from 296 ± 9 (d = 0.1 mm) to 380 ± 6 MPa (d = 0.06 mm), while maintaining a large elongation (14.8 % ± 1.2 %). The yield stress and elongation were superior to those of the cast counterparts by 2.9 and 4.0 times, respectively. In the sample with d = 0.04 mm, pores formed owing to excessive thermal energy input. Additionally, we investigated multiple strengthening mechanisms of the as-fabricated alloy. This is the first study to improve the mechanical properties of LPBF-fabricated Scalmalloy by optimizing the track-to-track interval and tuning the UFG fraction. © 2022 The Author(s)

引用

共 53 条

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