Enhancement in strength and ductility of laser powder bed fused Al–12Si alloy by introducing nanoscale precipitates

Liu, Mulin; Takata, Naoki; Suzuki, Asuka; Kobashi, Makoto; Kato, Masaki

doi:10.1016/j.addlet.2021.100008

Cited by 10 publications

(3 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In particular, the alloys AlSi10Mg, AlSi12 and AlSi7Mg are considered 'highly printable' [24]. For these materials, ultimate tensile strength (UTS) values between 300 and 450 MPa in as-built condition are reported [4,24,[27][28][29][30][31][32][33][34][35][36].…”

Section: Mechanical Properties Of Lpbf-processed Alsi Alloysmentioning

confidence: 99%

Influence of Contour Scan Variation on Surface, Bulk and Mechanical Properties of LPBF-Processed AlSi7Mg0.6

et al. 2023

View full text Add to dashboard Cite

Metal additive manufacturing technologies have great potential for future use in load-bearing aerospace applications, requiring a deeper understanding of mechanical performance and influencing factors. The objective of this study was to investigate the influence of contour scan variation on surface quality, tensile and fatigue strength for laser powder bed fusion samples made of AlSi7Mg0.6 material and to create high-quality as-built surfaces. The samples were produced with identical bulk and different contour scan parameters to accommodate the investigation of the impact of as-built surface texture on mechanical properties. The bulk quality was evaluated by density measurements according to Archimedes’ principle and tensile testing. The surfaces were investigated using the optical fringe projection method, and surface quality was assessed by the areal surface texture parameters Sa (arithmetic mean height) and Sk (core height, derived from material ratio curve). Fatigue life was tested at different load levels, and the endurance limit was estimated based on a logarithmic-linear relation between number of cycles and stress. All samples were found to have a relative density of more than 99%. Surface conditions distinctive in Sa and Sk were successfully created. The resulting mean values of the ultimate tensile strength σult are between 375 and 405 MPa for 7 different surface conditions. It was confirmed that the influence of contour scan variation on bulk quality is insignificant for the assessed samples. Regarding fatigue, one as-built condition was found to perform as well as surface post-processed parts and better than the as-cast material (compared to literature values). The fatigue strength at the endurance limit for 106 cycles is between 45 and 84 MPa for the three considered surface conditions.

show abstract

Section: Mechanical Properties Of Lpbf-processed Alsi Alloysmentioning

confidence: 99%

Influence of Contour Scan Variation on Surface, Bulk and Mechanical Properties of LPBF-Processed AlSi7Mg0.6

et al. 2023

View full text Add to dashboard Cite

show abstract

“…Post-heat treatments significantly change the microstructures. Low-temperature direct aging at around 100 • C introduces nano Si precipitates from the supersaturated solid solution and improves the tensile strength-ductility balance [37][38][39]. Heat treatments over 200 • C slightly affect the α grain size and orientations, whereas the cellular microstructure changes to a Si particle-dispersed microstructure with heat treatments [40,41].…”

Section: Introductionmentioning

confidence: 99%

Persistent Homology Analysis of the Microstructure of Laser-Powder-Bed-Fused Al–12Si Alloy

Suzuki,

Sasa,

Kobashi

et al. 2023

Materials

Self Cite

View full text Add to dashboard Cite

The laser powder bed fusion (L-PBF) process provides the cellular microstructure (primary α phase surrounded by a eutectic Si network) inside hypo-eutectic Al–Si alloys. The microstructure changes to the particle-dispersed microstructure with heat treatments at around 500 °C. The microstructural change leads to a significant reduction in the tensile strength. However, the microstructural descriptors representing the cellular and particle-dispersed microstructures have not been established, resulting in difficulty in terms of discussion regarding the structure–property relationship. In this study, an attempt was made to analyze the microstructure in L-PBF-built and subsequently heat-treated Al–12Si (mass%) alloys using the persistent homology, which can analyze the spatial distributions and connections of secondary phases. The zero-dimensional persistent homology revealed that the spacing between adjacent Si particles was independent of Si particle size in the as-built alloy, whereas fewer Si particles existed near large Si particles in the heat-treated alloy. Furthermore, the first principal component of a one-dimensional persistent homology diagram would represent the microstructural characteristics from cellular to particle-dispersed morphology. These microstructural descriptors were strongly correlated with the tensile and yield strengths. This study provides a new insight into the microstructural indices describing unique microstructures in L-PBF-built alloys.

show abstract

“…In L-PBF, a scanning laser irradiates the metal/alloy powder that is sequentially bedded on a base plate, which leads to selective melting and subsequent rapid solidification. Consequently, L-PBF-processed Al alloy products exhibit significantly refined microstructures [5][6][7][8], which lead to higher strengths than those of the Al alloys fabricated using conventional casting processes [9][10][11][12]. Al-Si-based alloys are known to be suitable for the L-PBF process [13][14][15]; however, L-PBF-processed Al-Si-based alloys exhibit reduced strength at temperatures higher than 200 • C [16].…”

Section: Introductionmentioning

confidence: 99%

Microstructural Variations in Laser Powder Bed Fused Al–15%Fe Alloy at Intermediate Temperatures

et al. 2022

Self Cite

View full text Add to dashboard Cite

The samples of the Al–15Fe (mass%) binary alloy that were additively manufactured by laser powder bed fusion (L-PBF) were exposed to intermediate temperatures (300 and 500 °C), and the thermally induced variations in their microstructural characteristics were investigated. The L-PBF-manufactured sample was found to have a microstructure comprising a stable θ-Al13Fe4 phase localized around melt-pool boundaries and several spherical metastable Al6Fe-phase particles surrounded by a nanoscale α-Al/Al6Fe cellular structure in the melt pools. The morphology of the θ phase remained almost unchanged even after 1000 h of exposure at 300 °C. Moreover, the nanoscale α-Al/Al6Fe cellular structure dissolved in the α-Al matrix; this was followed by the growth (and nucleation) of the spherical Al6Fe-phase particles and the precipitation of the θ phase. Numerous equiaxed grains were formed in the α-Al matrix during the thermal exposure, which led to the formation of a relatively homogenous microstructure. The variations in these microstructural characteristics were more pronounced at the higher investigated temperature of 500 °C.

show abstract

Enhancement in strength and ductility of laser powder bed fused Al–12Si alloy by introducing nanoscale precipitates

Cited by 10 publications

References 35 publications

Influence of Contour Scan Variation on Surface, Bulk and Mechanical Properties of LPBF-Processed AlSi7Mg0.6

Influence of Contour Scan Variation on Surface, Bulk and Mechanical Properties of LPBF-Processed AlSi7Mg0.6

Persistent Homology Analysis of the Microstructure of Laser-Powder-Bed-Fused Al–12Si Alloy

Microstructural Variations in Laser Powder Bed Fused Al–15%Fe Alloy at Intermediate Temperatures

Contact Info

Product

Resources

About