The Z-axis lifting height is significant in layer-by-layer fabrication using laser directed energy deposition (L-DED). In this paper, we have deeply examined the porosity and grain morphologies in the double layers of AlSi10Mg by blue laser directed energy deposition (BL-DED). After the deposition of a single track, the depositional head was raised by a certain Z-axis lifting height and then a second layer was deposited. As the Z-axis lifting height increases, the quantity density of pores in the second layer increases, leading to higher porosity. Especially, the boundary of the overlapping area exhibits the highest porosity, measuring 0.84%. The Z-axis lifting height can be set lower than the height of a single track, while maintaining high dimensional accuracy and surface quality.
TanZEEPangJHLKaminskiJ, et al.Characterisation of porosity, density, and microstructure of directed energy deposited stainless steel AISI 316L. Addit Manuf2019; 25: 286–296.
2.
WangAWangHWuY, et al.3D Printing of aluminum alloys using laser powder deposition: a review. Int J Adv Manuf Tech2021; 116: 1–37.
3.
SvetlizkyDZhengBButaT, et al.Directed energy deposition of Al 5xxx alloy using Laser engineered net shaping (LENS®). Mater Des2020; 192: 108763.
4.
DebRoyTWeiHLZubackJS, et al.Additive manufacturing of metallic components – process, structure and properties. Prog Mater Sci2018; 92: 112–224.
5.
ThompsonSMBianLShamsaeiN, et al.An overview of direct Laser deposition for additive manufacturing; part I: transport phenomena, modeling and diagnostics. Addit Manuf2015; 8: 36–62.
6.
GuDShiXPopraweR, et al.Material-structure-performance integrated laser-metal additive manufacturing. Science2021; 372: 1487.
7.
SvetlizkyDDasMZhengB, et al.Directed energy deposition (DED) additive manufacturing: physical characteristics, defects, challenges and applications. Mater Today2021; 49: 271–295.
8.
WeiHLLiuFQLiaoWH, et al.Prediction of spatiotemporal variations of deposit profiles and inter-track voids during laser directed energy deposition. Addit Manuf2020; 34: 101219.
9.
LiuZZhaoDWangP, et al.Additive manufacturing of metals: microstructure evolution and multistage control. J Mater Sci Technol2022; 100: 224–236.
10.
WangXLiuZGuoZ, et al.A fundamental investigation on three–dimensional laser material deposition of AISI316L stainless steel. Opt Laser Technol2020; 1: 106107.
11.
FengBWangCZhangQ, et al.Effect of laser hatch spacing on the pore defects, phase transformation and properties of selective laser melting fabricated NiTi shape memory alloys. Mater Sci Eng A2022; 840: 142965.
12.
ZhuGLiDZhangA, et al.The influence of laser and powder defocusing characteristics on the surface quality in laser direct metal deposition. Opt Laser Technol2012; 44: 349–356.
13.
BiJLeiZChenY, et al.Effect of process parameters on formability and surface quality of selective laser melted Al–Zn–Sc–Zr alloy from single track to block specimen. Opt Laser Technol2019; 118: 132–139.
14.
du PlessisA. Effects of process parameters on porosity in laser powder bed fusion revealed by X-ray tomography. Addit Manuf2019; 30: 100871.
15.
TangZWeiQGaoZ, et al.2000W Blue laser directed energy deposition of AlSi7Mg: process parameters, molten pool characteristics, and appearance defects. Virtual Phys Prototy2022; 1: 18.
16.
BeanGEWitkinDBMcLouthTD, et al.Effect of laser focus shift on surface quality and density of Inconel 718 parts produced via selective laser melting. Addit Manuf2018; 22: 207–215.
17.
ZhaoPZhangYLiuW, et al.Influence mechanism of laser defocusing amount on surface texture in direct metal deposition. J Mater Process Technol2023; 312: 117822.
18.
OnoKSatoYTakazawaY, et al.Development of high intensity multibeam laser metal deposition system with blue diode lasers for additively manufacturing of copper rod. J Laser Appl2021; 33: 042014.
19.
HsuH-WLoY-LLeeM-H. Vision-based inspection system for cladding height measurement in direct energy deposition (DED). Addit Manuf2019; 27: 372–378.
20.
BinegaEYangLSohnH, et al.Online geometry monitoring during directed energy deposition additive manufacturing using laser line scanning. Precis Eng2022; 73: 104–114.
21.
GarmendiaIPujanaJLamikizA, et al.Structured light-based height control for laser metal deposition. J Manuf Process2019; 42: 20–27.
22.
RibeiroKSBNúñezHHLVenterGS, et al.A hybrid machine learning model for in-process estimation of printing distance in laser directed energy deposition. Int J Adv Manuf Technol2023; 127: 3183–3194.
23.
WangHKawahitoYYoshidaR, et al.Development of a high-power blue laser (445nm) for material processing. Opt Lett2017; 42: 2251–2254.
24.
AsanoKTsukamotoMSechiY, et al.Laser metal deposition of pure copper on stainless steel with blue and IR diode lasers. Opt Laser Technol2018; 107: 291–296.
25.
SatoYTsukamotoMShobuT, et al.In situ X-ray observations of pure-copper layer formation with blue direct diode lasers. Appl Surf Sci2019; 480: 861–867.
26.
WangAWeiQLuoS, et al.Blue laser directed energy deposition of aluminum with synchronously enhanced efficiency and quality. Addit Manuf Lett2023; 5: 100127.
27.
WangAWeiQTangZ, et al.Effects of processing parameters on pore defects in blue laser directed energy deposition of aluminum by in and ex situ observation. J Mater Process Technol2023; 1: 118068.
28.
XiaoYKChenHBianZY, et al.Enhancing strength and ductility of AlSi10Mg fabricated by selective laser melting by TiB2 nanoparticles. J Mater Sci Technol2022; 109: 254–266.
29.
LiXPJiGChenZ, et al.Selective laser melting of nano-TiB2 decorated AlSi10Mg alloy with high fracture strength and ductility. Acta Mater2017; 129: 183–193.
30.
TodhunterLDLeachRKLawesSDA, et al.Industrial survey of ISO surface texture parameters. CIRP J Manuf Sci Technol2017; 19: 84–92.
31.
XueLAtliKCZhangC, et al.Laser powder bed fusion of defect-free NiTi shape memory alloy parts with superior tensile superelasticity. Acta Mater2022; 229: 117781.
32.
GroveCJerramDA. jPOR: an ImageJ macro to quantify total optical porosity from blue-stained thin sections. Comput Geosci2011; 37: 1850–1859.
33.
YamanakaKSaitoWMoriM, et al.Abnormal grain growth in commercially pure titanium during additive manufacturing with electron beam melting. Materialia2019; 6: 100281.
34.
LiJQuHBaiJ. Grain boundary engineering during the laser powder bed fusion of TiC/316L stainless steel composites: new mechanism for forming TiC-induced special grain boundaries. Acta Mater2022; 226: 117605.
35.
WangSNingJZhuL, et al.Role of porosity defects in metal 3D printing: formation mechanisms, impacts on properties and mitigation strategies. Mater Today2022; 59: 133–160.
Supplementary Material
Please find the following supplemental material available below.
For Open Access articles published under a Creative Commons License, all supplemental material carries the same license as the article it is associated with.
For non-Open Access articles published, all supplemental material carries a non-exclusive license, and permission requests for re-use of supplemental material or any part of supplemental material shall be sent directly to the copyright owner as specified in the copyright notice associated with the article.
