The grain growth mechanism of IN718 superalloy fabricated by selective laser melting (SLM) was studied. Epitaxial growth with the same crystallographic orientation or rotating by 90° across the melting pool boundary and competitive growth in the same melting pool were observed. Either of the two patterns of epitaxial growth can maintain the same grain across the melting pool boundary. Competitive growth is determined by both the heat flow direction and preferred crystallographic orientation. In SLM, the grains grow along the preferred crystallographic orientation owing to a high solidification rate. The smaller the deviation angles between the heat flow direction and the preferred crystallographic orientation, the faster the grain growth rate.
ChlebusEGruberKKuźnickaBEffect of heat treatment on the microstructure and mechanical properties of Inconel 718 processed by selective laser melting. Mater Sci Eng: A. 2015; 639:647–655. doi: 10.1016/j.msea.2015.05.035
2.
LiJZhaoZBaiPMicrostructure evolution and mechanical properties of IN718 alloy fabricated by selective laser melting following different heat treatments. J Alloys Compd. 2019; 772:861–870. doi: 10.1016/j.jallcom.2018.09.200
3.
TuchoWMCuvillierPSjolyst-KvernelandAMicrostructure and hardness studies of Inconel 718 manufactured by selective laser melting before and after solution heat treatment. Mater Sci Eng A. 2017; 689:220–232. doi: 10.1016/j.msea.2017.02.062
4.
KumarSSudhakar RaoGChattopadhyayKEffect of surface nanostructure on tensile behavior of superalloy IN718. Mater Des. 2014; 62:76–82. doi: 10.1016/j.matdes.2014.04.084
5.
SuiSTanHChenJThe influence of Laves phases on the room temperature tensile properties of Inconel 718 fabricated by powder feeding laser additive manufacturing. Acta Mater. 2019; 164:413–427. doi: 10.1016/j.actamat.2018.10.032
6.
BasakADasS.Epitaxy and microstructure evolution in metal additive manufacturing. Annu Rev Mater Res. 2016; 46:125–149. doi: 10.1146/annurev-matsci-070115-031728
7.
LiuFLinXHuangC.The effect of laser scanning path on microstructures and mechanical properties of laser solid formed nickel-base superalloy Inconel 718. J Alloys Compd. 2011; 509(13):4505–4509. doi: 10.1016/j.jallcom.2010.11.176
8.
MaMWangZZengX.Effect of energy input on microstructural evolution of direct laser fabricated IN718 alloy. Mater Charact. 2015; 106:420–427. doi: 10.1016/j.matchar.2015.06.027
9.
ParimiLLRaviAGClarkDMicrostructural and texture development in direct laser fabricated IN718. Mater Charact. 2014; 89:102–111. doi: 10.1016/j.matchar.2013.12.012
10.
HelmerHBauereißASingerRF.Grain structure evolution in Inconel 718 during selective electron beam melting. Mater Sci Eng A. 2016; 668:180–187. doi: 10.1016/j.msea.2016.05.046
11.
DindaGPDasguptaAKMazumderJ.Texture control during laser deposition of nickel-based superalloy. Scr Mater. 2012; 67(5):503–506. doi: 10.1016/j.scriptamat.2012.06.014
ClootsMUggowitzerPJWegenerKInvestigations on the microstructure and crack formation of IN738LC samples processed by selective laser melting using Gaussian and doughnut profiles. Mater Des. 2016; 89:291–299. doi: 10.1016/j.matdes.2015.10.027
14.
WangDSongCYangYInvestigation of crystal growth mechanism during selective laser melting and mechanical property characterization of 316L stainless steel parts. Mater Des. 2016; 100:291–299. doi: 10.1016/j.matdes.2016.03.111
15.
DengDPengaRLBrodinbHMicrostructure and mechanical properties of Inconel 718 produced by selective laser melting: sample orientation dependence and effects of post heat treatments. Mater Sci Eng A. 2018; 713:294–306. doi: 10.1016/j.msea.2017.12.043
16.
YuHLiJLinXAnomalous overgrowth of converging dendrites during directional solidification. J Cryst Growth. 2014; 402(36):210–214. doi: 10.1016/j.jcrysgro.2014.05.016
17.
AkamatsuSFaivreGIhleT.Symmetry-broken double fingers and seaweed patterns in thin-film directional solidification of a nonfaceted cubic crystal. Physl Rev E Stat Phys Plasmas Fluids Relat Interdiscipl Top. 1995; 51(5):4751–4773.
18.
AkamatsuSIhleT.Similarity law for the tilt angle of dendrites in directional solidification of non-axially-oriented crystals. Phys Rev.E. 1997; 56(56):4479–4485. doi: 10.1103/PhysRevE.56.4479
19.
AkamatsuSFaivreG.Anisotropy-driven dynamics of cellular fronts in directional solidification in thin samples. Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscipl Top. 1998; 58(3):3302–3315.
20.
YuCPucunBFeiLInvestigation on the precipitates of IN718 alloy fabricated by selective laser melting. Metals (Basel). 2019; 9:1128. https://doi.org/10.3390/met9101128.
21.
WanHYZhouZJLiCPEffect of scanning strategy on grain structure and crystallographic texture of Inconel 718 processed by selective laser melting. J Mater Sci Technol. 2018; 34(10):89–94. doi: 10.1016/j.jmst.2018.02.002
22.
ChenZWPhanMALDarvishK.Grain growth during selective laser melting of a Co–Cr–Mo alloy. J Mater Sci. 2017; 52(12):7415–7427. doi: 10.1007/s10853-017-0975-z
