Crack mitigation in additively manufactured AlCrFe2Ni2 high-entropy alloys through engineering phase transformation pathway

Crack mitigation in additively manufactured AlCrFe2Ni2 high-entropy alloys through engineering phase transformation pathway

Communications Materials

10.1038/s43246-024-00542-z

http://dx.doi.org/10.1038/s43246-024-00542-z

Shahryar Mooraj, Xizhen Dong, Shengbiao Zhang, Yanming Zhang, Jie Ren, Shuai Guan, Chenyang Li, Rameshwari Naorem, Nicolas Argibay, Wei Chen, Wentao Yan, Dierk Raabe, Zhongji Sun, Wen Chen

18 June 2024

Mooraj, S., Dong, X., Zhang, S., Zhang, Y., Ren, J., Guan, S., Li, C., Naorem, R., Argibay, N., Chen, W., Yan, W., Raabe, D., Sun, Z., & Chen, W. (2024). Crack mitigation in additively manufactured AlCrFe2Ni2 high-entropy alloys through engineering phase transformation pathway. Communications Materials, 5(1). https://doi.org/10.1038/s43246-024-00542-z

The far-from-equilibrium solidification during additive manufacturing often creates large residual stresses that induce solid-state cracking. Here we present a strategy to suppress solid-state cracking in an additively manufactured AlCrFe2Ni2 high-entropy alloy via engineering phase transformation pathway. We investigate the solidification microstructures formed during laser powder-bed fusion and directed energy deposition, encompassing a broad range of cooling rates. At high cooling rates (104−106 K/s), we observe a single-phase BCC/B2 microstructure that is susceptible to solid-state cracking. At low cooling rates (102−104 K/s), FCC phase precipitates out from the BCC/B2 matrix, resulting in enhanced ductility (~10 %) and resistance to solid-state cracking. Site-specific residual stress/strain analysis reveals that the ductile FCC phase can largely accommodate residual stresses, a feature which helps relieve residual strains within the BCC/B2 phase to prevent cracking. Our work underscores the value of exploiting the toolbox of phase transformation pathway engineering for material design during additive manufacturing.

Attribution 4.0 International (CC BY 4.0)

This research / project is supported by the Agency for Science, Technology and Research - Career Development Fund
Grant Reference no. : C222812017

This research / project is supported by the Agency for Science, Technology and Research - Young Individual Research Grant
Grant Reference no. : M22K3c0096

This research / project is supported by the Ministry of Education, Singapore - Academic Research Fund Tier 2
Grant Reference no. : MOE-T2EP50221-001

https://oar.a-star.edu.sg/communities-collections/articles/21156

2662-4443

Institute of Materials Research and Engineering

https://www.nature.com/articles/s43246-024-00542-z