Demands for ultrahigh strength in structural materials have been steadily increasing in response to environmental issues. Maraging alloys offer a high tensile strength and fracture toughness through a reduction of lattice defects and formation of intermetallic precipitates. The semi-coherent precipitates are crucial for exhibiting ultrahigh strength; however, they still result in limited work hardening and uniform ductility. Here, we demonstrate a strategy involving deformable semi-coherent precipitates and their dynamic phase transformation based on a narrow stability gap between two kinds of ordered phases. In a model medium-entropy alloy, the matrix precipitate acts as a dislocation barrier and also dislocation glide media; the grain-boundary precipitate further contributes to a significant work-hardening via dynamic precipitate transformation into the type of matrix precipitate. This combination results in a twofold enhancement of strength and uniform ductility, thus suggesting a promising alloy design concept for enhanced mechanical properties in developing various ultrastrong metallic materials.
Bibliographical noteFunding Information:
This work was supported by the National Research Foundation of Korea grant (NRF − 2020R1C1C1003554); the NRF of Korea grant funded by the Korea government (MSIT) (NRF-2022R1A5A1030054); the Fundamental Research Program of the Korean Institute of Materials Science (PNK8730); Samsung Research Funding & Incubation Center of Samsung Electronics (SRFC-MA1902-04); and the Korea Institute for Advancement of Technology (KIAT) grant funded by the Korean Government (MOTIE, P0002019, The Competency Development Program for Industry Specialist). H.N.H. was supported by the NRF of Korea grant funded by the Korea government (MSIT) (NRF − 2020R1A5A6017701). W.-S.K. was supported by the NRF of Korea funded by Ministry of Science and ICT (Grant No. NRF-2019M3D1A1079214) and INHA UNIVERSITY Research Grant.
© 2023, The Author(s).
ASJC Scopus subject areas
- General Chemistry
- General Biochemistry,Genetics and Molecular Biology
- General Physics and Astronomy