Authors
BC Zhou, T Yang, G Zhou, H Wang, JH Luan, ZB Jiao
Publication date
2021/2/15
Journal
Acta Materialia
Volume
205
Pages
116561
Publisher
Pergamon
Description
Control of discontinuous and continuous precipitation is crucial for tailoring the microstructure and mechanical properties of NiAl-strengthened steels. Through a combination of atom probe tomography, transmission electron microscopy, electron backscatter diffraction, first-principles calculations, and mechanical tests, we demonstrate that Cu is effective in not only promoting the nano-scale continuous NiAl precipitation but also in suppressing the coarse-scale discontinuous NiAl precipitation at grain boundaries, which results in the development of new NiAl-strengthened steels with a high yield strength (1400 MPa) and good ductility (10%). Our analyses indicate that the mechanisms for suppressing discontinuous NiAl precipitation are twofold. The main one is the acceleration of continuous NiAl precipitation through Cu partitioning, which swiftly reduces the matrix supersaturation, thereby decreasing the chemical …
Total citations
20212022202320244272225