First-principles Study on Effect of Alloying Elements on Co-precipitation of bcc-Cu / NiAl

Co-precipitation of bcc-Cu and NiAl is an effective strengthening method commonly used for high strength steel. To investigate thoroughly the effects of different alloying elements on the co-precipitation of bcc-Cu / NiAl, the interfacial properties of element X (X = Cr, Co, Mo, W, V, Mn)-doped bcc-Cu(001) / NiAl(001) interfaces were studied based on first principles. The analysis of interfacial adhesion work, interfacial energy and electronic properties could clarify the significance of interfacial alloying. The calculated results show that when the Al-terminal bcc-Cu/ NiAl interface dopes with Cr, Mo, W, V, Mn, the adhesion work increases, the interfacial energy decreases, promoting co-precipitation of bcc- Cu/ NiAl, but the effects are more stronger when Al replaced by Mo, W or V. The interfacial stability of Ni-terminal interface is lower than that of Al-terminal interface. The electron structure analysis shows that Cr, Co, Mo, W, V, Mn have obvious hybridization of electron orbitals with Cu atoms at the interface and significantly strengthen the interatomic interaction when Al-terminal bcc-Cu/ NiAl interface is doped. When Ni-terminal interface is doping, the hybridization degree is weak. After Mo, W and V doping the interface, the charge density at the interface increases, and stronger non-polar covalent bonds are formed between Cu atoms and alloying atoms. © 2024 Cailiao Daobaoshe/ Materials Review. All rights reserved.