Investigation of the role of Ni addition in nano-crystallization of Fe-based amorphous alloys

• Published in: Journal of alloys and compounds 2024-11, Vol.1005, p.176172, Article 176172
• Main Authors: Zhang, Xuanyuan, Huang, Xiaoying, Liang, Yunwu, Cai, Yuanfei, Chen, Yanan, Gao, Meng, Kawazoe, Yoshiyuki, Umetsu, Rie, Xiang, Mingliang, Zhao, Xiaojun, Wang, Yaocen, Wang, Junqiang, Zhang, Yan
• Format: Article
• Language: English
• Subjects: ab initio molecular dynamics; Diffusion ability; Nano-crystallization; Soft magnetic
• ISSN: 0925-8388
• DOI: 10.1016/j.jallcom.2024.176172

The influence of Ni addition on Fe-based nano-crystalline alloys during the nano-crystallization process is extensively studied by using first-principles molecular dynamics simulations and experiments. It was found that during the nucleation stage, Ni enhances the initial crystallization tendency by increasing the free energy difference between the amorphous and nano-crystalline structures, while prolonging the nano-crystallization process by capturing surrounding non-metallic elements. During grain growth stage, Ni addition effectively reduces the diffusion ability of P but increases that of Si and B, thereby limiting the ability of Ni to suppress grain growth by constraining elemental rearrangement. Regarding magnetic properties, samples were ultra-rapidly annealed at 773 K to achieve optimal crystallization process, with magnetic coercivity of 3.9 and 6.5 A/m for ribbons with and without Ni addition, respectively, and saturated magnetic flux density values of both approximately 1.78 T. The grain sizes were 21.0 and 21.5 nm, respectively. Therefore, certain amount of Ni addition can effectively reduce the coercivity of nano-crystalline alloys without significantly deteriorating the saturated magnetic flux density, but its ability of inhibit grain growth is limited. [Display omitted] •Ab-initio simulation to investigate the subtle change that occurs during the nano-crystallization process after Ni addition.•Local bonding preference and diffusion ability of Ni during nano-crystallization process analyzed by ab-initio simulation.•Experiments to investigate the thermal, structure and magnetic properties of nano-crystalline materials after Ni addition.•Potential compositional designing of Fe-based nano-crystalline alloys while doping Ni.