Diffusion bonding of high entropy alloy and stainless steel at a relative lower temperature via surface nano-crystallization treatment

 

氏名:Yangen Li , Heting Liao, Yuta Ebi, Taisei Sugiyama, Takashi Yajima, Rana Hossain, Yujie Jia, Shihao Zhu, Jiaqin Xu, Yusuke Nishii, Haruhi Ochi, Ayaka Satani, Souma Tanaka, Futaba Shiroto, Yuji Sato, Shuhei Shinzato, and Shigenobu Ogata

所属:Osaka University

概要:Sluggish diffusion effect of high entropy alloy limits its diffusion bonding with other components in practical applications. In this paper, the surface mechanical attrition treatment (SMAT) strategy for performing diffusion bonding joints of high entropy alloy (HEA) at a relative lower temperature is proposed. The EDS results demonstrate that the diffusion distance of Fe atoms increases significantly after SMAT since more gain boundaries are formed after SMAT. Furthermore, with this method the HEA/stainless steel joint can achieve a useable strength of 320 MPa at relative lower temperature of 850 °C (∼0.63 T_m, Temperature of melting). Molecular dynamics simulations show that the apparent diffusivity of Fe in the polycrystalline model is significantly higher than in the single-crystalline model because of fast diffusion at grain boundaries, i.e., the grain boundaries are fast diffusion channels. More detailed microstructure analysis indicates that although the density of dislocations increases after SMAT, its elemental diffusion ability is much weaker compared with grain boundaries. This study provides a feasible avenue for the application of diffusion bonding in HEAs, which could greatly broaden the applications fields of HEAs.

 

論文掲載,発表実績:
(学術雑誌掲載論文)

  • H. Gao, G. He, Q. Li, Y. Li, W. Hu, S. Zhou, F. Liu, J. Yi, Y. Zhang, Z. Cai, S. Ogata, L. Qiao and L. Gao. (2023). Diffusion bonding of high entropy alloy and stainless steel at a relative lower temperature via surface nano-crystallization treatment. Journal of Materials Research and Technology, 24, 475-487.

 




Posted : 2024年03月31日