2024年4月28日，课题组青年教师宋欣博士为第一作者的一篇论文“Rapid-thermal-process pre-treatment promoted precipitation towards strengthening hard magnetism of Sm2Co17-type magnets”被金属材料旗舰刊物ACTA MATERIALIA录用。祝贺他！

Abstract：

Dislocations can act as heterogeneous nucleation sites but their annihilations upon heating sacrifice point defects nearby, weakening the driving force for precipitate nucleation. In order to keep a high density of dislocations and point defects together, here rapid-thermal-process (RTP) pre-treatment was carried out to promote the precipitate nucleation in Sm2Co17-type permanent magnets that evolve gradual formation and dissociation of dislocations during concurrent precipitation and recrystallization. As exhibited in a model magnet Sm25Co49.3Fe17.1Cu5.6Zr3.0 (wt.%) with high-density dislocations at solution-treated state, the RTP pre-treatment can induce excess point defects owing to the migration of solute atoms towards equilibrium state and the quenching of point defects, and suppress the early-stage diffusion-controlled dissociation of dislocations. After whole-process isothermal aging and slow cooling, the RTP pre-treated magnet possesses much higher fraction of hexagonal SmCo5 (1:5H) nanoprecipitates than the non-pre-treated one, giving rise to an effective coercivity enhancement from 26.20 to 30.34 kOe and knee-point field from 14.43 to 19.20 kOe. These findings add insight into controlling precipitation in dislocation-bearing supersaturated solid solutions, which are feasible for strengthening the Sm-Co-based magnets.