中國(guó)有色金屬學(xué)報(bào)(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 27 No. 9 September 2017 |
（1. College of Physics and Electronic Information Engineering, Neijiang Normal University, Neijiang 641002, China; 2. School of Materials Science and Engineering, Sichuan University, Chengdu 610065, China）
Abstract:The effects of solidification rate and excessive Fe on phase formation and magnetocaloric properties of LaFe11.6xSi1.4 (x=1.1, 1.2) were investigated by XRD, SEM and VSM measurements. The XRD results show that the amount of LaFeSi phase in the as-cast melt-spun ribbons prepared by a copper wheel at a speed of 10 m/s is less than that in the as-cast arc melting buttons with the same x values. The annealed melt-spun ribbons contain smaller amount of La(Fe,Si)13 (1:13) phase than the corresponding annealed arc melting buttons. Although the melt-spun sample has finer crystalline grains of α-Fe, as indicated by SEM analysis, its crystalline size has not reached nano-scale. Therefore, the magnetic exchange-coupling between 1:13 phase and α-Fe phase has not been observed in melt-spun ribbons. Further, the maximum negative magnetic entropy change (-SMax) and relative cooling power (RCP) of annealed melt-spun ribbons under a field change of 0-2 T are weaker than those of the corresponding annealed arc melting buttons.
Key words: LaFe11.6xSi1.4 alloy; solidification rate; microstructure; magnetocaloric properties
