Reduced Annealing Time and Enhanced Magnetocaloric Effect of La(Fe, Al)13 Alloy by La-nonstoichiometry and Si-doping

Abstract

LaFe 13−x M x (M = Si, Al) alloys are promising for use in magnetic refrigeration. However, they require long annealing time (30 days) in order to optimize the magnetocaloric properties. Research has shown that the addition of extra La in off-stoichiometric alloys can greatly shorten the annealing time. Therefore, the purpose of this study is to investigate the influence of the extra addition of La on the annealing properties of a new off-stoichiometric La 1.7 Fe 11.6 Al 1.4−x Si x (x = 0, 0.1, 0.4) alloys. It was demonstrated that after a 36h annealing time, a large volume fraction of 1:13 magnetocaloric phase was obtained for all alloys. Further microstructural analysis of the off-stoichiometric La 1.7 Fe 11.6 Al 1.4−x Si x alloys revealed a facet-like grain morphology. The La 1.

Recent Progress of Synchrotron X-Ray Imaging and Diffraction on the Solidification and Deformation Behavior of Metallic Materials

“…However, the limited field of view makes it difficult to establish a solid connection between microscopic observations and macroscopic properties [13][14][15][16][17]. Scanning electron microscope (SEM), on the contrary, offers a larger field of view but often compromised spatial resolution [18][19][20]. In addition, the electron backscattering diffraction (EBSD) developed over the last three decades has been effectively applied in the characterization of grain structure and microplastic deformation in polycrystalline [21][22][23][24][25][26].…”

Microstructure and magnetocaloric properties in melt-spun and high-pressure hydrogenated La0.5Pr0.5Fe11.4Si1.6 ribbons*

“…It is usually requisite to perform a lengthy annealing treatment (about 30 days) to ensure homogenization of alloys. [9][10][11] In order to overcome such a difficulty, it is proposed that the directional solidification technology can directly obtain a large number of 1:13 phases. [12] The rapid solidification inhibits the formation of incipient iron phase and speeds up atomic diffusion during heat treatment.…”

2D single crystal Bragg-dip mapping by time-of-flight energy-resolved neutron imaging on IMAT@ISIS

“…Furthermore, the variation in (001) misorientation perpendicular to the withdrawal direction should be intrinsically related to the shape of the solid/liquid isotherm 11 . Unfortunately, standard microstructural investigation tools, such as optical and electron microscopy, are limited to 2D sample surface analysis 13 , 14 . There are some techniques for 3D reconstruction, however, they are time and labour intensive and provide only local reconstructions of small volumes 15 , 16 .…”