Abbreviation (ISO4): Journal of Materials Engineering
Editor in chief: Xiangbao CHEN
Journal of Materials Engineering >
Microstructural evolution and magnetocaloric properties of cold plastically deformed La0.6Pr0.4Fe10.7Co0.8Si1.5 alloy
Received date: 2023-05-19
Revised date: 2023-08-13
Online published: 2024-03-10
In order to improve the preparation process and practical process of magnetic refrigerant, a method of accelerating phase formation by cold compression plastic deformation at room temperature was proposed. The grain structure, phase composition and magneto-thermal effects of La0.6Pr0.4Fe10.7Co0.8Si1.5 alloy were systematically studied. The results show that with the increase of compression ratio, the number of grains per unit area increases and the grain size is uniform. Compared with the uncompressed sample, the proportion of magnetothermal phase increases after annealing under the same conditions. When the compression rate is 30%, the ratio of 1∶13 phase after 3 days annealing is 92.68%(volume fraction), and the pre deformed sample is obviously better than the undeformed sample.After annealing for 3 days, the Curie temperature (T C) of 30% pre-deformed La0.6Pr0.4Fe10.7Co0.8Si1.5 is 289 K, and the magnetic entropy change (ΔS max) is -7.1 J/(kg·K) under 2 T magnetic fields.The suitable Curie temperature and value of ΔS max make it an attractive potential candidate for the room temperature magnetic refrigeration application.
Key words: plastic deformation; 1∶13 phase; magnetocaloric effect; La(Fe,Si)13 alloy
Xu YANG , Bin FU , Jie HAN , Lianqi ZHANG . Microstructural evolution and magnetocaloric properties of cold plastically deformed La0.6Pr0.4Fe10.7Co0.8Si1.5 alloy[J]. Journal of Materials Engineering, 2023 , 51(11) : 189 -196 . DOI: 10.11868/j.issn.1001-4381.2023.000338
图1 La0.6Pr0.4Fe10.7Co0.8Si1.5样品的压缩示意图、应力-应变曲线和实物图(a)未压缩试样示意图;(b)压缩试样示意图;(c)应力-应变曲线;(d)产生“人字形”裂纹的试样;(e)边缘粉化脱落的试样Fig.1 Schematic diagrams,stress-strain curve,and physical images of the La0.6Pr0.4Fe10.7Co0.8Si1.5 samples(a)schematic diagram of uncompressed sample;(b)schematic diagram of compressed sample;(c)stress-strain curve;(d)sample with “herringbone” cracks;(e)sample with silted edges |
图4 两种样品XRD图谱精修后的结果(a)La0.6Pr0.4Fe10.7Co0.8Si1.5-0%;(b)La0.6Pr0.4Fe10.7Co0.8Si1.5-30%Fig.4 XRD patterns after Fullprof refinement of the two samples (a)La0.6Pr0.4Fe10.7Co0.8Si1.5-0%;(b)La0.6Pr0.4Fe10.7Co0.8Si1.5-30% |
表1 未压缩与30%压缩率La0.6Pr0.4Fe10.7Co0.8Si1.5样品的晶胞参数、R P、R WP、R exp和χ 2等信息Table 1 Cell parameters, R P, R WP, R exp and χ 2 of the La0.6Pr0.4Fe10.7Co0.8Si1.5 uncompressed and with 30% compression rate |
Compression | A/nm | b/nm | c/nm | Α/(°) | Β/(°) | Γ/(°) |
---|---|---|---|---|---|---|
0% | 1.145706 | 1.145706 | 1.145706 | 90 | 90 | 90 |
30% | 1.146592 | 1.146592 | 1.146592 | 90 | 90 | 90 |
Compression | R P | R WP | R exp | χ 2 | α-Fe/% | |
0% | 5.33 | 7.23 | 4.72 | 2.34 | 8.93 | |
30% | 3.59 | 4.59 | 4.54 | 1.02 | 4.11 |
图5 未压缩和压缩30% La0.6Pr0.4Fe10.7Co0.8Si1.5样品的SEM图像及EDS图谱(a)退火3天未压缩;(b)退火3天压缩30%;(c)退火5天压缩30%;(d)~(f)对应①②③位置的EDS图谱Fig.5 SEM and EDS images of La0.6Pr0.4Fe10.7Co0.8Si1.5 samples without and with 30% compression(a)annealed for 3 days without compression;(b)annealed for 3 days with 30% compression;(c)annealed for 5 days with 30% compression;(d)-(f)EDS spectra corresponding to position ①,② and ③ |
图6 未压缩和压缩率为30% La0.6Pr0.4Fe10.7Co0.8Si1.5样品中各相所占比例(a)退火3天未压缩;(b)退火3天压缩30%;(c)退火5天压缩30%Fig.6 Proportion of each phase in the uncompressed and 30% compressed La0.6Pr0.4Fe10.7Co0.8Si1.5 samples(a)annealed for 3 days without compression;(b)annealed for 3 days with 30% compression;(c)annealed for 5 days with 30% compression |
表2 30%预变形La0.6Pr0.4Fe10.7Co0.8Si1.5合金和几种典型MCE材料的居里温度(T C)、制冷剂容量(RC)及磁熵变(ΔH=2 T)Table 2 T C, RC and of pre-deformed 30% La0.6Pr0.4Fe10.7Co0.8Si1.5 alloy and several typical MCE materials |
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