Magnetocaloric Effect in a Ni2.25Mn0.75Ga0.93Si0.07 Alloy

• Published in: Journal of communications technology & electronics Vol. 68; no. 4; pp. 407 - 412
• Main Authors: Gaifullin, R. Yu, Gadzhiev, A. B., Aliev, A. M., Taskaev, S. V., Musabirov, I. I.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01-04-2023; Springer Nature B.V
• Subjects: Communications Engineering; Engineering; Forging; Low temperature; Martensitic transformations; Microstructure; Networks; ON THE 90th ANNIVERSARY OF VLADIMIR GRIGOR’EVICH SHAVROV; Phase transitions; Room temperature
• ISSN: 1064-2269; 1555-6557
• DOI: 10.1134/S1064226923040022

The results of a study of the magnetocaloric effect (MCE) in Ni
2.25
Mn
0.75
Ga
0.93
Si
0.07
alloy are presented in the cast state and in the state after multi-axial isothermal forging (MIF) at 700°C and true degree of deformation
e
= 3.19. It is shown that as a result of MIF, the initial equiaxed microstructure is transformed into a bimodal one in which large grains 100–200 µm in size are surrounded by a layer of fine-grained microstructure. As a result of MIF, the range of martensitic transformation is slightly shifted to the region of low temperatures by about 5°C. The analysis of phase transformations in the region of room temperatures shows that the intervals of martensitic and magnetic phase transformations are superimposed on each other. The MCE value in a magnetic field of 1.8 T is 0.59ºC in the initial cast state, and as a result of forging it decreases to 0.55°C.