Microstructural anisotropy of magnetocaloric gadolinium cylinders : effect on the mechanical properties of the material

Steiner Petrovič, Darja (avtor), Šturm, Roman (avtor), Naglič, Iztok (avtor), Markoli, Boštjan (avtor), Pepelnjak, Tomaž (avtor)

The development of advanced materials and technologies based on magnetocaloric Gd and its compounds requires an understanding of the dependency of mechanical properties on their underlying microstructure. Therefore, the aim of the study was to characterize microstructural inhomogeneities in the gadolinium that can be used in magnetocaloric refrigeration systems. Microstructures of magnetocaloric gadolinium cylinders were investigated by light microscopy and FE-SEM (Field Emission Scanning Electron Microscopy), EDS (Energy-dispersive X-ray Spectroscopy), and BSE (Back-scattered Electrons) in both the extrusion and the extrusion-transversal directions. XRD (X-ray Diffraction) analyses were performed to reveal the presence of calcium- and fluorine-based compounds. Metallographic characterization showed an oxidized and inhomogeneous microstructure of the cross-sections. The edges and the outer parts of the cylinders were oxidized more intensively on the surfaces directly exposed to the processing tools. Moreover, a significant morphological anisotropy of the non-metallic inclusions was observed. CaF inclusions act as active nucleation sites for internal oxidation. The non-metallic, Ca- and F-containing inclusions can be classified as complex calciumoxyfluorides. The solubility of Er and Yb in the CaF was negligible compared to the Gd matrix and/or the oxide phase. Lower mechanical properties of the material are a consequence of the lower structural integrity due to selective oxidation of surfaces and interfaces.

• Jezik: Angleški jezik
• Ključne besede: Gadolinium, magnetocaloric, inclusions, selective oxidation, mechanical properties
• Vrsta gradiva: Članek v reviji
• Tipologija: 1.01 - Izvirni znanstveni članek
• Organizacija: FS - Fakulteta za strojništvo ; NTF - Naravoslovnotehniška fakulteta
• Status publikacije: Objavljeno
• Različica publikacije: Objavljena publikacija
• Leto izida: 2016
• Št. strani: 14 str.
• Številčenje: Vol. 9, iss. 5, art. 382
• PID: 20.500.12556/RUL-131557
• UDK: 620.1:67.017(045)
• ISSN pri članku: 1996-1944
• DOI: 10.3390/ma9050382
• COBISS.SI-ID: 1206698
• Datum objave v RUL: 29.09.2021

Gradivo je del revije

• Naslov: Materials
• Skrajšan naslov: Materials
• Založnik: MDPI
• ISSN: 1996-1944
• COBISS.SI-ID: 33588485

Licence

• Licenca: CC BY 4.0, Creative Commons Priznanje avtorstva 4.0 Mednarodna
• Povezava: http://creativecommons.org/licenses/by/4.0/deed.sl
• Opis: To je standardna licenca Creative Commons, ki daje uporabnikom največ možnosti za nadaljnjo uporabo dela, pri čemer morajo navesti avtorja.
• Začetek licenciranja: 17.05.2016

Sekundarni jezik

• Jezik: Slovenski jezik
• Ključne besede: magnetokaloričnost, gadolinij, vključki, selektivna oksidacija, mehanske lastnosti