Sintering and magnetocaloric properties of gas atomised LaFe_11.0Si_1.2Co_0.8

ABSTRACT

The sintering behaviour of LaFe_11.0Si_1.2Co_0.8 powder produced by gas atomisation was examined to provide a basis for the application of powder metallurgical shaping technologies to magnetocaloric La(Fe,Si)₁₃-alloys. The aim was to establish sintering parameters for attaining both high densification and good magnetocaloric properties for the investigated particle sizes <10 µm and <25 µm. Dilatometry measurements and sintering trials were carried out and density, microstructure and entropy change ΔS of the sintered samples were analysed. For the fine particles <10 µm, the lowest investigated sintering temperature 1150°C results in a relative density of 97%, a low α-Fe content and a high ΔS = −5 J kg⁻¹ K⁻¹ (ΔH=2 T). For powder <25 µm, a two-stage process is required to achieve similar properties.

KEYWORDS:

• Magnetocaloric
• LaFeSi
• sintering
• powder metallurgy
• gas atomised powder

Disclosure statement

No potential conflict of interest was reported by the author(s).

Notes on contributor

Sandra Wieland studied material science at Technical University Dresden and is working at Fraunhofer IFAM since her graduation in 2014. Besides her occupation as a project manager, she pursued her doctoral thesis on sintering of magnetocaloric LaFeSi-alloys, which was completed in 2019. Curently, she is the head of the Functional Materials and Components group in the Powder Technology department at Fraunhofer IFAM.

ORCID

Sandra Wieland http://orcid.org/0000-0002-3655-7738