Fracture properties of La(Fe,Mn,Si)13 magnetocaloric materials

La(Fe,Mn,Si)(13) alloys are a promising material family for magnetic refrigeration. Challenges associated with their structural integrity during device assembly and operation requires deep understanding of the mechanical properties. Here we developed a workflow to quantitatively study the fracture properties of La(Fe,Mn,Si)(13) plates used in magnetic cooling devices. We employed microstructural characterisation, optical examination of defects, and four-point bending tests of samples with known defect sizes to evaluate their mechanical performance. We established the residual strength curve which directly links observed defects to mechanical strength. The estimated fracture toughness KC of hydrogenated La(Fe,Mn,Si)(13) is approximately 4 MPa center dot m(1/2) for the geometry employed. The established relationship between strength and crack length enables the prediction of mechanical performance through examination of defects via optical microscopy, therefore can be used industrially for directing plate selection to guarantee the mechanical stability of refrigeration devices.

Automated summary

La(Fe,Mn,Si)(13) alloys are promising materials for magnetic refrigeration, but their structural integrity during assembly and operation is a challenge that requires understanding of their mechanical properties. In this study, we developed a workflow to quantitatively study the fracture properties of La(Fe,Mn,Si)(13) plates used in magnetic cooling devices. By characterizing the microstructure, examining defects optically, and conducting four-point bending tests, we established a residual strength curve that directly relates observed defects to mechanical strength. The relationship between strength and crack length allows for the prediction of mechanical performance through optical microscopy, which can be used in industry to ensure the mechanical stability of refrigeration devices.