Alloy stabiliser advances magnetic cooling

GERMANY: Magnetic cooling company Magnotherm claims a significant advancement in the technology by protecting magnetocaloric alloys from corrosion and mechanical fracture.

Lanthanum-iron-silicon alloys are commercially available and considered within the caloric materials family as one of the most promising alternatives to gas compression cooling. However, they are also prone to corrosion and fracture. 

Preventing the degradation of magnetocaloric alloys during use is seen as pivotal to ensure reliable and maintenance-friendly device operation. 

Darmstadt–based Magnotherm has now shown that application-ready magnetocaloric alloys can be fully protected against corrosion and mechanical fracture during extended in-device operation solely relying on water as environmentally benign and efficient heat exchange medium. 

This has been achieved by combining Magnotherm’s proprietary copper coating with a tailored corrosion inhibitor mixture. This is said to have resulted in mechanical fracture, functional losses and corrosion being “near completely” suppressed during continuous use over three months. 

In a statement the company said: “Initial demonstration of stable operation means that this highly performative material, known for its brittleness and corrosivity in water, has taken a major leap in magnetocaloric materials science from promising theory to successful practical application. This represents a significant step in paving the way for the broad commercial application of magnetocaloric cooling systems, which are safe, low-maintenance, and refrigerant free.”