Design of Excellent Mechanical Performances and Magnetic Refrigeration via In Situ Forming Dual-Phase Alloys

Magnetic refrigeration technology can achieve higher energy efficiency based on the magnetocaloric effect (MCE). However, the practical application of MCE materials is hindered by their poor mechanical properties, making them challenging to process into devices. Conventional strengthening strategies usually lead to a trade-off with refrigeration capacity reduction. Here, a novel design is presented to overcome this dilemma by forming dual-phase alloys through in situ precipitation of a tough magnetic refrigeration phase within an intermetallic compound with excellent MCE. In the alloy 87.5Gd-12.5Co, incorporating the interconnected tough phase Gd contributes to enhanced strength (approximate to 505 MPa) with good ductility (approximate to 9.2%). The strengthening phase Gd simultaneously exhibits excellent MCE, enabling the alloy to achieve a peak refrigeration capacity of 720 J kg-1. Moreover, the alloy shows low thermal expansion induced by the synergistic effect of the two phases. It is beneficial for maintaining structural stability during heat exchange in magnetic refrigeration. The coupling interaction between the two magnetic phases can broaden the refrigeration temperature range and reduce hysteresis. This study guides the development of new high-performance materials with an excellent combination of mechanical and magnetic refrigeration properties as needed for gas liquefaction and refrigerators. A universal and straightforward method for preparing high-performance magnetocaloric effect (MCE) materials is proposed in this study. By employing a direct melting approach, the magnetocaloric phase precipitates within MCE intermetallic compounds. The prepared dual-phase alloy achieves a commendable equilibrium between refrigeration capacity and mechanical properties. This strategy holds significant promise for the large-scale production of magnetic refrigeration materials. image