High‐Throughput Screening of High‐Performance Magnetocaloric Materials by Gradient Additive Manufacturing.

Magnetic refrigeration based on magnetocaloric effect (MCE) has become a promising cooling technology to replace the traditional vapor compression refrigeration. However, traditional methods for searching MCE materials require producing many different compositions, causing unbearable workload and long experimental periods. Here, 3D printed La0.7Ce0.3Fe11.65Si1.35–Fe compositionally gradient alloys (CGAs) are successfully prepared using laser powder bed fusion equipped with a powder hopper with dual‐bin structure. This CGAs accelerate the high‐throughput screening for the best composition of La(Fe, Si)13/Fe with both high MCE and mechanical properties. The good interfacial compatibility between brittle 1:13 phase and reinforcing α‐Fe improves the mechanical properties significantly. Even after hydrogenation, the compressive strength and ultimate strain of the La(Fe, Si)13/Fe hydrides are ≈220% and ≈150% higher than those of stoichiometric La(Fe, Si)13. Meanwhile, the hydrogenated composite exhibits a large MCE under low magnetic field, e.g., the magnetic entropy change |Δ<italic>S</italic>M|max of 7.6 J kg−1 K−1 under 2 T is 52% higher than that of the benchmark Gd (5.0 J kg−1 K−1). Furthermore, this La(Fe, Si)13/Fe is 3D printed into various complex shapes suitable for heat exchangers. This study provides an innovative strategy for high‐throughput screening of new materials. [ABSTRACT FROM AUTHOR]