Enhanced microwave absorption performance of high-entropy (Mo0.2Cr0.2Nb0.2Ti0.2V0.2)4AlC3 MAX phase through high-energy ball milling

Herein, a 413-type high-entropy (Mo 0.2 Cr 0.2 Nb 0.2 Ti 0.2 V 0.2 ) 4 AlC 3 MAX phase was successfully prepared. To elucidate the influence of high-energy ball milling on microwave absorption performance, the microstructural evolution and electromagnetic characteristics of materials subjected to varying milling durations were comprehensively investigated. Via the ball-milling process, multiple reflections, polarization loss and conductive loss are largely improved due to particle size refinement, formation of thin flakes and increased shape anisotropy. Comparative analysis revealed substantial performance enhancement in samples milled for 1 h (M1) and 3 h (M3). The unmilled powders (M0) demonstrated a minimum reflection loss (RL min ) of -23.1 dB at 4.5 mm thickness and an effective absorption bandwidth (EAB) of 2.6 GHz at 5.0 mm. In contrast, M1 achieved a RL min low to -51.8 dB at 2.3 mm, while M3 exhibited an optimal EAB of 4.1 GHz at 1.06 mm. However, extending the milling duration to 6 h resulted in diminished absorption performance compared to M1 and M3, primarily due to compromised impedance matching characteristics. Therefore, via a proper ball-milling process, microwave absorption performance of high-entropy MAX phase powders can be remarkably boosted, providing a straightforward and effective approach for performance optimization in electromagnetic wave absorption applications.