Collaborative Optimization of Microwave Absorption and Thermal Properties of FeCo‐Glass Dual Shell Hollow Spheres Enabled by Alloying‐Induced Special Distribution Control

Abstract Hollow microsphere absorbents hold great potential for lightweight and multi‐band compatible design due to their inherent low density and thermal conductivity, but it remains a great challenge to rationally control the microstructures to achieve an optimal balance of low density, high mechanical strength, impedance matching, attenuation ability, and thermal performance. In this work, bimetallic alloys and glass are selected as the model materials for the functional and supporting shells to construct lightweight yet robust hollow microspheres. The rational design and highly efficient realization of the composition and miscibility control of the bimetallic alloy are first emphasized. An in‐depth investigation is conducted on the effects of metal type and component compatibility on the microstructure of the structural units (SU), and further on the electromagnetic and thermal performances. The results confirm the necessity and effectiveness of regulating the integrity and microstructure of the electromagnetic and thermal networks via alloying‐induced migration and aggregation behavior control. The optimized product exhibits comprehensive advantages of being simultaneously thin (1.69 mm), wide (5.20 GHz), light (0.81 g cm −3 ), strong (−23.8 dB), high mechanical strength (91.87% survival rate at 20 MPa) and low thermal conductivity (0.063 W m −1 K −1 ), indicating excellent radar‐infrared stealth capabilities and structural stability.