| Feb 25, 2026 |
A dual-phase silicon carbide ceramic reinforced with boron nitride nanosheets achieves 94.5% greater strength while absorbing radar waves for stealth applications.
(Nanowerk News) In aerospace engineering, materials face a fundamental tradeoff. They can either be structurally tough enough to survive extreme heat and pressure, or they can serve a functional purpose, like absorbing electromagnetic waves for stealth. Getting both at once has always been the problem. Materials designed to soak up radar waves tend to be porous, which makes them fragile. Dense, strong ceramics hold up under stress but bounce radar signals right back.
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A team led by Jun-Tong Huang at Nanchang Hangkong University in China has found a way around this dilemma. They’ve engineered a ceramic composite that is substantially tougher than previous versions while also working as a high-performance electromagnetic absorber.
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Their findings were published in the Journal of Advanced Ceramics (“Facilitating structural strengthening and electromagnetic wave absorption functionalization of dual-phase SiC ceramics via MBNS-dominated multiphase reinforcement strategy”).
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The key to the approach is a dual-phase silicon carbide (SiC) matrix reinforced with multilayer boron nitride nanosheets (MBNS). Boron nitride is well known for its thermal stability, but producing high-quality nanosheets at scale has been a persistent challenge. The team solved this with a “protective exfoliation” technique using three-roll milling, which allowed them to mass-produce intact nanosheets. These were then embedded into the SiC matrix through a carefully controlled sintering process.
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| This diagram summarizes the design strategy and superior performance of the newly developed dual-phase SiC composite (DS@4MBNS). The top schematic illustrates the fabrication of a dense, reinforced structure designed for efficient microwave absorption and simultaneous mechanical toughening through mechanisms like crack deflection and bridging. The radar chart (bottom left) highlights how DS@4MBNS (marked by the red star) breaks conventional material trade-offs, achieving an unprecedented balance of high flexural strength, fracture toughness, and electromagnetic absorption compared to other SiC-based ceramics. The charts on the bottom right quantify the significant improvements in minimum reflection loss and wider effective absorption bandwidth. (Image:Reproduced from DOI:10.26599/JAC.2025.9221234, CC BY) (click on image to enlarge)
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“Balancing structural strength with functional performance has been a long-standing obstacle for stealth materials in extreme environments,” Huang said. “We set out to design a microstructure that could bear mechanical loads and dissipate electromagnetic energy at the same time.”
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The results speak for themselves. The optimized composite, designated DS@4MBNS, showed a 94.5% jump in flexural strength, reaching 477 MPa, along with a nearly 50% improvement in fracture toughness at 6.02 MPa·m^(1/2), compared to standard silicon carbide ceramics.
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Huang explained that the nanosheets function as microscopic reinforcements. When cracks begin to spread through the ceramic, the horizontally aligned nanosheets deflect and bridge them, absorbing energy that would otherwise cause the material to fracture.
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But strength is only half the story. The material’s internal architecture, combining the semiconductor SiC matrix, dielectric nanosheets, and conductive nickel silicide (Ni₂Si) formed during processing, creates a complex network that traps and dissipates electromagnetic waves.
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Testing showed the composite reached a minimum reflection loss of −52.59 dB at 1.22 mm thickness and full Ku-band coverage (5.6 GHz bandwidth) at 1.09 mm thickness. Put simply, it absorbs the vast majority of incoming radar energy across frequencies used in satellite communications and radar systems.
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“We effectively turned the material’s internal interfaces into energy dissipation zones,” Huang said. “The interplay between dielectric loss and magnetic loss lets the material absorb electromagnetic waves without needing the kind of structural porosity that typically weakens these composites.”
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The work opens up possibilities for multifunctional armor, aero-engine blades, and nozzle liners, components that must endure punishing temperatures and mechanical stress while staying invisible to radar.
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Going forward, the team intends to apply this multiphase reinforcement strategy to other ceramic systems. “This is a scalable pathway,” Huang said. “Ultimately, we want to take these structural-functional integrated composites out of the lab and into real aerospace and defense applications.”
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