High performance X-band electromagnetic wave absorption of SiBCN metamaterials fabricated by direct pyrolysis

Electromagnetic wave (EMW)-absorbing ceramic metamaterials without doping absorbers were prepared by direct pyrolysis of polymer-derived SiBCN ceramics (PDC-SiBCN). The pyrolytic behavior of the ceramics, the effect of the pyrolysis temperature on the mechanical strength , and the EMW absorption properties of the metamaterials are discussed in detail. The mechanism of the enhanced EMW absorption by the metamaterials was further analyzed. The results indicated that PDC-SiBCN demonstrated the optimum impedance matching and absorption performance at a pyrolysis temperature of 1500 °C. The metamaterial can effectively absorb the full X-band when its thickness is in the range of 4.3–5.7 mm. When the thickness was adjusted to 4.7 mm, the minimum reflection coefficient (RC) reached − 26.6 dB. In addition, the flexural strength of the metamaterial was 31.2 MPa, and the compressive strength was 96.9 MPa, which is 60 times higher than that of the solid structure. This study provides a feasible guide for the simple fabrication of lightweight, high-strength, and high-performance EMW-absorbing materials.