Phase-Transformation Nanoparticles Synchronously Boosting Mechanical and Electromagnetic Performance of SiBCN Ceramics

Abstract

Precursor-derived silicoboron carbonitride ceramic (PDC-SiBCN) has attracted significant attention as an advanced electromagnetic (EM) wave-absorbing material. However, the inherent porous and brittle characteristics limit its application as a structural load component in an EM interference environment. In this study, phase-transformation HfO2 nanoparticles were incorporated into PDC-SiBCN to reduce volume shrinkage, improve bonding interactions, and control structural defects, simultaneously boosting the plastic deformation and EM performance of brittle ceramics. The obtained HfO2/SiBCN ceramic showed enhanced flexural strength of up to 430.1% compared with that of the pure SiBCN ceramic. Furthermore, the HfO2/SiBCN ceramic also demonstrated excellent high-temperature EM absorption. The minimum reflection coefficient (RCmin) could reach −45.26 dB, and the effective absorption bandwidth (EAB) covered 2.80 GHz of the X band at 2.28 mm thickness at room temperature. Furthermore, the RCmin can still reach −44.83 dB, and the EAB can cover 2.4 GHz at 1.58 mm even at 1073 K. This work shows that phase-transformation nanoparticles could simultaneously improve the deformation ability and EM wave absorption properties of SiBCN ceramics. The results could guide the design and preparation of PDCs with strong carrying capacity and excellent EM absorption, even in harsh environments.

Nanoparticles‐doped polymer‐derived SiCN ceramic with enhanced mechanical properties and electromagnetic wave absorption

“…As shown in Figure 4F, the trend of porosity is exactly opposite from the corresponding flexural strength. This is because the microcracks are filled with high‐strength HfO 2 nanoparticles, and the volume expansion caused by the t – m phase transformation during the pyrolysis procedure would further decrease the porosity 37 . Due to the relatively large intrinsic density of HfO 2 (5.89 g/cm 3 ), the variation of bulk density increases with the increase in HfO 2 content.…”

“…36 In addition, the entry of the SiCN phase into the lattice would cause further distortion. 37 As a result, the diffraction peaks would shift right from the normal position slightly. In this way, sharp peaks at 34.…”

UV-modification of Ag nanoparticles on α-MoCx for interface polarization engineering in electromagnetic wave absorption

“…7,8 Electromagnetic wave materials have a wide range of applications in EMI (electromagnetic interference) shielding [9][10][11] and civilian-military stealth coatings [12][13][14][15] and have thus attracted significant attention. As representative EWAMs, carbon-based composite materials, [16][17][18][19][20][21][22][23][24][25][26][27] transition metallic composites, [28][29][30][31][32][33][34][35] and non-metallic ceramic compounds [36][37][38][39][40] have shown high electromagnetic wave absorption and wide band coverage performances.…”

Boosting electromagnetic wave absorption of Ti 3AlC 2 by improving effective electrical conductivity

“…This is because dielectric loss (conduction loss and polarization loss) is the dominant electromagnetic wave loss mechanism for these high-temperature EMA materials, while the magnetic loss ability will be lost at a temperature higher than Curie point [8,9]. In recent years, non-oxide ceramics such as SiC [6,[10][11][12], SiBCN [13][14][15][16], and Si 3 N 4 [17][18][19][20] and oxide ceramics such as BaTiO 3 [21,22] and Mn 2 O 3 [23,24] have attracted widespread attention in both academia and industry due to their excellent polarization loss properties. Poor conduction loss is a typical issue with this sort of material since it is challenging to create a sufficiently strong conductive network in the ceramic matrix.…”