Ultrahigh-Temperature Ceramic-Polymer-Derived SiOC Ceramic Composites for High-Performance Electromagnetic...

Area of Science:

• Materials Science
• Ceramic Engineering
• Electromagnetics

Background:

• High-performance electromagnetic interference (EMI) shielding is critical for electronics and aerospace operating in high-temperature, harsh environments.
• Existing materials often fall short of the required shielding efficiency and durability under extreme conditions.

Purpose of the Study:

• To develop and characterize a novel composite material for high-performance EMI shielding.
• To investigate the EMI shielding properties of ultrahigh-temperature ceramic and polymer-derived SiOC ceramic (PDC-SiOC) composites.
• To evaluate the material's suitability for demanding aerospace and electronics applications.

Main Methods:

• Fabrication of composites using ZrB2 (zirconium diboride) and PDC-SiOC.
• Spark plasma sintering (SPS) was employed for material consolidation.
• Characterization of EMI shielding efficiency (SE_T) across the Ka-band (26.5-40 GHz) at various compositions and thicknesses.

Main Results:

• A composite with a normalized ZrB2 fraction of 50%, pyrolyzed at 1000 °C, achieved a significant SE_T of 72 dB (over 99.99999% shielding) at 3 mm thickness across the Ka-band.
• A maximum SE_T of 90.8 dB (over 99.9999999% shielding) was recorded at approximately 39.7 GHz with a 3 mm thick sample.
• The introduction of PDC-SiOC formed a unique t-ZrO2 interface, enhancing electrical conductivity and contributing to reflection-dominant shielding.

Conclusions:

• The developed ZrB2-PDC-SiOC composite demonstrates excellent EMI shielding performance, exceeding requirements for harsh environments.
• The material's reflection-dominant shielding mechanism and high efficiency make it a promising candidate for advanced electronics and aerospace applications.
• The unique t-ZrO2 interface plays a crucial role in the enhanced electrical conductivity and overall shielding effectiveness.