Various types of ceramics used in radome: A review

Abstract

Advanced tactical missiles need radomes of higher strength capable of withstanding higher velocities and temperatures and longer ight durations. Radomes must be stable at temperature above 1400 C and must have a low and steady thermal dielectric constant, low thermal expansion coe cient, high resistance to thermal shock, high sti ness and strength, high chemical stability, and high resistance against moisture. Silicon nitride, in comparison with other materials used in the fabrication of radomes (e.g., fused Silica, pyroceramics, etc.), enjoys superior properties, and it can also be used at ight speeds higher than Mach 7. In this paper, various types of raw materials used in the fabrication of radomes have been investigated.

Defect‐Engineered Graphene/Si3N4Multilayer Alternating Core‐Shell Nanowire Membrane: A Plainified Hybrid for Broadband Electromagnetic Wave Absorption

“…This decline in the ε′ values is due to the oxidation of the Si 3 N 4 to SiO 2 (the ε′ value of SiO 2 is 3.42, which is lower than that of 7.9 of Si 3 N 4 ) . [ 53 ] The decline in the value of ε″ may be due to a small amount of oxygen diffusing into the DG layer before the SiO 2 shell is formed on the Si 3 N 4 surface. Due to the ultrathin morphology feature of DG and the protection of the SiO 2 shell, the oxygen does not cause devastating damage to DG, which can be proved by HRTEM and EDS mapping images (Figure S10, Supporting Information).…”

Mechanical, thermal, and dielectric properties of glass mullite composites for low‐temperature cofired ceramic and radome applications

“…The radome's water absorption increases its dielectric constant and loss and also reduces its strength. 14 Glass-ceramic composites have been extensively studied in the literature for the LTCC applications with varying dielectric and thermomechanical properties, but not specifically for the radome applications. Luo et al 15 studied 50 wt% Al 2 O 3 /CaO-B 2 O 3 -SiO 2 glass that was fully densified at 875 • C. The composites had dielectric constant (loss) of 8.06 (0.0012) at 7 GHz, thermal conductivity of 1 W/m⋅K, and thermal expansion coefficient of 5.47 ppm/ • C. Hsiang et al 16 3 , a dielectric constant (loss) of 6.01 (0.004) at 1 KHz, elastic modulus of 67 GPa, and flexural strength of 94 MPa.…”

“…In addition, they must not only withstand high temperature without degradation in performance, but also must have resistance against rain erosion. The radome's water absorption increases its dielectric constant and loss and also reduces its strength 14 …”

The Influence of Si3N4w Volume Fraction on the Microstructure and Properties of Si3N4w/Si3N4 Composites via CVI Technique

“…High-temperature wave-transparent materials are used in spacecraft radomes and antenna windows, which require good mechanical and dielectric properties, as well as high-temperature resistance. Therefore, the development of novel wave-transparent materials with elevated wave transmittance and strength is of great significance for advanced and reliable applications (Medding, 1996;Bolivar et al, 2003;Ashok et al, 2007;Kandi et al, 2014;Hehdari et al, 2017).…”