Development of Silicon Nitride‐Based Ceramic Radomes — A Review

Abstract

Radome is an aerodynamic structural part attached to the fore‐end of a missile. It transmits electromagnetic signals with minimum attenuation and also protects radar communication system, and thus, the radomes are made of ceramics as they have desirable properties required by the radomes. The flexural strength, dielectric constant, and loss tangent values of various ceramic materials used in the development of radomes are important in the selection of radome materials. Different nose cone shapes of missile radomes are also important. Ceramic materials show variational properties with sintering time, temperature, and other additives. The existing different near‐net shape fabrication techniques for manufacturing of ceramic radomes are discussed and compared. Gelcasting is one of the manufacturing techniques to produce radomes with homogeneous and high green strength. Gelcast parts of silicon nitride ceramics are hard, tough, brittle, and wear‐resistant and are difficult to machine using conventional methods of machining. Therefore, laser‐assisted machining is used for fine finish of ceramic radomes with excellent surface integrity and productivity. This paper deals with a review of development of ceramic radomes, manufacturing methods for variety of applications.

C0.3N0.7Ti-SiC Toughed Silicon Nitride Hybrids with Non-Oxide Additives Ti3SiC2

“…Although several alternatives of structural ceramics have been proposed, silicon nitride (Si 3 N 4 )-based ceramics remain competitive due to their superior properties, involving high strength and hardness at elevated temperatures, high resistance to oxidation and chemical attack, low coefficient of tribological friction and thermal expansion, and low dielectric permittivity, etc. [1][2][3][4][5][6][7][8][9][10]. As important multifunctional materials, Si 3 N 4 ceramics have found wide range of successful application towards gas turbine engine components [10][11][12][13][14], cutting tools [11,15], radomes [2], and even integrated circuit [16,17], optical devices [18,19], etc.…”

“…Therefore, effective approaches to ensure rapid consolidation and high mechanical performance of Si 3 N 4 -based ceramics are actively being explored, including gas pressure sintering (GPS) [11], hot-pressing sintering (HPS) [20][21][22][23][24][25][26], hot isostatic pressing sintering (HIP) [27], spark plasma sintering (SPS) [26,28,29], and microwave sintering [1,30], etc. However, considering the requirement of high gas pressures for gas pressure sintering and extra current devices for SPS with a significantly higher furnace costs, HPS allows the dense and complex-shaped parts with medium cost [2]. Previous considerable efforts have demonstrated that fully dense Si 3 N 4 ceramics with superior strength could be achieved through liquid phase sintering by (d 50 = 5 µm, purity > 98%) were kindly provided by Forsman Scientific Co., Ltd., Beijing, China.…”

C_0.3N_0.7Ti-SiC Toughed Silicon Nitride Hybrids with Non-Oxide Additives Ti₃SiC₂

“…Although a number of alternatives of structural ceramics have been proposed, silicon nitride (Si3N4)-based ceramics remain competitive due to their superior properties, involving high strength and hardness at elevated temperatures, high resistance to oxidation and chemical attack, low coefficient of tribological friction and thermal expansion, and low dielectric permittivity, etc. [1][2][3][4][5][6][7][8][9] . As important multifunctional materials, Si3N4 ceramics have found wide range of successful application towards gas turbine engine components [10][11][12][13] , cutting tools [10,14] , radomes [2] , and even integrated circuit [15,16] , optical devices [17,18] , etc.…”

Surface modification of ultrafine silicon nitride powders by calcination

“…Silicon nitride ceramics have attracted considerable attention in recent decades due to their high strength retention at room and elevated temperatures, high thermal‐shock resistance, high‐temperature stability, hardness, excellent erosion resistance, and corrosion resistance . Owing to these characteristics, silicon nitride ceramics are widely used in various industries, such as automotive, aerospace, machinery, etc …”