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Self-growth silicon nitride whisker enhanced radar antenna window/radome and preparation method thereof

A radar antenna, self-growth technology, applied in the direction of the radiation unit cover, etc., can solve problems such as poor high temperature mechanical properties, achieve good thermal shock resistance, improve strength and high temperature resistance, and inhibit devitrification.

Inactive Publication Date: 2019-05-17
JIANGXI JIAJIEXINDA NEW MATERIAL TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, SiO 2f Crystallization occurs at 800°C, and the high-temperature mechanical properties are poor

Method used

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Examples

Experimental program
Comparison scheme
Effect test

preparation example Construction

[0019] The invention provides a self-grown Si 3 N 4 The preparation method of the whisker-enhanced radar antenna window / radome, the specific steps are as follows.

[0020] S1: SiO 2f Put the preform into the muffle furnace, raise the temperature to 250-300°C in the air environment for 1 hour, then keep it warm for 2-4 hours, cool down to room temperature with the furnace, and take it out.

[0021] S2: Incorporate nano-Si 3 N 4 Powder and Nano Y 2 o 3 Mix evenly, pour into the PVA aqueous solution, stir evenly at 95-100°C for 2-4 hours, add water continuously during the process to keep the total mass of the powder in 1L PVA aqueous solution at 15-30g, and obtain a mixed solution; among them, nano-Si 3 N 4 Powder and Nano Y 2 o 3 The mass ratio of is 100:(1-2).

[0022] S3: SiO after S1 treatment 2f The preform is placed in the mixed solution, pressurized to 1-2MPa and maintained for 0.5-1 hour; then taken out, and dried in a muffle furnace at 80-90°C for 6-12 hours. ...

Embodiment 1

[0029] This embodiment provides a self-grown Si 3 N 4 The preparation method of the whisker-enhanced radar antenna window / radome, the specific steps are as follows.

[0030] S1: SiO 2f Put the preform into the muffle furnace, raise the temperature to 250°C in the air environment for 1 hour, then keep the temperature for 2 hours, cool to room temperature with the furnace, and take it out.

[0031] S2: 1000g nano-Si 3 N 4 Powder with 10g Nano Y 2 o 3 Mix evenly, pour into 5L PVA aqueous solution, stir evenly at 95°C for 4 hours, add water continuously during the process to keep the concentration basically constant, and obtain a mixed solution.

[0032] S3: SiO after S1 treatment 2fThe preform was placed in the mixed solution, pressurized to 2MPa and kept under pressure for 1 hour; then it was taken out and dried in a muffle furnace at 90°C for 12 hours.

[0033] S4: SiO after S3 treatment 2f The preform was placed in silica sol with a concentration of 30%, pressurized t...

Embodiment 2

[0039] This embodiment provides a self-grown Si 3 N 4 The preparation method of the whisker-enhanced radar antenna window / radome, the specific steps are as follows.

[0040] S1: SiO 2f Put the preform into the muffle furnace, raise the temperature to 300°C in the air environment for 1 hour, then keep the temperature for 2 hours, cool to room temperature with the furnace, and take it out.

[0041] S2: Add 500g nano-Si 3 N 4 powder with 10g Nano Y 2 o 3 Mix evenly, pour into 3.5 LPVA aqueous solution, stir evenly at 100°C for 4 hours, add water continuously during the process to keep the concentration basically constant, and obtain a mixed solution.

[0042] S3: SiO after S1 treatment 2f The preform is placed in the mixed solution, pressurized to 1 MPa and maintained for 0.5 hours; then taken out and dried in a muffle furnace at 85°C for 10 hours.

[0043] S4: SiO after S3 treatment 2f The preform was placed in silica sol with a concentration of 30%, pressurized to 2MPa...

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Abstract

The invention relates to a self-growth Si3N4silicon nitride whisker enhanced radar antenna window / radome and a preparation method thereof. The preparation method comprises the following steps: S1, heating a SiO2f prefab and then insulating and cooling; S2, uniformly mixing Si3N4 with Y2O3 and then pouring a mixture into a PVA aqueous solution to obtain a mixed solution; S3, putting the prefab treated in S1 into a mixed solution, pressurizing, maintaining the pressure and then drying; S4, putting a dried substance into silica sol, pressurizing, impregnating and then drying; S5, carrying out heating and insulating treatment, and then cooling; S6, tapping the prefab treated in S5 until a surface embossed substance falls off, weighing and measuring the density; S7, repeating S3 to S6 until thedifference of two adjacent densities does not exceed 0.05 g / cm<3>. According to the radome, the bending strength is greater than 250 MPa, operating temperature is as high as 1500 DEG C, the thermal shock resistance is good, and use demands of a medium-high Mach aircraft on the radar antenna window / radome can be met.

Description

technical field [0001] The invention relates to the technical field of high-temperature manufacturing, in particular to a self-grown Si 3 N 4 Whisker enhanced radar antenna window / radome and method of making same. Background technique [0002] The radar antenna window / radome refers to the barrier located at the head and middle of the aircraft to protect the radar antenna system from harsh environments and to enable normal signal transmission. As the speed of the aircraft increases (> Mach 5), the surface temperature of the antenna window / radome is higher when the aircraft enters the atmosphere, so higher requirements are placed on the performance of the antenna window / radome, including good mechanical properties, resistance thermal shock performance, and excellent dielectric properties. At present, only continuous fiber-reinforced ceramic matrix composites can meet the application requirements of high Mach number antenna windows / radomes in the material system. [Jiang ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C04B35/81C04B35/84H01Q1/42
Inventor 吴宝林侯振华
Owner JIANGXI JIAJIEXINDA NEW MATERIAL TECH CO LTD