Process for preparing silicon nitride nano wave-pervious material

A silicon nitride and silicon nitride coating technology, applied in metal material coating process, gaseous chemical plating, coating and other directions, can solve the problem of increase in dielectric constant and dielectric loss, and deterioration of radome wave transmission performance. , unstable dielectric properties of materials, etc., to achieve the effect of dense surface, less machining allowance, and less damage to the matrix

Inactive Publication Date: 2008-08-13
NANJING UNIV OF AERONAUTICS & ASTRONAUTICS
View PDF0 Cites 18 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, its porous structure makes its surface easy to absorb moisture. Since the dielectric constant and dielectric loss of water are very large, the dielectric constant and dielectric loss of the material will increase sharply after moisture absorption, and the wave transmission performance of the radome will deteriorate. As the ambient temperature and humidity change, the moisture absorption rate of the material will also change, resulting in unstable dielectric properties of the material, so it must be densified on the surface

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Process for preparing silicon nitride nano wave-pervious material

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0015] Porous silicon nitride was selected as the substrate, and the process parameters prepared by chemical vapor deposition were set: the heating time was set to 3 hours, the deposition temperature was set to 1300 °C, the deposition time was 10 h, and the temperature of the bubbling bottle was set to 45 °C. The hydrogen flow rate is set at 400ml / min, the ammonia flow rate is set at 180ml / min, and the argon gas flow rate is set at 950ml / min. Process the porous silicon nitride substrate and ultrasonically clean it, dry it, put it into a chemical vapor deposition furnace, turn off the chemical vapor deposition furnace, then vacuumize, inject argon gas, and start heating according to the set procedure. When the temperature rises to 1300°C, the bubble bottle is heated to 45°C and kept constant, and hydrogen, ammonia, and argon are introduced according to the set flow rate to start deposition, and the deposition rate is very high. After several cycles of deposition in the above-me...

Embodiment 2

[0017] Porous silicon nitride was selected as the substrate, and the process parameters for the preparation of silicon nitride wave-transparent materials by chemical vapor deposition were set: the heating time was set to 2.5 hours, the deposition temperature was set to 1250°C, the deposition time was 10 hours, the temperature of the bubbling bottle The temperature is set at 40°C, the flow rate of hydrogen gas is set at 300ml / min, the flow rate of ammonia gas is set at 180ml / min, and the flow rate of argon gas is set at 950ml / min. Process the porous silicon nitride substrate and ultrasonically clean it, dry it, put it into a chemical vapor deposition furnace, turn off the chemical vapor deposition furnace, then vacuumize, inject argon gas, and start heating according to the set procedure. When the temperature rose to 1250°C, the bubbler was heated to 45°C and kept constant, and hydrogen, ammonia, and argon were introduced according to the set flow rate to start deposition, and t...

Embodiment 3

[0019] Porous silicon nitride composite material was selected as the substrate, and the process parameters for preparing silicon nitride wave-transmitting materials by chemical vapor deposition were set: the heating time was set to 2.5 hours, the deposition temperature was set to 1100°C, the deposition time was 10 hours, and the bubbling The temperature of the bottle is set at 35°C, the flow rate of hydrogen gas is set at 300ml / min, the flow rate of ammonia gas is set at 180ml / min, and the flow rate of argon gas is set at 950ml / min. Process the porous silicon nitride composite material substrate and ultrasonically clean it, dry it, put it into a chemical vapor deposition furnace, turn off the chemical vapor deposition furnace, then vacuumize it, inject argon gas, and start heating according to the set procedure. When the temperature rose to 1100°C, the bubble bottle was heated to 35°C and kept constant, and hydrogen, ammonia, and argon were introduced according to the set flow ...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The present invention relates to a method for preparing a transmitted wave material, especially to a method for preparing a silicon nitride high-temperature transmitted wave material used by the antenna cover. The invention is characterized in that the porous silicon nitride material is taken as the prefabricated body, the silicon tetrachloride and alkaline air are taken as the precursor, the hydrogen gas is taken as carrier gas and the argon gas is taken as the dilution gas, and the material is prepared with a low-pressure chemical vapor deposition method. The invention has the following characters: (1) the surface of silicon nitride coating is compact without cracking; (2) the bonding strength of the silicon nitride coating and the porous silicon nitride substrate is excellent; (3) the dielectric property of the prepared material is excellent, and the ablating resistance property is excellent; (4) the material has the characters of low density, excellent impact resistance, antioxygenic property and high strength, high hardness and excellent chemical inertness; (5) the material can be prepared to the approximate-dimension spaceflight transmitted wave material with complicated dimension, the machining allowance is low and the damage to the substrate is small.

Description

technical field [0001] The invention relates to a preparation method of a wave-transmitting material, in particular to a preparation method of a silicon nitride high-temperature wave-transmitting material. Background technique [0002] The microwave transparent material refers to a material with a transmittance greater than 70% for electromagnetic waves with a wavelength of 1 to 1000 mm and a frequency of 0.3 to 300 GHz. This material can be used to make radar radomes, as window materials for high-energy gyroscopes, as wave-transparent window materials for some medical instruments, and as microwave communication facilities. [0003] The study of foreign wave-transparent materials began in the 1950s, and experienced the development process from fiber-reinforced plastics to ceramic matrix composites. The United States has successively conducted research on silicon dioxide system, boron nitride system and silicon nitride system. The U.S. Aeronautical Materials Laboratory has ...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): C04B35/584C23C16/34
Inventor 陈照峰方聃王亮兵张颖承涵万水城吴王平严波李聪
Owner NANJING UNIV OF AERONAUTICS & ASTRONAUTICS
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap