Silicon nitride gradient porous capillary core for loop heat pipe and preparation method of silicon nitride gradient porous capillary core by combining coating method

A loop heat pipe and gradient porous technology, applied in the field of gradient porous capillary cores for loop heat pipes and its preparation, can solve problems such as singleness and complex processing, and achieve improved stability and reliability, large capillary suction, and realization The effect of efficient transfer

Active Publication Date: 2018-04-20
SHANGHAI INST OF CERAMIC CHEM & TECH CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, traditional capillary pumps have a single pore size and porosity, and it is difficult to achieve efficient transfer of steam while improving capillary suction.
Moreover, the traditional pressing process can only prepare some capillary core products with simple shapes, and the processing is complicated.

Method used

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  • Silicon nitride gradient porous capillary core for loop heat pipe and preparation method of silicon nitride gradient porous capillary core by combining coating method
  • Silicon nitride gradient porous capillary core for loop heat pipe and preparation method of silicon nitride gradient porous capillary core by combining coating method
  • Silicon nitride gradient porous capillary core for loop heat pipe and preparation method of silicon nitride gradient porous capillary core by combining coating method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0043] (1) Using the foaming method, the Si 3 N 4 Powder: Yttrium Oxide: Water: Polyvinyl Alcohol: n-Propyl Gallate The weight ratio is 100:5:72:1:5 After mixing evenly, stir vigorously at a speed of 2000rpm to obtain a foamy slurry and keep it at room temperature for 24 hours Cured, then placed in a 60°C oven to dry for 12 hours, and then sintered at 1800°C for 2 hours. A primary capillary wick with a larger pore size is prepared and subjected to preliminary processing. The pore diameter of the primary silicon nitride capillary core is 10-200 microns, and the porosity is 82%;

[0044] (2) Slurry configuration Add silicon nitride powder, sintering aid yttrium oxide, gelling agent isobutylene-maleic anhydride copolymer, and pore-forming agent PMMA into water, and after ball milling and mixing, the slurry is obtained. The nitriding The mass ratio of silicon powder, sintering aid, gelling agent, pore forming agent and water is 100:4:0.3:10:80;

[0045] (3) Coating a layer of ...

Embodiment 2

[0049] (1) The Si 3 N 4 : yttrium oxide: water: isobutylene-maleic anhydride copolymer uniformly mixed at a weight ratio of 100:6:120:0.5 to obtain a slurry, injected into a mold, cured at room temperature for 48 hours, and then dried in an oven at 80°C for 24 hours , sintered at 1750°C for 2 hours. A primary capillary wick with a larger pore size is prepared and subjected to preliminary processing. The pore diameter of the primary silicon nitride capillary core is 10-20 microns, and the porosity is 68%;

[0050] (2) Slurry configuration Add silicon nitride powder, sintering aid lutetium oxide, gelling agent isobutylene-maleic anhydride copolymer, and pore-forming agent starch into water, and after ball milling and mixing, the slurry is obtained. The nitriding The mass ratio of silicon powder, sintering aid, gelling agent, pore forming agent and water is 100:5:0.2:5:72;

[0051] (3) Coat a layer of silicon nitride slurry on the outside of the primary capillary pump, and co...

Embodiment 3

[0055] (1) adopt freeze-drying method, with Si 3 N 4 The weight ratio of powder: water: polyvinyl alcohol: polyethylene glycol can be 100:100:5:5. Mix evenly by mechanical wet ball milling to make a slurry. The resulting slurry was defoamed and vacuum degassed, poured into a mold, and then frozen at -50°C for 6 hours. After debonding, the green body was sintered at 1700° C. for 2 hours to prepare a primary capillary core with a relatively large pore size and perform preliminary processing. The pore diameter of the primary silicon nitride capillary core is 20-100 microns, and the porosity is 78%;

[0056] (2) Slurry configuration Add silicon nitride powder, sintering aid ytterbium oxide, gelling agent isobutylene-maleic anhydride copolymer, and pore-forming agent liquid paraffin into water, and after ball milling and mixing, the slurry is obtained. The mass ratio of silica powder, sintering aid, gelling agent, pore forming agent and water is 100:6:0.4:8:72;

[0057] (3) Sp...

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Abstract

The invention relates to a silicon nitride gradient porous capillary core for a loop heat pipe and a preparation method of the silicon nitride gradient porous capillary core by combining a coating method. The silicon nitride gradient porous capillary core comprises a primary silicon nitride capillary core and at least one silicon nitride micropore layer coating the outer surface of the primary silicon nitride capillary core, wherein the primary silicon nitride capillary core has the porosity of 60 to 90 percent and the pore diameter of 10 to 200 microns, and the silicon nitride micropore layerhas the porosity of 40 to 60 percent and the pore diameter of 0.1 to 1 micron.

Description

technical field [0001] The invention relates to a gradient porous capillary core for a loop heat pipe and a preparation method thereof, in particular to a method for preparing a silicon nitride gradient porous structure capillary core by a coating method. Background technique [0002] As an efficient phase change heat transfer device, the loop heat pipe is a key component for the stable and long-life operation of electronic components and aerospace devices at a constant temperature, and the main core of the capillary pump is one of the most critical components in the loop heat pipe. With the increasing power consumption of related instruments and equipment, the requirements for heat dissipation and constant temperature of the system are getting higher and higher. The main core of the existing metal capillary pump can no longer meet the requirements of stability and longevity in terms of heat dissipation and corrosion resistance. On the other hand, the capillary wick used in ...

Claims

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Application Information

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IPC IPC(8): C04B38/02C04B38/06C04B35/584C04B35/64C04B35/622
CPCC04B35/584C04B35/622C04B35/64C04B38/02C04B38/0645C04B2235/6562C04B2235/6567C04B2235/661C04B2235/775C04B38/0074C04B38/0054
Inventor 曾宇平姚冬旭王锋左开慧夏咏锋尹金伟梁汉琴
Owner SHANGHAI INST OF CERAMIC CHEM & TECH CHINESE ACAD OF SCI
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