Preparation method of loop heat pipe and porous silicon nitride ceramic

Abstract

The invention discloses a loop heat pipe and a preparation method of porous silicon nitride ceramic. The loop heat pipe is prepared from porous silicon nitride ceramic, of which the porosity is 50-70%, the strength is 10-30 MPa, and the average pore diameter is 0.5-1 [mu]m. The method comprises the following steps: with Si3N4 powder as a raw material, adding a sintering aid, and carrying out uniform mechanical wet ball milling mixing to form slurry; defoaming and degassing the slurry, freezing and curing the slurry at low temperature in a mold, and drying the material; putting the material into a muffle furnace for heat preservation to remove organic matter impurities; and finally, sintering the material in a sintering furnace at a high temperature to obtain the Si3N4 porous ceramic tube.The ceramic tube has the characteristics of high porosity, high strength, uniform pore structure distribution and the like, and can replace a metal loop heat tube to meet the use in the fields of loopheat tubes under a high-temperature condition and the like.

Description

technical field [0001] The invention belongs to the technical field of porous ceramics, and in particular relates to a preparation method of porous silicon nitride ceramics and a loop heat pipe of porous silicon nitride ceramics. Background technique [0002] The loop heat pipe is another member of the capillary-driven, phase-change heat transfer family, which has attracted much attention since the early 1970s. In recent years, with the combination of loop heat pipes and aerospace applications, the technology of loop heat pipes has been developed rapidly. Loop heat pipe, when the working medium is selected properly and the core structure is designed reasonably, its heat transfer capacity will reach 50kw / m, or even higher. [0003] As early as 1989, Russia applied the loop heat pipe to the Granat spacecraft for space flight tests to test its ability and reliability under long-term work, and finally achieved success. In 1994, Russia successfully conducted a temperature contr...

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Problems solved by technology

[0004] However, the loop heat pipes used in the above aerospace tests and related studies are all made of stainless steel or metal. Although they have good thermal control characteristics and structural characteristics in the thermal control system of spacecraft, when applied at high temperatures However, its high temperature stability, wear resistance and corrosion resistance cannot meet the further application requirements of aerospace in the future.

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