Method for connecting polysilazane with silicon carbide

Abstract

The invention belongs to the field of ceramic materials, and discloses a method for connecting polysilazane with silicon carbide. The method comprises the steps of smearing polysilazane on cleaned non-pressure silicon carbide substrates, then stacking two non-pressure silicon carbide substrates smeared with the polysilazane together in a smearing mode, and placing in a graphite crucible, applying 0.1 N axial force to a sample, heating the sample to 140 DEG C at the heating rate of 1 DEG C / min in the air environment, conducting heat preservation for 16-28 h, and conducting cross-linking curing; and placing a cross-linked and cured sample in a tubular furnace, applying 0.1 N axial force to the sample in a nitrogen atmosphere, heating to 240 DEG C at a heating rate of 1 DEG C / min, keeping the temperature for 1 h, then heating to 500 DEG C at the heating rate of 1 DEG C / min, keeping the temperature for 1 h, finally heating to 1300 DEG C at the heating rate of 1 DEG C / min, keeping the temperature for 2 h, and carrying out high-temperature sintering. The experimental connection method is simple to operate, and the sample can obtain higher connection strength.

Description

technical field [0001] The invention belongs to the field of ceramic materials, in particular to a method for connecting polysilazane to silicon carbide. Background technique [0002] In modern high-temperature structural materials, silicon carbide materials are due to their high elastic modulus, moderate density, small thermal expansion coefficient, high thermal conductivity, thermal shock resistance, high specific stiffness, and high dimensional stability. And a series of excellent physical properties such as isotropy of thermal and mechanical properties, widely used in ceramic ball bearings, valves, semiconductor materials, gyroscopes, measuring instruments, aerospace and other fields, has become an irreplaceable in many industrial fields s material. Silicon carbide has excellent physical and chemical properties: [0003] Mechanical properties: high hardness (Kirvin's hardness is 3000kg / mm2), can cut rubies; high wear resistance, second only to diamond. [0004] Therma...

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Problems solved by technology

[0007] Most of the preparation methods of silicon carbide composite materials adopt the preparation method of near-net shape, but in order to meet the requirements of high-precision assembly and use, it generally requires secondary processing to meet the requirements of its surface quality and size and shape accuracy. During the processing process, because SiC material not only has the characteristics of high hardness, high brittleness and low fracture toughness, it is also easy to cause brittle fracture of the material during the grinding process, leaving a surface broken layer on the surface of the material, and causing more serious damage. Surface and sub-surface damage will affect the processing accuracy and seriously affect its processing quality. Therefore, it is usually necessary to make these parts through the connection technology between ceramics

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