METHOD OF IMPREGNATION AND PRESSURIZED CARBONIZATION OF POROUS CARBON-CARBON BLANKS BASED ON PITCH BINDERS Russian patent published in 2023 - IPC C04B35/532 C04B35/83 

FIELD: mechanical engineering.

SUBSTANCE: production of carbon-carbon composite materials with high density and strength, which can be used in aviation, rocket, and space engineering. A method has been proposed for impregnation and pressurized carbonization of porous carbon-carbon blanks based on pitch binders, which includes impregnation of the blanks with molten pitch in vacuum, loading the container with the blanks into a high-pressure apparatus and heating under pressure. Initially, the blanks are impregnated with pitch in a container at a temperature of 250-280°C and a residual pressure of less than 0.02 MPa, followed by holding pitch-filled containers with blanks under the same conditions for 1-2 hours. After this, further impregnation is carried out in the high-pressure apparatus, at the maximum pressure on the container with blanks of 20-25 MPa at a temperature of 30-70°C above the temperature at the stage of vacuum impregnation, for 2-3 hours, then heating is carried out at the rate of 15-20°C/h in the range of 400-550°C at the blanks at the maximum pressure on the container of 20-25 MPa. The blanks carbonization process is carried out in the temperature range of 550-650°C at the maximum pressure on the container of 20-25 MPa for 2-3 hours. The temperature on the surface of the container containing the blanks is indicated by the average value of the readings of 3 thermocouples installed at the top, middle, and bottom of its side surface, and at the blanks.

EFFECT: achievement of the specified characteristics of carbon-carbon materials using pressures of no more than 25 MPa in a shorter technological cycle without compromising the strength properties.

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