JP5836050B2 - Method and apparatus for densifying porous structure - Google Patents

Description

  The present invention can make a porous structure having a large number of fine cavities, for example, a high-density porous structure that can withstand use as a nozzle liner of a spacecraft or a high-speed flying object, or can withstand use as a brake disk. The present invention relates to a high-density method and high-density device for a porous structure suitable for making a high-density porous structure.

Conventionally, as a method for increasing the density of the porous structure described above, for example, the method described in Patent Document 1 is known.
In this method for densifying a porous structure, when densifying a porous structure having a large number of fine cavities, for example, a porous structure made of carbon, first, the porous structure is converted into a hydrocarbon-based structure. Then, the liquid phase precursor and the porous structure immersed in the liquid phase precursor are heated by induction heating (or resistance heating) of the graphite derivative. Thus, carbon (or graphite), which is a decomposition component of the liquid phase precursor to be decomposed, is impregnated and deposited in a number of fine cavities of the porous structure.

No. 01-040796

However, in the above-described method for densifying the porous structure, the heated derivative is heated by induction heating (or resistance heating) to heat the liquid phase precursor and the porous structure immersed in the liquid phase precursor. In this case, since a heated derivative made of graphite, which is difficult in strength, is used, for example, a high-density porous structure required for a spacecraft nozzle liner cannot be manufactured.
In addition, even if the density of the porous structure close to the requirement can be achieved, it is necessary to increase the thickness of the heated derivative as long as graphite is used, and as a result, heating for growing carbon is required. There is a problem that a lot of time has to be spent, that is, it takes several days to manufacture, and it has been a conventional problem to solve these problems.

  The present invention has been made by paying attention to the above-described conventional problems. For example, it is possible to manufacture a high-density porous structure required for a nozzle liner of a spacecraft. An object of the present invention is to provide a high-density method and high-density device for a porous structure that can realize significant shortening.

In the invention according to claim 1 of the present invention, carbon is impregnated and vapor-deposited in a porous structure having a large number of fine cavities (including fine holes), for example, a porous structure made of carbon. A method of densifying the porous structure, wherein the porous structure is subjected to HIP treatment for densifying the carbon fiber three-way preform by isotropically compressing it at high pressure a plurality of times. Supported by a heated derivative comprising a high density C / C composite (carbon fiber reinforced carbon composite) having a density of 1.95 g / cm ³ or more, preferably about 2.00 g / cm ^3. The porous structure supported by the substrate is immersed in a liquid phase precursor that is a liquid hydrocarbon, and then the heated derivative is heated by at least one of induction heating and resistance heating to form the liquid phase precursor. Soaked in the body and this liquid phase precursor The porous structure is heated, and the decomposition product of the liquid phase precursor decomposed by at least one of induction heating and resistance heating is formed into a number of fine cavities of the porous structure. The structure is characterized in that it is impregnated and vapor-deposited. The structure of the method for densifying the porous structure is used as a means for solving the above-described conventional problems.

Further, in the method for densifying a porous structure according to claim 2 of the present invention, the porous structure formed by impregnating and vapor-depositing decomposition products of the liquid phase precursor into a large number of fine cavities, It is set as the structure manufactured integrally with the said heating derivative to support.
Furthermore, in the method for densifying a porous structure according to claim 3 of the present invention, the porous structure formed by impregnating and vapor-depositing a decomposition product of the liquid phase precursor into a large number of fine cavities includes: It is configured such that it is separated from the heated derivative to be supported and is manufactured as a separate product.

On the other hand, the invention according to claim 4 of the present invention is a porous structure in which a carbon structure is impregnated and vapor-deposited in a large number of fine cavities of a porous structure having a large number of fine cavities to increase the density of the porous structure. An apparatus for densifying a body, a reactor containing a liquid phase precursor which is a liquid hydrocarbon, and the liquid phase precursor disposed in the reactor and contained in the reactor is porous. density is 1.95 g / cm ³ or more you support in a state of being immersed quality structure, preferably a heating derivative consisting 2.00 g / cm ³ order of C / C composite, the heating derivative induction heating and Heating at least one of resistance heating, heating the liquid phase precursor and the porous structure immersed in the liquid phase precursor in the reactor, the induction heating and resistance heating Before decomposition by heating at least one of the A power supply unit that impregnates and deposits a decomposition product of the liquid phase precursor in a number of fine cavities of the porous structure, and a control that controls the amount of power supplied from the power supply unit according to the temperature of the heating derivative It is set as the structure provided with the part.

  In the porous structure densification method and the densification apparatus according to the present invention, hydrocarbon-based, for example, cyclohexane can be used as the liquid phase precursor.

  Further, in the method and apparatus for densifying a porous structure according to the present invention, the shape of the heating derivative is not particularly limited, and may be a columnar, cylindrical, or flat plate heating derivative. If the heating derivative has a columnar shape or a cylindrical shape, the porous structure is supported around the periphery, and if the heating derivative has a flat plate shape, the porous structure is formed on one side. Support as if pasting the body.

  In the case of a cylindrical heating derivative, resistance heating can be performed by directly energizing through an electrode, and induction heating can be performed by arranging an induction coil on the outside. In the case of a cylindrical heating derivative, induction heating can be performed if the induction coil is disposed outside or inside. In the case of a flat heating derivative, resistance heating is performed by directly energizing through an electrode. Can do.

In densified methods and densification apparatus of the porous structure of the present invention has a density in the heating derivative 1.95 g / cm ³ or more, a desirably high density C / C composite of about 2.00 g / cm ³ Therefore, the porous structure according to claim 2 of the present invention has a high density, which functions as a heating derivative having a high thermal conductivity (similar to that of graphite) and excellent in thermal shock. In the case where the heated derivative is produced as a product integrally with a porous structure formed by impregnating and vapor-depositing a decomposition product of a liquid phase precursor into a large number of fine cavities, as in the case of a method for forming a spacecraft, for example, a nozzle liner of a spacecraft. Therefore, it is possible to produce a high-density porous structure required for the above.

  On the other hand, as in the method for densifying a porous structure according to claim 3 of the present invention, a porous structure formed by impregnating and vapor-depositing decomposition products of a liquid phase precursor into a large number of fine cavities is obtained from a heated derivative. When separated and commercialized separately, for example, a high-density porous structure required for a brake disk can be produced. In any case, production of this high-density porous structure is possible. The time required for this will be greatly reduced.

  In the porous structure densification method and the densification apparatus according to the present invention, since the above-described configuration is adopted, the required high-density porous structure is obtained after realizing a significant reduction in manufacturing time. The very good effect that it is possible to produce is brought about.

  Further, in the method for densifying a porous structure according to claim 2 of the present invention, since it has the above-described configuration, for example, a high-density porous structure required for a nozzle liner of a spacecraft can be manufactured. On the other hand, the method for densifying a porous structure according to claim 3 of the present invention has the above-described configuration. For example, a high-density porous structure required for a brake disk can be manufactured. In any case, it is possible to achieve a very good effect that it is possible to achieve a significant reduction in the time required for the production of this dense porous structure.

1 is a configuration explanatory view simply showing a device for densifying a porous structure according to an embodiment of the present invention. FIG. It is manufacturing process explanatory drawing of the heating derivative of the densification apparatus in FIG. It is a block diagram which shows the density increase point by the density increase apparatus of the porous structure in FIG. It is an expanded sectional explanatory view showing the heating derivative by other examples in the densification device of the porous structure concerning the present invention. FIG. 5 is an enlarged cross-sectional explanatory view showing a heated derivative according to still another embodiment of the porous structure densifying apparatus according to the present invention.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 shows an apparatus for densifying a porous structure according to an embodiment of the present invention. In this embodiment, a case where the porous structure is a carbon preform will be described as an example.

  As shown in FIG. 1, this porous structure densification apparatus 1 includes a reactor 2 that contains a liquid phase precursor C, and a precursor supply pump that supplies the liquid phase precursor C to the reactor 2. 3, a heating derivative 4 disposed in the reactor 2 and supported in a state in which the carbon preform W as a porous structure is immersed in the liquid phase precursor C accommodated in the reactor 2, and this heating The derivative 4 is heated by resistance heating by supplying power through the electrodes 5a and 5b, and the liquid precursor C and the carbon preform W immersed in the liquid precursor C are heated in the reactor 2. A power supply unit 6 that closes the upper end opening of the reactor 2, a condenser 7 that condenses the undecomposed liquid phase precursor C that is not consumed by the reaction by the heating, and a liquid phase precursor from the reactor 2. A precursor discharge valve 8 for discharging the body C is provided. Between the derivatives 4 and the power supply unit 6, the control unit 10 for controlling the amount of power supplied from the power supply unit 6 in accordance with the temperature of the heating derivative 4 is disposed.

In this case, the heated derivative 4 is a cylindrical one made of a high-density C / C composite having a density of 1.99 g / cm ³ and a thermal conductivity of 100 W / M / K, and is used as a liquid phase precursor C. Hydrocarbon cyclohexane was used as

  As shown in FIG. 2, the heating derivative 4 having a cylindrical shape is woven in three dimensions with PAN-based carbon fibers using acrylic fibers or pitch-based carbon fibers using by-products such as petroleum and coal ( Forming a three-way preform (by forming a carbon fiber in a cylindrical shape), a pitch impregnation step b using an easily impregnated pitch, and isolating the three-way preform subjected to this step b at high pressure. HIP processing step c for performing HIP processing to be compressed and a graphitization step d for graphitizing the three-way preform subjected to the HIP processing step c at a high temperature to produce a pitch impregnation step b, HIP processing step c And the graphitization step d is repeated a plurality of times (in this example, 10 times), thereby realizing densification of the heating derivative 4 and high thermal conductivity.

When densifying the carbon preform W having a large number of fine cavities using the porous structure densifying device 1, as shown in FIG. 3, the density of the carbon preform W is 1.99 g in the block B1. The carbon preform W supported by the cylindrical heating derivative 4 made of a high-density C / C composite of / cm ³ is immersed in the liquid phase precursor C in the block B2.

  Thereafter, in block B3, the heating dielectric 4 is heated to 1000 to 1300 ° C. by resistance heating by supplying power (high frequency current of 10 to 40 kHz) from the power supply unit 6 via the electrodes 5a and 5b to the reactor. 2, the liquid phase precursor C and the carbon preform W immersed in the liquid phase precursor C are heated, and the decomposition product of the liquid phase precursor C decomposed by this heating is converted into a number of fine particles of the carbon preform W. When the cavity is impregnated and vapor-deposited, the density of the carbon preform W is increased.

  During this time, the amount of power supplied from the power supply unit 6 to the heating derivative 4 is controlled by the control unit 10 in accordance with the temperature of the heating derivative 4, undecomposed hydrocarbons are condensed in the condenser 7, and the decomposed hydrogen is exhausted. It is discharged to the outside through the mouth 9.

As described above, in the porous structure densifying apparatus 1 according to the present embodiment, as the heating derivative 4, the HIP process of compressing and densifying the three-way carbon fiber preform isotropically at high pressure. Since a high density C / C composite having a density of 1.99 g / cm ³ is used, it functions as a heating derivative 4 with high thermal conductivity and excellent thermal shock. In addition, this high density Thus, the time required for manufacturing the carbon preform W can be greatly shortened.

Accordingly, the porous structure densifying apparatus 1 according to the present embodiment using a high-density C / C composite having a density of 1.99 g / cm ^{3 as} the heating derivative 4 and a density of 1.74 g / as the heating derivative. A densifying device according to Comparative Example 1 using a C ³ C / C composite and a conventional densifying device according to Comparative Example 2 using graphite having a density of about 1.7 g / cm ³ as a heating derivative. Thus, the density of the carbon preform W was increased. Table 1 shows the specifications and results of the heated derivatives of this example and comparative examples 1 and 2.

As can be seen from Table 1, in the porous structure densification apparatus 1 according to this example, a carbon preform W having a product density of 1.74 g / cm ³ was obtained in a short time of about 20 hours. On the other hand, in the densification apparatus according to Comparative Example 1, it takes a long period of 5 days to obtain a carbon preform W having a product density of 1.70 g / cm ³ , and further, graphite is used as a heating derivative. In the conventional densifying device according to Comparative Example 2, it took 6 days to obtain a carbon preform W having a product density of 1.68 g / cm ³ , and the graphite heating derivative itself was Damaged.

  From this, it was proved that the high-density carbon preform W according to the present example can produce the high-density carbon preform W while realizing a significant reduction in the production time.

  In the above-described embodiments, the case where hydrocarbon-based cyclohexane is used as the liquid phase precursor C is shown, but the present invention is not limited to this.

  Moreover, although the case where the heating derivative 4 comprised the column shape was shown in the above-mentioned Example, it is not limited to this, A cylindrical or flat heating derivative can be employ | adopted, heating If the derivative has a cylindrical shape, it is supported by fitting a porous structure around it, and if the heated derivative has a flat shape, the porous structure is attached to one side. And support.

  Further, in the above-described embodiment, the case where resistance heating is performed by directly energizing the columnar heating derivative 4 through the electrodes 5a and 5b is not limited to this. For example, as shown in FIG. 4, induction heating can be achieved by arranging an induction coil 15 outside a columnar heating derivative 14 fitted with a carbon preform W around it, as shown in FIG. In the case of the cylindrical heating derivative 24, induction heating can be performed if the induction coil 25 is disposed inside the heating derivative 24 in which the carbon preform W is fitted.

  Here, in the case where the carbon preform W is fitted around the cylindrical heating derivative 24 shown in FIG. 5, the carbon preform W and the heating derivative 24 supporting the carbon preform W are integrated into a product. In this way, for example, a spacecraft nozzle liner that requires high density can be manufactured, while the carbon preform W is separated from the heated derivative that supports it. It may be made to be manufactured as a separate product. In this case, for example, a brake disk requiring high density can be manufactured.

  The configurations of the porous structure densification method and the densification device according to the present invention are not limited to the configurations of the above-described embodiments.

DESCRIPTION OF SYMBOLS 1 Densification apparatus 2 of porous structure 2 Reactor 4,14,24 Heating derivative 6 Electric power supply part 10 Control part C Liquid phase precursor W Carbon preform (porous structure)

Claims (4)

A method of densifying and vapor-depositing carbon in a large number of fine cavities of a porous structure having a large number of fine cavities, thereby densifying the porous structure,
High density C having a density of 1.95 g / cm ³ or more manufactured by performing HIP treatment for densifying the porous structure by compressing a three-way carbon fiber preform isotropically at high pressure. After being supported by a heated derivative comprising a / C composite and immersing the porous structure supported by the heated derivative in a liquid phase precursor that is a liquid hydrocarbon ,
Heating the heated derivative at least one of induction heating and resistance heating to heat the liquid phase precursor and the porous structure immersed in the liquid phase precursor;
A porous structure characterized in that a decomposition product of the liquid phase precursor that decomposes by heating at least one of induction heating and resistance heating is impregnated and deposited in a number of fine cavities of the porous structure. Body densification method.   2. The porous structure according to claim 1, wherein the porous structure formed by impregnating and vapor-depositing the decomposition product of the liquid phase precursor into a large number of fine cavities is manufactured as one product with the heating derivative supporting the porous structure. Body densification method.   The porous structure formed by impregnating and vapor-depositing the decomposition product of the liquid phase precursor into a large number of fine cavities is separated from the heated derivative supporting the porous structure and is manufactured as a separate product. Method for densifying a porous structure. A porous structure densifying device for impregnating and vapor-depositing carbon in the numerous fine cavities of a porous structure having many fine cavities, and densifying the porous structure,
A reactor containing a liquid phase precursor which is a liquid hydrocarbon;
The reactor in disposed in said porous structures you supported while immersed density is 1.95 g / cm ³ or more C / C composite in the contained the liquid phase precursor into the reactor A heated derivative consisting of
The heated derivative is heated by at least one of induction heating and resistance heating to heat the liquid phase precursor and the porous structure immersed in the liquid phase precursor in the reactor. A power supply unit for impregnating and vapor-depositing a decomposition product of the liquid phase precursor, which is decomposed by at least one of induction heating and resistance heating, into a plurality of fine cavities of the porous structure;
A device for densifying a porous structure, comprising: a control unit that controls an amount of power supplied from the power supply unit according to a temperature of the heating derivative.

Images