A C / HfB2-HfC-Cu composite material and its preparation method

Abstract

The present invention relates to a C / HfB2-HfC-Cu composite material and a preparation method thereof. The C / HfB2-HfC-Cu composite material is prepared by a method combining precursor infiltration and pyrolysis (PIP) with reactive melt infiltration (RMI). The method first deposits a pyrolytic carbon interface layer on the surface of the fibers of a carbon fiber preform, then uses the PIP process to prepare a porous low-density C / C-B4C substrate, and then uses a hafnium-copper alloy infiltrant to perform reactive melt infiltration on the porous low-density C / C-B4C substrate to obtain the C / HfB2-HfC-Cu composite material. The preparation temperature of the present invention is low, and the prepared composite material has excellent oxidation and ablation resistance.

Description

Technical Field

[0001] This patent belongs to the field of ultra-high temperature ceramic matrix composites, and particularly relates to a C / HfB2-HfC-Cu composite material and a preparation method thereof. Background Art

[0002] Carbon fiber reinforced ultra-high temperature ceramic matrix composites are widely used in the nose cones and leading edges of high-speed aircraft, and the nozzles of solid rocket engines due to their excellent mechanical, high-temperature resistance, and anti-oxidation and ablation properties. The main preparation methods include precursor infiltration and pyrolysis (PIP), chemical vapor infiltration (CVI), and reactive melt infiltration (RMI). The PIP and CVI processes have long production cycles, high costs, and low densities of the prepared composites. The RMI process has the advantages of low cost, short cycle, and high density of the prepared composites.

[0003] The carbides and oxides of Hf have higher melting points and lower high-temperature vapor pressures than those of Zr, so they have better anti-oxidation and ablation properties. However, due to the very high melting point of pure Hf (2231 °C), it is difficult to carry out the reactive melt infiltration process on it, and the high-temperature melt is likely to damage the carbon fiber, resulting in the deterioration of its mechanical properties. Summary of the Invention

[0004] To solve the deficiencies of the prior art, the present invention provides a C / HfB2-HfC-Cu composite material and a preparation method thereof.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] In the first aspect, the present invention provides a preparation method of a C / HfB2-HfC-Cu composite material, comprising the following steps:

[0007] Deposit a pyrolytic carbon interface layer on the fiber surface of the carbon fiber preform by chemical vapor deposition;

[0008] Impregnate the carbon fiber preform deposited with the pyrolytic carbon interface layer with a boron carbide precursor solution, and then carry out curing and high-temperature pyrolysis to prepare a porous low-density C / C-B4C substrate;

[0009] Perform reactive melt infiltration on the porous low-density C / C-B4C substrate with a hafnium copper alloy infiltrant to prepare a C / HfB2-HfC-Cu composite material.

[0010] Preferably, the carbon fiber preform is a needle-punched preform with a density of 0.45 - 0.65 g / cm 3 .

[0011] Preferably, the carbon fiber preform is preheated at a high temperature before depositing the pyrolytic carbon interface layer. The temperature of the high-temperature preheating treatment is 1800 - 2000 °C, and the heat preservation time is 2 - 3 h.

[0012] Preferably, the pyrolytic carbon interface layer is deposited on the surface of the carbon fiber preform by chemical vapor deposition. The carbon source used is propylene, the carrier gas is nitrogen, the deposition temperature is 800 - 1100 °C, and the deposition time depends on the density of the carbon fiber preform after depositing the pyrolytic carbon.

[0013] Preferably, the density of the carbon fiber preform after depositing the pyrolytic carbon is 0.9 - 1.1 g / cm 3 。

[0014] Preferably, the boron carbide precursor solution is a borate ester solution.

[0015] Preferably, the impregnation temperature is 10 - 100 °C, the impregnation pressure is 0.5 - 2 MPa, and the impregnation time is 0.5 - 2 h; the curing temperature is 100 - 350 °C, the curing pressure is 0.5 - 2 MPa, and the curing time is 0.5 - 2 h; the high-temperature pyrolysis temperature is 1700 - 1800 °C, and the pyrolysis time is 2 - 4 h.

[0016] Preferably, the density of the porous low-density C / C-B4C substrate is 1.2 - 1.4 g / cm 3 。

[0017] Preferably, the hafnium copper alloy infiltrant is one of HfCu2, HfCu or Hf2Cu.

[0018] Preferably, the temperature of the reactive infiltration is 1200 - 1500 °C, and the heat preservation time is 1 - 2 h.

[0019] In a second aspect, the present invention provides a C / HfB2-HfC-Cu composite material prepared by the above method.

[0020] Compared with the prior art, the present invention has at least the following beneficial effects:

[0021] The present invention uses a hafnium copper alloy with a relatively low melting point (such as HfCu2, HfCu or Hf2Cu) as the reactive infiltration alloy infiltrant. The preparation process temperature is low, which can reduce the damage to the composite material and keep the material in good mechanical properties; at the same time, compared with C, B4C and Cu have a smaller wetting angle at high temperature, so the melt has better wettability with it, which is more conducive to the progress of reactive infiltration, making the material have a higher density and a lower porosity; in addition, Cu in the composite material matrix can also play a role in sweating cooling. Detailed Embodiments

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0023] The present invention provides a method for preparing a C / HfB2-HfC-Cu composite material, comprising the following steps:

[0024] (1) Depositing a pyrolytic carbon interface layer on the surface of the fibers of a carbon fiber preform by chemical vapor deposition;

[0025] (2) Impregnating the carbon fiber preform deposited with the pyrolytic carbon interface layer with a boron carbide precursor solution, and then performing curing and high-temperature pyrolysis to prepare a porous low-density C / C-B4C substrate;

[0026] (3) Reactively infiltrating the porous low-density C / C-B4C substrate with a hafnium copper alloy infiltrant to prepare a C / HfB2-HfC-Cu composite material.

[0027] In the present invention, a porous low-density C / C-B4C substrate is first prepared by the PIP process using a boron carbide precursor solution for the carbon fiber preform after carbon deposition, and then a C / HfB2-HfC-Cu composite material is prepared by reactive infiltration using a hafnium copper alloy infiltrant on this basis. The present invention discovers that the hafnium copper alloy infiltrant has better wettability in a porous low-density substrate containing B4C than in a porous low-density C / C substrate.

[0028] According to some preferred embodiments, the density of the carbon fiber preform is preferably 0.45-0.65 g / cm 3 , and a high-temperature preheating treatment at 1800-2000 °C for 2-3 h is performed before carbon deposition; in the chemical vapor deposition process, the carbon source used is propylene, the carrier gas is nitrogen, the deposition temperature is preferably 800-1100 °C, and the deposition time depends on the density of the carbon fiber preform after depositing pyrolytic carbon; the density of the preform after depositing pyrolytic carbon is preferably 0.9-1.1 g / cm 3 .

[0029] According to some preferred embodiments, the preparation process parameters of the porous low-density C / C-B4C substrate are preferably as follows: the impregnation temperature is 10-100°C, the impregnation pressure is 0.5-2 MPa, and the impregnation time is 0.5-2 h; the curing temperature is 100-350°C, the curing pressure is 0.5-2 MPa, and the curing time is 0.5-2 h; the high-temperature pyrolysis temperature is 1700-1800°C, and the pyrolysis time is 2-4 h; the density of the porous low-density C / C-B4C substrate is preferably 1.2-1.4 g / cm 3 。

[0030] According to some preferred embodiments, the infiltration alloy infiltrant is one of hafnium copper alloys HfCu2, HfCu or Hf2Cu; the temperature of the reactive infiltration is preferably 1200-1500°C, and the holding time is preferably 1-2 h.

[0031] To more clearly illustrate the technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with embodiments.

[0032] Example 1

[0033] A C / HfB2-HfC-Cu composite material and its preparation method are as follows:

[0034] (1) The needled carbon fiber preform with a density of 0.6 g / cm 3 is subjected to a high-temperature preheating treatment at 1800°C for 2 h, and then a pyrolytic carbon interface layer is deposited on it by chemical vapor deposition. The carbon source used is propylene, the carrier gas is nitrogen, and the deposition temperature is preferably 900°C; the density of the preform after depositing pyrolytic carbon is 1.05 g / cm 3 。

[0035] (2) The carbon fiber preform deposited with a pyrolytic carbon interface layer is impregnated with a borate solution, and then subjected to curing and high-temperature pyrolysis treatments to prepare a porous low-density C / C-B4C substrate. The impregnation temperature is room temperature, the impregnation pressure is 1 MPa, and the impregnation time is 1.5 h; the curing temperature is 220°C, the curing pressure is 1 MPa, and the curing time is 1.5 h; the high-temperature pyrolysis temperature is 1800°C, and the pyrolysis time is 3 h; the density of the prepared porous low-density C / C-B4C substrate is 1.27 g / cm 3 。

[0036] (3) The porous low-density C / C-B4C substrate is subjected to reactive infiltration using an Hf2Cu alloy infiltrant, and the infiltration process parameters are 1500°C / 1 h to prepare a C / HfB2-HfC-Cu composite material.

[0037] After testing, the density of the C / HfB2-HfC-Cu composite material obtained in this example is 3.92 g / cm 3, the flexural strength is 256 MPa, and the linear ablation rate is 0.2×10 -3 mm / s, and the mass ablation rate is 0.5×10 -3 g / s.

[0038] Example 2

[0039] A C / HfB2-HfC-Cu composite material and a preparation method thereof, and the specific steps are as follows:

[0040] (1) The needled carbon fiber preform with a density of 0.6 g / cm 3 is subjected to a high-temperature preheating treatment at 1800 °C for 2 h, and then a pyrolytic carbon interface layer is deposited on it by chemical vapor deposition. The carbon source used is propylene, the carrier gas is nitrogen, and the deposition temperature is preferably 900 °C; the density of the preform after depositing pyrolytic carbon is 1.05 g / cm 3 .

[0041] (2) The carbon fiber preform deposited with a pyrolytic carbon interface layer is impregnated with a borate solution, and then subjected to curing and high-temperature pyrolysis treatment to prepare a porous low-density C / C-B4C substrate. The impregnation temperature is room temperature, the impregnation pressure is 1 MPa, and the impregnation time is 1.5 h; the curing temperature is 220 °C, the curing pressure is 1 MPa, and the curing time is 1.5 h; the high-temperature pyrolysis temperature is 1800 °C, and the pyrolysis time is 3 h; the density of the prepared porous low-density C / C-B4C substrate is 1.29 g / cm 3 .

[0042] (3) The porous low-density C / C-B4C substrate is subjected to reactive melt infiltration with a HfCu alloy infiltrant, and the melt infiltration process parameters are 1400 °C / 1 h to prepare a C / HfB2-HfC-Cu composite material.

[0043] After testing, the density of the C / HfB2-HfC-Cu composite material obtained in this example is 3.58 g / cm 3 , the flexural strength is 272 MPa, the linear ablation rate is 0.8×10 -3 mm / s, and the mass ablation rate is 2×10 -3 g / s.

[0044] The specific embodiments of the present invention disclosed above are intended to help understand the content of the present invention and implement it accordingly. Those of ordinary skill in the art can understand that various substitutions, changes, and modifications are possible without departing from the spirit and scope of the present invention. The present invention should not be limited to the content disclosed in the embodiments of this specification, and the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A preparation method of a C / HfB2-HfC-Cu composite material, characterized in that, It includes the following steps: (1) Deposit a pyrolytic carbon interface layer on the fiber surface of the carbon fiber preform by chemical vapor deposition; (2) Impregnate the carbon fiber preform deposited with the pyrolytic carbon interface layer with a boron carbide precursor solution, and then carry out curing and high-temperature pyrolysis to prepare a porous low-density C / C-B4C substrate; (3) Carry out reactive melt infiltration on the porous low-density C / C-B4C substrate with a hafnium copper alloy infiltrant to prepare a C / HfB2-HfC-Cu composite material.

2. The preparation method according to claim 1, characterized in that: The carbon fiber preform is a needle-punched preform with a density of 0.45 - 0.65 g / cm 3 .

3. The preparation method according to claim 1, characterized in that: Before depositing the pyrolytic carbon interface layer, perform a high-temperature preheating treatment on the carbon fiber preform. The temperature of the high-temperature preheating treatment is 1800-2000 °C, and the holding time is 2-3 h.

4. The preparation method according to claim 1, characterized in that: In the chemical vapor deposition method, the carbon source used is propylene, the carrier gas is nitrogen, the deposition temperature is 800-1100 °C, and the deposition time depends on the density of the carbon fiber preform after depositing the pyrolytic carbon.

5. The preparation method according to claim 4, characterized in that: The density of the carbon fiber preform after depositing pyrolytic carbon is 0.9 - 1.1 g / cm 3 .

6. The preparation method according to claim 1, characterized in that: The boron carbide precursor solution is a borate ester solution.

7. The preparation method according to claim 1, wherein: The impregnation temperature is 10-100 °C, the impregnation pressure is 0.5-2 MPa, and the impregnation time is 0.5-2 h; the curing temperature is 100-350 °C, the curing pressure is 0.5-2 MPa, and the curing time is 0.5-2 h; the high-temperature pyrolysis temperature is 1700-1800 °C, and the pyrolysis time is 2-4 h.

8. The preparation method according to claim 1, wherein: The density of the porous low-density C / C-B4C substrate is 1.2-1.4 g / cm 3 .

9. The preparation method according to claim 1, characterized in that: In step (3), the hafnium copper alloy infiltrant is one of HfCu2, HfCu or Hf2Cu; the reactive melt infiltration temperature is 1200-1500 °C, and the holding time is 1-2 h.

10. A C / HfB2-HfC-Cu composite material prepared by the method according to any one of claims 1-9.