CN109553430A - A kind of SiC with compound interfacef/ SiC ceramic based composites and preparation method thereof - Google Patents

Abstract

A kind of SiC with compound interface_f/ SiC ceramic based composites, which is characterized in that be made of CVD-SiC coating, PIP-SiC matrix, compound interface and SiC fiber, the CVD-SiC coating is the coat of silicon carbide of chemical vapour deposition technique preparation, with a thickness of 100 ~ 500 μm；The compound interface is the interface BN, ZrO₂Interface, LaPO₄Wherein any two kinds, three kinds of alternate cycle superpositions at interface and the interface SiC, cycle period number is 3 ~ 5 times, and the PIP-SiC matrix is using the Polycarbosilane silicon carbide that pyrolysis is formed in situ；The volume ratio that the SiC fiber accounts for composite material is 40 ~ 60%, it is to prepare MULTILAYER COMPOSITE interface on silicon carbide fibre surface using Different Preparation that, which there is 5 ~ 20nm thickness pyrolytic carbon layer preparation method on surface, then SiC matrix is filled using PIP method, SiC coating in surface is finally prepared using CVD method.The present invention prepares SiC_f/ SiC ceramic based composites obdurability is high, oxidation resistance is strong, and preparation process is simple.

Description

A kind of SiC with compound interfacef/ SiC ceramic based composites and preparation method thereof

Technical field

It is the present invention relates to a kind of ceramic matric composite and preparation method thereof, in particular to a kind of with compound interface SiC _f / SiC ceramic based composites and preparation method thereof.

Background technique

SiC ceramic is because it is with systems such as good high temperature resistant, low-density, Gao Biqiang, Gao Bimo, anti-oxidant and anti-erosions Column excellent properties, to have the potentiality for taking over metal as high-temperature structural material of new generation.Further, since its excellent is partly led Metastable dielectric properties under bulk properties and high temperature, SiC also have good application prospect in terms of microwave absorbing material.So And since the fracture toughness of SiC pure metals is low, brittle fracture is shown as, its application is limited.At present gradually by SiC _f Replaced/SiC ceramic matrix composite material.Continuous SiC fiber toughening Si ceramic matric composite (SiC _f / SiC) because of excellent high temperature power Learn performance, inoxidizability, thermodynamic stability, corrosion resistance and aero engine turbine blades, combustion liner set and Nuclear reactor etc. has broad application prospects.

A large number of studies show that the boundary layer between fiber and matrix is for SiC _f The mechanical property of/SiC ceramic matrix composite material has weight The influence wanted.Boundary layer can prevent fiber from being etched, and effectively transmit the load between fiber and matrix, so that fiber plays Carrying effect.Suitable boundary layer can enable the toughening mechanisms such as crack deflection, interfacial detachment and spike protein gene play, in turn Improve the mechanical property of composite material.

Pyrolytic carbon (PyC) and hexagonal boron nitride (Hexagonal-BN) are two kinds of most common improvement SiC _f //SiC is compound The layered interface layer of material mechanical performance.However, since PyC can be aoxidized at 400 DEG C or more, so that SiC _f //SiC is compound The mechanical property of material at high temperature is remarkably decreased, to limit SiC _f The high temperature application of //SiC ceramic matrix composite material.H-BN has The similar layered crystal structure with pyrolytic carbon (PyC) also has preferable antioxygenic property (800 furthermore compared with pyrolytic carbon DEG C), the liquid B formed after oxidation₂O₃Crackle can be made up, be preferable interface phase candidate material, become the coke of research this year Point.

Another improves SiC _f The method of/SiC ceramic matrix composite material high-temperature oxidation resistant is that introducing one is laminated in the composite Suitable oxide has various stress induced processes (such as interface shearing, twin, phase transformation) as interface phase, these compounds, Fiber-matrix bonding, and the antioxygenic property having had can be weakened.The material of one of possible application is ZrO₂, coating When reaching ideal structure, SiC _f / SiC ceramic matrix composite material spike protein gene is obvious, shows and SiC _f / BN/SiC composite material is comparable Or preferably antioxygenic property and destroy the service life.Y₂O₃Stable t-ZrO₂It can occur under the induction of matrix cracking growth stress t-ZrO₂To m-ZrO₂Phase transformation, and become larger with volume, improve the fracture toughness of composite material in this way, and had Antioxygenic property.

Document " BN coatings prepared by Low pressure chemical vapor deposition Using boron trichloride-ammonia-hydrogen-argon mixture gases, Yu Cheng, Surface and Coating Technology " is at 1000 DEG C and BCl₃-NH₃-H₂Under-Ar system condition, using low pressure Learn vapour deposition process (LPCVD) deposited BN coating in graphite matrix, and prepared coating is the t-BN of turbine layer structure, It is changed into the good h-BN of crystal property at 1300 DEG C or more.

Document " SiC _f The research of //SiC ceramic matrix composite material interface modification coating, Liu Baolin, the National University of Defense technology " is using chemical gas Phase sedimentation prepares the interface different-thickness BN in SiC fiber surface, has studied BN interface coating thickness to SiC _f //SiC composite wood Material mechanical property and influences, with BN coating layer thickness increase, SiC _f The bending strength of //SiC ceramic matrix composite material, elasticity modulus and disconnected Split toughness and be in the trend of first increases and then decreases.

Document " Microstructural features of the ZrO₂ interfacial coatings on SiC Fibers before and after exposition to air at high temperatures, N.I. Baklanova, Journal of the European Ceramic Society ", which have studied, is deposited on SiC fiber surface ZrO₂Interface coating exposes microstructure features before and after high temperature air to the open air, although ZrO₂There is strong between SiC fiber Si-O-Zr bonding, but fibre strength is not damaged substantially, the strong interface I/F of formation is conducive to composite material de- The damage of external oxidation atmosphere is protected the fibers from during viscous.

Although the interface BN, ZrO₂The antioxygenic property of composite material, but the simple interface BN can be improved in interface to a certain degree Use temperature or lower, simple ZrO₂Interfacial phase change toughening is limited, can not play the role of deflecting crackle.Therefore, in order into One step improves the oxidation resistance of composite material, and the multi-component multi-layer interface for mutually deriving micro-structure from layered crystal structure interface is set Meter, multi-component multi-layer interface are mainly (X-Y)_nThe multilayer interface phase of type, wherein X is mainly crack deflection material, and Y is that one kind can Crack deflection and oxidation resistant function can be achieved at the same time in oxidation resistant material, this interface.

Summary of the invention

The technical problem to be solved by the present invention is to overcome the deficiencies in the prior art, it is desirable to provide a kind of with compound interface SiC _f / SiC ceramic based composites are made of CVD-SiC coating, PIP-SiC matrix, compound interface and SiC fiber, described CVD-SiC coating be chemical vapour deposition technique preparation coat of silicon carbide, with a thickness of 100 ~ 500 μm；The compound interface For the interface BN, ZrO₂Interface, LaPO₄Wherein any two kinds, three kinds of alternate cycle superpositions at interface and the interface SiC, cycle period Number is 3 ~ 5 times, and single layer BN interfacial thickness is 80 ~ 200nm, single layer ZrO₂Interfacial thickness is 50 ~ 200nm, single layer LaPO₄Interface With a thickness of 20 ~ 200nm, single layer SiC interfacial thickness is 50 ~ 100nm；The PIP-SiC matrix is in situ using Polycarbosilane It is pyrolyzed the silicon carbide formed；The volume ratio that the SiC fiber accounts for composite material is 40 ~ 60%, and there is 5 ~ 20nm thickness pyrolytic carbon on surface Layer.

In addition to this, the present invention also provides a kind of SiC with compound interface _f Its preparation of/SiC ceramic based composites Method, which is characterized in that comprise the following sequential steps:

(1) silicon carbide fibre is woven into fiber preform, is heat-treated 1 ~ 2h in 700 ~ 900 DEG C of argon atmospheres；

(2) using propylene as carbon source, argon gas is protective gas, 900 ~ 1000 DEG C of depositing temperature, 1 ~ 5h of sedimentation time, using chemical gas Phase sedimentation prepares pyrocarbon coating in fiber surface；

(3) interface BN is prepared using dip-coating method, boric acid and urea are the boron source and nitrogen source of dip-coating method, sodium tetraborate In ethanol by the dissolution of the proportion of mass fraction 1:2 ~ 3 by boric acid and urea it is made into boric acid-urea ethanol solution, so for additive The sodium tetraborate for adding mass fraction 3 ~ 9% afterwards, obtains sodium tetraborate-boric acid-urea ethanol solution, using sodium tetraborate-boron Acid-urea ethanol solution impregnating by pressure silicon carbide fibre precast body part is put into tube furnace after 100 ~ 120 DEG C of drying in nitrogen High-temperature heat treatment under atmosphere；

(4) interface SiC is prepared using chemical vapor infiltration, is warming up to reaction temperature under vacuum atmosphere, is passed through certain trichlorine Methyl-monosilane, hydrogen permeate 3 ~ 6h of sedimentation time as diluent gas as carrier gas, argon gas；

(5) ZrO is prepared using sol-gel method₂Interface, yttrium nitrate hexahydrate are molten by the molar ratio of 1:30 ~ 32 with zirconium oxychloride octahydrate It in deionized water, instills ammonium hydroxide and adjusts PH to 12, generate white oxide zirconium gel, deionized water is cleaned zirconium oxide gel and removed Then foreign ion instills dust technology and adjusts PH to 2, white oxide zirconium gel switchs to white oxide zirconium colloidal sol, then stir to White oxide zirconium colloidal sol is changed into transparent zirconium oxide colloidal sol, using zirconia sol impregnation carbonization silica fibre precast body, after dry It is put into tube furnace, the sintering of argon atmosphere constant-pressure and high-temperature；

(6) LaPO is prepared using electrophoretic deposition₄Interface, according to magnesium chloride hexahydrate: LaPO₄Powder quality ratio is 1:(10 ~ 20) After mixing, it is added in dehydrated alcohol and is made into suspension, LaPO₄Concentration is 2 ~ 10g/L, is negative with silicon carbide fibre precast body Pole, using graphite electrode as positive electrode, 10 ~ 25mA/cm of current density², be inserted into ultrasonic vibration stick, sedimentation time be 5 ~ 10min, then after drying at room temperature, heating heat treatment；

(7) step (3), (4), (5), (6) any two of them step 3 ~ 5 time are repeated；

(8) SiC matrix is then prepared using infiltration pyrolysis method, using Polycarbosilane-xylene solution as precursor, impregnating by pressure, It is put into high temperature furnace and heats up after solidification, heat preservation heat treatment, repeated impregnations cracking technology 9 ~ 12 times, until material rate of body weight gain is lower than 2%；

(7) SiC coating is prepared using chemical vapour deposition technique, using trichloromethyl silane as silicon carbide gas source, hydrogen as carrier gas, For argon gas as diluent gas, reaction temperature is 1000 ~ 1200 DEG C, and infiltration sedimentation time is 20 ~ 30h；

(8) SiC with compound interface is finally obtained _f / SiC ceramic based composites.

It is higher using temperature that the invention has the advantages that: 1, composite laminate periodicity interfacial structures, and toughening effect is more preferable；2, it makes Standby technical process is simple；3, surface C VI-SiC coating protects composite material base, further increases the anti-oxidant energy of composite material Power.

Specific embodiment

Combined with specific embodiments below, the present invention is furture elucidated, it should be understood that these embodiments are merely to illustrate the present invention Rather than limit the scope of the invention, after the present invention has been read, those skilled in the art are to various equivalences of the invention It is as defined in the appended claims that the modification of form falls within the application.

Embodiment 1

With (BN/SiC)_nThe SiC of compound interface _f / SiC ceramic based composites

(1) silicon carbide fibre is woven into fiber preform, is heat-treated 1h in 900 DEG C of argon atmospheres；

(2) using propylene as carbon source, argon gas is protective gas, 900 DEG C of depositing temperature, sedimentation time 3h, using chemical vapor deposition Method prepares pyrocarbon coating in fiber surface；

(3) interface BN is prepared using dip-coating method, boric acid and urea are the boron source and nitrogen source of dip-coating method, sodium tetraborate In ethanol by the dissolution of mass fraction 1:2 proportion by boric acid and urea it is made into boric acid-urea ethanol solution, then for additive The sodium tetraborate for adding mass fraction 3%, obtains sodium tetraborate-boric acid-urea ethanol solution, using sodium tetraborate-boric acid-urine Plain ethanol solution impregnating by pressure silicon carbide fibre precast body part is put into tube furnace high temperature in a nitrogen atmosphere after 120 DEG C of drying Heat treatment；

(4) interface SiC is prepared using chemical vapor infiltration, is warming up to reaction temperature under vacuum atmosphere, is passed through certain trichlorine Methyl-monosilane, hydrogen is as carrier gas, and for argon gas as diluent gas, infiltration sedimentation time is 5h；

(5) step (3), (4) two steps 5 time are repeated；

(6) SiC matrix is then prepared using infiltration pyrolysis method, using Polycarbosilane-xylene solution as precursor, impregnating by pressure, It is put into high temperature furnace and heats up after solidification, heat preservation heat treatment, repeated impregnations cracking technology 11 times, until material rate of body weight gain is lower than 2%；

(7) SiC coating is prepared using chemical vapour deposition technique, using trichloromethyl silane as silicon carbide gas source, hydrogen as carrier gas, For argon gas as diluent gas, reaction temperature is 1150 DEG C, and infiltration sedimentation time is 20h；

(8) finally obtaining has (BN/SiC)_nThe SiC of compound interface _f / SiC ceramic based composites.

The material has the advantages that (BN/SiC)_nThe anti-oxidant energy in interface can be improved in SiC sub-layer in composite interface structures Power, BN sub-layer has excellent crack deflection ability, more preferable to ceramic matrix toughening effect, can promote composite material high-temperature stable Property, surface C VI-SiC coating protects composite material, further increases the oxidation resistance of composite material.

Embodiment 2

With (ZrO₂/SiC)_nThe SiC of compound interface _f / SiC ceramic based composites

(silicon carbide fibre is woven into fiber preform by (1), is heat-treated 1h in 900 DEG C of argon atmospheres；

(2) using propylene as carbon source, argon gas is protective gas, 900 DEG C of depositing temperature, sedimentation time 3h, using chemical vapor deposition Method prepares pyrocarbon coating in fiber surface；

(3) ZrO is prepared using sol-gel method₂Interface, yttrium nitrate hexahydrate and zirconium oxychloride octahydrate are dissolved in by 1:32 molar ratio It in ionized water, instills ammonium hydroxide and adjusts PH to 12, generate white oxide zirconium gel, deionized water cleans zirconium oxide gel and removes impurity Then ion instills dust technology and adjusts PH to 2, white oxide zirconium gel switchs to white oxide zirconium colloidal sol, stirs for 24 hours at 80 DEG C, White oxide zirconium colloidal sol is changed into transparent zirconium oxide colloidal sol, using zirconia sol impregnation carbonization silica fibre precast body, after dry It is put into tube furnace, the sintering of argon atmosphere constant-pressure and high-temperature；

((4) prepare the interface SiC using chemical vapor infiltration, are warming up to reaction temperature under vacuum atmosphere, are passed through certain trichlorine Methyl-monosilane, hydrogen is as carrier gas, and for argon gas as diluent gas, infiltration sedimentation time is 5h；

(5) step (3), (4) two steps 5 time are repeated；

(6) SiC matrix is then prepared using infiltration pyrolysis method, using Polycarbosilane-xylene solution as precursor, impregnating by pressure, It is put into high temperature furnace and heats up after solidification, heat preservation heat treatment, repeated impregnations cracking technology 11 times, until material rate of body weight gain is lower than 2%；

(7) SiC coating is prepared using chemical vapour deposition technique, using trichloromethyl silane as silicon carbide gas source, hydrogen as carrier gas, For argon gas as diluent gas, reaction temperature is 1150 DEG C, and infiltration sedimentation time is 20h；

(8) finally obtaining has (ZrO₂/SiC)_nThe SiC of compound interface _f / SiC ceramic based composites.

The material has the advantages that (BN/SiC)_nThe anti-oxidant energy in interface can be improved in SiC sub-layer in composite interface structures Power, ZrO₂Under stress, induction is undergone phase transition sub-layer, crack tip can be made to be closed, so that crackle is prevented to further expand, It is more preferable to ceramic matrix toughening effect, composite material high-temperature stability can be promoted, surface C VI-SiC coating protects composite material, Further increase the oxidation resistance of composite material.

It above are only two specific embodiments of the invention, but the design concept of the present invention is not limited to this, all benefits It is made a non-material change to the present invention with this design, should belong to the behavior for invading the scope of protection of the invention.But it is all Without departing from the content of technical solution of the present invention, according to the technical essence of the invention any type of letter to the above embodiments Single modification, equivalent variations and remodeling, still fall within the protection scope of technical solution of the present invention.

Claims (1)

1. a kind of SiC with compound interface _f The preparation method of/SiC ceramic based composites, it is characterised in that including following The step of sequence:

(1) silicon carbide fibre is woven into fiber preform, is heat-treated 1 ~ 2h in 700 ~ 900 DEG C of argon atmospheres；

(2) using propylene as carbon source, argon gas is protective gas, 900 ~ 1000 DEG C of depositing temperature, 1 ~ 5h of sedimentation time, using chemical gas Phase sedimentation prepares pyrocarbon coating in fiber surface；

(3) interface BN is prepared using dip-coating method, boric acid and urea are the boron source and nitrogen source of dip-coating method, sodium tetraborate In ethanol by the dissolution of the proportion of mass fraction 1:2 ~ 3 by boric acid and urea it is made into boric acid-urea ethanol solution, so for additive The sodium tetraborate for adding mass fraction 3 ~ 9% afterwards, obtains sodium tetraborate-boric acid-urea ethanol solution, using sodium tetraborate-boron Acid-urea ethanol solution impregnating by pressure silicon carbide fibre precast body part is put into tube furnace after 100 ~ 120 DEG C of drying in nitrogen High-temperature heat treatment under atmosphere；

(4) interface SiC is prepared using chemical vapor infiltration, is warming up to reaction temperature under vacuum atmosphere, is passed through certain trichlorine Methyl-monosilane, hydrogen permeate 3 ~ 6h of sedimentation time as diluent gas as carrier gas, argon gas；

(5) ZrO is prepared using sol-gel method₂Interface, yttrium nitrate hexahydrate are dissolved in zirconium oxychloride octahydrate by the molar ratio of 1:30 ~ 32 It in deionized water, instills ammonium hydroxide and adjusts PH to 12, generate white oxide zirconium gel, deionized water cleans zirconium oxide gel and removes impurity elimination Then matter ion instills dust technology and adjusts PH to 2, white oxide zirconium gel switchs to white oxide zirconium colloidal sol, then stirs to white Color zirconia sol is changed into transparent zirconium oxide colloidal sol, using zirconia sol impregnation carbonization silica fibre precast body, puts after dry Enter in tube furnace, the sintering of argon atmosphere constant-pressure and high-temperature；

(6) LaPO is prepared using electrophoretic deposition₄Interface, according to magnesium chloride hexahydrate: LaPO₄Powder quality ratio is 1:(10 ~ 20) it is mixed After conjunction, it is added in dehydrated alcohol and is made into suspension, LaPO₄Concentration is 2 ~ 10g/L, using silicon carbide fibre precast body as cathode, Using graphite electrode as positive electrode, 10 ~ 25mA/cm of current density², it is inserted into ultrasonic vibration stick, sedimentation time is 5 ~ 10min, Then after drying at room temperature, heating heat treatment；

(7) step (3), (4), (5), (6) any two of them step 3 ~ 5 time are repeated；

(8) SiC matrix is then prepared using infiltration pyrolysis method, using Polycarbosilane-xylene solution as precursor, impregnating by pressure, It is put into high temperature furnace and heats up after solidification, heat preservation heat treatment, repeated impregnations cracking technology 9 ~ 12 times, until material rate of body weight gain is lower than 2%；

(7) SiC coating is prepared using chemical vapour deposition technique, using trichloromethyl silane as silicon carbide gas source, hydrogen as carrier gas, For argon gas as diluent gas, reaction temperature is 1000 ~ 1200 DEG C, and infiltration sedimentation time is 20 ~ 30h；

(8) SiC with compound interface is finally obtained _f / SiC ceramic based composites.