CN1275908C

CN1275908C - Method of quickly preparing high heat conductiving carbon/carbon composite material

Info

Publication number: CN1275908C
Application number: CN 200410012434
Authority: CN
Inventors: 刘朗; 高晓晴; 郭全贵; 史景利
Original assignee: Shanxi Institute of Coal Chemistry of CAS
Current assignee: Shanxi Institute of Coal Chemistry of CAS
Priority date: 2004-07-21
Filing date: 2004-07-21
Publication date: 2006-09-20
Anticipated expiration: 2024-07-21
Also published as: CN1597620A

Abstract

The present invention relates to a method of quickly preparing high heat conductivity carbon/carbon composite materials, which comprises the following steps: intermediate phase asphalt is oxidized in the air at the temperature of 200 to 240 DEG C for 0.5 to 3 hours; short intermediate phase asphalt base carbon fiber with the size of 1 to 10mm and the treated intermediate phase asphalt are uniformly mixed in the mass ratio of 1:0.5 to 2; when the temperature of the mixture is raised from a room temperature to the temperature of 350 to 400 DEG C under ordinary pressure, the mixture is pressurized to 20 to 40MPa. When the mixture is heated to 1300 to 1500 DEG C, the pressure is converted into 5 to 20 MP. Finally, when the mixture is heated to 2600 to 3000 DEG C, constant pressure is kept for 30 to 60 minutes. The present invention has the characteristics of simple manufacturing process, short periodicity, low cost, convenient process regulation, high heat conductivity of prepared carbon/carbon products.

Description

A kind of quick method for preparing the high thermal conductivity carbon/carbon composite

Technical field

The invention belongs to the preparation method of the high heat conduction carbon/carbon composite of a kind of staple fibre enhanced.

Technical background

Carbon/carbon composite has low density, high strength at high temperature, anti-ablation, anti-thermal shock, high heat conductance, low thermal coefficient of expansion, well grinds a series of excellent properties such as sassafras polishing machine, good chemical stability, is widely used in space flight, aviation, military project, field such as civilian.At present carbon matrix of carbon/carbon composite materials mainly by chemical vapour deposition (CVD, CVI), flood macromolecule resin or pitch then charing obtain.Obtain fine and close carbon/carbon composite and need pass through hundreds of even the deposition of thousands of hours long periods or repeated multiple times dipping-charing, make that production technique is loaded down with trivial details, the cycle is tediously long, cost is higher, seriously having restricted it further uses and development [Li Hejun, Li Kezhi, present situation and thinking [J] are used in carbon/carbon composite research. the plain technology .2001 (5) of charcoal: 24～27].

In addition, along with development of science and technology, the high power density device is tending towards miniaturization, Highgrade integration, lightweight.For guaranteeing the equipment steady-state operation, needing in time derives the heat that produces, thereby the heat-conductive characteristic of material has been proposed requirements at the higher level.The high thermal conductivity of carbon/carbon composite excellence has been subjected to common people certainly, mainly concentrate at present the development [Qiu Haipeng of the fibre-reinforced high heat conduction carbon/carbon composite of the continuous charcoal of mesophase pitch base, Song Yongzhong, Guo Quangui, Deng. high heat conduction charcoal fiber and C-base composte material [J] thereof. functional materials, 2002,33 (5): 473-476].But, make made high heat conduction carbon/carbon composite cost costliness because used continuous fibre costs an arm and a leg, fiber establishment moulding expense is also higher; Also have long shortcoming of the above production cycle in addition, thereby Application Areas is subjected to very big restriction.

Summary of the invention

The purpose of this invention is to provide a kind of preparation method who has high thermal conductivity, with short production cycle, carbon/carbon composite that cost is low with the short carbon fiber enhanced.

It is raw material that the present invention selects mesophase pitch base short carbon fiber and mesophase pitch for use, and employing integrated-type, charing, graphite turn to the hot-pressing sintering technique of one, prepares the short carbon fiber/carbon composite of high thermal conductivity fast.

The following step that comprises of carbon/carbon composite preparation method of the present invention:

(1) mesophase pitch oxidation 0.5～3 hour in 200～240 ℃ of air;

(2) 1～10mm mesophase pitch base short carbon fiber and the mesophase pitch of handling through (1) are mixed by 1: 0.5～2 mass ratio;

(3) with (2) compound under normal pressure when room temperature rises to 350～400 ℃, be pressurized to 20～40MPa, make pressure become 5～20MPa when being warming up to 1300～1500 ℃, be warming up to 2600～3000 ℃ of constant voltages at last 30～60 minutes.

Aforesaid mesophase pitch softening temperature is 230～330 ℃, intermediate phase content 70～100%.

The mesophase pitch based carbon fiber is preferably selected self thermal conductivity, modulus, the higher short carbon fiber of intensity as mentioned above.

The thermal conductivity of high heat conduction carbon/carbon composite of the present invention can be controlled by changing processing parameter, quality proportioning, pitch kind, kinds of fibers and length.

The present invention has following advantage:

1. raw material is easy to get, and technology is simple, and is with short production cycle, instant effect.

2. the carbon/carbon composite thermal conductivity of this method production is higher than the thermal conductivity of traditional thermally conductive material aluminium far away.

3. the carbon/carbon composite of this method production has good mechanical property.

Specific implementation method

Embodiment 1

With softening temperature is 237 ℃, intermediate phase content is that 70% mesophase pitch was 200 ℃ of oxidations 0.5 hour, after to be 8～10mm mesophase pitch base short carbon fiber with 0.5: 1 quality proportioning mix with length then, put into mould, rise to 350 ℃ from room temperature under the normal pressure, the 30MPa that pressurizes then is warming up to 1300 ℃, is to be warming up to 2600 ℃ under the 15MPa at pressure afterwards, and it is 1.74g/cm that insulation, pressurize can make density in 60 minutes ³High heat conduction carbon/carbon composite, the sample of preparation is cut into the sample of 10mm * 10mm * 20mm specification, through polishing, ultrasonic cleaning and oven dry, according to GB-3399-82 (88) relatively method test its thermal conductivity,, the room temperature thermal conductivity that records the vertical forming pressing direction is 334w/mk.

Embodiment 2

With softening temperature is 253 ℃, intermediate phase content is that 80% mesophase pitch was 200 ℃ of oxidations 3 hours, after to be 8～10mm mesophase pitch base short carbon fiber with 2: 1 quality proportioning mix with length then, put into mould, rise to 400 ℃ from room temperature under the normal pressure, being warming up to 1400 ℃ then under 35MPa pressure, is to be warming up to 2600 ℃ under the 5MPa at pressure afterwards, and it is 1.79g/cm that insulation, pressurize can make density in 30 minutes ³High heat conduction carbon/carbon composite, test is 370w/mk with the room temperature thermal conductivity that example 1 records the vertical forming pressing direction.

Embodiment 3

With softening temperature is 280 ℃, intermediate phase content is that 100% mesophase pitch was 220 ℃ of oxidations 2 hours, after to be 6～8mm mesophase pitch base short carbon fiber with 1.6: 1 quality proportioning mix with length then, put into mould, rise to 380 ℃ from room temperature under the normal pressure, being warming up to 1500 ℃ then under 25MPa pressure, is to be warming up to 2800 ℃ under the 10MPa at pressure then, and it is 1.82g/cm that insulation, pressurize can make density in 30 minutes ³High heat conduction carbon/carbon composite, the test with example 1, the room temperature thermal conductivity that records the vertical forming pressing direction is 432w/mk.

Embodiment 4

With softening temperature is 280 ℃, intermediate phase content is that 100% mesophase pitch was 210 ℃ of oxidations 1 hour, after to be 4～6mm mesophase pitch base short carbon fiber with 1: 1 quality proportioning mix with length then, put into mould, rise to 400 ℃ from room temperature under the normal pressure, being warming up to 1500 ℃ then under 30MPa pressure, is that 15MPa is warming up to 2800 ℃ at pressure afterwards, and it is 1.79g/cm that insulation, pressurize can make density in 60 minutes ³High heat conduction carbon/carbon composite, the test with example 1, the room temperature thermal conductivity that records the vertical forming pressing direction is 420w/mk.

Embodiment 5

With softening temperature is 330 ℃, intermediate phase content is 240 ℃ of oxidations of mesophase pitch of 100% 2 hours, after to be 1～3mm mesophase pitch base short carbon fiber with 2: 1 quality proportioning mix with length then, put into mould, rise to 400 ℃ from room temperature under the normal pressure, be warming up to 1500 ℃ then under 25MPa pressure, be warming up to 3000 ℃ afterwards under pressure 20MPa, it is 1.86g/cm that insulation, pressurize can make density in 30 minutes ³High heat conduction carbon/carbon composite, the test with example 1, the room temperature thermal conductivity that records the vertical forming pressing direction is 405w/mk.

Claims

1, the method for the high heat conduction carbon/carbon composite of a kind of quick preparation is characterized in that comprising the steps:

(1) mesophase pitch oxidation 0.5～3 hour in 200～240 ℃ of air;

(2) 1～10m m mesophase pitch base short carbon fiber and the mesophase pitch of handling through (1) are mixed by 1: 0.5～2 mass ratio;

2, the method for the high heat conduction carbon/carbon composite of a kind of quick preparation as claimed in claim 1 is characterized in that described mesophase pitch softening temperature is 230～330 ℃, intermediate phase content 70～100%.