CN107673761A

CN107673761A - A kind of preparation method of big specification compact silicon carbide ceramic plate

Info

Publication number: CN107673761A
Application number: CN201711021544.6A
Authority: CN
Inventors: 王明峰; 亓锡云; 王明祥; 石威
Original assignee: WEIFANG HUAMEI FINE TECHNICAL CERAMICS CO Ltd
Current assignee: Shandong Huamei New Material Technology Co ltd
Priority date: 2017-10-27
Filing date: 2017-10-27
Publication date: 2018-02-09
Anticipated expiration: 2037-10-27
Also published as: CN107673761B

Abstract

The invention discloses a kind of preparation method of big specification compact silicon carbide ceramic plate, it is related to reaction sintering silicon carbide ceramic technical field, including batch mixing, mist projection granulating, it is hot-forming, humidify drying, processing, high temperature is dried and reaction-sintered step, matched by unconventional using carborundum, mist projection granulating and it is hot-forming after carry out humidification drying, during reaction-sintered, add the silica flour of base substrate weight 200~300% and keep oxygen-free environment, it ensure that the silicon carbide ceramics plate after sintering does not ftracture, it is fine and close, even density, and high yield rate, it is 600~800mm to solve in sintering length, width is 400~600mm, technology barrier when thickness is 40~60mm big specification silicon carbide ceramics plate, domestic blank is filled up, success substitutes import, reduce the use cost of application field.

Description

A kind of preparation method of big specification compact silicon carbide ceramic plate

Technical field

The present invention relates to a kind of preparation method of silicon carbide ceramics plate, more particularly to a kind of length is 600~800mm, width The preparation method for the big specification compact silicon carbide ceramic plate for being 40~60mm for 400~600mm, thickness is spent, belongs to carborundum pottery Porcelain technical field.

Background technology

Silicon carbide ceramics has that elevated temperature strength is big, inoxidizability is strong, wear resistance is good, heat endurance is good, thermal coefficient of expansion It is small, thermal conductivity is big, hardness is high and anti-thermal shock and the good characteristic such as resistant to chemical etching, and mechanical behavior under high temperature is (intensity, anti-compacted Denaturation etc.) it is optimal in known ceramic material, so as to obtain more and more extensive application, its feeler is almost stretched all over all Industrial circle, more and more important effect is played in Material Field, and be increasingly subject to the attention of people.

According to different industrial circles, different operating mode use environments, carbofrax material can be used, utilizes various techniques, system Different types of silicon carbide ceramics structural member is made to meet application demand.But for big specification silicon carbide ceramics plate because it is super Length, ultra-wide, the design feature of super thick, it, which is prepared, encounters formula, shaping, drying, the technology barrier such as burns till, and particularly easily goes out The problems such as now cracking, Density inhomogeneity, compactness is poor, raw burn, becomes the technological difficulties in industry and make blank.

The content of the invention

In order to solve the above-mentioned technical problem, the invention provides a kind of preparation side of big specification compact silicon carbide ceramic plate Method, particularly prepare length be 600~800mm, the silicon carbide ceramics plate that width is 400~600mm, thickness is 40~60mm When, guarantee plate does not ftracture, fine and close, even density, and high yield rate.

The technical solution adopted by the present invention is：A kind of preparation method of big specification compact silicon carbide ceramic plate, the carbonization The length of silicon ceramic wafer is 600~800mm, width is 400~600mm, thickness is 40~60mm, and the preparation method includes following Step：

1) graphite powder that 1~2 parts by weight purity is 99.8~99.9% and 25~30 parts by weight purity are 99.8 by batch mixing After~99.9% carborundum powder mixing, then the zinc stearate of 2~4 parts by weight and the poly- second of 15~20 parts by weight are added wherein Enol, uniform stirring, obtain compound；

2) mist projection granulating obtains being granulated powder using drying machine with centrifugal spray to the compound mist projection granulating；

3) the hot-forming granulation powder by preparation loads metal die, using 500~600T hot presses, in temperature 180 ~200 DEG C, under conditions of 35~55MPa of pressure, pressurize and after release, obtain the base substrate of thermal pressing moulded board；

4) humidification, which is dried, is placed in the base substrate of shaping in humidification drying equipment, in 30~50 DEG C of temperature, humidity 40~60% Under conditions of, slowly humidification is dried 100~120 hours；

5) process repairing type and corresponding working process is carried out to the dried base substrate using machining equipment, complete to need The plate for the accurate geometry shape wanted；

6) base substrate Jing Guo working process is placed in high temperature drying chamber by high temperature drying, in 100~120 DEG C of conditions of temperature Under, dry 40~60 hours；

7) base substrate described in the more than one piece by high temperature drying is emitted on bearing and burning rack by reaction-sintered side by side, and adds base substrate Weight 200~300%, the metallic silicon power that purity is 98~99%, are fitted into vacuum electric furnace；After the electric furnace power transmission, true Under dummy status, after rising to 1900~2100 DEG C by room temperature with the times of 40~60 hours, constant temperature 8~10 hours；Again with 10~20 The time of hour, helium fast cooling is filled to 300 DEG C；Heat up again, 1400 were risen to by 300 DEG C with the times of 5~10 hours~ 1600 DEG C, constant temperature 5~7 hours；Again with the time of 30~50 hours, stop power transmission after being cooled to 100 DEG C, be naturally cooling to be less than Come out of the stove to obtain the silicon carbide ceramics plate after room temperature.

After employing above-mentioned technical proposal, the beneficial effects of the invention are as follows：

1) content of increase carborundum unconventional in batch mixing proportioning, experiment proves, base substrate is realized the increase of density, Improve the compactness of sintered body.

2) the granulation powder after mist projection granulating is hot-forming, pressurization at high temperature contributes between base substrate powder particles Contact and diffusion, so as to reduce sintering temperature, shorten sintering time, it is easier to be molded.

3) by silicon carbide ceramics laminin base first in drying equipment humidify slowly humidification drying, then carry out high temperature drying and instead Should sinter, can effectively solve traditional drying mode cause billet surface moisture evaporation it is too fast, with base substrate internal moisture diffusion not phase Adapt to, aqueous inequality inside and outside base substrate, base substrate is easy to crack and problem on deformation.

4) in sintering step, the metallic silicon power amount of base substrate weight 200~300% is added, and first time heating, cooling is burnt Knot process, base substrate is realized the increase of intensity, density, improve the compactness of sintered body；It can be realized quickly by being filled with helium Cooling；Second of heating, cooling sintering process, avoids the generation of raw burn problem, while have detected sintered body in the condition of high temperature Under variable condition, it is ensured that sintering quality.Above-mentioned sintering process is carried out under oxygen-free environment, and experiment proves, this burns to improving The compactness and reduction plate body cracking of knot body are most important.

5) it is emitted on and is held on buck side by side with 50~100mm spacing, can be made full use of to hold and burn space, increase the loading of plate Amount, improve production efficiency.

In summary, disclosed preparation method, matched by unconventional using carborundum, mist projection granulating and heat Carry out humidification drying after molded, during reaction-sintered, the silica flour for adding base substrate weight 200~300% simultaneously keeps oxygen-free environment, protects Demonstrate,proved the silicon carbide ceramics plate after sintering do not ftracture, be fine and close, even density, and high yield rate, it is 600 to solve in sintering length Technology barrier during the big specification silicon carbide ceramics plate that~800mm, width are 400~600mm, thickness is 40~60mm, is filled up Domestic blank, successfully substitutes import, reduces the use cost of application field.

Embodiment

With reference to embodiment, the present invention will be further described.

Embodiment 1

The silicon carbide ceramics plate that length x width x thickness is 600mm × 400mm × 40mm is prepared with following methods, including Following steps：

1) graphite powder that 1 parts by weight purity is 99.8~99.9% and 25 parts by weight purity are 99.8~99.9% by batch mixing Carborundum powder mixing after, then add the zinc stearate of 2 parts by weight and the polyvinyl alcohol of 15 parts by weight wherein, uniform stirring, Obtain compound；

3) the hot-forming granulation powder by preparation loads metal die, using 500~600T hot presses, in temperature 180 DEG C, under conditions of pressure 35MPa, pressurize and after release 4 times, obtain the base substrate of thermal pressing moulded board；

4) humidification, which is dried, is placed in the base substrate of shaping in humidification drying equipment, under conditions of 30 DEG C of temperature, humidity 40%, Slowly humidification is dried 100 hours；

6) base substrate Jing Guo working process is placed in high temperature drying chamber by high temperature drying, under the conditions of 100 DEG C of temperature, is done Dry 40 hours；

7) base substrate spacing 100mm described in the more than one piece by high temperature drying is emitted on bearing and burning rack by reaction-sintered side by side, And add base substrate weight 300%, the metallic silicon power that purity is 98~99%, it is fitted into vacuum electric furnace；After the electric furnace power transmission, Under vacuum conditions, after rising to 1900 DEG C by room temperature with the time of 40 hours, constant temperature 8 hours；Again with the time of 10 hours, helium is filled Gas fast cooling is to 300 DEG C；Heat up again, rise to 1400 DEG C by 300 DEG C with the times of 5 hours, constant temperature 5 hours；It is small with 30 again When time, stop power transmission after being cooled to 100 DEG C, be naturally cooling to be less than room temperature after come out of the stove to obtain the silicon carbide ceramics plate.

Embodiment 2

The silicon carbide ceramics plate that length x width x thickness is 700mm × 500mm × 50mm is prepared with following methods, including Following steps：

1) batch mixing by graphite powder that 1.4 parts by weight purity are 99.8~99.9% and 28 parts by weight purity be 99.8~ After 99.9% carborundum powder mixing, then the zinc stearate of 3 parts by weight and the polyvinyl alcohol of 18 parts by weight are added wherein, uniformly Stirring, obtains compound；

3) the hot-forming granulation powder by preparation loads metal die, using 500~600T hot presses, in temperature 190 DEG C, under conditions of pressure 45MPa, pressurize and after release 5 times, obtain the base substrate of thermal pressing moulded board；

4) humidification, which is dried, is placed in the base substrate of shaping in humidification drying equipment, under conditions of 40 DEG C of temperature, humidity 50%, Slowly humidification is dried 110 hours；

6) base substrate Jing Guo working process is placed in high temperature drying chamber by high temperature drying, under the conditions of 110 DEG C of temperature, is done Dry 50 hours；

7) base substrate spacing 70mm described in the more than one piece by high temperature drying is emitted on bearing and burning rack by reaction-sintered side by side, and Add base substrate weight 250%, the metallic silicon power that purity is 98~99%, be fitted into vacuum electric furnace；After the electric furnace power transmission, Under vacuum state, after rising to 2000 DEG C by room temperature with the times of 50 hours, constant temperature 9 hours；Again with the time of 15 hours, helium is filled Fast cooling is to 300 DEG C；Heat up again, rise to 1500 DEG C by 300 DEG C with the times of 8 hours, constant temperature 6 hours；Again with 40 hours Time, stop power transmission after being cooled to 100 DEG C, be naturally cooling to be less than room temperature after come out of the stove to obtain the silicon carbide ceramics plate.

Embodiment 3

The silicon carbide ceramics plate that length x width x thickness is 800mm × 600mm × 60mm is prepared with following methods, including Following steps：

1) graphite powder that 2 parts by weight purity are 99.8~99.9% and 30 parts by weight purity are 99.8~99.9% by batch mixing Carborundum powder mixing after, then add the zinc stearate of 4 parts by weight and the polyvinyl alcohol of 20 parts by weight wherein, uniform stirring, Obtain compound；

3) the hot-forming granulation powder by preparation loads metal die, using 500~600T hot presses, in temperature 200 DEG C, under conditions of pressure 55MPa, pressurize and after release, obtain the base substrate of thermal pressing moulded board；

4) humidification, which is dried, is placed in the base substrate of shaping in humidification drying equipment, under conditions of temperature 50 C, humidity 60%, Slowly humidification is dried 120 hours；

6) base substrate Jing Guo working process is placed in high temperature drying chamber by high temperature drying, under the conditions of 120 DEG C of temperature, is done Dry 60 hours；

7) base substrate described in the more than one piece by high temperature drying is emitted on bearing and burning rack by reaction-sintered side by side, and adds base substrate Weight 200%, the metallic silicon power that purity is 98~99%, are fitted into vacuum electric furnace；After the electric furnace power transmission, in vacuum state Under, after rising to 2100 DEG C by room temperature with the times of 60 hours, constant temperature 10 hours；Again with the time of 20 hours, the fast prompt drop of helium is filled Temperature is to 300 DEG C；Heat up again, rise to 1600 DEG C by 300 DEG C with the times of 10 hours, constant temperature 7 hours；Again with 50 hours when Between, stop power transmission after being cooled to 100 DEG C, be naturally cooling to come out of the stove to obtain the silicon carbide ceramics plate after being less than room temperature.

The performance parameter of ceramic wafer, see the table below after the key step and sintering of above-described embodiment and comparative example：

The present invention is not limited to above-mentioned specific embodiment, its contribution to prior art do not lie in its some step and Some parameter, and it is the combination of these steps and technological parameter, nor be obtained with by limited number of time experiment , some indexs employ unconventional setting, such as：The ratio of graphite powder and carborundum, it is considered that be 1:2~5, and this Invention but employs 1~2:25~30, meanwhile, in reaction-sintered step, also increase the dosage of metallic silicon power, it is considered that The ratio of base substrate and metallic silicon power is 1:0.3~0.4 is rational, but the application employs 1:2~3 ratio, so as to one Act solve long-standing problem those of ordinary skill in the art prepare length be 600~800mm, width is 400~600mm, thickness Technology barrier during the big specification silicon carbide ceramics plate for 40~60mm is spent, ensures that the ceramic wafer after sintering does not ftracture, be fine and close, be close Degree is uniform, and high yield rate, has filled up domestic blank, substitutes import, reduces the use cost of application field.

Claims

1. a kind of preparation method of big specification compact silicon carbide ceramic plate, the length of the silicon carbide ceramics plate for 600~ 800mm, width are 400~600mm, thickness is 40~60mm, it is characterised in that the preparation method comprises the following steps：

1) batch mixing by graphite powder that 1~2 parts by weight purity is 99.8~99.9% and 25~30 parts by weight purity be 99.8~ After 99.9% carborundum powder mixing, then the zinc stearate of 2~4 parts by weight and the polyethylene of 15~20 parts by weight are added wherein Alcohol, uniform stirring, obtain compound；

3) the hot-forming granulation powder by preparation loads metal die, using 500~600T hot presses, in temperature 180~200 DEG C, under conditions of 35~55MPa of pressure, pressurize and after release, obtain the base substrate of thermal pressing moulded board；

4) humidification, which is dried, is placed in the base substrate of shaping in humidification drying equipment, in the bar of 30~50 DEG C of temperature, humidity 40~60% Under part, slowly humidification is dried 100~120 hours；

5) process repairing type and corresponding working process is carried out to the dried base substrate using machining equipment, complete what is needed The plate of accurate geometry shape；

6) base substrate Jing Guo working process is placed in high temperature drying chamber by high temperature drying, under the conditions of 100~120 DEG C of temperature, Dry 40~60 hours；

7) base substrate described in the more than one piece by high temperature drying is emitted on bearing and burning rack by reaction-sintered side by side, and adds base substrate weight 200~300%, purity is 98~99% metallic silicon power, is fitted into vacuum electric furnace；After the electric furnace power transmission, in vacuum shape Under state, after rising to 1900~2100 DEG C by room temperature with the times of 40~60 hours, constant temperature 8~10 hours；Again with 10~20 hours Time, fill helium fast cooling to 300 DEG C；Heat up again, 1400~1600 are risen to by 300 DEG C with the times of 5~10 hours DEG C, constant temperature 5~7 hours；Again with the time of 30~50 hours, stop power transmission after being cooled to 100 DEG C, be naturally cooling to be less than room temperature After come out of the stove to obtain the silicon carbide ceramics plate.

2. the preparation method of big specification compact silicon carbide ceramic plate as claimed in claim 1, it is characterised in that in the hot pressing In forming step, the hot press obtains the base by after the granulation powder pressurization in the metal die and release 4~5 times Body.

3. the preparation method of big specification compact silicon carbide ceramic plate as claimed in claim 1, it is characterised in that in the reaction In sintering step, the spacing between the base substrate being emitted on side by side on bearing and burning rack is 50~100mm.