CN116354731A - Two-step sintering method for fine-grain submicron structure ceramic - Google Patents
Two-step sintering method for fine-grain submicron structure ceramic Download PDFInfo
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Abstract
The invention discloses a two-step sintering method of fine-grain submicron structure ceramics, which has the technical scheme that: sintering and preserving heat for 5-15min at T1 temperature, sintering and preserving heat for 18-22h at T2 temperature, wherein the T1 temperature is 1540-1560 ℃, and the T2 temperature is 1450-1470 ℃. The sintering process uses common heating equipment to heat, the performance of the sintering process can reach products consistent with expensive equipment such as hot pressing, microwaves, discharging, vacuum and the like, and the investment is small; the conventional one-step sintering method can cause the grain boundary to migrate too quickly to cause the growth of grains at the end of sintering due to the temperature rise, and the two-part sintering method can inhibit the migration of the boundaries in a set temperature range (dynamic window), so that the diffusion of the grain boundary is increased and the compactness is increased; as the T2 temperature is diffused in the sintering dynamics window range, the growth of crystal grains is restrained, the crystal grains are promoted to develop and develop finely and have good compactness, and the product has better toughness and mechanical property.
Description
Technical Field
The invention relates to the field of ceramics, in particular to a two-step sintering method of fine-grain submicron structure ceramics.
Background
In the equipment manufacturing industry, the structural ceramic is used as a novel inorganic nonmetallic material and has excellent performances of high temperature resistance, abrasion resistance, corrosion resistance, oxidation resistance, creep reduction at high temperature and the like. In the crystal structure, the element binding force of the structural ceramic is mainly ionic bond, covalent bond or ionic covalent bond, and the structural ceramic has good mechanical property due to the bond energy, but lacks an independent sliding system, has poor toughness, and can cause cracking once stressed, thus seriously affecting the product performance. In order to change the situation, researchers grind and modify the powder to make the powder in submicron and nanometer level, so that the powder has high activity and is easy to sinter. However, the fine powder is easy to agglomerate and cause secondary growth of crystal grains in the sintering process, and the microscopic uniformity of the product is affected. The physical properties of ceramic materials are largely dependent on microstructure, with the grain size affecting the most, the smaller the grains, the higher the strength and the better the toughness. As a sintering process in the preparation process, if a conventional sintering method is used, a certain compactness and a uniform microstructure of the material are difficult to obtain. The traditional sintering process adopts high sintering temperature and long heat preservation time, the extreme sintering condition can lead to irregular growth of crystal grains and generation of uneven microstructure at the end stage of sintering, and the adoption of hot pressing equipment has large investment and limitation, which is not beneficial to conventional production. In 1990, a two-part sintering method is proposed, and the technology mainly comprises the steps of rapidly heating to high temperature in a first stage, rapidly cooling to a lower temperature in a second stage, and preserving heat for a period of time, so that densification process can not be stopped while grain growth is inhibited, and therefore, ceramic with high density and fine grains can be sintered. Because of no special requirements on equipment, the technology can be popularized. The two sintering processes of the nano ceramic are seen at various report ends at home and abroad. However, there are very few reports of two-part sintering of submicron ceramics. For this reason we have found, through constant exploration, a set of two-part sintering methods suitable for submicron ceramics.
Submicron (100 nm-1.0 um) ceramic means that in the microstructure of ceramic materials, the grain size, the grain boundary width, the air holes, the defect size and the like are all in submicron level, and due to fine grains and large sintering activity, abnormal growth of the grains can be caused particularly by overhigh temperature in the later stage of sintering, and the complete densification is difficult to achieve. The two-part sintering method can effectively inhibit the growth of grains in the final stage of sintering on the premise of completing densification of ceramic. Densification and grain growth are competing processes in the ceramic sintering densification process, the grain growth is driven by a chemical site gradient caused by the size difference among grains, and densification is realized through pore removal, and the pore removal depends on the sintering compressive stress to which the pores are subjected. The grain growth and densification process correspond to different temperature ranges, so that the sintering mechanism for inhibiting the growth of grains can be controlled to increase densification by controlling the sintering temperature, thereby obtaining the fine-grain ceramic with high density. Alumina powder of 0.5 μm D50 was selected for one-step (OSS) and two-step sintering (TSS), density was measured by archimedes drainage and grain size was measured by TEM. In the experiment, 0.5 micrometer particles are uniaxially pressurized under the pressure of 500MPa, then 150 MPa isostatic pressure is adopted, the heating rate of the green body 5 ℃/mm is increased to 600 ℃ for heat preservation for 1 hour for glue discharging, then the temperature is increased to the set temperature 1540 ℃ at the rate of 8 ℃/mm, and the temperature is naturally reduced after heat preservation for 30 mm. The density of the sample was 3.93/cm3 by the drainage method, and the grain size was 20. Mu.m by an optical microscope. The powder with the same particle size is sintered by a two-part sintering method (TSS), the heating rate of the green body 5 ℃/mm is increased to 600 ℃/mm, the temperature is kept for 1 hour, then the temperature is increased to a set temperature T1 (1560 ℃ to 1540 ℃) according to 10 ℃/mm, the temperature is not kept, the temperature is reduced to T2 (1470 ℃ to 1450 ℃) according to 10 ℃/mm, the temperature is kept for 20 hours, the temperature is naturally reduced, the density 3.989/cm3 is measured by a drainage method, and the grain size is 15 microns by EMS. When the crystal grains are observed to be fine through a microscope, the crystal grain boundary is clear and has no pores, and the requirements of the sintering submicron-level compactness and uniformity by a two-step sintering method are met.
Before the traditional pressureless sintering enters the sintering later stage and the density reaches 90%, the air holes in the green body are in an open hole state, the pinning effect is started to move the grain boundary, the grains grow slowly, the open holes are closed and shrink and disappear along with the temperature rise, the pinning effect is weakened, the grains can grow abnormally, the sintering of the ceramic is mainly performed in two processes of grain growth and densification, the grain boundary migration and diffusion change processes correspond to, and different change processes correspond to different temperature ranges. The two-part sintering method is to obtain a reasonable relative density (85% -90%) by heating to a higher temperature, so that the pores in the green body are in subcritical and unstable states, and when the ceramic is subjected to the subsequent second-step sintering, the dense ceramic can be obtained by discharging the pores at a lower temperature for a certain time, so that abnormal growth of grains in the final stage of sintering is avoided.
The preparation method of the ultra-thin alumina ceramic green body with the submicron structure is disclosed in the China patent with the prior publication number of CN109049289B, and is characterized by comprising the following steps: (1) preparation of slurry; (2) drying and dehydrating; (3) rough rolling; (4) finish rolling and forming; the invention obviously improves the green density of the ultrathin alumina ceramic substrate by a rolling process and can obviously improve the sintering property of the material, thereby being convenient for obtaining the ultrathin alumina ceramic substrate with a submicron structure.
And as shown in the prior Chinese patent with the publication number of CN104491923A, the nano/micro crystal gradient structure calcium phosphate biological ceramic material comprises three different gradient crystal structure layers, namely a nano crystal structure surface layer, a nano/micro crystal structure transition layer, a micro crystal structure center layer and the like, as well as a preparation method and application thereof. The method is characterized in that the HA biological ceramic with a nano-and micro-crystal gradient change structure is obtained by configuring a sintering temperature gradient distribution field. The nano crystal layer of the material endows the material with unique biological activity, the micro crystal layer ensures the mechanical property of the material, the nano crystal layer and the micro crystal layer are in gradient transition and are tightly combined, and the mechanical property of the material and natural hard tissues can be matched by adjusting the nano/micro layer structure combination, so that the multifunctional requirement of the biological material is met.
The above patents all have some advantages, but have some disadvantages that submicron powder is not as active as nano powder compared with nano ceramic, and has fewer lattice defects, so that higher sintering activation energy is needed to reach a certain theoretical density. If the sintering temperature T1 in the first step does not reach 85% -90% of the theoretical density, the inter-crystal pores in the ceramic cannot be diffused, and even if the temperature of T2 is increased or the heat preservation time is prolonged, the theoretical density is not reached. If the temperature T1 is unchanged, too high a temperature T2 can activate migration movement of grain boundaries to cause grain growth. If the T2 holding time is too long, grain boundary diffusion causes some smaller grains to be gradually engulfed by adjacent grains and ripening to occur, thereby causing the grains to grow.
Disclosure of Invention
In view of the problems mentioned in the background art, an object of the present invention is to provide a two-step sintering method for fine-grain sub-micron structured ceramics, which solves the problems mentioned in the background art.
The technical aim of the invention is realized by the following technical scheme:
the fine-grain submicron structure ceramic is sintered at the temperature of T1 and is kept for 5-15min, and is sintered at the temperature of T2 and is kept for 18-22h, wherein the temperature of T1 is 1540-1560 ℃, and the temperature of T2 is 1450-1470 ℃.
Preferably, the material is sintered and insulated for 9min at T1 temperature, and sintered and insulated for 20h at T2 temperature, wherein the T1 temperature is 1550 ℃ and the T2 temperature is 1460 ℃.
Preferably, when sintering at the temperature T1, sintering is performed in a common oxidizing atmosphere with the free oxygen content of 4% -5%.
Preferably, when sintering at the temperature T1, sintering is performed in a neutral atmosphere with the free oxygen content of 1% -1.5%.
Preferably, after the T2 sintering temperature, the temperature is reduced along with the furnace for cooling.
Preferably, before the temperature T1, the sintering curve includes six stages of segment No. 1, segment No. 2, segment No. 3, segment No. 4, segment No. 5, and segment No. 6.
Preferably, the temperature of the section No. 1 is room temperature and the duration is 240min, the temperature of the section No. 2 is 150 ℃ and the duration is 300min, and the temperature of the section No. 3 is 300 ℃ and the duration is 120min.
Preferably, the temperature of the section number 4 is 300 ℃, the duration is 360min, the temperature of the section number 5 is 600 ℃, the duration is 180min, the temperature of the section number 6 is 600 ℃ and the duration is 93min, the section numbers 1 to 6 are degreasing and adhesive discharging stages, and the organic matters of the green body are discharged more thoroughly through the heat absorption and release reaction.
In summary, the invention has the following advantages:
1. the novel sintering process can be heated by common heating equipment, the performance can completely reach the products consistent with expensive equipment such as hot pressing, microwaves, discharging, vacuum and the like, and the investment is small;
2. the conventional one-step sintering method can cause the grain boundary to migrate too quickly to cause the growth of grains due to the temperature rise in the final sintering stage, and the two-part sintering method can inhibit the migration of the grain boundary in a set temperature range (dynamic window), so that the diffusion of the grain boundary is increased and the compactness is increased;
3. as the T2 temperature is diffused in the sintering dynamics window range, the growth of crystal grains is restrained, the crystal grains are promoted to develop and develop finely and have good compactness, and the product has better toughness and mechanical property.
Drawings
FIG. 1 is a grain diagram of a one-step sintering process;
FIG. 2 is a grain diagram of a two-step sintering process.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
Example 1
Referring to fig. 1, the fine-grain submicron structure ceramic is sintered and heat-preserved for 5min at T1 temperature, sintered and heat-preserved for 18h at T2 temperature, wherein the T1 temperature is 1540 ℃ and the T2 temperature is 1450 ℃.
Wherein, when sintering at the T1 temperature, sintering is carried out under the common oxidizing atmosphere with the free oxygen content of 4 percent.
Wherein, when sintering at the temperature T1, neutral gas with the free oxygen content of 1% is adopted for heat preservation for 2 hours for sintering.
Wherein after the T2 sintering temperature, it is cooled to 1200 ℃, followed by cooling.
Before the temperature T1, the sintering curve comprises six stages of segment number 1, segment number 2, segment number 3, segment number 4, segment number 5 and segment number 6.
The temperature of the section No. 1 is room temperature and the duration is 240min, the temperature of the section No. 2 is 150 ℃ and the duration is 300min, and the temperature of the section No. 3 is 300 ℃ and the duration is 120min.
The temperature of the section No. 4 is 300 ℃, the duration is 360min, the temperature of the section No. 5 is 600 ℃, the duration is 180min, the temperature of the section No. 6 is 600 ℃, the duration is 93min, and the section No. 1 to the section No. 6 are degreasing and adhesive discharging stages.
The novel sintering process can be heated by common heating equipment, the performance of the novel sintering process can completely reach products consistent with expensive equipment such as hot pressing, microwaves, discharging, vacuum and the like, and the investment is small; the conventional one-step sintering method can cause the grain boundary to migrate too quickly to cause the growth of grains due to the temperature rise in the final sintering stage, and the two-part sintering method can inhibit the migration of the grain boundary in a set temperature range (dynamic window), so that the diffusion of the grain boundary is increased and the compactness is increased; as the T2 temperature is diffused in the sintering dynamics window range, the growth of crystal grains is restrained, the crystal grains are promoted to develop and develop finely and have good compactness, and the product has better toughness and mechanical property.
Example 2
Referring to fig. 1, the fine-grain submicron structure ceramic is sintered and heat-preserved for 15min at T1 temperature, sintered and heat-preserved for 22h at T2 temperature, wherein the T1 temperature is 1560 ℃ and the T2 temperature is 1470 ℃.
Wherein, when sintering at the T1 temperature, sintering is carried out under a common oxidizing atmosphere with the free oxygen content of 5 percent.
Wherein, when sintering at the T1 temperature, sintering is carried out in a neutral atmosphere with the free oxygen content of 1.5 percent.
Wherein, after the T2 sintering temperature, the temperature is reduced and cooled along with the furnace.
Before the temperature T1, the sintering curve comprises six stages of segment number 1, segment number 2, segment number 3, segment number 4, segment number 5 and segment number 6.
The temperature of the section No. 1 is room temperature and the duration is 240min, the temperature of the section No. 2 is 150 ℃ and the duration is 300min, and the temperature of the section No. 3 is 300 ℃ and the duration is 120min.
The temperature of the section No. 4 is 300 ℃, the duration is 360min, the temperature of the section No. 5 is 600 ℃, the duration is 180min, the temperature of the section No. 6 is 600 ℃, the duration is 93min, and the section No. 1 to the section No. 6 are degreasing and adhesive discharging stages.
The novel sintering process can be heated by common heating equipment, the performance of the novel sintering process can completely reach products consistent with expensive equipment such as hot pressing, microwaves, discharging, vacuum and the like, and the investment is small; the conventional one-step sintering method can cause the grain boundary to migrate too quickly to cause the growth of grains due to the temperature rise in the final sintering stage, and the two-part sintering method can inhibit the migration of the boundaries in a set temperature range (dynamic window), so that the diffusion of the grain boundary is increased and the compactness is increased; as the T2 temperature is diffused in the sintering dynamics window range, the growth of crystal grains is restrained, the crystal grains are promoted to develop and develop finely and have good compactness, and the product has better toughness and mechanical property.
Example 3
Referring to fig. 1, the fine-grain submicron structure ceramic is sintered and insulated for 9min at T1 temperature, sintered and insulated for 20h at T2 temperature, wherein the T1 temperature is 1550 ℃, and the T2 temperature is 1460 ℃.
Wherein, when sintering at the T1 temperature, sintering is carried out under a common oxidizing atmosphere with the free oxygen content of 4.5 percent.
Wherein, when sintering at the T1 temperature, sintering is carried out in a neutral atmosphere with the free oxygen content of 1 percent.
Wherein, after the T2 sintering temperature, the temperature is reduced and cooled along with the furnace.
Before the temperature T1, the sintering curve comprises six stages of segment number 1, segment number 2, segment number 3, segment number 4, segment number 5 and segment number 6.
The temperature of the section No. 1 is room temperature and the duration is 240min, the temperature of the section No. 2 is 150 ℃ and the duration is 300min, and the temperature of the section No. 3 is 300 ℃ and the duration is 120min.
The temperature of the section No. 4 is 300 ℃, the duration is 360min, the temperature of the section No. 5 is 600 ℃, the duration is 180min, the temperature of the section No. 6 is 600 ℃, the duration is 93min, and the section No. 1 to the section No. 6 are degreasing and adhesive discharging stages.
The novel sintering process can be heated by common heating equipment, the performance of the novel sintering process can completely reach products consistent with expensive equipment such as hot pressing, microwaves, discharging, vacuum and the like, and the investment is small; the conventional one-step sintering method can cause the grain boundary to migrate too quickly to cause the growth of grains due to the temperature rise in the final sintering stage, and the two-part sintering method can inhibit the migration of the boundaries in a set temperature range (dynamic window), so that the diffusion of the grain boundary is increased and the compactness is increased; as the T2 temperature is diffused in the sintering dynamics window range, the growth of crystal grains is restrained, the crystal grains are promoted to develop and develop finely and have good compactness, and the product has better toughness and mechanical property.
Two-step sintering curve of product
| Segment number | Temperature (. Degree. C.) | Time (min) | Remarks |
| Segment number 1 | Room temperature | 240 | Evaporation of moisture |
| Segment number 2 | 150 | 300 | |
| Segment number 3 | 300 | 120 | |
| Segment number 4 | 300 | 360 | |
| Segment number 5 | 600 | 180 | Volatilizing organic matters |
| Segment number 6 | 600 | 93 | |
| Segment number 7 | (1560-1540) | 9 | Grain boundary migration |
| Segment number 8 | (1470-1450) | 1200 | Grain boundary diffusion |
| Segment number 9 | (1470-1450) | 150 | |
| Segment number 10 | 1200 | -121 | |
| Segment number 11 | |||
| Segment number 12 | |||
| Segment number 13 | |||
| Segment number 14 | |||
| Segment number 15 |
Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made therein without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.
Claims (8)
1. The two-step sintering method of fine-grain submicron structure ceramics is characterized in that: sintering and preserving heat for 5-15min at T1 temperature, sintering and preserving heat for 18-22h at T2 temperature, wherein the T1 temperature is 1540-1560 ℃, and the T2 temperature is 1450-1470 ℃.
2. The two-step sintering method of fine-grain submicron structured ceramics according to claim 1, characterized in that: sintering and preserving heat for 9min at T1 temperature, and sintering and preserving heat for 20h at T2 temperature, wherein the T1 temperature is 1550 ℃ and the T2 temperature is 1460 ℃.
3. The two-step sintering method of fine-grain submicron structured ceramics according to claim 1, characterized in that: when sintering at the temperature T1, sintering is carried out in a common oxidizing atmosphere with the free oxygen content of 4% -5%.
4. The two-step sintering method of fine-grain submicron structured ceramics according to claim 1, characterized in that: when sintering at the temperature T1, sintering is carried out in a neutral atmosphere with the free oxygen content of 1-1.5%.
5. The two-step sintering method of fine-grain submicron structured ceramics according to claim 1, characterized in that: and cooling along with furnace cooling after the T2 sintering temperature.
6. The two-step sintering method of fine-grain submicron structured ceramics according to claim 1, characterized in that: before the T1 temperature, the sintering curve comprises six stages of segment number 1, segment number 2, segment number 3, segment number 4, segment number 5 and segment number 6.
7. The two-step sintering method of fine-grain submicron structure ceramics according to claim 6, characterized in that: the temperature of the section No. 1 is room temperature and the duration is 240min, the temperature of the section No. 2 is 150 ℃ and the duration is 300min, and the temperature of the section No. 3 is 300 ℃ and the duration is 120min.
8. The two-step sintering method of fine-grain submicron structured ceramics according to claim 1, characterized in that: the temperature of the section No. 4 is 300 ℃, the duration is 360min, the temperature of the section No. 5 is 600 ℃, the duration is 180min, the temperature of the section No. 6 is 600 ℃ and the duration is 93min, and the sections No. 1 to No. 6 are degreasing and adhesive discharging stages.
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5656218A (en) * | 1995-05-19 | 1997-08-12 | Industrial Technology Research Institute | Method for making high performance self-reinforced silicon carbide using a pressureless sintering process |
| US20030209541A1 (en) * | 2000-08-04 | 2003-11-13 | Jiping Cheng | Method and apparatus for the preparation of transparent alumina ceramics by microwave sintering |
| US20050255239A1 (en) * | 2002-05-24 | 2005-11-17 | Weiguang Zhu | Process for producing nanorcrystalline composites |
| JP2008150247A (en) * | 2006-12-18 | 2008-07-03 | Toyama Prefecture | Manufacturing method of piezoelectric ceramic, piezoelectric ceramic, and piezoelectric element |
| JP2010042969A (en) * | 2008-08-18 | 2010-02-25 | Toyama Prefecture | Manufacturing method of piezoelectric ceramic, piezoelectric ceramic, and piezoelectric element |
| CN103396118A (en) * | 2013-07-19 | 2013-11-20 | 广州有色金属研究院 | Firing method of ultrafine-grained zirconia ceramic |
| CN108658589A (en) * | 2018-05-28 | 2018-10-16 | 南京理工大学 | The preparation method of sub-micro crystal alumina ceramic tool matrix material |
-
2023
- 2023-03-30 CN CN202310323623.1A patent/CN116354731A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5656218A (en) * | 1995-05-19 | 1997-08-12 | Industrial Technology Research Institute | Method for making high performance self-reinforced silicon carbide using a pressureless sintering process |
| US20030209541A1 (en) * | 2000-08-04 | 2003-11-13 | Jiping Cheng | Method and apparatus for the preparation of transparent alumina ceramics by microwave sintering |
| US20050255239A1 (en) * | 2002-05-24 | 2005-11-17 | Weiguang Zhu | Process for producing nanorcrystalline composites |
| JP2008150247A (en) * | 2006-12-18 | 2008-07-03 | Toyama Prefecture | Manufacturing method of piezoelectric ceramic, piezoelectric ceramic, and piezoelectric element |
| JP2010042969A (en) * | 2008-08-18 | 2010-02-25 | Toyama Prefecture | Manufacturing method of piezoelectric ceramic, piezoelectric ceramic, and piezoelectric element |
| CN103396118A (en) * | 2013-07-19 | 2013-11-20 | 广州有色金属研究院 | Firing method of ultrafine-grained zirconia ceramic |
| CN108658589A (en) * | 2018-05-28 | 2018-10-16 | 南京理工大学 | The preparation method of sub-micro crystal alumina ceramic tool matrix material |
Non-Patent Citations (1)
| Title |
|---|
| N.J. LÓH等: "Effect of temperature and holding time on the densification of alumina obtained by two-step sintering", CERAMICS INTERNATIONAL, pages 8269 - 8275 * |
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