CN114031391B - Preparation method of high-strength magnesia-alumina spinel transparent ceramic - Google Patents
Preparation method of high-strength magnesia-alumina spinel transparent ceramic Download PDFInfo
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Abstract
The application provides a preparation method of high-strength magnesia-alumina spinel transparent ceramic, wherein a biscuit is subjected to low-temperature treatment, vacuum pressureless sintering and high-temperature rapid hot isostatic pressing sintering to prepare the magnesia-alumina spinel transparent ceramic with a double-peak structure, micron-sized small grains are distributed among hundred-micron-sized large grains, the highest transmittance of the magnesia-alumina spinel transparent ceramic in a visible light wave band is more than 83 percent after polishing, the average bending strength is more than 270MPa, the average hardness is more than 13.8GPa, and the magnesia-alumina spinel transparent ceramic has the characteristics of high transmittance, high compactness, high optical uniformity and high bending strength. The magnesia-alumina spinel transparent ceramic product prepared by the method does not contain a sintering aid and does not generate a second phase, the strength is obviously improved under the condition of keeping higher transmittance, the preparation period is short, and the method is suitable for batch production of the magnesia-alumina spinel transparent ceramic product with a large caliber and a complex shape.
Description
Technical Field
The invention relates to the technical field of optical material preparation, in particular to a preparation method of high-strength magnesium aluminate spinel transparent ceramic.
Background
The magnesia-alumina spinel transparent ceramic not only has good optical transmittance in ultraviolet, visible light and infrared light wave bands, but also has the characteristics of high hardness, high strength, impact resistance, corrosion resistance, wear resistance, good electrical insulation performance and the like, and is widely applied to the fields of transparent armors, infrared optical windows/seeker fairings and the like.
The preparation of the magnesia-alumina spinel transparent ceramic comprises the following methods: 1) The magnesium aluminate spinel transparent ceramic is prepared by a hot pressing and hot isostatic pressing combined method, but the phenomenon of lower mechanical property generally exists; 2) The magnesia-alumina spinel transparent ceramic is prepared by adopting novel sintering technologies such as microwave sintering, spark plasma sintering and the like, although the sintered body can be quickly compacted in a short time to obtain the ceramic with fine crystal grains and excellent mechanical properties, the method is only suitable for preparing a small sample wafer with the diameter of 10-20 mm at present, is not suitable for preparing a large-caliber thick material, and easily causes the hot spot phenomenon of the material or reduces the optical properties of the material due to the pollution of a mould material in the preparation process; 3) The pressureless sintering method is adopted to prepare the magnesia-alumina spinel transparent ceramic, although the manufacturing cost is low, and the materials with complex shapes and large calibers can be produced in large batch, the defects of high sintering temperature, long heat preservation time and difficult elimination of in-crystal micropores in the later sintering period lead to the difficulty in further improving the optical performance; 4) The magnesia-alumina spinel transparent ceramic is prepared by adopting a method of combining pressureless sintering with hot isostatic pressing sintering, and adding a sintering aid, wherein the addition of the sintering aid can promote densification and inhibit grain growth, and improve the mechanical property of the material to a certain extent, but the addition of a large amount of the sintering aid can lead the sintering aid to be easily enriched in a grain boundary and even to have a second phase, and can reduce the optical property of the material.
Disclosure of Invention
In view of the above-mentioned defects or shortcomings in the prior art, the present application aims to provide a method for preparing a high-strength magnesia-alumina spinel transparent ceramic, which is different from the conventional pressureless sintering method, and comprises the steps of firstly carrying out low-temperature treatment on a biscuit to eliminate nano-scale micropores affecting the transmittance of optics, especially visible light wave band, and then carrying out vacuum pressureless sintering and high-temperature rapid hot isostatic pressing treatment to finally form a unique bimodal structure with micron-sized small grains distributed among hundred-micron large grains. The magnesia-alumina spinel transparent ceramic prepared by the method does not contain a sintering aid and does not generate a second phase, the strength is obviously improved under the condition of keeping higher transmittance, the preparation period is short, and the method is suitable for batch production of the magnesia-alumina spinel transparent ceramic with large caliber and complex shape.
The application provides a preparation method of high-strength magnesium aluminate spinel transparent ceramic, which comprises the following steps:
for MgAl 2 O 4 Pretreating ceramic powder to obtain powder A;
taking the powder A for gel injection molding, and then carrying out cold isostatic pressing treatment to obtain a biscuit B;
carrying out low-temperature treatment on the biscuit B to obtain a biscuit C;
carrying out vacuum sintering on the biscuit C to obtain a pre-sintered body D;
and carrying out high-temperature rapid hot isostatic pressing treatment on the pre-sintered body D to obtain the transparent ceramic E.
Further, for MgAl 2 O 4 The ceramic powder is pretreated, which comprises the following steps:
taking MgAl 2 O 4 Adding absolute ethyl alcohol or deionized water into the ceramic powder;
adding grinding balls and MgAl 2 O 4 The mass ratio of the ceramic powder to the grinding ball is 1: (2-4);
performing ball milling for 6-12 h at the rotating speed of 45-60 r/min to obtain ceramic slurry;
and (3) freeze-drying the ceramic slurry to obtain powder A, wherein the freezing temperature is-40 to-60 ℃.
Furthermore, the pressure of cold isostatic pressing treatment is 180-300 MPa, and the pressure maintaining time is 15-30 min.
Further, the biscuit B is subjected to low-temperature treatment, and the method comprises the following steps:
and (3) placing the biscuit B in a low-temperature muffle furnace, heating to 700-1100 ℃, and then preserving heat for 2-6 h.
Specifically, the biscuit B is treated at low temperature, so that the nano-scale crystal grains in the biscuit B can be promoted to grow uniformly, the crystal grains are continuously fused and grow, and the nano-scale micropores are gradually fused and grow to be close to micron-scale and have no crystal inner holes, so that the 0.1-1 micron-scale micropores influencing the visible light transmittance are eliminated to the maximum extent, and the optical transmittance of the material is improved.
Further, the biscuit C is subjected to vacuum sintering, and the method comprises the following steps:
placing the biscuit C into a first crucible and then placing the biscuit C into a vacuum sintering furnace;
vacuum pumping is carried out to 10 -1 ～10 -2 Pa；
Heating to 1350-1500 deg.c and maintaining for 5-10 hr.
Specifically, the biscuit C is subjected to vacuum sintering, the sintering temperature is lower than the traditional pressureless sintering temperature, the grain densification speed is greatly increased and the grain growth speed is slow in the temperature range, and the grain growth is controlled while the densification is realized.
Further, the high-temperature rapid hot isostatic pressing treatment is carried out on the pre-sintered body D, and the method comprises the following steps:
placing the pre-sintered body D into a second crucible and then placing the second crucible into a hot isostatic pressing furnace;
filling inert gas argon into the hot isostatic pressing furnace;
heating to 1550-1850 deg.C, keeping the pressure at 150-220 Mpa, keeping the temperature for 0.5-2 h, and heating at a rate of 10 deg.C/min or higher.
Specifically, a certain amount of argon is filled into the hot isostatic pressing furnace, then the filling is stopped, the furnace is heated, and the pressure in the furnace gradually rises to reach a set value along with the rise of the temperature. The high-temperature rapid hot isostatic pressing treatment is adopted, based on the results of eliminating nano holes and densification through vacuum pressureless sintering in a low-temperature treatment stage, residual micron-sized air holes can be rapidly transferred and eliminated, most of grains do not have enough time to grow up, and a unique double-peak structure is gradually formed, namely micron-sized small grains are distributed around hundred-micron large grains. The bimodal structure can ensure that the ceramic material has good optical performance and is beneficial to preventing crack propagation and stress release.
Furthermore, the material of the grinding ball is zirconia or alumina.
Furthermore, the crucible I is made of alumina or zirconia, and the purity is more than 99%.
Furthermore, the second crucible is made of tungsten or BN, and the purity is more than 99%.
Further, before the biscuit C is placed in the first crucible, embedded powder is added into the first crucible, wherein the embedded powder is a mixture of alumina powder and magnesia powder, and the purity is not lower than 99%.
In conclusion, the application discloses a preparation method of high-strength magnesium aluminate spinel transparent ceramic, which has the beneficial effects that a biscuit B is subjected to low-temperature treatment to eliminate nano-scale micropores affecting the transmittance of optical, especially visible light wave band, and then vacuum pressureless sintering is carried out, as the temperature is lower than the traditional pressureless sintering temperature, the grain densification rate is far higher than the grain growth rate, densification is realized on the basis of controlling the grain growth, then high-temperature quick hot isostatic pressing treatment is carried out, the residual micron-scale micropores are promoted to be quickly eliminated, and simultaneously most grains do not have sufficient time to grow up, so that the magnesium aluminate spinel transparent ceramic E with the bimodal structure of micron-scale small grains distributed among hundred-micron large grains is prepared, after polishing, the highest transmittance of the magnesium aluminate spinel transparent ceramic E is more than 83 percent in the visible light wave band, the average bending strength is more than 270MPa, the average hardness is more than 13.8GPa, and the characteristics of high transmittance, high degree, high optical uniformity and high bending strength. The method can be used for preparing the magnesia-alumina spinel transparent ceramic product with the size being more than or equal to 100mm, does not add a sintering aid, does not generate a second phase, obviously improves the strength under the condition of keeping higher transmittance, has short preparation period, and is suitable for batch production of the magnesia-alumina spinel transparent ceramic product with large caliber and complex shape.
Drawings
Fig. 1 is a microscopic morphology of the calcined body prepared in example 1 of the present application.
Fig. 2 is a microscopic morphology of the calcined body prepared in comparative example 1 of the present application.
FIG. 3 is an SEM microstructure of a cross section of a finished transparent ceramic article prepared in example 1 of the present application.
FIG. 4 shows the SEM microstructure of the cross section of the transparent ceramic product prepared in example 1 of the present application after etching.
FIG. 5 shows the micro-morphology of the finished transparent ceramic product prepared in comparative example 4 of the present application.
Detailed Description
The present application will be described in further detail with reference to the following drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the relevant invention and not restrictive of the invention. The present application will now be described in detail with reference to the drawings, in conjunction with the following examples.
Example 1
A preparation method of high-strength magnesia-alumina spinel transparent ceramic comprises the following steps:
(1) Preparation of powder A
Taking 214gMgAl 2 O 4 Adding ceramic powder into absolute ethyl alcohol and adding MgAl 2 O 4 The mass ratio of the ceramic powder to the grinding ball is 1:2 adding zirconia grinding balls, then carrying out ball milling at the rotating speed of 60r/min for 8h to obtain ceramic slurry, and carrying out freeze drying on the ceramic slurry at the temperature of-60 ℃ to obtain powder A.
(2) Preparation of biscuit B
And (3) taking the powder A, forming by adopting a gel injection molding method, sealing by using a rubber sheath, placing in a cold isostatic press, boosting the pressure to 250MPa, maintaining the pressure for 15min, and taking out to obtain a biscuit B.
(3) Preparation of biscuit C
And (3) placing the biscuit B in a low-temperature muffle furnace, heating the biscuit B to 1000 ℃ along with the furnace, preserving the heat for 6 hours, cooling the biscuit B to room temperature along with the furnace, and taking out the biscuit C to obtain the biscuit C.
(4) Preparation of preburning body D
Placing the biscuit C into a zirconia crucible filled with embedded powder, and placing the biscuit C and the zirconia crucible into a vacuum sintering furnace together, wherein the vacuum degree of the vacuum sintering furnace is 10 -2 Pa, heating to 1450 ℃ along with the furnace, preserving heat for 10h, then cooling to room temperature along with the furnace, and taking out to obtain a pre-sintered body D. The embedding powder is a mixture of alumina powder and magnesia powder, and the purity is not lower than 99%.
(5) Preparation of transparent ceramic E
And putting the pre-sintered body D into a tungsten crucible, putting the tungsten crucible into a hot isostatic pressing furnace, then filling inert gas argon into the hot isostatic pressing furnace, rapidly heating to 1600 ℃ at a heating rate of 12 ℃/min, raising the pressure of the hot isostatic pressing furnace to 200Mpa, then preserving the heat for 2 hours, then cooling to room temperature along with the furnace, and taking out to obtain the transparent ceramic E. The purity of the tungsten crucible is not less than 99%.
And polishing the transparent ceramic E by using diamond suspension with the average particle size of 2.5 mu m as a polishing medium to obtain a magnesia-alumina spinel transparent ceramic product with the product size phi of 100 multiplied by 10mm.
Example 2
A preparation method of high-strength magnesia-alumina spinel transparent ceramic comprises the following steps:
(1) Preparation of powder A
Taking 214gMgAl 2 O 4 Adding ceramic powder into absolute ethyl alcohol and adding MgAl 2 O 4 The ceramic powder and the grinding ball are mixed according to the mass ratio of 1:3 adding alumina grinding balls, then carrying out ball milling at the rotating speed of 50r/min for 10h to obtain ceramic slurry, and carrying out freeze drying on the ceramic slurry at the temperature of-50 ℃ to obtain powder A.
(2) Preparation of biscuit B
And (3) taking the powder A, forming by adopting a gel injection molding method, sealing by using a rubber sheath, placing in a cold isostatic press, boosting the pressure to 220MPa, maintaining the pressure for 20min, and taking out to obtain a biscuit B.
(3) Preparation of biscuit C
And (3) placing the biscuit B in a low-temperature muffle furnace, heating to 1100 ℃ along with the furnace, preserving the heat for 4 hours, cooling to room temperature along with the furnace, and taking out to obtain a biscuit C.
(4) Preparation of preburning body D
Placing the biscuit C into a zirconia crucible filled with embedded powder, and placing the biscuit C and the zirconia crucible into a vacuum sintering furnace together, wherein the vacuum degree of the vacuum sintering furnace is 10 -2 Pa, heating to 1400 ℃ along with the furnace, preserving the heat for 10h, then cooling to room temperature along with the furnace, and taking out to obtain a presintered body D. The embedding powder is a mixture of alumina powder and magnesia powder, and the purity is not lower than 99%.
(5) Preparation of transparent ceramic E
And putting the pre-sintered body D into a tungsten crucible, putting the tungsten crucible into a hot isostatic pressing furnace, then filling inert gas argon into the hot isostatic pressing furnace, rapidly heating to 1850 ℃ at the heating rate of 10 ℃/min, raising the pressure of the hot isostatic pressing furnace to 200Mpa, then preserving the heat for 1h, then cooling to room temperature along with the furnace, and taking out to obtain the transparent ceramic E. The purity of the tungsten crucible is not less than 99%.
And polishing the transparent ceramic E by using diamond suspension with the average particle size of 2.5 mu m as a polishing medium to obtain a magnesia-alumina spinel transparent ceramic product with the product size phi of 100 multiplied by 10mm.
Example 3
A preparation method of high-strength magnesia-alumina spinel transparent ceramic comprises the following steps:
(1) Preparation of powder A
Adding 214g of MgAl2O4 ceramic powder into absolute ethyl alcohol according to the weight of MgAl 2 O 4 The ceramic powder and the grinding ball are mixed according to the mass ratio of 1:4, grinding the ball by using an alumina ball, then carrying out ball milling at the rotating speed of 45r/min for 12h to obtain ceramic slurry, and carrying out freeze drying on the ceramic slurry at the temperature of-40 ℃ to obtain powder A.
(2) Preparation of biscuit B
Taking the powder A, forming by adopting a gel injection molding method, sealing by using a rubber sheath, placing in a cold isostatic press, boosting the pressure to 180MPa, maintaining the pressure for 30min, and taking out to obtain a biscuit B:
(3) Preparation of biscuit C
And (3) placing the biscuit B in a low-temperature muffle furnace, heating to 900 ℃ along with the furnace, preserving heat for 6 hours, cooling to room temperature along with the furnace, and taking out to obtain a biscuit C.
(4) Preparation of preburning body D
Placing the biscuit C into an alumina crucible filled with embedded powder, and placing the biscuit C and the alumina crucible together into a vacuum sintering furnace, wherein the vacuum degree of the vacuum sintering furnace is 10 -2 Pa, heating to 1500 ℃ along with the furnace, preserving heat for 10h, then cooling to room temperature along with the furnace, and taking out to obtain a pre-sintered body D. The embedding powder is a mixture of alumina powder and magnesia powder, and the purity is not lower than 99%.
(5) Preparation of transparent ceramic E
And putting the pre-sintered body D into a BN crucible, putting the BN crucible into a hot isostatic pressing furnace, then filling inert gas argon into the hot isostatic pressing furnace, rapidly heating to 1750 ℃ at the heating rate of 10 ℃/min, raising the pressure of the hot isostatic pressing furnace to 180Mpa, then preserving the heat for 1h, then cooling to room temperature along with the furnace, and taking out to obtain the transparent ceramic E. The purity of the BN crucible is not less than 99%.
And polishing the transparent ceramic E by using diamond suspension with the average particle size of 2.5 mu m as a polishing medium to obtain a magnesia-alumina spinel transparent ceramic product with the product size phi of 100 multiplied by 10mm.
To better illustrate the good performance of the transparent ceramic products prepared in this application, the following comparative examples were prepared:
comparative example 1
Comparative example 1 was prepared according to the procedure and parameters of example 1, except that:
the technical process for preparing the biscuit C is omitted, the biscuit B is directly adopted to prepare the pre-sintered body D, and the specific steps are as follows:
placing the biscuit B into a zirconia crucible filled with embedded powder, and placing the biscuit B and the zirconia crucible together into a vacuum sintering furnace, wherein the vacuum degree of the vacuum furnace is 10 -2 Pa, heating to 1450 ℃ along with the furnace, preserving heat for 10h, then cooling to room temperature along with the furnace, and taking out to obtain a pre-sintered body D. The embedding powder is a mixture of alumina powder and magnesia powder, and the purity is not lower than 99%.
As shown in fig. 1, the micro-morphology of the pre-sintered body D prepared in example 1, and as shown in fig. 2, the micro-morphology of the pre-sintered body D prepared in comparative example 1, it can be seen by comparison that the pre-sintered body D prepared in example 1 is subjected to low-temperature treatment, nano-scale particles grow uniformly, most of nano-scale micropores are fused and removed, the pore size of the remaining micropores reaches nearly the micrometer level, while the pre-sintered body D prepared in comparative example 1 is not sintered at low Wen Moya, but is subjected to only vacuum pressureless sintering, many nano-scale micropores still remain, and the uniformity of crystal grains is also low, which indicates that the low-temperature pressureless sintering has a good effect on promoting the uniform growth of crystal grains and fusing and removing the nano-scale micropores.
Through transmittance tests on the transparent ceramic E prepared in example 1 and the transparent ceramic E prepared in comparative example 1, the highest transmittance of the transparent ceramic E prepared in example 1 is more than 83 percent in a visible light wave band range (a test sample is 2mm thick), while the highest transmittance of the transparent ceramic E prepared in comparative example 1 is less than 78 percent, and in practical observation, the transparent ceramic E prepared in comparative example 1 and not subjected to low-temperature pressureless sintering is fog-white, while the transparent ceramic E prepared in example 1 and subjected to low-temperature pressureless sintering is clear and transparent in the interior and free of fog defects, which indicates that nanometer micropores causing fog-white are difficult to be completely removed through hot isostatic pressing sintering in the later period, so that the optical performance is reduced.
Comparative example 2
Comparative example 2 was prepared according to the procedure and parameters of example 1, except that:
the process for preparing the powder A is not carried out, but MgAl is adopted 2 O 4 The method for directly preparing the biscuit B from the ceramic powder comprises the following specific steps:
taking 214gMgAl 2 O 4 Putting the ceramic powder into a mould;
putting the die into a powder tablet press, pressurizing to 30MPa, maintaining the pressure for 4min, forming and taking out MgAl 2 O 4 And sealing the ceramic wafer by using a rubber sleeve, placing the ceramic wafer in a cold isostatic press, boosting the pressure to 250MPa, maintaining the pressure for 15min, and taking out the ceramic wafer to obtain a biscuit B.
Comparative example 3
Comparative example 3 was prepared according to the procedure and parameters of comparative example 2, except that:
the heating temperatures for preparing the pre-sintered body D are different, and the specific steps are as follows:
placing the biscuit C into a zirconia crucible filled with embedded powder, and placing the biscuit C and the zirconia crucible into a vacuum sintering furnace together, wherein the vacuum degree of the vacuum sintering furnace is 10 -2 Pa, heating to 1500 ℃ along with the furnace, preserving heat for 10h, then cooling to room temperature along with the furnace, and taking out to obtain a pre-sintered body D. The embedding powder is a mixture of alumina powder and magnesia powder, and the purity is not lower than 99%.
In order to verify the density structure uniformity of the biscuits B prepared by different molding techniques, four parts of each biscuit B prepared in example 1, comparative example 1 and comparative example 2 were randomly sampled for wax sealing, and density testing was performed by an Archimedes drainage method, with the test results shown in Table 1. In order to verify the optical uniformity of the transparent ceramic products manufactured by different molding techniques, 4 points were randomly selected for each of the transparent ceramic products manufactured in example 1, comparative example 1, and comparative example 2 to perform a transmittance test (at 780 nm), and the test results are shown in table 1. It can be seen that the average relative density of the biscuit B prepared by the wet gel injection molding technology and the dry compression molding technology is not much different, but the density of the biscuit B prepared by the wet gel injection molding technology is more uniform, the inside of the biscuit B prepared by the dry compression molding technology is more agglomerated, the obtained magnesia-alumina spinel transparent ceramic product has macroscopic 'white spots' and shows poorer optical uniformity, and the 'white spots' are gradually reduced along with the increase of the pressureless high-temperature sintering temperature by comparing the comparative example 2 with the comparative example 3, so that the optical transmittance of the transparent ceramic product prepared by the comparative example 3 is improved, but still is obviously lower than that of the transparent ceramic product prepared by the wet gel injection molding technology in the example 1. The optical uniformity of the transparent ceramic product can be obviously improved by adopting the wet gel injection molding technology to prepare the biscuit B and carrying out low-temperature pressureless sintering.
TABLE 1
| Examples of the invention | Counting number | Relative Density of biscuit B | Maximum visible light transmittance |
| Example 1 | 4 | 48.9％，48.2％，48.7％，49.1％ | 83.75％，83.29％，83.64％，83.43％ |
| Comparative example 2 | 4 | 48.2％，49.3％，47.8％，49.1％ | 76.11％，78.58％，77.99％，76.92％ |
| Comparative example 3 | 4 | 47.3％，48.5％，49.6％，49.3％ | 81.84％，80.01％，82.43％，80.94％ |
Comparative example 4
The magnesium aluminate spinel transparent ceramic product is prepared by hot pressing/hot isostatic pressing technology, which is detailed in rare metal materials and engineering (2015, supplement 1, volume 44), wherein the influence of heat treatment on the performance of the magnesium aluminate spinel transparent ceramic (pages 105-108), the transmittance, bending strength and hardness performance data are shown in table 2, and the microstructure is shown in fig. 5.
In order to verify the performance difference between the transparent ceramic products prepared by the preparation method of the present application and the transparent ceramic products prepared by the prior art, the transparent ceramic products prepared in examples 1, 2 and 3 were tested for transmittance, hardness and bending strength, and the test results are shown in table 2, which shows that the transmittance, bending strength and hardness of the transparent ceramic products prepared in examples 1, 2 and 3 are all higher than those of comparative example 4, and the bending strength and hardness are lower, thus the transparent ceramic products prepared by the present application have more excellent optical performance and mechanical performance.
TABLE 2
| Performance of | Example 1 | Example 2 | Example 3 | Comparative example 4 |
| Maximum visible light transmittance% | 83 | 85 | 84 | 82 |
| Flexural strength/MPa | 302 | 285 | 271 | 160 |
| hardness/GPa | 14.04 | 13.83 | 13.98 | 12.89 |
The microscopic morphology of the section of the transparent ceramic product prepared in the embodiment 1, the embodiment 2 and the embodiment 3 is similar to the microscopic morphology of the section after etching, so that only the SEM microscopic morphology of the section of the transparent ceramic product prepared in the embodiment 1 and the SEM microscopic morphology of the section after etching are listed, as shown in figures 3 and 4 respectively, it can be seen that the transparent ceramic product prepared by low-temperature treatment, vacuum pressureless sintering and high-temperature rapid hot isostatic pressing has a bimodal structure, namely micron-sized small grains are distributed around hundred-micron-sized large grains, the structure is favorable for preventing crack expansion and stress release, the mechanical property of the material is effectively improved, and the average bending strength reaches more than 270 MPa. As shown in FIG. 5, the microscopic morphology of the transparent ceramic product prepared in comparative example 4 shows that the grain sizes are all over 100 μm, the bending strength is only 160MPa, and the fracture resistance is poor. Therefore, the magnesia-alumina spinel transparent ceramic product prepared by the method has more excellent mechanical properties.
It can be seen from the above embodiments that the present application provides a method for preparing a high-strength magnesium aluminate spinel transparent ceramic, wherein a magnesium aluminate spinel transparent ceramic E with a bimodal structure, in which micron-sized small grains are distributed among hundreds of microns, is prepared by low-temperature treatment, vacuum pressureless sintering and high-temperature rapid hot isostatic pressing treatment, and after polishing, has a highest visible light transmittance of > 83%, an average bending strength of > 270MPa, and an average hardness of > 13.8GPa, and has the characteristics of high transmittance, high degree of densification, high optical uniformity, and high bending strength. The method can be used for preparing the magnesia-alumina spinel transparent ceramic product with the size being more than or equal to 100mm, does not add a sintering aid, does not generate a second phase, obviously improves the strength under the condition of keeping higher transmittance, has short preparation period, and is suitable for batch production of the magnesia-alumina spinel transparent ceramic product with large caliber and complex shape.
It should be understood that the above-mentioned embodiments of the present invention are only examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention, and it will be obvious to those skilled in the art that other variations or modifications may be made on the basis of the above description, and all embodiments may not be exhaustive, and all obvious variations or modifications may be made within the scope of the present invention.
Claims (6)
1. A preparation method of high-strength magnesium aluminate spinel transparent ceramics is characterized by comprising the following steps:
for MgAl 2 O 4 The ceramic powder is pre-treated and then,obtaining powder A;
taking the powder A for gel injection molding, and then carrying out cold isostatic pressing treatment to obtain a biscuit B;
carrying out low-temperature treatment on the biscuit B to obtain a biscuit C;
carrying out vacuum sintering on the biscuit C to obtain a pre-sintered body D;
carrying out high-temperature rapid hot isostatic pressing treatment on the pre-sintered body D to obtain transparent ceramic E;
wherein, for MgAl 2 O 4 The ceramic powder is pretreated, which comprises the following steps:
taking MgAl 2 O 4 Adding absolute ethyl alcohol or deionized water into the ceramic powder;
adding grinding balls and MgAl 2 O 4 The mass ratio of the ceramic powder to the grinding ball is 1: (2~4);
performing ball milling for 6 to 12h at the rotating speed of 45 to 60r/min to obtain ceramic slurry;
carrying out freeze drying on the ceramic slurry to obtain powder A, wherein the freezing temperature is minus 40 to minus 60 ℃;
and (2) carrying out low-temperature treatment on the biscuit B, wherein the low-temperature treatment comprises the following steps:
placing the biscuit B in a low-temperature muffle furnace, heating to 900-1100 ℃, and then preserving heat for 4-6 h;
and (3) carrying out vacuum sintering on the biscuit C, wherein the vacuum sintering comprises the following steps:
placing the biscuit C into a first crucible and then placing the biscuit C into a vacuum sintering furnace;
vacuum pumping is carried out to 10 -1 ～10 -2 Pa；
Heating to 1350-1500 ℃, and then preserving heat for 5-10 h;
and carrying out high-temperature rapid hot isostatic pressing treatment on the pre-sintered body D, wherein the method comprises the following steps:
placing the presintered body D into a second crucible and then placing the second crucible into a hot isostatic pressing furnace;
filling inert gas argon into the hot isostatic pressing furnace;
heating to 1550 to 1850 ℃, keeping the pressure at 150 to 220Mpa, keeping the temperature for 0.5 to 2h, and keeping the heating rate at more than or equal to 10 ℃/min.
2. The method for preparing a high-strength transparent magnesia alumina spinel ceramic according to claim 1, wherein the cold isostatic pressing treatment pressure is 180-300 MPa, and the dwell time is 15-30 min.
3. The method for preparing a high-strength transparent magnesia alumina spinel ceramic as claimed in claim 1, wherein the material of the grinding balls is zirconia or alumina.
4. The method as claimed in claim 1, wherein the crucible is made of alumina or zirconia with a purity of > 99%.
5. The method for preparing high-strength transparent magnesia alumina spinel ceramic as claimed in claim 4, wherein the second crucible is made of tungsten or BN, and the purity is more than 99%.
6. The preparation method of the high-strength magnesia-alumina spinel transparent ceramic according to claim 4, wherein the biscuit C is placed in the first crucible before being placed in the first crucible, embedding powder is added into the first crucible, and the embedding powder is a mixture of alumina powder and magnesia powder, and the purity is not lower than 99%.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20150344372A1 (en) * | 2014-05-27 | 2015-12-03 | Fraunhofer-Gesellschaft Zur Foerderung Der Angewandten Forschung E.V. | Transparent spinel ceramics and method for the production thereof |
| CN106630996A (en) * | 2016-12-12 | 2017-05-10 | 天津津航技术物理研究所 | Preparation method of gel injection molding MgAl2O4 biscuit |
| CN107352994A (en) * | 2017-08-04 | 2017-11-17 | 中国科学院上海硅酸盐研究所 | A kind of preparation method of light-weight magnesite-alumina spinel refractories |
| CN108484156A (en) * | 2018-04-12 | 2018-09-04 | 武汉理工大学 | A kind of spinel solid solution crystalline ceramics preparation method based on the processing of powder resistant to hydrolysis and gel casting forming |
| CN114538913A (en) * | 2022-02-17 | 2022-05-27 | 大连海事大学 | Pure-phase nano MgAl with high sintering activity2O4Powder and preparation method and application thereof |
-
2021
- 2021-11-26 CN CN202111423351.XA patent/CN114031391B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20150344372A1 (en) * | 2014-05-27 | 2015-12-03 | Fraunhofer-Gesellschaft Zur Foerderung Der Angewandten Forschung E.V. | Transparent spinel ceramics and method for the production thereof |
| CN106630996A (en) * | 2016-12-12 | 2017-05-10 | 天津津航技术物理研究所 | Preparation method of gel injection molding MgAl2O4 biscuit |
| CN107352994A (en) * | 2017-08-04 | 2017-11-17 | 中国科学院上海硅酸盐研究所 | A kind of preparation method of light-weight magnesite-alumina spinel refractories |
| CN108484156A (en) * | 2018-04-12 | 2018-09-04 | 武汉理工大学 | A kind of spinel solid solution crystalline ceramics preparation method based on the processing of powder resistant to hydrolysis and gel casting forming |
| CN114538913A (en) * | 2022-02-17 | 2022-05-27 | 大连海事大学 | Pure-phase nano MgAl with high sintering activity2O4Powder and preparation method and application thereof |
Non-Patent Citations (1)
| Title |
|---|
| MgAl2O4透明陶瓷的凝胶注成型及其性能研究;张培培;《中国优秀博硕士学位论文全文数据库（硕士） 工程科技I辑》;20200115(第1期);第22页第3段，第23页图2-1，第42页第1段，第44页第3段，第49页第1段，图3-38，第55页第1，3-4段 * |
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