WO2018223544A1 - 一种发光陶瓷及其制备方法 - Google Patents

一种发光陶瓷及其制备方法 Download PDF

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WO2018223544A1
WO2018223544A1 PCT/CN2017/100562 CN2017100562W WO2018223544A1 WO 2018223544 A1 WO2018223544 A1 WO 2018223544A1 CN 2017100562 W CN2017100562 W CN 2017100562W WO 2018223544 A1 WO2018223544 A1 WO 2018223544A1
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zro
particles
powder
phosphor
matrix
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李乾
陈雨叁
许颜正
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Shenzhen Appotronics Corp Ltd
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Definitions

  • the invention relates to a luminescent ceramic and a preparation method thereof.
  • the blue laser excitation of fluorescent materials to obtain visible light technology has made significant progress in the field of laser display, and has been recognized by the market, and related technologies continue to receive attention.
  • the hotspots and difficulties in current research are mainly to develop new fluorescent materials (wavelength conversion materials, luminescent materials) for the characteristics of laser-excited phosphors. These materials must have excellent performance, such as high optical conversion efficiency, high brightness, and unit light-emitting area. Can withstand higher power laser irradiation, high thermal conductivity, long life and so on.
  • the traditional silica gel package phosphor technology and glass package phosphor technology can not meet the needs of high-end products.
  • the temperature of silicone can not exceed 200-250 °C. It is easy to age and work for a long time under high temperature environment. Not long; the thermal conductivity of silicone encapsulation and glass encapsulation materials generally does not exceed 2W / (m ⁇ k), in the fixed excitation scheme (corresponding to the rotary excitation scheme), can not withstand high power or even large Power laser irradiation.
  • Luminescent ceramics are an ideal choice because luminescent ceramics have higher heat and thermal conductivity than silica and glass-encapsulated phosphors.
  • the traditional YAG (Y 3 Al 5 O 12 ) pure phase luminescent ceramics are still weaker in luminescent properties than silica gel and glass packages; especially in ultra-thin packaging, the light effect caused by total reflection of the interface The loss is great. Therefore, using other high thermal conductivity ceramic materials to encapsulate the phosphor, such as YAG-Al 2 O 3 (PIA, Phosphor In Alumina) prepared by using Al 2 O 3 encapsulated YAG phosphor, can obtain better than pure phase YAG luminescent ceramics. Performance is the direction that deserves in-depth research.
  • luminescent ceramics tend to be more precise, after a luminescent ceramic in which Al 2 O 3 encapsulated phosphor is prepared, a series of processes of cutting, smoothing, polishing, dividing, coating, soldering, etc. are required, thereby illuminating
  • the mechanical properties of ceramics are very high, especially for their toughness.
  • the present invention has been made to solve the above problems. Accordingly, it is an object of the present invention to provide a luminescent ceramic which can simultaneously satisfy the improvement in the toughness of a luminescent ceramic without significantly affecting the optical properties of the luminescent ceramic.
  • the present invention provides a luminescent ceramic characterized by comprising an Al 2 O 3 matrix, ZrO 2 particles, and phosphor particles.
  • the luminescent ceramic according to the present invention wherein the phosphor particles and the ZrO 2 particles are uniformly dispersed in the Al 2 O 3 matrix. Further, the ZrO 2 particles are dispersed between grain boundaries of the Al 2 O 3 matrix.
  • the luminescent ceramic according to the present invention wherein the content of the ZrO 2 particles is 0.05 to 5% by mass, preferably 0.2 to 3% by mass, more preferably 0.5 to 1% by mass based on the mass of the Al 2 O 3 substrate.
  • the luminescent ceramic according to the present invention wherein the mass ratio of the phosphor particles to the Al 2 O 3 matrix is from 1:4 to 9:1, preferably from 1:4 to 3:1, more preferably 1:3. 1:1.
  • the luminescent ceramic according to the present invention wherein the ZrO 2 particles have a particle diameter of 0.05 to 1 ⁇ m, preferably 0.05 to 0.7 ⁇ m, particularly preferably 0.05 to 0.35 ⁇ m, and the phosphor particles have a particle diameter of 10 to 50 ⁇ m.
  • the crystal grain size of the Al 2 O 3 matrix is 0.05 to 5 ⁇ m, preferably 0.15 to 5 ⁇ m, particularly preferably 0.15 to 3 ⁇ m; and/or the ZrO 2 particles
  • the raw material powder has a particle diameter of 0.05 to 0.7 ⁇ m, preferably 0.05 to 0.2 ⁇ m, and the raw material powder of the phosphor particles has a particle diameter of 10 to 25 ⁇ m, preferably 15 to 17 ⁇ m, and the particle diameter of the Al 2 O 3 raw material powder. It is 0.05 to 1 ⁇ m, preferably 0.1 to 0.3 ⁇ m.
  • the luminescent ceramic according to the present invention further comprising a sintering aid, and the sintering aid is at least one selected from the group consisting of Y 2 O 3 , MgO, CaO, SiO 2 , TiO 2 , BaO, CaF 2 , and BaF 2 .
  • Y 2 O 3 and/or MgO are preferably Y 2 O 3 .
  • the present invention also provides a method for preparing a luminescent ceramic, characterized in that it comprises the following steps:
  • Step 1 a preparation step of a mixed powder comprising an Al 2 O 3 matrix, ZrO 2 particles, and phosphor particles;
  • Step 2 a step of pressing and sintering the above mixed powder to obtain a luminescent ceramic.
  • step 1 comprises the following steps:
  • Step a a preparation step of a mixed powder of the Al 2 O 3 substrate and the ZrO 2 particles and an optional sintering aid;
  • Step b a step of mixing the above mixed powder with the phosphor particles, ball milling, drying, and sieving.
  • step a may be replaced by the step a', the step a' comprising: a solution of a suspension of the raw material powder of the Al 2 O 3 matrix and a precursor of ZrO 2 a step of mixing and coprecipitating with a solution of a precursor of an optional sintering aid; and a step of centrifuging, washing, drying, calcining, and sieving the obtained product.
  • step 1 comprises the following steps:
  • Step I a step of mixing a mixed suspension of an Al 2 O 3 raw material powder and a phosphor with a solution of a precursor of ZrO 2 and a precursor of a precursor of a sintering aid, and then coprecipitating;
  • Step II a step of centrifuging, washing, drying, calcining, and sieving the product obtained in the step I.
  • the luminescent ceramic of the present invention by adding an appropriate amount of small-diameter ZrO 2 to the luminescent ceramic of the Al 2 O 3 encapsulated phosphor, the phosphor particles and the ZrO 2 particles are uniformly dispersed in the Al 2 O 3 matrix, thereby not only improving the toughness of the luminescent ceramic. And does not adversely affect the optical properties of the luminescent ceramic. Moreover, ZrO 2 can also function as scattering particles to homogenize incident light. Therefore, the luminescent ceramic of the present invention has excellent characteristics of high light efficiency, high thermal conductivity, and adjustable blue light transmittance, and can be applied to a high performance laser light source, particularly a precision laser light source system.
  • Fig. 1 is a schematic view showing the structure of a luminescent ceramic of the present invention.
  • Example 2 is a scanning electron micrograph of a sample obtained in Example 1.
  • the luminescent ceramic of the present invention includes an Al 2 O 3 matrix, ZrO 2 particles, and phosphor particles.
  • the phosphor particles having a large particle diameter are uniformly dispersed in the Al 2 O 3 matrix
  • the ZrO 2 particles having a small particle diameter are located between the grain boundaries of the Al 2 O 3 matrix.
  • Fig. 1 is a schematic view showing the structure of a luminescent ceramic of the present invention.
  • 1 represents an Al 2 O 3 matrix
  • 2 represents ZrO 2 particles
  • 3 represents phosphor particles.
  • the luminescent ceramic of the present invention is characterized in that a fine grain of Al 2 O 3 is used as a matrix, and a large phosphor particle is uniformly dispersed in an Al 2 O 3 matrix, and a small ZrO is used.
  • the particles are located between the grain boundaries of the Al 2 O 3 matrix.
  • the phosphor particles are continuously surrounded by crystal grains of the Al 2 O 3 matrix.
  • the phosphor particles in the ceramic can absorb the excitation light and emit the laser; in particular, the blue light can be excited to emit yellow visible light; the dense and fine grained Al 2 O 3 matrix has good light transmission performance, and the excited visible light can be worn.
  • the Al 2 O 3 matrix exits the outside of the ceramic.
  • the smaller ZrO 2 particles can function to increase the toughness of the luminescent ceramic and do not adversely affect the luminescent properties of the luminescent ceramic.
  • ZrO 2 can also function as scattering particles to homogenize incident light.
  • the luminescent ceramic according to the present invention wherein the ZrO 2 particles have a particle diameter of 0.05 to 1 ⁇ m, preferably 0.05 to 0.7 ⁇ m, particularly preferably 0.05 to 0.35 ⁇ m.
  • the luminescent ceramic according to the invention wherein the phosphor particles have a particle diameter of 10 to 50 ⁇ m, preferably 10 to 30 ⁇ m, particularly preferably 10 to 25 ⁇ m.
  • the luminescent ceramic according to the present invention wherein the crystal grain size of the Al 2 O 3 matrix is 0.05 to 5 ⁇ m, preferably 0.15 to 5 ⁇ m, particularly preferably 0.15 to 3 ⁇ m.
  • the mechanism of the optical and mechanical properties of the luminescent ceramic of the present invention will be described below.
  • an appropriate amount of ZrO 2 nanopowder is added, and the tetragonal phase t-ZrO 2 and the monoclinic phase are used in the process of heating and cooling using ZrO 2 grains.
  • the volume change characteristic produced by the reversible transformation of m-ZrO 2 is toughened by the microcrack phase transformation toughening.
  • ZrO 2 is a white opaque component in the light-transmitting Al 2 O 3 matrix, which usually affects the light transmittance of the Al 2 O 3 matrix.
  • ZrO 2 can function to scatter incident light to make the incident light uniform, and it does not substantially absorb light, and does not cause loss of light. Therefore, the final effect is that the addition of ZrO 2 particles does not significantly affect the optical properties of the luminescent ceramics, and ZrO 2 can significantly enhance the mechanical properties of the luminescent ceramics and can act as scattering particles to homogenize incident light.
  • the content of ZrO 2 is 0.05 to 5% by mass, preferably 0.2 to 3% by mass, and more preferably 0.5 to 1% by mass based on the mass of the Al 2 O 3 substrate.
  • the toughening effect is not remarkable.
  • the content of ZrO 2 is more than 5% by mass, the ZrO 2 phase in the luminescent ceramic is more pronounced, and the reflection of the incident blue light is more remarkable.
  • the blue light content of the light emitted by the yellow luminescent ceramic is increased, and the yellow light is increased. The content will decrease, which will result in a decrease in the overall luminous efficacy of the luminescent ceramic.
  • the content of ZrO 2 is 0.05 to 5% by mass, preferably 0.2 to 3% by mass, not only the toughening effect can be exhibited, but also the light effect of the luminescent ceramic is not adversely affected, and the scattering granule can be used as a scattering particle. The role of incident light.
  • the content of ZrO 2 can be increased to increase the number of white spots.
  • the content of ZrO 2 may be a relatively high value within the above range, for example, 4 to 5% by mass.
  • ZrO 2 acts as a scattering particle to make the emitted white light more uniform.
  • the phosphor is not particularly limited, and a phosphor commonly used in the field of luminescent ceramics can be used.
  • the phosphor preferably used is selected from the group consisting of Ca 3 (Al, Sc) 2 Si 3 O 12 , (Gd, Tb, Y, Lu) 3 (Al, Ga) 5 O 12 , Y 3 Mg 2 AlSi 2 O 12 and at least one doped Ce 3+ phosphor, preferably wherein Y 3 Al 5 O 12 phosphor doped with Ce 3+ i.e. YAG:Ce 3+ phosphor.
  • the mass ratio of the phosphor particles to the Al 2 O 3 matrix is from 1:4 to 9:1, preferably from 1:4 to 3:1, more preferably from 1:3 to 1:1. Further, the content of the phosphor particles is 15 to 90% by mass, preferably 15 to 50% by mass, based on the total amount of the Al 2 O 3 matrix, the ZrO 2 particles, the phosphor particles, and the sintering aid present.
  • the small particle size of the ZrO 2 particles is one of the key factors for achieving the toughening effect.
  • the ZrO 2 raw material powder has a particle diameter of 0.05 to 0.7 ⁇ m, preferably 0.05 to 0.2 ⁇ m, particularly preferably 0.05 to 0.1 ⁇ m. If the particle size of the ZrO 2 raw material powder is too large, white spots are formed in the luminescent ceramic, and the toughening effect is not good at the same time.
  • the particle size range of the ZrO 2 raw material powder is slightly smaller than the particle size range of ZrO 2 in the luminescent ceramic; it can be understood that when the ZrO 2 raw material powder as a raw material is in the whole preparation process, partial agglomeration may occur. And during the sintering process, some ZrO 2 grains will grow abnormally without inhibition; therefore, the particle size range of ZrO 2 in the luminescent ceramic may be slightly larger than the particle size of the ZrO 2 raw material powder; but based on the uniformity of dispersion The change in the particle size of ZrO 2 is not too significant.
  • the particle diameter of the Al 2 O 3 raw material powder is 0.05 to 1 ⁇ m, preferably 0.1 to 0.3 ⁇ m.
  • the phosphor raw material powder has a particle diameter of 10 to 25 ⁇ m, preferably 15 to 17 ⁇ m. It should be noted that fine-grained Al 2 O 3 has good mechanical properties in luminescent ceramics, and its strength and toughness are superior to those of large-grained Al 2 O 3 matrix. Generally, due to the abnormal growth of crystal grains during agglomeration and sintering, the particle size of some Al 2 O 3 raw material powders is increased by 3 to 5 times. It will be understood that this phenomenon is equally applicable to other components of the present invention.
  • the use of the Al 2 O 3 raw material powder having a small particle size during the preparation process the added ZrO 2 simultaneously acts to suppress the excessive (abnormal) growth of the Al 2 O 3 , thus enhancing the strength of the luminescent ceramic. And resilience has a positive impact.
  • sintering is favored at a lower temperature.
  • the melting point of YAG is 1970 ° C
  • the melting point of Al 2 O 3 is 2000 ° C.
  • Al 2 O 3 is required first.
  • YAG does not enter or rarely enter the liquid phase sintering, only a very small amount of phase migration occurs.
  • the Al 2 O 3 powder in the raw material is an ultrafine powder having a nanometer-high specific surface area, and the average particle diameter is 0.05 to 1 ⁇ m, preferably 0.1 to 0.3 ⁇ m.
  • a dense Al 2 O 3 ceramic can be fired at about 1500 ° C, which is much lower than the melting point of the large particle YAG, and Al 2 O 3 can be realized.
  • the sintering is completed and YAG does not participate in the sintering, so the main particle morphology is unchanged.
  • the luminescent ceramic of the present invention may include a sintering aid.
  • the example of the sintering aid is not particularly limited, and an auxiliary agent commonly used in the art can be used.
  • the sintering aid may be at least one selected from the group consisting of Y 2 O 3 , MgO, CaO, and SiO 2 .
  • Y 2 O 3 and/or MgO, more preferably Y 2 O 3 is preferable as the sintering aid of the present invention.
  • the content of the sintering aid is 0.05 to 5% by mass, preferably 0.05 to 3% by mass, and more preferably 0.5 to 1% by mass based on the mass of the Al 2 O 3 substrate.
  • Y 2 O 3 powder particles When Y 2 O 3 powder particles are used as an auxiliary agent, it can be used as a sintering aid for luminescent ceramics to promote liquid phase sintering, or as a stabilizer for ZrO 2 , so that the phase transition behavior of ZrO 2 is not so severe. Moderate volume change.
  • MgO and Y 2 O 3 can be used as auxiliaries for luminescence ceramic sintering, which can significantly improve liquid phase sintering and lower the sintering temperature.
  • Y 2 O 3 and MgO are all minor additives, and if their content is less than 0.05% by mass relative to the mass of the Al 2 O 3 matrix, the auxiliary action is reduced; if their content is more than 5% by mass, Affects the transparency of the Al 2 O 3 matrix.
  • the three powder particles of ZrO 2 , Y 2 O 3 and MgO need to be thoroughly mixed with the Al 2 O 3 nano powder particles in order to function most effectively.
  • the relative density of the luminescent ceramic of the present invention is 4.1 to 4.31 g/cm 3 .
  • the method for producing the luminescent ceramic of the present invention is further explained below.
  • the method for producing the luminescent ceramic of the present invention is not particularly limited as long as the powder can be uniformly mixed.
  • the method for preparing the luminescent ceramic of the present invention comprises the following steps:
  • Step 1 a preparation step of a mixed powder comprising an Al 2 O 3 matrix, ZrO 2 particles, and phosphor particles;
  • Step 2 a step of pressing and sintering the above mixed powder to obtain a luminescent ceramic.
  • the step 1 may adopt a solid phase method or a liquid phase method.
  • the liquid phase method further includes a sol-gel method, a coprecipitation method, an alkoxide hydrolysis method, and the like, and among them, a coprecipitation method is particularly preferable.
  • step 1 will be described by taking the solid phase method and the coprecipitation method as examples.
  • a method of preparing a mixed powder comprising an Al 2 O 3 matrix, ZrO 2 particles, and phosphor particles by a solid phase method includes the following steps:
  • Step a a preparation step of a mixed powder of an Al 2 O 3 substrate and ZrO 2 particles and an optional sintering aid
  • Step b a step of mixing the above mixed powder with a phosphor, ball milling, drying, and sieving.
  • the preparation of a mixed powder of an Al 2 O 3 substrate and ZrO 2 particles and an optional sintering aid can be obtained by a method comprising: a raw material powder of an Al 2 O 3 matrix and a raw material of ZrO 2 particles and optionally The powder of the raw material of the sintering aid is mixed and subjected to a step of ball milling (referred to as first ball milling).
  • a raw material powder of an Al 2 O 3 matrix and a raw material of a raw material of ZrO 2 particles and a raw material of an optional sintering aid are charged into a polytetrafluoroethylene ball mill tank, and an appropriate amount of ethanol is added as a grinding solvent, and an appropriate amount is added.
  • the ceramic dispersant is used as a dispersing agent and ball-milled with an ultra-low wear rate zirconia ball, and the ball milling time is 1 to 72 h, preferably 24 to 36 h.
  • the raw material powder of the Al 2 O 3 matrix is mixed and ground with the raw material powder of the ZrO 2 particles and the raw material powder of the optional sintering aid, and therefore the number of rotations of the ball mill is not particularly limited.
  • the dispersing agent is not particularly limited, and a dispersing agent commonly used in the art can be used.
  • a dispersing agent commonly used in the art can be used.
  • examples thereof include inorganic salts such as sodium silicate, sodium tripolyphosphate, sodium hexametaphosphate, etc.; lower organic substances such as sodium stearate, sodium citrate, sodium alkylsulfonate, etc.; polymers such as polyacrylic acid and salts thereof , polyvinyl alcohol and the like.
  • the mixed powder of the Al 2 O 3 matrix obtained by the above step a and the mixed powder of the ZrO 2 particles and the optional sintering aid is mixed with the phosphor particles, and then ball milled at a low speed (referred to as a second ball milling), and the ball milling time is 10 to 120 min, preferably 30 to 50 min.
  • the number of revolutions of the ball mill is 30-100 r/min. It should be noted that the main purpose of using low speed is to control the impact force on the phosphor particles during ball milling to avoid damage to the surface morphology of the phosphor particles.
  • the first ball milling time is longer in order to thoroughly mix the Al 2 O 3 powder with the ZrO 2 particles and the optional sintering aid powder, and the powder of the ZrO 2 particles and the optional sintering aid must be mixed with the Al 2 O 3 powder. Full mixing to ensure even diffusion.
  • the second ball milling time is shorter because the phosphor particles are larger and easier to disperse. If the ball milling time is too long, the grain surface morphology of the phosphor is easily damaged, which affects the luminescence property.
  • the dry powder is obtained by vacuum drying at a constant temperature.
  • the dry powder is calcined in a muffle furnace at 500 to 650 ° C to remove organic components in the powder. Then, the calcined powder was passed through a mesh of 80 mesh, 150 mesh, and 200 mesh to obtain a raw material powder having high fluidity.
  • step a that is, the preparation of a mixed powder of an Al 2 O 3 substrate and ZrO 2 particles and an optional sintering aid can also be obtained by a coprecipitation method.
  • the method comprises the following steps (referred to as step a'): mixing a suspension of a raw material powder of an Al 2 O 3 matrix with a solution of a precursor of ZrO 2 and a precursor of an optional sintering aid and making Al 2 a step of coprecipitating the O 3 substrate with ZrO 2 and an optional sintering aid; and a treatment step of centrifuging, washing, drying, calcining, and sieving the obtained product.
  • a suspension of the raw material powder of the Al 2 O 3 matrix was prepared. Specifically, the raw material powder of the Al 2 O 3 matrix was mixed with the PEG aqueous solution, and then ultrasonicated for 1 to 3 hours and then used. Ultrasound is to destroy the secondary agglomeration between the particles, allowing the powder to disperse as much as possible in the solution.
  • the concentration of the PEG aqueous solution may be 1 to 3% by mass.
  • the precursor of ZrO 2 is then formulated into a mixed salt solution together with the precursor of the adjuvant if present.
  • the solution concentration may be from 0.01 to 1 mol/L.
  • ZrO 2 precursors can be used ZrOCl 2 ⁇ 8H 2 O.
  • auxiliary agent contains Y 2 O 3
  • Y(NO 3 ) 3 ⁇ 6H 2 O can be used as an auxiliary precursor;
  • the auxiliary agent contains MgO
  • an inorganic magnesium salt such as Mg(NO 3 ) 2 ⁇ 6H 2 can be used.
  • MgCl 2 ⁇ 6H 2 O, MgSO 4 ⁇ 7H 2 O, and the like When MgO and Y 2 O 3 are used together as an auxiliary agent for luminescence ceramic sintering, the mass percentage ratio of the MgO precursor to the Y 2 O 3 precursor may be 1:2 to 3:1.
  • a suspension of the raw material powder of the Al 2 O 3 matrix is mixed with a precursor solution of ZrO 2 and a possible auxiliary agent, stirred, and then the pH of the mixed solution is adjusted by using ammonia water or an ammonium hydrogencarbonate solution to obtain a coprecipitation.
  • Composite powder suspension Then, the obtained composite powder suspension is centrifuged, and the obtained powder is washed with water for 2 to 8 times, and vacuum-dried at 50 to 150 ° C for 1 to 10 hours. Then, the obtained dry powder is calcined to remove impurities, and then granulated by 80 mesh, 150 mesh, and 200 mesh sieves with air cooling to obtain a highly fluid Al 2 O 3 matrix and ZrO 2 particles and optional auxiliary agents.
  • the calcination temperature and the calcination time are not particularly limited and may be selected according to different auxiliary agents, but usually the calcination temperature is 200 to 500 ° C, and the calcination time is 1 to 5 hours.
  • the temperature during the stirring is set to 20 to 80 ° C, preferably 40 to 60 ° C, and the number of rotations is 100 to 300 r/m, preferably 170 to 250 r/m.
  • the concentration of the aqueous ammonia solution or the ammonium hydrogencarbonate solution used in the coprecipitation may be 0.01 to 0.1 mol/L.
  • the pH of the solution can be controlled to be about 8 to 10, preferably 9 to 9.5.
  • a suitable pH value is very important for the dispersion and deflocation of Al 2 O 3 ultrafine powder particles.
  • the stirring time may be from 1 to 5 h, preferably from 2 to 3 h, after maintaining a suitable pH.
  • a forward titration method may be employed in which ammonia water or an ammonium hydrogencarbonate solution is added dropwise to the mixed solution to precipitate the nanoparticles of the ZrO 2 and the sintering aid. These nanoparticles will partially adhere to the surface of the phosphor particles and the surface of the Al 2 O 3 particles. Under the action of magnetic stirring, these precipitated suspended particles will mix very uniformly with the Al 2 O 3 nanoparticles in the suspension. Together.
  • the dosage of the auxiliary agent added in this way can be smaller, the mixing is more uniform, and the effect is more remarkable.
  • a method for preparing a luminescent ceramic by a coprecipitation method comprises the following steps:
  • Step I a step of mixing a mixed suspension of the Al 2 O 3 raw material powder and the phosphor with a solution of a precursor of ZrO 2 and a solution of a precursor of the optional sintering aid, and then coprecipitating;
  • Step II a step of centrifuging, washing, drying, calcining, and sieving the product obtained in the above step.
  • a citric acid-NaOH solution is prepared, then PEG4000 is added, and after ultrasonic dissolution, a phosphor and a nano-Al 2 O 3 powder are added, and after ultrasonic dispersion, the mixture is stirred on a magnetic stirrer to obtain a phosphor-Al 2 O. 3 mixed suspension.
  • the phosphor with the Al 2 O 3 mass ratio of the phosphor :Al 2 O 3 1:4 ⁇ 9:1 .
  • the precursor of ZrO 2 is formulated into a mixed salt solution together with the precursor of the sintering aid if present.
  • the solution concentration may be from 0.01 to 1 mol/L.
  • examples of the precursor of ZrO 2 and the precursor of the sintering aid are the same as described above.
  • step I The steps of centrifuging, drying, calcining, and sieving the product obtained in the above step I are the same as those in the step a' described in the above solid phase method. Thereby, a mixed powder of phosphor particles, an Al 2 O 3 matrix, ZrO 2 particles and, if present, a sintering aid is obtained.
  • a mixed suspension of a phosphor and an Al 2 O 3 substrate is first prepared, and then mixed with a mixed solution of a precursor of ZrO 2 and a precursor of a sintering aid which is present.
  • the order of addition of the raw materials is not limited thereto, and the mixed suspension of the Al 2 O 3 matrix may be mixed with the mixed solution of the precursor of ZrO 2 and the precursor of the sintering aid if present, and then with the phosphor.
  • the suspension is mixed.
  • the sintering method may be a direct sintering method, a hot press sintering method or a spark plasma sintering method.
  • the mixed powder obtained in the step 1 is charged into a mold, and the sheet is pressed under a pressure of 20 to 40 MPa, and the obtained sample is subjected to cold isostatic pressing treatment at 200 MPa, and then the sample is placed in a sintering furnace. Internally, it is sintered under a protective atmosphere such as nitrogen, argon or hydrogen.
  • the sintering temperature may be from 1,450 to 1,750 ° C, preferably from 1,550 to 1,650 ° C.
  • the sintering time can be from 30 min to 20 h, preferably from 60 min to 10 h.
  • the hot press sintering method can greatly reduce the sintering temperature of the material by applying pressure while sintering, and is an ideal process for preparing the above materials.
  • the hot pressing method has a high heating rate, and a vacuum atmosphere or a protective gas atmosphere can be used, and it can be applied to sintering of various types of materials.
  • the hot press sintering method When the hot press sintering method is employed, the mixed powder obtained in the step 1 is charged into a mold, Pre-compression is carried out under a pressure of 5-15 MPa, and then the mold is placed in a hot press sintering furnace and sintered under vacuum or argon atmosphere.
  • the sintering temperature may be from 1,250 to 1,650 ° C, preferably from 1,350 to 1,550 ° C; the sintering pressure is preferably from 30 to 200 MPa, preferably from 40 to 100 MPa, more preferably from 40 to 75 MPa; and the sintering time may be from 5 minutes to 6 hours, preferably from 30 minutes to 3 hours.
  • the SPS technology of spark plasma sintering has its own characteristics. It can mainly heat the sample by pulse current to make the sample melt quickly. It is generally believed that SPS has the following densification pathways: (1) local high temperature is generated by discharge and ionization between grains, causing evaporation and melting on the surface of powder particles, directly promoting the process of densification; (2) pulse current Under the action of the powder particles, the surface of the powder particles is easily activated, and various diffusion effects are enhanced, thereby promoting the process of densification.
  • each particle uniformly heats itself to activate the surface of the particle, thereby having high thermal efficiency, and the sintered body can be dense in a relatively short period of time, and the sintering temperature of the fine powder can be effectively reduced.
  • the mixed powder obtained in the step 1 was charged into a mold, pre-compressed under a pressure of 5 to 15 MPa, and then the mold was placed in an SPS sintering furnace to be sintered under a vacuum atmosphere.
  • the sintering temperature may be 1250 to 1550 ° C, preferably 1350 to 1450 ° C; the sintering time is 30 min to 6 h, preferably 60 min to 4 h; and the sintering pressure is 30 to 200 MPa, preferably 40 to 100 MPa.
  • the luminescent ceramic of the present invention has excellent characteristics of high light efficiency, high thermal conductivity, and adjustable blue light transmittance, and can be applied to a high performance laser light source, particularly a precision laser light source system.
  • a scanning electron microscope photograph of the luminescent ceramic of the present invention was taken by an Hitachi scanning electron microscope Hitachi S-3400N (manufactured by Hitachi, Japan) at an acceleration voltage of 15.0 kV.
  • the fracture toughness of the obtained luminescent ceramic is measured by a one-sided notched beam method.
  • a three-point bending test was performed, the span was 20 mm, and the indenter pressing rate was 0.05 mm ⁇ min -1 .
  • the test was carried out on a DCS-5000 Shimadzu material testing machine. Record the breaking load P and calculate the fracture toughness value Kic according to the following formula:
  • the raw material is high-purity ultrafine Al 2 O 3 nano powder with a particle size of 0.08-0.2 ⁇ m; high-purity ultra-fine nano ZrO 2 powder with a particle size of 0.05-0.1 ⁇ m; high-purity commercial YAG:Ce 3+ fluorescence
  • the powder has a particle size of 15 to 17 ⁇ m.
  • a certain amount of Al 2 O 3 powder and ZrO 2 powder were weighed so that the content of the ZrO 2 powder was 1% by mass of the Al 2 O 3 powder.
  • the two powders were charged into a polytetrafluoroethylene ball mill jar, an appropriate amount of ethanol was added as a grinding solvent, and an appropriate amount of sodium silicate was added as a dispersing agent, and ball milling was performed with an ultra-low wear rate zirconia ball.
  • the number of revolutions of the ball mill was 120r/min, ball milling time is 36h.
  • the YAG:Ce phosphor is added to the ball mill tank so that the mass percentage of the phosphor particles accounts for 20% by mass of the total powder, and the second ball milling is performed at a low speed, and the number of revolutions of the ball mill is 60 r/min.
  • the ball milling time is 40 minutes.
  • the total powder is the sum of Al 2 O 3 powder, ZrO 2 powder and phosphor powder.
  • the dried powder was obtained by vacuum drying at 60 ° C under constant temperature.
  • the dry powder was calcined at 500 ° C in a muffle furnace to remove organic components in the powder for 5 hours.
  • the calcined powder was granulated through a mesh of 80 mesh, 150 mesh, and 200 mesh to obtain a raw material powder having high fluidity.
  • FIG. 2 A scanning electron micrograph of the obtained luminescent ceramic is shown in Fig. 2.
  • the circle in the figure is a YAG:Ce phosphor particle, and the black region is an alumina region.
  • the particle size of the alumina is small, and is shown here as a continuous phase.
  • the refractory toughness value of the luminescent ceramic obtained in the present example was 5.56 MPa ⁇ m 1/2 .
  • the Al 2 O 3 nanopowder and the YAG:Ce phosphor used in this example were the same as in Example 1.
  • the Y 2 O 3 powder used was a high-purity ultrafine nano Y 2 O 3 powder having a particle diameter of 0.05 to 0.1 ⁇ m.
  • the ball mill tank After the end of the first ball milling, an appropriate amount of YAG:Ce phosphor was added to the ball mill tank so that the mass percentage of the phosphor particles accounted for 50% by mass of the total powder.
  • the second ball milling was carried out at a low speed, the number of revolutions of the ball mill was 60 r/min, and the ball milling time was 40 min.
  • the total powder is the sum of Al 2 O 3 powder, ZrO 2 powder, Y 2 O 3 powder, and phosphor powder.
  • the dried powder was obtained by vacuum drying at 60 ° C under constant temperature.
  • the dry powder was calcined at 650 ° C in a muffle furnace to remove organic components in the powder for 1 hour.
  • the calcined powder was granulated through a mesh of 80 mesh, 150 mesh, and 200 mesh to obtain a raw material powder having high fluidity.
  • the Al 2 O 3 nanopowder and the YAG:Ce phosphor used in this example were the same as in Example 1.
  • the solution two was added to the solution one to obtain a solution three, which was a mixed solution of YAG:Ce phosphor particles and a nano-Al 2 O 3 powder suspension + nitrate, and the stirring was continued using a magnetic stirrer.
  • the temperature was set to 40 ° C and the speed was 250 r/m.
  • a 0.05 mol/L aqueous ammonia solution was prepared, and the mixed suspension 3 which was continuously stirred was slowly dropped until the pH of the mixed suspension was controlled to about 9. After maintaining the pH value, stirring was continued for 2.5 hours to obtain a coprecipitated composite powder suspension IV.
  • the suspension was centrifuged, and the obtained powder was washed with water 4 times, and then vacuum dried at 80 ° C for 5 hours.
  • the obtained dry powder is calcined at 500 ° C to remove impurities, and kept for 5 hours, and then air-cooled with the furnace to obtain a YAG-Al 2 O 3 -ZrO 2 -Y 2 O 3 mixed powder, which is then sieved through 80 mesh, 150 mesh, and 200 mesh. Granules, which give high flow of raw material powder.
  • the sintering temperature is 1750 °C. After heat preservation for 20 h, after sintering, the furnace was cooled to obtain a light-emitting composite ceramic material YAG-Al 2 O 3 -ZrO 2 -Y 2 O 3 , that is, PIA-ZrO 2 -Y 2 O 3 .
  • the Al 2 O 3 nanopowder and the YAG:Ce phosphor used in this example were the same as in Example 1.
  • a 1.5% by mass aqueous solution of PEG was prepared, and an appropriate amount of Al 2 O 3 nanopowder was mixed with an aqueous solution of PEG, and the Al 2 O 3 solution was ultrasonicated for 1.5 hours and then used as a solution. Ultrasound is to destroy the secondary agglomeration between the particles, allowing the powder to disperse as much as possible in the solution.
  • the solution one was mixed with the solution two to obtain a mixed suspension three, which was placed on a magnetic stirrer and continuously stirred, and the temperature was set to 60 ° C, and the rotation speed was 250 r / m.
  • Ammonium bicarbonate was used as a precipitant to prepare an aqueous solution of about 0.05 mol/L, and the mixed suspension 3 which was continuously stirred was slowly dropped until the pH of the mixed suspension was controlled to about 9. After maintaining a suitable pH value, stirring was continued for 2.5 hours to obtain a coprecipitated composite powder suspension.
  • the suspension was centrifuged, and the obtained powder was washed with water 4 times, and then vacuum dried at 80 ° C for 5 hours.
  • the obtained dry powder is calcined at 500 ° C to remove impurities, and kept for 5 h, and then air-cooled to obtain an Al 2 O 3 -ZrO 2 -Y 2 O 3 -MgO mixed powder, which is then sieved through 80 mesh, 150 mesh, and 200 mesh. grain.
  • Al 2 O 3 -ZrO 2 -Y 2 O 3 -MgO mixed powder and YAG:Ce phosphor were weighed so that the mass ratio of the total powder:YAG:Ce phosphor was 2:1.
  • the two powders were placed in a Teflon ball mill jar, and an appropriate amount of ethanol was added as a grinding solvent. No dispersing agent was used, and ball milling was performed with an ultra-low wear rate zirconia ball, and the ball milling time was 30 min.
  • the total powder is the sum of Al 2 O 3 powder, ZrO 2 powder, Y 2 O 3 powder, MgO powder, and phosphor powder.
  • the dry powder is obtained by vacuum drying at 60 ° C, and then 80 mesh, 150 mesh, The 200 mesh sieve was granulated to obtain a high fluidity raw material powder.
  • the luminescent ceramic of Example 5 was prepared in the same manner as in Example 1 except that the mass percentage of the phosphor particles was 90% by mass based on the total powder.
  • the luminescent ceramic of Comparative Example 1 was prepared in the same manner as in Example 1 except that ZrO 2 was not added.
  • the fracture toughness value of Example 1 was higher than the fracture toughness value of Comparative Example 1 by about 20%. It can be seen that by sufficiently mixing the ZrO 2 particles and the phosphor with the Al 2 O 3 matrix and uniformly dispersing in the Al 2 O 3 matrix, the toughness of the luminescent ceramic is greatly improved, and the luminescent ceramic is not adversely affected.
  • the optical properties, and ZrO 2 as a scattering particle can play the role of homogenizing incident light.

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Abstract

一种发光陶瓷及其制备方法，包括Al 2O 3基质、ZrO 2颗粒和荧光粉颗粒，可通过固相法或液相法获得。

Description

一种发光陶瓷及其制备方法 技术领域
本发明涉及一种发光陶瓷及其制备方法。
背景技术
蓝色激光激发荧光材料获得可见光的技术，作为一种全新的光源技术，在激光显示领域中的应用获得了显著的进展，并受到了市场的认可，相关技术不断获得重视。当前研究的热点和难点主要是针对激光激发荧光粉的特性来开发新型的荧光材料(波长转换材料、发光材料)，这些材料必须拥有优秀的性能，比如光学转换效率高，亮度高，单位发光面积能够承受更大功率激光照射，具有高导热性能，寿命长等。
随着要求的提高，传统的硅胶封装荧光粉技术和玻璃封装荧光粉技术已经不能满足高端产品需要，硅胶的承受温度往往不能超过200-250℃，长时间工作在高温环境下很容易老化，寿命不长；硅胶封装和玻璃封装的材料，其热导率一般不超过2W/(m·k)，在固定式激发方案中(与之对应的是旋转式激发方案)，无法承受大功率甚至超大功率的激光照射。
发光陶瓷是一个很理想的选择，因为发光陶瓷的耐热和热导率等性能都高于硅胶和玻璃封装荧光粉。但是，传统的YAG(即钇铝石榴石(Y3Al5O12))纯相发光陶瓷在发光性能上还弱于硅胶和玻璃封装；特别是超薄封装时，界面全反射造成的光效损失很大。因此，使用其他高导热率陶瓷材料对荧光粉进行封装，如Al2O3封装YAG荧光粉制备YAG-Al2O3(PIA，Phosphor In Alumina)，能够获得比纯相YAG发光陶瓷更优秀的性能，是值得深入研究的方向。
由于发光陶瓷更趋向于精密化应用，因此在制备出Al2O3封装荧光粉的 发光陶瓷后，还需要经过一系列的切割、磨平、抛光、分割、镀膜、焊接等工艺，从而对发光陶瓷的机械性能要求很高，特别是对其强韧性能的要求很高。
因此，如何获得兼具光学性能与机械性能的发光陶瓷是研究的重要课题。
发明内容
发明要解决的问题
为了解决上述问题而进行本发明。因此，本发明的目的是提供能够同时满足发光陶瓷的韧性得到提高而又不显著影响发光陶瓷的光学性能的发光陶瓷。
用于解决问题的方案
本发明提供一种发光陶瓷，其特征在于，其包括Al2O3基质、ZrO2颗粒和荧光粉颗粒。
根据本发明所述的发光陶瓷，其中所述荧光粉颗粒与所述ZrO2颗粒均匀地分散于所述Al2O3基质中。进一步，所述ZrO2颗粒分散于所述Al2O3基质的晶界之间。
根据本发明所述的发光陶瓷，其中所述ZrO2颗粒的含量为所述Al2O3基质质量的0.05～5质量％，优选0.2～3质量％，更优选0.5～1质量％。
根据本发明所述的发光陶瓷，其中所述荧光粉颗粒与所述Al2O3基质的质量比为1∶4～9∶1，优选1∶4～3∶1，更优选1∶3～1∶1。
根据本发明所述的发光陶瓷，其中所述ZrO2颗粒的粒径为0.05～1μm、优选0.05～0.7μm、特别优选为0.05～0.35μm，所述荧光粉颗粒的粒径为10～50μm、优选10～30μm、特别优选10～25μm，所述Al2O3基质的晶粒的粒径为0.05～5μm，优选0.15～5μm，特别优选为0.15～3μm；和/或，所述ZrO2颗粒的原料粉末的 粒径为0.05～0.7μm，优选0.05～0.2μm，所述荧光粉颗粒的原料粉末的粒径为10～25μm、优选15～17μm，所述Al2O3原料粉末的粒径为0.05～1μm、优选0.1～0.3μm。
根据本发明所述的发光陶瓷，其进一步包括烧结助剂，且所述烧结助剂选自Y2O3、MgO、CaO、SiO2、TiO2、BaO、CaF2、BaF2的至少一种，优选Y2O3和/或MgO，更优选Y2O3。
另外，本发明还提供发光陶瓷的制备方法，其特征在于，其包括以下步骤：
步骤1：包含Al2O3基质、ZrO2颗粒和荧光粉颗粒的混合粉末的制备步骤；
步骤2：将上述混合粉末压制、烧结，以获得发光陶瓷的步骤。
根据本发明所述的制备方法，其中所述步骤1包括以下步骤：
步骤a：所述Al2O3基质与所述ZrO2颗粒和任选的烧结助剂的混合粉末的制备步骤；
步骤b：将上述混合粉末与所述荧光粉颗粒混合、球磨、干燥、过筛的步骤。
根据本发明所述的制备方法，其中所述步骤a可采用步骤a′代替，所述步骤a′包括：将所述Al2O3基质的原料粉末的悬浮液与ZrO2的前体的溶液和任选的烧结助剂的前体的溶液混合并共沉淀的步骤；以及将获得的产物离心分离、洗涤、干燥、煅烧和过筛的步骤。
根据本发明所述的制备方法，其中所述步骤1包括以下步骤：
步骤I：将Al2O3原料粉末和荧光粉的混合悬浮液与ZrO2的前体的溶液和任选的烧结助剂的前体的溶液混合、然后共沉淀的步骤；
步骤II：将步骤I获得的产物离心分离、洗涤、干燥、煅烧、过筛的步骤。
发明的效果
本发明中，通过在Al2O3封装荧光粉的发光陶瓷中添加适量小粒径ZrO2， 使得荧光粉颗粒和ZrO2颗粒均匀分散于Al2O3基质中，不仅能够提高发光陶瓷的韧性，而且不会不利地影响发光陶瓷的光学性能。并且，ZrO2还可以作为散射颗粒，起到匀化入射光的作用。因此，本发明的发光陶瓷具有高光效、高热导率、蓝光透过率可调的优异特性，并且可应用于高性能激光光源，特别是精密化的激光光源系统。
附图说明
图1为本发明的发光陶瓷的结构示意图。
图2为实施例1中获得的样品的扫描电子显微镜照片。
具体实施方式
以下通过具体实施方案更详细地说明本发明的发光陶瓷及其制备方法。
本发明的发光陶瓷包括Al2O3基质、ZrO2颗粒和荧光粉颗粒。其中，粒径大的荧光粉颗粒均匀分散于Al2O3基质中，粒径小的ZrO2颗粒位于Al2O3基质的晶界之间。
图1为本发明的发光陶瓷的结构示意图。其中1表示Al2O3基质，2表示ZrO2颗粒，3表示荧光粉颗粒。由图1所示可知，本发明的发光陶瓷的结构特征在于，以晶粒细小的Al2O3相为基质，较大的荧光粉颗粒均匀分散于Al2O3基质中，较小的ZrO2颗粒位于Al2O3基质的晶界之间。并且，荧光粉颗粒被Al2O3基质的晶粒连续包围。陶瓷中的荧光粉颗粒能够吸收激发光发出受激光；具体的可以收到蓝光的激发发出黄色可见光；致密且晶粒细小的Al2O3基质有良好的透光性能，被激发的可见光可以穿过Al2O3基质出射到陶瓷外面。较小的ZrO2颗粒能够起到提高发光陶瓷的韧性的作用，并且不会不利地影响发光陶瓷的发光性能。并且，ZrO2还可以作为散射颗粒，起到匀化入射光的作用。
根据本发明所述的发光陶瓷，其中所述ZrO2颗粒的粒径为0.05～1μm，优选0.05～0.7μm，特别优选为0.05～0.35μm。
根据本发明所述的发光陶瓷，其中所述荧光粉颗粒的粒径为10～50μm，优选10～30μm，特别优选10～25μm。
根据本发明所述的发光陶瓷，其中所述Al2O3基质的晶粒的粒径为0.05～5μm，优选0.15～5μm，特别优选为0.15～3μm。
以下说明本发明的发光陶瓷兼具光学性能与机械性能的机理。本发明中，在制备Al2O3封装荧光粉的发光陶瓷时，添加适量的ZrO2纳米粉末，利用ZrO2晶粒在升温和降温过程中，四方晶相t-ZrO2和单斜晶相m-ZrO2的可逆转化产生的体积变化特性，通过微裂纹相变增韧对发光陶瓷进行增韧。即加热过程中温度经过约1200℃时，m-ZrO2转变为t-ZrO2，体积收缩；冷却过程中温度经过约1000℃时，t-ZrO2转变为m-ZrO2，体积膨胀。ZrO2体积收缩和膨胀的过程，会在陶瓷基体中产生微小的裂纹或者弹性后效应力，当陶瓷受力断裂或者快要断裂时，微裂纹或应力会吸收或抵消导致陶瓷断裂的应力，因此使陶瓷可以承受更大的应力而不易断裂，从而增强了陶瓷的强韧性。ZrO2颗粒的小粒径化和分散化，是增韧效果实现的关键。另外，ZrO2是透光的Al2O3基质中的白色不透明成分，通常情况下会影响Al2O3基质的透光性。本发明中，出人意料地通过使ZrO2的粒径较小且添加量较少，对蓝光入射和黄光出射的影响都很小。另外，ZrO2作为白色颗粒，能够起到对入射光进行散射从而使入射光均匀的作用，并且其基本上不会对光进行吸收，不会造成光的损失。因此，最终效果是ZrO2颗粒的添加不会显著影响发光陶瓷的光学性能，ZrO2又可以明显增强发光陶瓷的机械性能并且可以作为散射颗粒起到匀化入射光的作用。
本发明的发光陶瓷中，ZrO2的含量为Al2O3基质质量的0.05～5质量％，优选0.2～3质量％，更优选0.5～1质量％。当ZrO2的含量小于0.05质量％时，其增 韧作用不明显。当ZrO2的含量高于5质量％时，发光陶瓷中的ZrO2相会更明显，会使入射的蓝光受到的反射更显著，这时黄色发光陶瓷发出的光中蓝光含量会提高，黄光含量会降低，会导致发光陶瓷的整体光效下降。当ZrO2的含量在0.05～5质量％，优选为0.2～3质量％时，不仅能够起到增韧效果，不会不利地影响发光陶瓷的光效，而且还可以作为散射颗粒，起到匀化入射光的作用。
另外，需要说明的是，当需要发出均匀白光的陶瓷时，可以增加ZrO2的含量以增加白点的数量。此时，ZrO2的含量可以为上述范围内的较高值，如4～5质量％。ZrO2起到了散射粒子的作用，能够使得出射的白光更均匀。
关于荧光粉，没有特别限定，可使用发光陶瓷领域常用的荧光粉。本发明中，优选使用的荧光粉为选自Ca3(Al，Sc)2Si3O12、(Gd，Tb，Y，Lu)3(Al，Ga)5O12、Y3Mg2AlSi2O12中的至少一种且掺杂Ce3+的荧光粉，其中优选Y3Al5O12掺杂Ce3+的荧光粉即YAG∶Ce3+荧光粉。
荧光粉颗粒与Al2O3基质的质量比为1∶4～9∶1，优选1∶4～3∶1，更优选1∶3～1∶1。另外，荧光粉颗粒的含量为Al2O3基质、ZrO2颗粒、荧光粉颗粒和如果存在的烧结助剂的总量的15～90质量％，优选15～50质量％。
如上所述，ZrO2颗粒的小粒径化是增韧效果实现的关键因素之一。本发明中，ZrO2原料粉末的粒径为0.05～0.7μm，优选0.05～0.2μm，特别优选0.05～0.1μm。如果ZrO2原料粉末的粒径过大，会在发光陶瓷中形成白点，同时增韧效果不好。需要说明的是，这里的ZrO2原料粉末的粒径范围略小于发光陶瓷中ZrO2的粒径范围；可以理解，当作为原料的ZrO2原料粉末在整个制备过程中，可能会出现部分团聚现象，并且在烧结过程中，部分ZrO2晶粒会不受抑制的异常长大；因此，发光陶瓷中ZrO2的粒径范围可能会略大于ZrO2原料粉末的粒径；但是基于分散的均匀性，ZrO2粒径的变化不会过于显著。
另外，Al2O3原料粉末的粒径为0.05～1μm，优选0.1～0.3μm。荧光粉原料 粉末的粒径为10～25μm，优选15～17μm。需要说明的是，细晶粒的Al2O3在发光陶瓷中具有良好的机械性能，其强度和韧性优于大晶粒的Al2O3基质。通常，由于团聚和烧结过程中晶粒的异常长大现象，部分Al2O3原料粉末粒径会增大3～5倍。可以理解，这一现象同样适用于本发明中的其他成分。但是，本发明中，采用粒径较小的Al2O3原料粉末在制备过程中，添加的ZrO2同时起到抑制Al2O3过度(异常)长大的作用，因此对增强发光陶瓷强度和韧性有积极的影响。
氧化铝晶粒大小落于本发明范围中的时候，有利于烧结在较低温度进行。例如，当使用YAG∶Ce3+荧光粉作为本发明的荧光粉时，YAG的熔点为1970℃，Al2O3的熔点为2000℃，要形成上述的发光陶瓷材料，要求Al2O3先进入液相烧结，产生主要的物相迁移，YAG不进入或很少量进入液相烧结，只产生极小量的物相迁移。因此原料中Al2O3粉体选用纳米级高比表面积的超细粉体，平均粒径为0.05～1μm，优选0.1～0.3μm。选用小粒径的纳米Al2O3粉末，在热压烧结的条件下，可以在1500℃左右烧成致密的Al2O3陶瓷，远低于大颗粒YAG的熔点，可实现Al2O3完成烧结而YAG不参与烧结，因此主要颗粒形貌不变的目的。
另外，本发明的发光陶瓷可以包括烧结助剂。烧结助剂的例子不特别限定，可使用本领域常用的助剂。例如，烧结助剂可为选自Y2O3、MgO、CaO、SiO2的至少一种。其中，优选Y2O3和/或MgO、更优选Y2O3作为本发明的烧结助剂。烧结助剂的含量为Al2O3基质质量的0.05～5质量％，优选0.05～3质量％，更优选0.5～1质量％。
当使用Y2O3粉末颗粒作为助剂时，既可以作为发光陶瓷的烧结助剂，促进液相烧结，也可以作为ZrO2的稳定剂，使ZrO2的相变行为不那么剧烈，为相对缓和的体积变化。
MgO和Y2O3一起可以作为发光陶瓷烧结的助剂，可以显著提高液相烧 结，降低烧结温度。Y2O3、MgO都是微量含量的助剂，如果它们的含量相对于Al2O3基质质量低于0.05质量％，则助剂作用减少；如果它们的含量高于5质量％，则会影响Al2O3基质的透明度。ZrO2、Y2O3、MgO这三种粉末颗粒都需要与Al2O3纳米粉末颗粒充分地混合，才能最有效地发挥作用。
另外，本发明的发光陶瓷的相对致密度为4.1～4.31g/cm3。相对致密度越高，热导率、光效、机械性能均会有所提高，特别是热导率会得到很大提高。
以下进一步说明本发明的发光陶瓷的制备方法。
如上所述，需要使ZrO2和如果存在的烧结助剂与Al2O3基质粉末充分均匀地混合才能最有效地发挥作用。因此，本发明的发光陶瓷的制备方法不特别限定，只要能够使粉末均匀混合即可。
具体地，本发明的发光陶瓷的制备方法包括以下步骤：
步骤1：包含Al2O3基质、ZrO2颗粒和荧光粉颗粒的混合粉末的制备步骤；
步骤2：将上述混合粉末压制、烧结，以获得发光陶瓷的步骤。
步骤1
其中，步骤1可以采用固相法，也可采用液相法。液相法又包括溶胶-凝胶法、共沉淀法、醇盐水解法等，其中特别优选共沉淀法。
下面分别以固相法和共沉淀法为例说明上述步骤1。
<固相法>
本发明中，通过固相法制备包含Al2O3基质、ZrO2颗粒和荧光粉颗粒的混合粉末的方法包括以下步骤：
步骤a：Al2O3基质与ZrO2颗粒和任选的烧结助剂的混合粉末的制备步骤；
步骤b：将上述混合粉末与荧光粉混合、球磨、干燥、过筛的步骤。
步骤a
Al2O3基质与ZrO2颗粒和任选的烧结助剂的混合粉末的制备可以通过以下方法获得，所述方法包括：将Al2O3基质的原料粉末与ZrO2颗粒的原料和 任选的烧结助剂的原料的粉末混合并进行球磨(称为第一次球磨)的步骤。
具体地，将Al2O3基质的原料粉末与ZrO2颗粒的原料和任选的烧结助剂的原料的粉末装入聚四氟乙烯球磨罐中，添加适量的乙醇作为研磨溶剂，添加适量的陶瓷分散剂作为分散剂，用超低磨失率的氧化锆球进行球磨，球磨时间为1～72h，优选为24～36h。由此，获得Al2O3基质与ZrO2和任选的烧结助剂的混合粉末。第一次球磨是使Al2O3基质的原料粉末与ZrO2颗粒的原料和任选的烧结助剂的原料粉末混合和磨细，因此对球磨的转速没有特别限定。
其中，分散剂不特别限定，可使用本领域常用的分散剂。其例子包括：无机盐类如硅酸钠、三聚磷酸钠、六偏磷酸钠等；低级有机物如硬脂酸钠、柠檬酸钠、烷基磺酸钠等；聚合物如聚丙烯酸及其盐、聚乙烯醇等。
步骤b
将通过上述步骤a获得的Al2O3基质与ZrO2颗粒和任选的烧结助剂的混合粉末与荧光粉颗粒混合，然后在低速下进行球磨(称为第二次球磨)，球磨时间为10～120min，优选为30～50min。球磨的转数为30-100r/min。需要说明的是，采用低速的主要目的在于控制球磨时对荧光粉颗粒的冲击力度，避免对荧光粉颗粒表面形态的破坏。
第一次球磨时间较长，是为了充分混合Al2O3粉末与ZrO2颗粒和任选的烧结助剂粉末，ZrO2颗粒和任选的烧结助剂的粉末必须和Al2O3粉末进行充分的混合，保证扩散均匀。第二次球磨时间较短，是因为荧光粉的颗粒较大，较易于分散，如果球磨时间过长，容易损坏荧光粉的晶粒表面形态，影响发光性能。
球磨结束后，采用真空恒温干燥获得干粉。干粉在马弗炉中在500～650℃下进行煅烧，以除去粉末中的有机成分。然后，将煅烧后的粉末过80目、150目、200目筛，得到高流动性的原料粉末。
上述的步骤a即Al2O3基质与ZrO2颗粒和任选的烧结助剂的混合粉末的 制备也可通过共沉淀法获得。该方法包括以下步骤(称为步骤a′)：将Al2O3基质的原料粉末的悬浮液与ZrO2的前体的溶液和任选的烧结助剂的前体的溶液混合并使Al2O3基质与ZrO2和任选的烧结助剂共沉淀的步骤；以及将获得的产物离心分离、洗涤、干燥、煅烧和过筛的处理步骤。
首先，配制Al2O3基质的原料粉末的悬浮液。具体地，将Al2O3基质的原料粉末与PEG水溶液混合，然后超声1～3h后备用。超声是为了破坏颗粒之间的二次团聚，让粉末在溶液中尽可能地分散。其中，PEG水溶液的浓度可为1～3质量％。
然后，将ZrO2的前体与如果存在的助剂的前体一起配制成混合盐溶液。溶液浓度可为0.01～1mol/L。其中，ZrO2的前体可使用ZrOCl2·8H2O。在助剂包含Y2O3时，可使用Y(NO3)3·6H2O作为助剂前体；在助剂包含MgO时，可使用无机镁盐如Mg(NO3)2·6H2O、MgCl2·6H2O、MgSO4·7H2O等。当MgO和Y2O3一起作为发光陶瓷烧结的助剂时，MgO前体与Y2O3前体的质量百分比比例可为1∶2～3∶1。
进一步，将Al2O3基质的原料粉末的悬浮液与ZrO2和可能存在的助剂的前体溶液混合、搅拌，然后通过使用氨水或碳酸氢铵溶液调节混合溶液的pH，以获得共沉淀的复合粉体悬浮液。然后，将获得的复合粉体悬浮液离心分离，对获得的粉体进行水洗2～8次，在50～150℃真空干燥1～10个小时。然后，将获得的干粉煅烧以去除杂质，之后随炉空冷，过80目、150目、200目筛造粒，从而得到高流动性的Al2O3基质与ZrO2颗粒和任选的助剂的混合粉末。煅烧温度和煅烧时间不特别限定，可根据不同的助剂进行选择，但通常煅烧温度为200～500℃，煅烧时间为1～5小时。
上述搅拌时的温度设置为20～80℃，优选40～60℃，转速为100～300r/m，优选为170～250r/m。
共沉淀时使用的氨水溶液或碳酸氢铵溶液的浓度可为0.01～0.1mol/L。溶 液的PH值可控制在8～10左右，优选为9～9.5。合适的PH值对于Al2O3超细粉体颗粒的分散和解絮凝非常重要。保持合适的PH值后搅拌时间可为1～5h，优选为2～3h。
在调节溶液pH值时，可采用正向滴定法，即在混合溶液中滴入氨水或碳酸氢铵溶液，以使ZrO2和烧结助剂的纳米颗粒析出。这些纳米颗粒会有部分附着在荧光粉颗粒的表面以及Al2O3颗粒的表面，在磁力搅拌的作用下，这些析出的悬浮颗粒会与悬浮液中的Al2O3纳米颗粒非常均匀地混合在一起。这种方式添加的助剂剂量可以更小，混合更均匀，效果更显著。
<共沉淀法>
本发明中，通过共沉淀法制备发光陶瓷的方法包括以下步骤：
步骤I：将Al2O3原料粉末与荧光粉的混合悬浮液与ZrO2的前体的溶液和任选的烧结助剂的前体的溶液混合、然后共沉淀的步骤；
步骤II：将以上步骤获得的产物离心分离、洗涤、干燥、煅烧、过筛的步骤。
步骤I
首先，配制柠檬酸-NaOH溶液，然后加入PEG4000，超声溶解后，加入荧光粉和纳米Al2O3粉末，超声分散后，置于磁力搅拌器上不停搅拌，从而获得荧光粉-Al2O3混合悬浮液。其中，荧光粉与Al2O3的质量比为荧光粉∶Al2O3＝1∶4～9∶1。
将ZrO2的前体与如果存在的烧结助剂的前体一起配制成混合盐溶液。溶液浓度可为0.01～1mol/L。其中，ZrO2的前体和烧结助剂的前体的例子与上述相同。
将上述获得的荧光粉-Al2O3混合悬浮液与ZrO2和任选的烧结助剂的前体溶液混合、搅拌，然后通过使用氨水或碳酸氢铵溶液调节混合溶液的pH，以获得共沉淀的复合粉体悬浮液。该步骤与上述固相法中记载的步骤a′中的相 同。
步骤II
以上步骤I中获得的产物离心分离、干燥、煅烧、过筛的步骤与上述固相法中记载的步骤a′中的相同。由此，获得荧光粉颗粒、Al2O3基质、ZrO2颗粒和如果存在的烧结助剂的混合粉末。
另外，虽然上述共沉淀法中，首先制备荧光粉与Al2O3基质的混合悬浮液，然后再与ZrO2的前体和如果存在的烧结助剂的前体的混合溶液混合。但是，原料的添加顺序并不限于此，也可以将Al2O3基质的混合悬浮液与ZrO2的前体和如果存在的烧结助剂的前体的混合溶液混合之后，再与荧光粉的悬浮液混合。
步骤2
称取适量步骤1中获得的荧光粉颗粒、Al2O3基质、ZrO2颗粒和任选的烧结助剂的混合粉末装入耐高温模具如石墨模具中进行压制，然后进行烧结，之后随炉冷却，从而获得本发明的发光陶瓷复合材料。
烧结方法可采用直接烧结法、热压烧结法或放电等离子烧结SPS(spark plasma sintering)法。
当采用直接烧结法时，将步骤1中获得的混合粉末装入模具中，在20～40MPa的压力下进行压片，将所得样片再经过200MPa冷等静压处理，然后将样片放入烧结炉内，在氮气、氩气、氢气等保护气氛下烧结。烧结温度可为1450～1750℃，优选1550～1650℃。烧结时间可为30min～20h，优选60min-10h。
热压烧结法可以通过一边施加压力，一边烧结的方式，可极大地降低材料的烧结温度，是制备上述材料的理想工艺方法。同时热压法的升温速度快，可以使用真空气氛或者保护气体气氛，能够适用于多种类型的材料烧结。
当采用热压烧结法时，将步骤1中获得的混合粉末装入模具中，在 5-15MPa压强下进行预压制，然后将模具放入热压烧结炉内，在真空条件或氩气气氛下进行烧结。烧结温度可为1250～1650℃，优选1350～1550℃；烧结压力优选30～200MPa，优选40～100MPa，更优选40～75MPa；烧结时间可为5min～6h，优选30min～3h。
放电等离子烧结SPS技术除了具有热压烧结的特点外，还具有自己的特点，主要是可以通过脉冲电流对样品加热，使样品快速烧结。一般认为SPS、存在以下几种致密化途径：(1)晶粒间的放电及电离化产生局部高温，在粉末颗粒表面引起蒸发和熔化，直接促进了致密化的过程；(2)在脉冲电流的作用下，粉末颗粒表面容易活化，各种扩散作用都得到加强，从而促进了致密化的过程。放电等离子烧结体内每个颗粒均匀地自身发热使颗粒表面活化，因而具有很高的热效率，可在相当短的时间内使烧结体致密，并能很有效地降低细粉的烧结温度。
当采用SPS法烧结时，将步骤1中获得的混合粉末装入模具中，在5-15MPa压强下进行预压制，然后将模具放入SPS烧结炉内在真空气氛下进行烧结。烧结温度可为1250～1550℃，优选1350～1450℃；烧结时间为30min～6h，优选60min～4h；烧结压力为30～200MPa，优选40～100MPa。
如上所述，通过在含有Al2O3基质的发光陶瓷中添加ZrO2，并且使ZrO2与Al2O3基质和荧光粉充分均匀地混合，不仅能够提高发光陶瓷的强韧性能，而且不会不利地影响发光陶瓷的光学性能。由此，使得本发明的发光陶瓷具有高光效、高热导率、蓝光透过率可调的优异特性，并且可应用于高性能激光光源，特别是精密化的激光光源系统。
实施例
以下通过实施例进一步详细说明本发明，但本发明不限于以下实施例。
首先描述实施例中获得的发光陶瓷的结构特征和物理性质的表征。
(1)扫描电子显微镜照片的拍摄
本发明的发光陶瓷的扫描电子显微镜照片通过日立扫描电子显微镜Hitachi S-3400N(由日本Hitachi公司生产)在15.0kv的加速电压下拍摄。
(2)断裂韧性的测量
本发明中，通过单边切口梁法测量所得发光陶瓷的断裂韧性。试样尺寸为高度×宽度×长度＝5mm×2.5mm×25mm。将试样沿高度方向切割出深度为2.5mm、宽度小于0.2mm的切口后，进行三点弯曲试验，跨距为20mm，压头下压速率为0.05mm·min-1。试验在DCS-5000型岛津材料试验机上进行。记录断裂载荷P，并根据下式计算断裂韧性值Kic：
Kic＝PL/BW3/2·f(a/W)
在试样高宽比W/B＝2，高跨比W/L＝1/4的条件下，f(a/W)的值为2.665。
实施例1：
原料选用高纯度超细Al2O3纳米粉末，粉末粒径为0.08～0.2μm；选用高纯度超细纳米ZrO2粉末，粒径为0.05～0.1μm；选用高纯商用YAG∶Ce3+荧光粉，粒径为15～17μm。
称取一定数量的Al2O3粉末和ZrO2粉末，以使ZrO2粉末的含量为Al2O3粉末的1质量％。将两种粉末装入聚四氟乙烯球磨罐中，添加适量的乙醇作为研磨溶剂，添加适量的硅酸钠作为分散剂，用超低磨失率的氧化锆球进行球磨，球磨的转数为120r/min，球磨时间为36h。
第一次球磨结束后，添加YAG∶Ce荧光粉到球磨罐中，以使荧光粉颗粒的质量百分比占总粉料的20质量％，低速进行第二次球磨，球磨的转数为60r/min，球磨时间为40min。总粉料为Al2O3粉末、ZrO2粉末和荧光粉粉末的总和。
两次球磨结束后，在60℃下真空恒温干燥获得干粉。将干粉在马弗炉中进行500℃的煅烧，除去粉末中的有机成分，时间为5小时。
煅烧后的粉末过80目、150目、200目筛造粒，得到高流动性的原料粉末。
称取适量原料粉末装入石墨模具中，在5MPa压强下进行预压制，然后将石墨模具放入热压烧结炉内，在氩气气氛下烧结，烧结温度1500℃，保温10min，烧结压力为40MPa。烧结完成后，卸除压力并随炉冷却。由此，获得YAG-Al2O3-ZrO2发光陶瓷复合材料，即PIA-ZrO2。
所得发光陶瓷的扫描电镜照片示于图2中。图中的圆形为YAG∶Ce荧光粉颗粒，黑色区域为氧化铝区域，氧化铝的颗粒尺寸很小，在此显示为连续的相。
另外，本实施例中获得的发光陶瓷的断裂韧性值为5.56MPa·m1/2。
实施例2：
本实施例使用的Al2O3纳米粉末和YAG∶Ce荧光粉均与实施例1中相同。使用的Y2O3粉末为高纯度超细纳米Y2O3粉末，粒径为0.05～0.1μm。
称取适量Al2O3粉末、ZrO2粉末和Y2O3粉末，以使ZrO2粉末的含量为Al2O3粉末的0.2质量％，使Y2O3粉末的含量为Al2O3粉末的0.5质量％。将三种粉末装入聚四氟乙烯球磨罐中，添加适量的乙醇作为研磨溶剂，添加适量的硅酸钠作为分散剂，用超低磨失率的氧化锆球进行球磨，球磨的转数为120r/min，球磨时间为36小时。
第一次球磨结束后，添加适量YAG∶Ce荧光粉到球磨罐中，以使荧光粉颗粒的质量百分比占总粉料的50质量％。低速进行第二次球磨，球磨的转数为60r/min，球磨时间为40min。总粉料为Al2O3粉末、ZrO2粉末、Y2O3粉末和荧光粉粉末的总和。
两次球磨结束后，在60℃下真空恒温干燥获得干粉。干粉在马弗炉中进行650℃的煅烧，除去粉末中的有机成分，时间为1小时。
煅烧后的粉末过80目、150目、200目筛造粒，得到高流动性的原料粉。
称取适量原料粉末装入石墨模具中，在15MPa压强下进行预压制，然后将石墨模具放入热压烧结炉内，在氩气气氛下烧结，烧结温度1250℃，保温 6h，烧结压力为100MPa。烧结完成后，卸除压力并随炉冷却。由此，获得YAG-Al2O3-ZrO2-Y2O3发光陶瓷复合材料，即PIA-ZrO2-Y2O3。
实施例3：
本实施例使用的Al2O3纳米粉末和YAG∶Ce荧光粉均与实施例1中相同。
按荧光粉∶Al2O3＝1∶3的质量比，称取适量荧光粉和高纯Al2O3纳米粉末。
配制pH值为5.0的柠檬酸-NaOH溶液，浓度为1.0mol/L，然后加入1.5质量％的PEG4000，超声溶解后，加入称量好的YAG∶Ce3+荧光粉颗粒和纳米Al2O3粉末，超声分散后，加磁力搅拌子，置于磁力搅拌器上不停搅拌，获得荧光粉-Al2O3混合悬浮液，即为溶液一。
按ZrO2∶Al2O3＝0.5质量％∶100质量％的比例，称取适量的ZrOCl2·8H2O，按Y2O3∶Al2O3＝1质量％∶100质量％的比例，称取适量的Y(NO3)3·6H2O，将两种硝酸盐水合物一起配制成浓度为0.05mol/L的硝酸盐混合溶液，即为溶液二。
将溶液二加入溶液一中，获得溶液三，为YAG∶Ce荧光粉颗粒和纳米Al2O3粉末悬浮液+硝酸盐的混合溶液，继续使用磁力搅拌器不停搅拌。温度设置为40℃，转速为250r/m。
配制0.05mol/L的氨水溶液，缓慢滴入被不断搅拌的混合悬浮液三，直到将混合悬浮液的PH值控制在9左右。保持该PH值后继续搅拌2.5h，获得共沉淀的复合粉体悬浮液四。
将悬浮液离心分离，对获得的粉体进行水洗4次，然后在80℃真空干燥5小时。获得的干粉在500℃下煅烧以去除杂质，保温5h，之后随炉空冷，得到YAG-Al2O3-ZrO2-Y2O3混合粉末，之后过80目、150目、200目筛造粒，得到高流动性的原料粉。
称取适量原料粉末装入模具中，在40MPa压力下进行压片，所得样片再经过200MPa冷等静压处理，然后将样片放入氢气烧结炉内，在氢气气氛下烧结，烧结温度1750℃，保温20h，烧结完成后随炉冷却，获得发光复合陶 瓷材料YAG-Al2O3-ZrO2-Y2O3，即PIA-ZrO2-Y2O3。
实施例4：
本实施例使用的Al2O3纳米粉末和YAG∶Ce荧光粉均与实施例1中相同。
配制1.5质量％的PEG水溶液，将适量的Al2O3纳米粉末与PEG水溶液混合，将Al2O3溶液超声1.5h后备用，此为溶液一。超声是为了破坏颗粒之间的二次团聚，让粉末在溶液中尽可能地分散。
按ZrO2∶Al2O3＝3质量％∶100质量％的比例，称取适量的ZrOCl2·8H2O，按(MgO+Y2O3)∶Al2O3＝3质量％∶100质量％的比例，称取适量的Mg(NO3)2·6H2O和Y(NO3)3·6H2O，其中Mg(NO3)2·6H2O与Y(NO3)3·6H2O的质量百分比比例为1∶2。三种硝酸盐一起溶于去离子水，配制成浓度为0.05M的硝酸盐溶液，此外溶液二。
将溶液一与溶液二混合得到混合悬浮液三，放置于磁力搅拌器之上不断搅拌，温度设置为60℃，转速为250r/m。
以碳酸氢铵作为沉淀剂，配成约0.05mol/L的水溶液，缓慢滴入被不断搅拌的混合悬浮液三，直到将混合悬浮液的PH值控制在9左右。保持合适的PH值后继续搅拌2.5h，获得共沉淀的复合粉体悬浮液。
将悬浮液离心分离，对获得的粉体进行水洗4次，然后在80℃真空干燥5小时。获得的干粉在500℃下煅烧以去除杂质，保温5h，之后随炉空冷，得到Al2O3-ZrO2-Y2O3-MgO混合粉末，之后过80目、150目、200目筛造粒。
称取适量的Al2O3-ZrO2-Y2O3-MgO混合粉和YAG∶Ce荧光粉，以使总粉料∶YAG∶Ce荧光粉的质量比为2∶1。将两种粉末装入聚四氟乙烯球磨罐中，添加适量的乙醇作为研磨溶剂，不再使用任何分散剂，用超低磨失率的氧化锆球进行球磨，球磨时间为30min。总粉料为Al2O3粉末、ZrO2粉末、Y2O3粉末、MgO粉末和荧光粉粉末的总和。
球磨结束后，在60℃下真空恒温干燥获得干粉，之后过80目、150目、 200目筛造粒，得到高流动性的原料粉。
称取适量原料粉末装入石墨模具中，在5MPa压强下进行预压制，然后将石墨模具放入SPS烧结炉内，在真空气氛下烧结，烧结温度1450℃，保温3h，烧结压力为80MPa。烧结完成后，卸除压力并随炉冷却，获得发光复合陶瓷材料YAG-Al2O3-ZrO2-Y2O3-MgO，即PIA-ZrO2-Y2O3-MgO。
实施例5：
除了使荧光粉颗粒的质量百分比占总粉料的90质量％之外，以与实施例1相同的方法制备实施例5的发光陶瓷。
对比例1：
除了没有添加ZrO2之外，以与实施例1相同的方法制备对比例1的发光陶瓷。对比例1中获得发光陶瓷的断裂韧性值Kic＝4.59MPa·m1/2。
将实施例1的发光陶瓷的断裂韧性值与对比例1的发光陶瓷的断裂韧性值比较可知，实施例1的断裂韧性值比对比例1的断裂韧性值高约20％。由此可知，通过使ZrO2颗粒和荧光粉充分与Al2O3基质混合并均匀地分散于Al2O3基质中，极大地提高了发光陶瓷的强韧性能，不会不利地影响发光陶瓷的光学性能，并且ZrO2作为散射颗粒能够起到匀化入射光的作用。
虽然已参考示例性实施方案对本申请进行了详细说明，但应理解本发明不限于此。对于所属技术领域的技术人员来说，在不脱离本发明构思的前提下进行的改变或改进都应当视为属于本发明的保护范围。

Claims (11)

  1. 一种发光陶瓷，其特征在于，其包括Al2O3基质、ZrO2颗粒和荧光粉颗粒。
  2. 根据权利要求1所述的发光陶瓷，其中所述荧光粉颗粒均匀地分散于所述Al2O3基质中；所述ZrO2颗粒分散于所述Al2O3基质的晶界之间。
  3. 根据权利要求1或2所述的发光陶瓷，其中所述ZrO2颗粒的含量为所述Al2O3基质质量的0.05～5质量％。
  4. 根据权利要求1所述的发光陶瓷，其中所述荧光粉颗粒与所述Al2O3基质的质量比为1∶4～9∶1。
  5. 根据权利要求1所述的发光陶瓷，其中所述ZrO2颗粒的粒径为0.05～1μm；所述荧光粉颗粒的粒径为10～50μm；所述Al2O3基质的晶粒的粒径为0.05～5μm；
    和/或，
    所述ZrO2颗粒的原料粉末的粒径为0.05～0.7μm；所述荧光粉颗粒的原料粉末的粒径为10～25μm；所述Al2O3原料粉末的粒径为0.05～1μm。
  6. 根据权利要求5所述的发光陶瓷，其中所述ZrO2颗粒的粒径为0.05～0.35μm。
  7. 根据权利要求1所述的发光陶瓷，其进一步包括烧结助剂，且所述烧结助剂选自Y2O3、MgO、CaO、SiO2、TiO2、BaO、CaF2、BaF2中的至少一种。
  8. 一种根据权利要求1所述的发光陶瓷的制备方法，其特征在于，其包括以下步骤：
    步骤1：包含Al2O3基质、ZrO2颗粒和荧光粉颗粒的混合粉末的制备步骤；
    步骤2：将上述混合粉末压制、烧结，以获得发光陶瓷的步骤。
  9. 根据权利要求8所述的制备方法，其中所述步骤1包括以下步骤：
    步骤a：所述Al2O3基质与所述ZrO2颗粒和任选的烧结助剂的混合粉末的 制备步骤；
    步骤b：将上述混合粉末与所述荧光粉颗粒混合、球磨、干燥、过筛的步骤。
  10. 根据权利要求9所述的制备方法，其中所述步骤a可采用步骤a′代替，所述步骤a′包括：将所述Al2O3基质的原料粉末的悬浮液与ZrO2的前体的溶液和任选的烧结助剂的前体的溶液混合并共沉淀的步骤；以及将获得的产物离心分离、洗涤、干燥、煅烧和过筛的步骤。
  11. 根据权利要求8所述的制备方法，其中所述步骤1包括以下步骤：
    步骤I：将Al2O3原料粉末和荧光粉的混合悬浮液与ZrO2的前体的溶液和任选的烧结助剂的前体的溶液混合、然后共沉淀的步骤；
    步骤II：将步骤I获得的产物离心分离、洗涤、干燥、煅烧、过筛的步骤。
PCT/CN2017/100562 2017-06-09 2017-09-05 一种发光陶瓷及其制备方法 Ceased WO2018223544A1 (zh)

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