Spherical fluorescent ceramic material capable of uniformly emitting light

Abstract

The invention discloses a spherical fluorescent ceramic material capable of uniformly emitting light. The spherical fluorescent ceramic material comprises spherical YAG-Al2O3 ceramic and Ce: YAG transparent ceramic coated on the outer layer. The spherical YAG-Al2O3 ceramic is used for scattering blue laser, and the Ce: YAG transparent ceramic is used for absorbing blue light to generate fluorescence conversion; and the two are combined together through vacuum sintering. The fluorescent material designed by the invention is uniform in spatial luminescence; secondary optical elements are not needed, the integration is high, and the method is suitable for industrialization.

Description

Technical Field

[0001] The invention relates to the field of laser lighting, and in particular to a spherical fluorescent ceramic material with uniform light emission. Background Art

[0002] At present, laser diodes (LD) are considered to be excellent candidates for the next generation of lighting technology. Their unique directional light emission and high brightness are unmatched by LED light sources. More importantly, the efficiency of blue light LD will exceed that of blue light LED in the future, which means that laser lighting sources will penetrate into various fields such as indoor lighting, home lighting, and road lighting.

[0003] In indoor lighting and health lighting systems, uniform spatial light distribution and no speckle are basic requirements. In LD lighting systems, there are mainly transmissive and reflective systems. Both transmissive and reflective lighting systems have laser speckle, so how to obtain a uniform lighting source is imminent.

[0004] In addition, under LD excitation, the spatial light distribution of fluorescent ceramics is Lambert light source emission, and the spatial light distribution can be optimized after the shaping of secondary optical elements. However, the current light-emitting form is multi-point light-emitting, that is, 2π light-emitting, and the irradiation space fails to cover the entire three-dimensional space. The solution of combining LED three-dimensional distribution is large in size and difficult in optical design.

[0005] Therefore, it is necessary to design a new structure that can illuminate the entire space environment (4π space), such as a spherical fluorescent block material, which uses laser for remote excitation, has a small light source and more uniform spherical light emission. Summary of the invention

[0006] The object of the present invention is to provide a spherical fluorescent ceramic material that emits light uniformly and has a simple and effective lighting structure to achieve spatially uniform light emission.

[0007] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is as follows: a uniformly luminous spherical fluorescent ceramic material, including a spherical YAG-Al2O3 ceramic and a Ce:YAG transparent ceramic coated on the outer layer, the spherical YAG-Al2O3 ceramic is used to scatter blue laser, and the Ce:YAG transparent ceramic is used to absorb blue light to generate fluorescence conversion, and the two are combined together by vacuum sintering.

[0008] Preferably, the spherical radius of the spherical YAG-Al2O3 ceramic is 5 to 8 mm; the content of Al2O3 is 30 to 60 wt.%;

[0009] Preferably, the spherical YAG-Al2O3 ceramic is a porous ceramic with an internal porosity of 20 to 40 vol.%.

[0010] Preferably, the thickness of the Ce:YAG transparent ceramic is 0.2-0.5 mm, and the Ce doping concentration is 0.05-0.10 at.%.

[0011] Preferably, the uniformly luminous spherical fluorescent ceramic material is prepared by the following steps:

[0012] Step 1: Prepare spherical YAG-Al2O3 ceramic blank by gel casting or 3D printing;

[0013] Step 2: preparing an outer layer Ce:YAG transparent ceramic blank by gel casting;

[0014] Step 3: vacuum sintering the composite structure blank obtained in step 2.

[0015] Preferably, in step three, the vacuum sintering temperature is 1740-1760° C. and kept at this temperature for 10 hours; then the temperature is lowered to 1000° C. at a rate of 1-1.5° C. / min, and then naturally lowered to room temperature.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. Creatively designed spherical structure fluorescent ceramics, high scattering source spherical YAG-Al2O3 ceramics scatter blue light more evenly, and then the blue light excites the outer layer Ce: YAG transparent ceramics to achieve 4π white light illumination. Under laser excitation, the material has a light-to-light conversion efficiency of 260-300lm / W and a spatial color temperature of 5668-6315K.

[0018] 2. Compared with the current transmissive and reflective laser lighting sources, the fluorescent ceramic material and lighting structure of the present invention do not require subsequent secondary optical shaping elements, have a higher degree of integration, and are suitable for industrialization. In addition, the existing packaging structure will lose a large amount of light beams and reduce efficiency. The fluorescent ceramic material of the present invention is full-body luminous and has a higher luminous efficiency.

[0019] 3. The internal high scattering source is a ceramic material with high thermal conductivity, which can serve as a heat dissipation base for the outer luminescent material, ensuring the stable operation of the outer luminescent ceramic under high-power laser excitation.

[0020] 4. The spherical fluorescent ceramic material of the present invention is prepared by gel injection molding and one-step sintering, and the cooling rate is controlled to avoid its large shrinkage affecting deformation. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the material of the present invention;

[0022] In the figure, 01, spherical YAG-Al2O3 ceramics, 02, Ce:YAG transparent ceramics

[0023] Figure 2 It is a schematic diagram of scattering and luminescence of the material of the present invention under blue laser excitation. DETAILED DESCRIPTION

[0024] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] Example 1

[0026] like Figure 1 As shown, a uniformly luminous spherical fluorescent ceramic material includes a spherical Al2O3 ceramic 01 and a Ce:YAG transparent ceramic 02 coated on the outer layer.

[0027] The spherical YAG-Al2O3 ceramic 01 has a spherical radius of 5 mm, wherein the content of Al2O3 is 30 wt.%, and is a porous ceramic with an internal porosity of 20 vol.%. The thickness of the Ce:YAG transparent ceramic 02 is 0.2 mm, and the Ce doping concentration is 0.10 at.%.

[0028] The above-mentioned spherical fluorescent ceramic material is prepared by the following steps:

[0029] Step 1. Prepare spherical YAG-Al2O3 ceramic blank by gel injection molding: mix anhydrous ethanol, organic monomer acrylamide, cross-linking agent methylenebisacrylamide, and dispersant PEI, then add Al2O3 and Y2O3 powders, and put them into a ball mill for ball milling; wherein, anhydrous ethanol is 1.5 times the total mass of the raw material powder; organic monomer acrylamide is 0.03 times the total mass of the raw material powder; cross-linking agent methylenebisacrylamide is 0.01 times the total mass of the raw material powder; dispersant PEI is 0.01 times the total mass of the raw material powder. After the ball milling is completed, add the catalyst tetramethylethylenediamine and stir; wherein, the catalyst tetramethylethylenediamine is 0.015 times the total mass of the raw material powder. After stirring, pour the slurry into a spherical hollow mold and wait for it to solidify; after a certain strength is formed, demold it and then dry it to complete the YAG-Al2O3 ceramic blank;

[0030] Step 2. Prepare the outer layer Ce:YAG transparent ceramic blank by gel injection molding: mix anhydrous ethanol, organic monomer acrylamide, cross-linking agent methylenebisacrylamide, and dispersant PEI, then add CeO2 powder, Al2O3 and Y2O3 powder, and put them into a ball mill for ball milling; wherein, anhydrous ethanol is 1.5 times the total mass of the raw material powder; organic monomer acrylamide is 0.03 times the total mass of the raw material powder; cross-linking agent methylenebisacrylamide is 0.01 times the total mass of the raw material powder; dispersant PEI is 0.01 times the total mass of the raw material powder. After the ball milling is completed, add the catalyst tetramethylethylenediamine and stir; wherein, the catalyst tetramethylethylenediamine is 0.015 times the total mass of the raw material powder. After stirring, pour the slurry into a spherical hollow mold containing the YAG-Al2O3 ceramic blank and wait for it to solidify; after a certain strength is formed, demold it and then dry it to obtain a composite structure ceramic blank;

[0031] Step 3: Place the composite structure ceramic blank into a vacuum sintering furnace for vacuum sintering: the sintering temperature is 1760°C and kept for 10 hours; then cool down to 1000°C at a rate of 1.5°C / min, and then naturally cool to room temperature to form a spherical fluorescent ceramic material.

[0032] like Figure 2 As shown, the spherical fluorescent ceramic material is placed under a blue laser, the spherical YAG-Al2O3 ceramic 01 is used to scatter the blue laser, and the Ce:YAG transparent ceramic 02 is used to absorb the blue light for fluorescence conversion; the light-to-light conversion efficiency reaches 260lm / W, and the spatial color temperature is 6315K.

[0033] Example 2

[0034] like Figure 1 As shown, a uniformly luminous spherical fluorescent ceramic material includes a spherical YAG-Al2O3 ceramic 01 and a Ce:YAG transparent ceramic 02 coated on the outer layer.

[0035] The spherical YAG-Al2O3 ceramic 01 has a spherical radius of 8 mm and an Al2O3 content of 60 wt. %; it is a porous ceramic with an internal porosity of 40 vol. %. The thickness of the Ce:YAG transparent ceramic 02 is 0.5 mm and the Ce doping concentration is 0.05 at. %.

[0036] The above-mentioned spherical fluorescent ceramic material is prepared by the following steps:

[0037] Step 1: Prepare spherical YAG-Al2O3 ceramic blanks by 3D printing: Mix dispersant DS-195H and photoinitiator 819, then add Al2O3 and Y2O3 powders, and place them in a ball mill for ball milling; wherein, the dispersant DS-195H is 2.5 times the total mass of the raw material powders, and the photoinitiator 819 is 3 times the total mass of the raw material powders. After the ball milling, a ceramic slurry is formed; the slurry is placed under the 3D printer, and the spherical YAG-Al2O3 ceramic blank is printed according to the spherical structure; wherein, the laser printing power is 1200mW, the scanning width is 0.1, and the physical speed is 1000mm / s.

[0038] Step 2. Prepare the outer layer Ce:YAG transparent ceramic blank by gel injection molding: mix anhydrous ethanol, organic monomer acrylamide, cross-linking agent methylenebisacrylamide, and dispersant PEI, then add CeO2 powder, Al2O3 and Y2O3 powder, and put them into a ball mill for ball milling; wherein, anhydrous ethanol is 1.5 times the total mass of the raw material powder; organic monomer acrylamide is 0.03 times the total mass of the raw material powder; cross-linking agent methylenebisacrylamide is 0.01 times the total mass of the raw material powder; dispersant PEI is 0.01 times the total mass of the raw material powder. After the ball milling is completed, add the catalyst tetramethylethylenediamine and stir; wherein, the catalyst tetramethylethylenediamine is 0.015 times the total mass of the raw material powder. After stirring, pour the slurry into a spherical hollow mold containing the YAG-Al2O3 ceramic blank and wait for it to solidify; after a certain strength is formed, demold it and then dry it to obtain a composite structure ceramic blank;

[0039] Step 3: Place the composite structure blank into a vacuum sintering furnace for vacuum sintering: the sintering temperature is 1740°C and kept for 10 hours; then cool down to 1000°C at a rate of 1°C / min, and then naturally cool to room temperature to form a spherical fluorescent ceramic material.

[0040] like Figure 2 As shown, the spherical fluorescent ceramic material is placed under a blue laser, the spherical YAG-Al2O3 ceramic 01 is used to scatter the blue laser, and the Ce:YAG transparent ceramic 02 is used to absorb the blue light for fluorescence conversion; the light-to-light conversion efficiency reaches 300lm / W, and the spatial color temperature is 5668K.

[0041] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with the technical field within the technical scope disclosed by the present invention and within the spirit and principle of the present invention should be covered by the protection scope of the present invention.

Claims

1. A spherical fluorescent ceramic material with uniform light emission, characterized in that: It includes spherical YAG-Al2O3 ceramics and Ce:YAG transparent ceramics coated on the outer layer. The spherical YAG-Al2O3 ceramics are used to scatter blue lasers, and the Ce:YAG transparent ceramics are used to absorb blue light to generate fluorescence conversion. The two are combined together through vacuum sintering.

2. The uniformly luminous spherical fluorescent ceramic material according to claim 1, characterized in that: The spherical radius of the spherical YAG-Al2O3 ceramic is 5-8 mm; the content of Al2O3 is 30-60 wt.%.

3. The uniformly luminous spherical fluorescent ceramic material according to claim 1, characterized in that: The spherical YAG-Al2O3 ceramic is a porous ceramic with an internal porosity of 20 to 40 vol.%.

4. The uniformly luminous spherical fluorescent ceramic material according to claim 1, characterized in that: The thickness of the Ce:YAG transparent ceramic is 0.2-0.5 mm, and the Ce doping concentration is 0.05-0.10 at.%.

5. The uniformly luminous spherical fluorescent ceramic material according to claim 1, characterized in that: The uniformly luminous spherical fluorescent ceramic material is prepared by the following steps: Step 1: Prepare spherical YAG-Al2O3 ceramic blank by gel casting or 3D printing; Step 2: preparing an outer layer Ce:YAG transparent ceramic blank by gel casting; Step 3: vacuum sintering the composite structure blank obtained in step 2.

6. The uniformly luminous spherical fluorescent ceramic material according to claim 5, characterized in that: In step three, the vacuum sintering temperature is 1740-1760° C. and kept at this temperature for 10 hours; then the temperature is lowered to 1000° C. at a rate of 1-1.5° C. / min, and then naturally lowered to room temperature.

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