WO2014114790A1 - Polykristalline keramiken, deren herstellung und verwendungen - Google Patents
Polykristalline keramiken, deren herstellung und verwendungen Download PDFInfo
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- WO2014114790A1 WO2014114790A1 PCT/EP2014/051512 EP2014051512W WO2014114790A1 WO 2014114790 A1 WO2014114790 A1 WO 2014114790A1 EP 2014051512 W EP2014051512 W EP 2014051512W WO 2014114790 A1 WO2014114790 A1 WO 2014114790A1
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Definitions
- the invention relates to polycrystalline ceramics with specifically set scattering power.
- the polycrystalline ceramic comprises an optoceramic phase and a pore phase.
- the invention also provides a process for producing such ceramics and their uses.
- the polycrystalline ceramics are preferably used as converters.
- a converter is capable of absorbing light of a certain wavelength and emitting light of a different wavelength.
- Ceramic converters are basically known from the prior art. However, conventional converter materials do not include pore phases. Finally, the manufacturing processes were optimized so that the ceramics had no pores. In addition, known from the prior art converters are usually intended for operation in transmission and constructed accordingly. By contrast, the converter materials according to the invention are intended for operation in remission.
- Transparent ceramics are widely known from a number of applications. Translucent, hexagonal Al 2 O 3 is used for the production of discharge bodies for high-pressure discharge lamps. Also Sc 2 0 3 and Y 2 0 3 are used. Eu-doped (Y, Gd) 2 O 3 , Pr: Ce: Gd 2 O 2 S, Ce-doped lutetium-aluminum garnet (LuAG) and doped pyrochlors are known as
- Scintillationsm aterial known for CT devices Aluminum oxynitrides, spinel and nanoscale Al 2 O 3 are used as high-strength materials as antiballistic protective media.
- Y 2 0 3 serves as I R-transmittive medium for the range VIS to mid-IR as well as for chemically resistant windows in coating systems.
- Transparent rare-earth-doped yttrium-aluminum-garnet (YAG) ceramics are used, for example, as laser rods or when doping with cerium as the converter material.
- two prerequisites must be fulfilled for the production of highly transparent ceramics.
- a pore-free structure must be produced by a suitable choice of powder and in conjunction with the process control (powder preparation, shaping, sintering, possibly hot isostatic pressing). Otherwise, a light beam may be scattered at the pores trapped in the grain boundary region or in the grain. Also, no uncontrolled remaining second phases may be positioned in the grain boundary area. Possibly.
- the sintering aids used are ideally incorporated as components in the single-phase mixed crystal structure.
- applications of translucent ceramics are known in which very deliberately scattering should be set. For CT scanners, as much as possible path length (a few mm) must absorb as much high-energy excitation radiation as possible.
- LED converter materials are active media that partially absorb the relatively low wavelength (primary radiation) LED light source radiation, directly or through a plurality of intermediate steps, thereby creating electron-hole pairs. Their recombination leads to the excitation of a nearby Aktivator scholars. The latter is lifted into an excited metastable state. Its relaxation leads, depending on the choice of activator, to the emission of long-wave light (secondary radiation). Since the emitted light has a lower energy than the excitation light, this conversion is also called "down conversion". In addition, part of the unabsorbed primary radiation passes through the converter, with primary and secondary radiation in turn giving a hue that differs from that of the primary radiation.
- a blue LED is usually combined with a yellow phosphor, which is mostly cerium-doped yttrium-aluminum-garnet powder. Mixture of partly transmitted blue light and yellow fluorescence radiation produces white light.
- a suitable ceramic converter eg a Ce: YAG converter, must absorb as much as possible blue radiation of an exciting blue LED over a path length of ⁇ 1 mm, ideally ⁇ 0.5 mm, otherwise it can emit the emitted radiation in the forward direction (low remission) , In these cases, a suitable tailoring of absorption, emission and remission by the material structure or the material composition is required.
- the aspects of high quantum efficiency, high Stokes efficiency, high absorption efficiency and high light output are also of extreme importance for converter materials.
- the material must be economical to produce.
- Converter materials are manufactured so that freedom from pores is achieved. Therefore, the converters have no pore phase.
- US 4,174,973 refers to the absence of pores as an advantage of the developed converter material.
- the provision of an optoceramic converter is also known.
- US 2004/0145308 A1 describes an LED with at least one
- None of the ceramics of the prior art is designed so that it is suitable for remission operation, in particular as a converter of a laser diode.
- the object of the present invention is solved by the subject matters of the claims.
- the problem is solved by a polycrystalline Ceramics comprising at least one pore phase and at least one optoceramic phase, preferably consists thereof.
- a converter comprising or consisting of this ceramic and the use of the ceramic as a converter, preferably in remission and in particular in laser diodes.
- the optoceramic phase is crystalline, it preferably consists of densely arranged crystallites.
- the optoceramic phase has densities, based on the theoretical density of the respective material, of preferably at least 85%, more preferably at least 90%.
- the optoceramic phase has densities, based on the theoretical density of the respective material, of at most 99%, more preferably at most 97%, further preferably at most 95%.
- the pore phase comprises scattering centers with specifically set size, volume and geometry.
- the pore phase has a content of at least 1% by volume, preferably at least 2.5% by volume, more preferably at least 5% by volume and most preferably at least 10% by volume of the polycrystalline ceramic of this invention. If the proportion of the pore phase is lower, the desired scattering can not be achieved.
- the proportion of the pore phase on the polycrystalline ceramic should preferably not exceed 50% by volume, more preferably 40% by volume and particularly preferably 30% by volume.
- the ceramics according to the invention are temperature-stable despite the pore phase. Heat that collects in the pores can be transported out through the grain boundaries and ceramic grains without the ceramics cracking. Therefore, the ceramics are also suitable for use at high temperatures.
- the polycrystalline ceramics of this invention are particularly suitable for applications requiring scattering, such as in converters for laser diodes.
- the ceramics according to the invention are also suitable for use at high temperatures, which can occur, for example, in converters for LD in the remission structure.
- the materials of this invention can be used. Therefore, a luminous body according to the invention comprising the polycrystalline ceramic of this invention is also suitable.
- a CT scanner according to the invention the
- the optoceramic phase comprises crystallites, which preferably have a cubic crystal structure.
- the optoceramic phase preferably consists of these crystallites.
- the crystallites may be selected from garnets, cubic sesquioxides, spinels, perovskites, pyrochlors, fluorites, oxynitrides, and mixed crystals of two or more of said materials.
- the crystallites may also have non-cubic structure.
- the crystallites are preferably oxidic.
- the crystallites preferably have a diameter of at most 50 ⁇ , more preferably at most 20 ⁇ , even more preferably at most 10 ⁇ , even more preferably at most 8 ⁇ , even more preferably at most 7.5 ⁇ , even more preferably at most 5 ⁇ , most preferably at most 3 ⁇ on. If the crystallites are too large, the optical properties of the optoceramic phase are adversely affected.
- the crystallites preferably have a diameter of at least 0.2 ⁇ , more preferably at least 0.5 ⁇ , even more preferably at least 1 ⁇ , even more preferably at least 2 ⁇ , more preferably at least 2.5 ⁇ on. If the crystallites are too small, the optoceramic phase is not stable enough.
- the indicated diameters of the crystallites are Martin diameters.
- the determination of the diameter is preferably carried out by microscopic methods, in particular by light microscopy.
- A is preferably from the
- A preferably originates from the group of alkaline earth metals or from the zinc group and B preferably originates from the boron group.
- Preferred garnets are yttrium-aluminum-garnet (YAG), yttrium-gadolinium-aluminum-garnet (YGAG), gadolinium-gallium-garnet (GGG), lutetium-aluminum-garnet (LuAG), lutetium-aluminum ium - gallium garnet (LuAGG), yttrium-scandium-aluminum granate (YSAG) and mixtures thereof.
- Preferred cubic sesquioxides are Y 2 O 3 , Gd 2 O 3 , Sc 2 O 3 , Lu 2 O 3 , Yb 2 O 3 and mixtures thereof.
- Preferred oxynitrides are AION, BaSiON, SrSiON and mixtures thereof.
- Preferred spinels are ZnAl 2 0 4 , MgAl 2 0 4 and their mixed phases.
- the optoceramic phase may comprise one or more optically active centers.
- the active sites are preferably selected from the group consisting of rare earth ions and transition metal ions.
- the active sites are selected from the group of rare earth ions.
- the ions of the following elements are particularly preferred: Ce, Cr, Eu, Nd, Tb, Er, Pr, Sm and mixtures thereof. Further preferred are Ce, Cr, Eu, Tb, Pr,
- Particularly preferred active center is Ce.
- the active center serves to convert incident radiation of one wavelength into radiation of another wavelength.
- the optoceramic phase preferably comprises the active center in a mass fraction of at least 0.01% by weight, more preferably at least 0.03% by weight, and most preferably at least 0.045% by weight.
- the active center should preferably be present in a proportion of not more than 1% by weight, more preferably not more than 0.7% by weight and more preferably not more than 0.55% by weight. Adhering to these values, excellent conversion is achieved.
- the optoceramic phase can be translucent or transparent. Preferably, the optoceramic phase is transparent to visible light.
- a ceramic or phase is "transparent to visible light” if it has a net transmittance greater than 25% in a 50 nm wide range within the visible light spectrum (from 380 nm to 800 nm)
- This pure transmission of the optoceramic phase is preferably even greater than 60%, more preferably greater than 80%, more preferably greater than 90%, and particularly preferably greater than 95%. This refers to the pure transmission at a layer thickness of 2 mm.
- the pore phase comprises at least one scattering center and is embedded in the optoceramic phase.
- the pore phase comprises a plurality of scattering centers which are embedded in the optoceramic phase.
- a "scattering center" in the sense of the present invention preferably means a pore, preferably the pores have sizes of 0.1 to 100 ⁇ m, more preferably of 0.5 to 50 ⁇ m and particularly preferably of 3 to 5 ⁇ m
- Ceramics according to the invention preferably have pores with an area fraction in the cross-section of at least 1%, more preferably at least 3% and even more preferably at least 4%
- the ceramic according to the invention preferably has pores with an area fraction in the cross section of at most 25%, more preferably at most 15%. and even more preferably at most 10% If the porosity is too high, the ceramic is not sufficiently stable and the desired reflectance values can not be achieved.
- the pores have geometries which are selected from spherical pores, ovoid pores and elongated pores.
- the pores Preferably, have geometries selected from ovoid pores and elongated pores. Very particular preference is given to ovoid pores. With ovoid pores, the desired scattering can be achieved particularly well.
- Pore size, pore volume and pore geometry are adjusted in a targeted manner via the production process and the pore phase formers used.
- an increase in the sintering temperature correlates positively with the size of the pores.
- the pores vary in size and shape also depending on the pore phase former used.
- the ratio of the maximum to the minimum diameter of each one pore of the spherical pores is in the range of 1: 1 to 1, 09: 1.
- the ratio of the maximum to the minimum diameter of the ovoid pores is in the range of 1.1: 1 to 2.9 1.
- the ratio of the maximum to the m-internal diameter of the elongated pores is in the range of 3: 1 to 15: 1. Particularly preferred are ovoid pores with a ratio of 2.5: 1. To determine said ratio, the maximum diameter is the largest diameter of a pore, the minimum is the smallest diameter of the same pore. Both the ovoid pores and the elongated pores can vary depending on
- Embodiment of the invention vary in size.
- Large ovoid pores have a maximum diameter of 20-50 ⁇ and a minimum diameter of 10-20 ⁇ .
- Small ovoid pores have a maximum diameter of 2-6 ⁇ and a minimum diameter of 1-3 ⁇ .
- Large elongated pores have a maximum diameter of 20-50 ⁇ and a minimum diameter of 2-8 ⁇ .
- Small elongated pores have a maximum diameter of 5-15 ⁇ and a minimum diameter of 1-5 ⁇ .
- a preferred embodiment of the invention contains especially pores with a maximum diameter ⁇ 10 ⁇ . Too large pores reduce the quantum efficiency of the conversion process because the converted light is trapped in them.
- pores size and the number of pores per unit volume can be adjusted according to the invention.
- a reduction in the number of pores per unit volume is achieved in particular via an increase in the sintering aid concentration and / or the addition of pore phase formers.
- the density of the ceramic is preferably at least 80%, more preferably at least 85%, more preferably at least 90%, even more preferably at least 93% of the theoretical density.
- the density of ceramics is preferably at most 96.5%, more preferably 95.5% of the theoretical density.
- the density of the ceramic is adjusted according to the invention by the type and concentration of the pore phase former and / or the concentration of the sintering aid.
- the density of the ceramic can also be influenced by the sintering temperature and / or the heating rate. With high heating rates denser ceramics are obtained. With lower density ceramics, higher scattering can be achieved.
- the heating rate is preferably at least 0.5 K / min, more preferably at least 1 K / min, even more preferably at least 2 K / min, more preferably at least 4 K / min. However, the heating rate should not be too high. Otherwise, more thermal stresses can occur. In addition, too dense ceramics can be obtained.
- Heating rate is preferably at most 50 K / min, more preferably at most 20 K / min, even more preferably at most 10 K / min, more preferably at most 5 K / min.
- the pores are created through the targeted addition of pore-phase formers in the manufacturing process.
- plastics in particular thermoplastics, are not as well suited as pore phase formers according to the invention, such as saccharides.
- plastics in particular thermoplastics, are not as well suited as pore phase formers according to the invention, such as saccharides.
- Polymethyl methacrylate, polyethylene, polytetrafluoroethylene, polypropylene, polyamide, polyethylene terephthalate, polyvinyl chloride and polycarbonate are preferably not used as pore phase formers.
- the pore phase formers preferably comprise natural or synthetic saccharides.
- the pore phase formers consist of natural or synthetic saccharides.
- the pore phase formers consist of natural saccharides.
- the pore phase formers are preferably selected from mono-, di- or polysaccharides, in particular from sugars or starch.
- a preferred pore-phase former is, for example, powdered sugar.
- Preferred powdered sugar contains in addition to the di-saccharide about 1 to 10 wt .-% corn starch.
- Particularly preferred powdered sugar contains in addition to the di-saccharide about 3 wt .-% corn starch.
- the sintering behavior of the ceramic material itself is preferably not affected.
- the sintering process is the same with or without pore-phase former. This is an advantage of natural pore phase formers over synthetic pore phase formers.
- the monosaccharides are selected from fructose, glucose, mannose and galactose.
- Particularly preferred monosaccharides are glucose and fructose.
- Disaccharides are preferably selected from lactose, maltose and sucrose. Disaccharides are readily soluble in water, sparingly soluble in ethanol, and insoluble in most organic solvents. Since the mixtures for producing the converter ceramics are preferably made in alcoholic solutions, disaccharides are particularly suitable as pore phase formers. A particularly preferred disaccharide is sucrose.
- Preferred polysaccharides have more than 10 monosaccharide building blocks.
- Suitable monosaccharide building blocks have been found to be pentoses and hexoses, more preferably selected from glucose, galactose, xylose, fructose, arabinose, mannose, mannuronic acid, guluronic acid, gulose and mixtures thereof.
- the polysaccharides are polycondensates of glucose monomers. More preferably, the glucose monomers are connected by ⁇ -1,4- and / or ⁇ -1, 6-glycosidic bonds, more preferably the polysaccharides have the general formula (C 6 H 10 O5) n.
- the molar mass of the polysaccharides is preferably> 10 5 g / mol.
- the polysaccharides are preferably selected from potato starch, potato flour, rice starch, corn starch, wheat starch and mixtures thereof, more preferably selected from rice starch, corn starch, wheat starch and mixtures from that.
- Particularly preferred as a pore phase former is rice starch.
- Rice starch produces the most homogeneous pore distribution.
- the particle size of the polysaccharides is preferably less than 200 ⁇ . More preferably, the particle size of the polysaccharides less than 185 ⁇ , more preferably less than 180 ⁇ .
- the particle size is preferably determined by light microscopy; while the Martin diameter is determined.
- Starch can physically bind, swell and gelatinize many times its own weight in water under the influence of heat. When heated with water, the starch swells at 47-57 ° C, the layers burst, and at 55-
- starch paste which has different stiffness depending on the type of starch.
- Corn starch paste has a greater rigidity than wheat starch paste.
- Wheat starch paste has a greater stiffening power than potato starch paste.
- the starch paste decomposes more or less easily under acidification.
- Potato flour, potato starch or mixtures thereof are preferably used to produce spherical pores.
- rice starch is preferably used.
- corn starch is preferably used.
- di- and / or polysaccharides When di- and / or polysaccharides are used as pore phase formers, ceramics with lower density can be obtained compared to ceramics for the production of which monosaccharides have been used as pore phase formers. A lower density usually correlates with a higher scattering. With di- and / or polysaccharides as pore phase formers so ceramics can be obtained with which a higher scattering can be achieved. On the other hand, monosaccharides can usually be better burned out of the ceramics than di- and polysaccharides. After this
- ceramics with higher quantum yield can be obtained with monosaccharides as pore phase former in comparison to ceramics for whose production di- and / or polysaccharides were used as pore phase former.
- the pore phase is homogeneously embedded in the optoceramic phase.
- An inhomogeneous distribution of pores reduces the quantum efficiency of the conversion process.
- the homogeneity of the distribution of the pores can be adjusted in a targeted manner.
- the use of potato starch as pore-phase former leads to a rather inhomogeneous distribution of the pores.
- the use of wheat starch as a pore former leads to a more homogeneous distribution of the pores over the sintered body.
- the most homogeneous distribution of the pores is achieved with rice starch as pore phase former.
- the homogeneity of the pore distribution is determined by means of scanning electron microscopy.
- the preferred high quantum efficiency for converter materials is achieved by the preferably cubic crystal structure of the optoceramic phase and the transparency resulting therefrom.
- the quantum yield is kept high by the production method according to the invention and the presence of pores in the polycrystalline ceramic according to the invention.
- Quantum yield in the sense of the present invention is the ratio between the number of emitted photons (light quantum) per number of absorbed photons.
- the quantum yield of the polycrystalline ceramics according to the invention is preferably more than 60%, more preferably more than 70%, even more preferably more than 80%, even more preferably more than 85%, even more preferably more than 88% and most preferably about 90%.
- the quantum yield is particularly high when monosaccharides are used as pore phase former.
- the polycrystalline ceramic at a wavelength of 600 nm and a sample thickness of 1 mm, a remission of 70 to 100%, preferably 75 to 95%, particularly preferably 75 to 90%.
- Polycrystalline ceramics with such remissions are particularly well suited as a converter in backscatter mode, in particular as a HBLED and LD converter.
- the remission can be measured in a spectrophotometer with an integration sphere, advantageously including the Fresnel reflection. Sample thicknesses of 1 mm have proven to be advantageous.
- the remission at 600 nm is a measure of the scattering of the material. The assessment of the dispersion should be made outside the excitation spectrum, but preferably within the emission spectrum. The choice of the evaluation wavelength 600 nm fulfills this condition. The larger the scatter, the more the material remits at 600 nm.
- the blue remission can be increased compared to ceramics which did not use void phase formers.
- the object according to the invention is furthermore achieved by a process for the production of polycrystalline ceramics according to the invention.
- This method preferably comprises the following steps: a. Providing a mixture of the starting materials of the optoceramic phase b. Adding pore phase formers which comprise at least one saccharide and optionally sintering aids to the mixture c. Producing a shaped body from the mixture d. Sintering the shaped body
- the shaped body produced in step c) is additionally pre-sintered, preferably at temperatures between 500 and 1200 ° C. This has the advantage that the carbonates leaving the pore phase formers are completely removed from the green body
- Debinding is best carried out under a gas flow, wherein the gas is preferably selected from oxygen, forming gas, argon, nitrogen and mixtures thereof. Oxygen is particularly preferred, because reduced constituents can be oxidized again.
- the mixture of the starting materials preferably also contains the optically active ingredient. In this way, a particularly uniform doping is achieved. In addition, can be dispensed with expensive subsequent doping process, such as the "dip-coating process".
- Powder with primary particles with diameters ⁇ 1 ⁇ preferably
- nanoscale size ( ⁇ 300 nm), more preferably with
- Primary particle diameters of 50 to 250 nm are weighed in proportion to the target composition.
- the diameters mentioned are preferably determined by means of dynamic light scattering.
- Target composition may be around the stoichiometric range of
- Garnet composition vary, ie either about 0.01-10 mol% in the Y 2 0 3 -rich or Gd 2 0 3 -rich or 0.01-10 mol% in the Al 2 0 3 -rich or AI 2 0 3 -Ga 2 0 3 -rich side protrude.
- the mixture is preferably mixed with ethanol. This is preferably carried out with Al 2 0 3 balls in a ball mill and more preferably for 12 to 16 h. Before an optional second mixture in a tumbler for preferably 10 to 24 hours, the mixture is optionally
- the sintering aid is preferably selected from TEOS, colloidal Si0 2 , Si0 2 nanopowder, Si0 2 ⁇ m powder and CaC0 3 .
- a particularly preferred sintering aid is TEOS.
- TEOS is preferably used in concentrations of 0 to 1 wt .-%, particularly preferably in concentrations of 0.1 to 0.5 wt .-%.
- TEOS serves for the optimal adjustment of the pore number.
- the grinding suspension is optionally dried on a rotary evaporator or granulated in a spray dryer.
- the powder is then preferably pressed uniaxially into slices or rods.
- the uniaxial pressure conditions are preferably between 10 and 50 MPa, the printing times preferably at a few seconds to 1 min.
- the preformed compact is preferably post-compacted in a cold isostatic press, wherein the compacting pressure is preferably between 100 and 300 MPa.
- the pressure transfer medium is preferably water or oil.
- binder is preferably burned out in a first thermal step, if necessary.
- the annealing time is preferably 1 to 24 hours.
- the temperature is preferably between 600 and 1000 ° C.
- the burnt out green body is then preferably in a chamber furnace
- Garnet phase from about 1350 to 1450 ° C.
- the sintering to a ceramic body takes place at higher temperatures, preferably between 1550 and 1800 ° C for 2 to 24 hours.
- the sample can again reoxidized (eg 1000 ° C, 5 hours, 0 2 flow).
- the result is preferably optically translucent and homogeneous body
- Converter materials can be further processed.
- the volume fraction of the pore phase formers on the mixture is preferably at least 1%, more preferably at least 2.5%, and more preferably at least 10%.
- the proportion of pore phase formers should preferably not exceed a value of 50% by volume. If the volume fraction is too low, the desired remission can not be achieved. If the volume is too high, the mechanical stability is impaired.
- the production method according to the invention makes it possible to produce a polycrystalline ceramic having an optoceramic phase and a pore phase.
- Polycrystalline ceramic can be adjusted specifically.
- Figure 1 shows the influence of different pore phase formers as well as the influence of the heating rate on the density of the ceramic.
- the sintering temperature was the same for all ceramics shown in Figure 1.
- powdered sugar disaccharide + 3% by weight corn starch
- ceramics with lower density were obtained in comparison with ceramics, for the production of which glucose (monosaccharide) was used as pore phase former.
- glucose monosaccharide
- Figure 2 shows that the sintering behavior of Ce: YAG does not change by adding monosaccharide or disaccharide + 3 wt% polysaccharide as the pore phase former.
- the sintering behavior of the ceramic material itself is therefore not influenced by the natural pore-phase former.
- the heating rate was 10 K / min.
- Figure 3 shows the influence of different pore phase formers on the quantum yield and the blue remission.
- Ceramics for the production of which monosaccharide or disaccharide + 3% by weight polysaccharide was used as the pore phase former, show an increased blue remission in comparison with ceramics, for the production of which no pore phase former was used.
- Powder with primary particles with diameters ⁇ 1 ⁇ m diameter of 2.5 moles of Al 2 O 3 , 1, 4965 moles of Y 2 O 3 and 0.0863 moles of CeO 2 are weighed out in relation to the target composition. After addition of dispersing and binding agents, the mixture is mixed with ethanol and Al 2 O 3 balls in a ball mill for 12 to 16 h.
- the grinding suspension is optionally dried on a rotary evaporator or granulated in a spray dryer.
- the powder is then pressed uniaxially into slices or rods.
- the uniaxial pressure conditions are 10 MPa, the printing times are 30 s.
- the preformed compact is placed in a cold isostatic press
- the pressure transmission medium is water.
- binder is burned out in a first thermal step.
- the annealing time is 6 h and the temperature at 700 ° C.
- burned-out green bodies are then sintered in a chamber furnace under an enriched O 2 atmosphere, ie, flowing oxygen in a normal chamber furnace.
- the sintering temperatures and times are based on the sintering behavior of the mixture, ie after formation of the composition, the further compression takes place to a ceramic with defined pores.
- Ce: Y 3 Al 5 0i 2 the garnet phase forms from about 1350 to 1450 ° C.
- the sintering to a ceramic body occurs at higher temperatures, between 1650 and 1700 ° C for 3h. It creates optically translucent and homogeneous body that too
- Converter materials can be further processed.
- Example 2 The procedure was carried out as in Example 1 with the modification that after mixing in the ball mill, a second mixture was carried out in a tumbler for 10 to 24 hours. By mixing in the tumbler, an increase in homogeneity takes place, and thus form single-phase YAG microstructure with only a few unreacted Al 2 0 3 grains.
- Example 2 The procedure was carried out as in Example 2, wherein 0.15 wt .-% TEOS was added as a sintering aid before the second mixture in the tumbler to the mixture.
- the TEOS is activated by adding water:
- Example 4 The process was carried out as in Example 4 with the modification that TEOS also added 20% by volume of rice starch (based on the batch).
- Example 5 The process was carried out as in Example 5 with the modification that instead of the rice starch 10 vol .-% potato starch were used.
- Example 6 The procedure was carried out as in Example 6 with the modification that instead of the potato starch 10 vol .-% wheat starch was used. It was visible under the SEM that when using wheat starch, the pores were elongated and smaller than potato starch. The pores were more homogeneously distributed than the potato starch.
- Example 5 The process was carried out as in Example 5 with the modification that only 10% by volume of rice starch was used.
Abstract
Description
Claims
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JP2015554179A JP6223468B2 (ja) | 2013-01-28 | 2014-01-27 | 多結晶セラミックス、その製造および使用 |
CN201480006289.6A CN104955786B (zh) | 2013-01-28 | 2014-01-27 | 多晶陶瓷、其制备方法和用途 |
KR1020157021289A KR101747015B1 (ko) | 2013-01-28 | 2014-01-27 | 다결정 세라믹, 이의 제법 및 이의 용도 |
US14/809,309 US20150329777A1 (en) | 2013-01-28 | 2015-07-27 | Polycrystalline ceramics, their preparation and uses |
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DE102013100821.6A DE102013100821B4 (de) | 2013-01-28 | 2013-01-28 | Polykristalline Keramiken, deren Herstellung und Verwendungen |
DE102013100821.6 | 2013-01-28 |
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US14/809,309 Continuation US20150329777A1 (en) | 2013-01-28 | 2015-07-27 | Polycrystalline ceramics, their preparation and uses |
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JP (1) | JP6223468B2 (de) |
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CN (1) | CN104955786B (de) |
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MY177277A (en) * | 2014-03-03 | 2020-09-10 | Covalent Mat Corporation | Wavelength converting member |
JP6141948B2 (ja) * | 2015-11-30 | 2017-06-07 | 大電株式会社 | 紫外線発光蛍光体、発光素子、及び発光装置 |
US10947448B2 (en) * | 2017-02-28 | 2021-03-16 | Nichia Corporation | Method for manufacturing wavelength conversion member |
CN108017412A (zh) * | 2017-12-13 | 2018-05-11 | 魏健 | 一种植入量子技术功能的陶瓷球的制备方法 |
CN110615679B (zh) * | 2019-06-25 | 2022-07-01 | 苏州创思得新材料有限公司 | 一种高光效陶瓷荧光片 |
CN113024252A (zh) * | 2019-12-09 | 2021-06-25 | 上海航空电器有限公司 | 白光激光照明用多级孔结构陶瓷荧光体及其制备方法 |
CN117185832A (zh) * | 2022-06-01 | 2023-12-08 | 深圳市绎立锐光科技开发有限公司 | 复相荧光陶瓷、复相荧光陶瓷的制备方法以及发光装置 |
DE102022113940A1 (de) | 2022-06-02 | 2023-12-07 | Schott Ag | Verfahren zum Feststellen eines thermischen Qualitätsmaßes eines Probenkörpers |
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WO2011094404A1 (en) * | 2010-01-28 | 2011-08-04 | Osram Sylvania Inc. | Luminescent ceramic converter and method of making same |
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US4174973A (en) | 1979-01-29 | 1979-11-20 | Gte Laboratories Incorporated | Transparent yttria ceramics containing magnesia or magnesium aluminate |
JPH0848583A (ja) * | 1994-08-10 | 1996-02-20 | Asahi Optical Co Ltd | 多孔質セラミックスの製造方法及び該方法に用いる圧粉体 |
JP4836348B2 (ja) * | 2001-04-19 | 2011-12-14 | 株式会社ニッカトー | 耐久性にすぐれたアルミナ質焼結体からなる熱処理用部材 |
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2013
- 2013-01-28 DE DE102013100821.6A patent/DE102013100821B4/de active Active
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2014
- 2014-01-27 WO PCT/EP2014/051512 patent/WO2014114790A1/de active Application Filing
- 2014-01-27 TW TW103102889A patent/TW201446703A/zh unknown
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- 2014-01-27 KR KR1020157021289A patent/KR101747015B1/ko active IP Right Grant
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DE10349038A1 (de) * | 2002-10-22 | 2004-05-13 | Osram Opto Semiconductors Gmbh | Lichtquelle mit einer LED und einem Lumineszenzkonversionskörper und Verfahren zum Herstellen des Lumineszenzkonversionskörpers |
WO2007107917A2 (en) * | 2006-03-21 | 2007-09-27 | Philips Intellectual Property & Standards Gmbh | Electroluminescent device |
EP2216834A1 (de) * | 2007-11-29 | 2010-08-11 | Nichia Corporation | Lichtemittierende vorrichtung und verfahren zu ihrer herstellung |
WO2011094404A1 (en) * | 2010-01-28 | 2011-08-04 | Osram Sylvania Inc. | Luminescent ceramic converter and method of making same |
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US20150329777A1 (en) | 2015-11-19 |
KR20150103281A (ko) | 2015-09-09 |
CN104955786B (zh) | 2018-06-29 |
KR101747015B1 (ko) | 2017-06-14 |
JP2016510299A (ja) | 2016-04-07 |
CN104955786A (zh) | 2015-09-30 |
JP6223468B2 (ja) | 2017-11-01 |
TW201446703A (zh) | 2014-12-16 |
DE102013100821B4 (de) | 2017-05-04 |
DE102013100821A1 (de) | 2014-07-31 |
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