CN1316695C - Ceramic light-gathering cavity material, ceramic light-gathering cavity and making method thereof - Google Patents

Abstract

The invention discloses a ceramic light concentrating cavity material, which is composed of two schemes, one of which is composed of alumina powder, sintering aid and activator, wherein the alumina powder accounts for 92.6-93.7% of the ceramic light concentrating cavity material wt%, the rest are sintering aids and activators; the second is composed of alumina powder doped with activators and sintering aids, wherein the weight ratio of alumina powder doped with activators and sintering aids is 95.12-95.73 : 4.32-4.89, wherein the activator is a rare earth oxide; the present invention also discloses a method for manufacturing a ceramic concentrating cavity with any of the above materials and a ceramic concentrating cavity. Agent mixing, making green body, sintering molding. The light-gathering cavity prepared by the invention has high relative density, excellent electromechanical performance and high reflectivity, so as to meet the requirements of various solid-state lasers.

Description

Ceramic concentrating cavity material, ceramic concentrating cavity and manufacturing method thereof

technical field

The invention belongs to the technical field of lasers, and relates to a light-gathering cavity for solid-state lasers, in particular to a ceramic light-gathering cavity material and a manufacturing method of the ceramic light-gathering cavity, and to the ceramic light-gathering cavity itself.

Background technique

At present, the materials selected for the concentrating cavity of solid-state lasers mainly include metal cavity (gold, silver, and aluminum are plated on the metal substrate), polymer cavity (polytetrafluoroethylene), glass cavity (ceramic powder is wrapped in a glass tube) middle) and ceramic cavity. The processing technology of the metal cavity is complicated, and the precision of the reflective surface is high. Under laser irradiation, the reflective surface is prone to oxidation; the polymer material has poor resistance to strong laser radiation damage, and the material is easy to age, which will lead to a decrease in reflection efficiency; the glass cavity adopts It is to press high-reflectivity ceramic powder into the cavity formed by the gap between the glass tube and the metal tube. This structural design defect leads to high manufacturing cost and low cavity strength. Under high-power working conditions and cooling Under the action of the medium, it is extremely easy to break; while the irradiation light field of the ceramic material to the laser working substance is more uniform, it can form a uniform pumping of the whole cross-section, and can realize high-power pumping input. Oxidation, corrosion resistance, easy to clean; in terms of reliability and service life, ceramic materials have greater advantages than other materials.

US Patent (Pat4858243) reports the manufacturing method of the pump concentrating cavity. The material used is mica, which is a glass ceramic concentrating cavity composed of 55% crystalline phase and 45% glass phase. The main feature of this material is that it can directly process the material into different shapes of concentrating cavities by machining, which eliminates the need for ceramic technology to pre-manufacture the material into the required shape, then sinter and process it. However, its reflectivity is relatively low. In the laser absorption band, the highest reflectivity value is less than 90%, which cannot meet the requirements of the high reflectivity of the material for the light-gathering cavity.

Alumina ceramics is a kind of engineering ceramics with a wide range of uses, which can be used in integrated circuit substrates, crucibles, wear-resistant parts, vacuum insulation shells, high-temperature structural materials, etc. However, when it is applied in the above fields, it mainly takes advantage of its excellent mechanical and electrical properties. The composition and microstructure of the material cannot fully meet the requirements of optical properties, thus hindering the display of other excellent properties.

U.S. Patent (Pat4802186) reported the manufacturing method of ceramic pump concentrating cavity. In the method, alumina powder with a purity of 99.7% and a particle size of 0.45 μm was used, and it was sintered at 1400 ° C after molding. The ceramic concentrating cavity made by this method The optical cavity can obtain a reflectivity of 96.8%, but due to the low sintering temperature of the concentrating cavity, the sintered density can only reach 78% of its theoretical density. The structure of this ceramic material is relatively loose, the surface of the ceramic body is rough, and the porosity is high. During use, the ceramic surface will absorb impurities, which is not easy to clean, resulting in a decrease in the reflectivity of the concentrating cavity. In addition, the loose structure also leads to poor performance of the concentrating cavity in resisting strong laser radiation.

Meet the requirements for high-power laser use. The present invention aims to improve the composition of alumina formula by adding appropriate amount of sintering aids and activators, so that the concentrating cavity can be used in various solid lasers while maintaining the excellent electromechanical properties of alumina ceramics.

Contents of the invention

In order to solve the defects in the above technologies, the object of the present invention is to provide a ceramic light concentrating cavity material with high reflection efficiency, high sintering density and low porosity.

Another object of the present invention is to use the ceramic light concentrating cavity made of the above materials, which can be widely used in various types of solid-state lasers.

The invention also provides a manufacturing method of the ceramic light concentrating cavity.

In order to achieve the above object, the present invention adopts the following technical solutions: a ceramic light concentrating cavity material, which is characterized in that it is composed of alumina powder, sintering aid and activator, wherein alumina powder accounts for the 92.6-93.7wt%, and the rest are sintering aids and activators; the sintering aids are composed of at least one of calcium oxide, silicon oxide and magnesium oxide, wherein 0-1.40wt% of calcium oxide is added, and silicon oxide is 1.95-4.88wt%, magnesium oxide is 0-1.29wt%, and the activator is yttrium oxide, which accounts for 1.96-2.53wt% of the ceramic concentrating cavity material.

The present invention can also adopt the following technical solutions: a ceramic light concentrating cavity material, which is composed of alumina powder doped with an activator and a sintering aid, and the weight ratio of the alumina powder doped with an activator and the sintering aid is 95.12-95.73: 4.32-4.89; wherein, the activator is a rare earth oxide, and the rare earth oxide is the weight ratio of yttrium oxide and alumina powder in the alumina powder doped with the activator of yttrium oxide 2.03-2.66: 97.34-97.97; the sintering aid is composed of at least one of calcium oxide, silicon oxide and magnesium oxide, wherein calcium oxide is added at 0-1.40wt%, silicon oxide is 1.95-4.88wt%, and magnesium oxide is It is 0-1.29wt%.

The sintering aid is at least one of calcium oxide, silicon oxide or magnesium oxide, and their respective weight percentages in the ceramic concentrating cavity material are: calcium oxide 0-1.44wt%, silicon oxide 1.95-4.88wt% , magnesium oxide is 0-1.29wt%.

The alumina powder in the above two kinds of ceramic concentrating cavity materials is α phase, the purity is greater than or equal to 99.7%, and the particle size _D50 is 0.6 μm; the calcium oxide and magnesium oxide are analytical reagents, and the purity of the silicon oxide is It is greater than or equal to 99.5%, and the particle size D ₅₀ is 1.2 μm; the yttrium oxide is industrial fluorescent grade, and its purity is greater than or equal to 99.5%.

In order to achieve the above object, the present invention simultaneously provides a method for manufacturing a ceramic light concentrating cavity using any of the above ceramic light concentrating cavity materials, which is characterized in that it includes the following steps:

1) Calcining the alumina powder and the activator to form a solid solution after uniform mixing. The calcination temperature is 1200-1240° C. and the holding time is 60 minutes. The solid solution is aluminum oxide and yttrium oxide compound.

2) mixing the solid solution obtained in step 1) with the sintering aid;

3) molding the mixture of step 2) into a green body through a mold;

4) The green body formed in step 3) is sintered at high temperature to form a ceramic concentrating cavity. The sintering temperature is 1540-1570° C. and the holding time is 60-90 minutes.

The activator in the above step 1) is yttrium oxide, and 1.96-2.53 wt% of yttrium oxide is added to the 92.6-93.7wt% alumina powder.

Step 2) The sintering aid is at least one of calcium oxide, silicon oxide or magnesium oxide, which respectively account for the weight percentage of the ceramic concentrating cavity material: calcium oxide 0-1.44wt%, silicon oxide 1.95- 4.88wt%, magnesium oxide is 0-1.29wt%.

The molding green body method of above-mentioned step 3) can adopt a kind of in cold pressing, grouting, gel injection, isostatic pressing method, wherein, the forming pressure of isostatic pressing method is 100-200MPa, and holding time is 1-200MPa. 3 minutes;

The present invention also provides a ceramic concentrating cavity manufactured by using the above materials and methods, which is characterized in that it is sintered by sintering 95.12-95.73 wt% of alumina powder doped with an activator and 4.32-4.89 wt% of a sintering aid , wherein the sintering aid is at least one of calcium oxide, silicon oxide or magnesium oxide, which respectively account for the weight percentage of the ceramic concentrating cavity material: calcium oxide 0-1.44wt%, silicon oxide 1.95-4.88wt%, Magnesium oxide 0-1.29 wt%. The alumina powder doped with the activator is a solid solution obtained by mixing and calcining yttrium oxide and alumina powder with a weight ratio of 2.03-2.66:97.34-97.97.

The present invention adopts above-mentioned design, has following technical effect and advantage:

The density of the ceramic concentrating cavity made according to the present invention is about 95% of the theoretical density, and the actual reflectance of the material in the effective absorption band of the solid-state laser>98%, (500nm-1000nm), its test value is higher than that of the U.S. patent ( Pat4802186) reported results. The test results are shown in Figure 1-Figure 4.

The modified alumina ceramic reflective cavity has high mechanical strength, good insulation, and corrosion resistance. Due to the high sintering density of the material, the reflective surface of the concentrating cavity can withstand high-intensity laser irradiation in use, and the remaining dirt is easy to clean. The concentrating cavity referred to in the present invention can be shaped by various methods, and the manufacturing cost is lower than that of metal and glass concentrating cavities; the ceramic concentrating cavity is in the working state mainly based on diffuse reflection, so the pumping is uniform and can improve The quality of the laser beam.

Description of drawings

Fig. 1 is the reflection spectrum line of embodiment one of the present invention

Fig. 2 is the reflection spectrum line of embodiment two of the present invention

Fig. 3 is the reflection spectrum line of embodiment three of the present invention

Fig. 4 is the reflection spectrum line of embodiment four of the present invention

Detailed ways

The invention aims to provide a method for improving the formula composition of alumina by adding an appropriate amount of sintering aid and activator, while maintaining the excellent electromechanical properties of alumina ceramics, making the concentrating cavity applicable to various solid-state lasers.

In the examples, the calcium carbonate and magnesium oxide used are analytical reagents, the alumina powder used is α phase, the purity is greater than or equal to 99.7%, and the particle size _D50 is 0.6 μm; the purity of silicon oxide is greater than or equal to 99.5%, and the particle size _D50 It is 1.2μm; the purity of yttrium oxide is greater than or equal to 99.5%.

In the embodiment, the green body and the sintering process adopt conventional methods. According to the different needs of the shape and size of the light-gathering cavity, green bodies of various shapes are formed through isostatic pressing, coagulation casting, and grouting methods, such as rectangular cross-section, round shaped cross-section, elliptical cross-section, etc., and finally these green bodies are placed in a high-temperature furnace for sintering, so that they can maintain high mechanical strength while having high reflectivity.

The aluminum oxide powder used in the examples is a product of the brand name CT-3000 produced by Alcoa.

Embodiment one:

186.2 grams of microcrystalline alumina powder and 3.92 grams of yttrium oxide were mixed and ball milled on a ball mill for 12 hours, then put into a corundum crucible, calcined at 1200 ° C, and kept for 60 minutes, and 190.1 grams of the calcined powder was mixed with 8.4 grams of silicon oxide gram and 1.38 grams of magnesium oxide are then mixed and ball milled to obtain ceramic powder for the concentrating cavity.

Performance test: Take 200 grams of mixed raw materials, add 15 mL of polyvinyl alcohol aqueous solution with a concentration of 4%, pass through a 40-mesh sieve to granulate after stirring. Place the granulated powder in a steel mold, and form a disc with a diameter of 60 mm and a thickness of 5 mm under a pressure of 100 MPa. Finally, put the disc into a silicon-molybdenum rod furnace and sinter at 1540 ° C for 90 minutes.

The bulk density of the sample was measured by the drainage method, and the obtained bulk density was 3.58g/cm ³ , and the relative density was 95.3%. The reflectance of the sample was measured by the spectrophotometer integrating sphere method. The test results are shown in Figure 1. The reflectance is 98-99% (500-1000nm).

Embodiment two

187.4 grams of microcrystalline alumina powder and 3.92 grams of yttrium oxide were mixed and milled on a ball mill for 12 hours, then put into a corundum crucible, calcined at 1240 ° C, and kept for 60 minutes, and the above-mentioned calcined powder 191.3 grams and calcium oxide 2.86 gram, 3.86 grams of silicon oxide, and 1.92 grams of magnesium oxide are mixed and ball milled to obtain the ceramic powder for the concentrating cavity.

Performance test: Take the mixed raw materials, add 15ML of polyvinyl alcohol aqueous solution with a concentration of 4%, pass through a 40-mesh sieve to granulate after stirring. Place the granulated powder in a steel mold, and form a disc with a diameter of 60 mm and a thickness of 5 mm under a pressure of 100 MPa. Finally, put the disc into a silicon-molybdenum rod furnace and sinter at 1570 ° C for 60 minutes. The bulk density of the sample was measured by the drainage method, and the obtained bulk density was 3.48g/cm ³ , and the relative density was 95.6%; the reflectance of the sample was measured by the spectrophotometer integrating sphere method, and the test results are shown in Figure 2. 98.5-99% (700-1000nm).

Embodiment three

186.4 grams of microcrystalline alumina powder and 5.06 grams of yttrium oxide were mixed and milled on a ball mill for 12 hours, then put into a corundum crucible, calcined at 1220 ° C, and kept for 60 minutes, and the above-mentioned calcined powder 191.46 grams and calcium oxide 0.78 gram, 5.32 grams of silicon oxide, and 2.58 grams of magnesium oxide are mixed and ball milled to obtain the ceramic powder for the concentrating cavity.

Performance test: Take the mixed raw materials, add 15ML of polyvinyl alcohol aqueous solution with a concentration of 4%, pass through a 40-mesh sieve to granulate after stirring. Place the granulated powder in a steel mold, and form a disc with a diameter of 60 mm and a thickness of 5 mm under a pressure of 100 MPa. Finally, put the disc into a silicon-molybdenum rod furnace and sinter at 1560 ° C for 70 minutes. The bulk density of the sample was measured by the drainage method, and the obtained bulk density was 3.54g/cm ³ , and the relative density was 95.1%; the reflectance of the sample was measured by the spectrophotometer integrating sphere method, and the test results are shown in Figure 3. 98.4-99%, (600-1200nm).

Embodiment four

185.2 grams of microcrystalline alumina powder and 5.06 grams of yttrium oxide were mixed and milled on a ball mill for 12 hours, then put into a corundum crucible, calcined at 1230 ° C, and kept for 60 minutes, and 190.26 grams of the calcined powder was mixed with 9.76 grams of silicon oxide Then carry out mixing and ball milling to obtain the ceramic powder for the concentrating cavity.

Performance test: Take the mixed raw materials, add 15ML of polyvinyl alcohol aqueous solution with a concentration of 4%, pass through a 40-mesh sieve to granulate after stirring. Place the granulated powder in a steel mold, and form a disc with a diameter of 60 mm and a thickness of 5 mm under a pressure of 100 MPa. Finally, put the disc into a silicon-molybdenum rod furnace and sinter at 1550 ° C for 80 minutes. The bulk density of the sample was measured by the drainage method, and the obtained bulk density was 3.49g/cm ³ , and the relative density was 95.7%. The reflectance of the sample was measured by the spectrophotometer integrating sphere method. The test results are shown in Figure 3. The reflectance is 98.4-98.9% (600-1300nm).

Embodiment five

According to the chemical composition ratio and process steps described in Example 1, the ceramic powder for the concentrating cavity is produced, and the above powder is packed into a rubber mold, and the isostatic pressing method is adopted, the pressure is 100MPa, and the holding time is 3 After 10 minutes, the ceramic blank is formed, and then the blank is properly shaped with a lathe. Finally, the blank is placed in a high-temperature silicon-molybdenum rod furnace, sintered at 1540 ° C, and the holding time is 90 minutes to obtain a ceramic concentrating cavity.

The performance test was carried out by the same method as in Example 1, and the volume density of this ceramic concentrating cavity was 3.42 g/cm ³ . The relative density reaches 93.6%. Using this ceramic light collecting cavity, the output efficiency of the pulsed laser is 3.1%, and the output efficiency of the continuous laser is 2.8%.

Embodiment six

According to the chemical composition ratio and process steps described in Example 2, the ceramic powder for the concentrating cavity is produced, and the ceramic blank is formed by using the gel injection process. The implementation method is as follows: 12.95 grams of methylolacrylamide, 2.59 grams of methylene bisacrylamide, 7 milliliters of polyacrylamide, and 100 milliliters of water were added to 500 grams of the above-mentioned powder, and then mixed on a ball mill for 24 hours; Add 1.7 milliliters of 10% ammonium persulfate solution and 0.5 milliliters of tetramethylethylenediamine to the mud obtained after mixing, pour into a molding mold after stirring evenly and put it into a 60° C. oven for 25 minutes.

The ceramic concentrating cavity blank that has been solidified in the oven is then properly shaped by a lathe, and finally the blank is placed in a high-temperature silicon-molybdenum rod furnace, sintered at 1570 ° C, and the holding time is 60 minutes to obtain a ceramic concentrating cavity.

The performance test was carried out by the same method as in Example 1. The volume density of this ceramic concentrating cavity was 3.50 g/cm ³ , and the relative density reached 95%. The overall laser efficiency of YAG laser is increased by 15% by adopting this kind of ceramic light collecting cavity.

Embodiment seven

According to the chemical composition ratio and process steps described in Example 3, the ceramic powder for the light concentrating cavity is manufactured. Using the gel injection process method, the ceramic blank is molded, and the implementation method is as follows: 12.95 grams of methylol acrylamide, 2.59 grams of methylenebisacrylamide, 7 milliliters of polyacrylamide, water 100 milliliters is then placed on a ball mill and mixed for 24 hours; add 1.7 milliliters of ammonium persulfate solution with a concentration of 10% and 0.5 milliliters of tetramethylethylenediamine to the mud obtained after mixing, and pour it into a molding mold after stirring evenly and put Put it into an oven at 60°C for 25 minutes.

From the ceramic concentrating cavity blank that has been solidified in the oven, the blank is properly shaped with a lathe, and finally the blank is placed in a high-temperature silicon-molybdenum rod furnace, sintered at 1560 ° C, and the holding time is 70 minutes to obtain a ceramic concentrating cavity.

The performance test was carried out with the same method as in Example 1, and the volume density of this ceramic concentrating cavity was 3.45 g/cm ³ . The relative density reaches 94%. The overall laser efficiency used in the YAG laser is increased by 14.7% by adopting this ceramic light-gathering cavity.

Embodiment eight

According to the chemical composition ratio and process steps described in Example 4, the ceramic powder for the concentrating cavity is produced. The ceramic blank is molded by using the gel injection process method. The implementation method is as follows: 12.95 grams of methylolacrylamide, 2.59 grams of methylene bisacrylamide, 7 milliliters of polyacrylamide, and 100 milliliters of water were added to 500 grams of the above-mentioned powder, and then mixed on a ball mill for 24 hours; Add 1.7 milliliters of 10% ammonium persulfate solution and 0.5 milliliters of tetramethylethylenediamine to the mud obtained after mixing, pour into a molding mold after stirring evenly and put it into a 60° C. oven for 25 minutes.

The blank of the ceramic concentrating cavity that has been solidified from the oven. Then the blank is properly shaped with a lathe, and finally the blank is placed in a high-temperature silicon-molybdenum rod furnace, sintered at 1550 ° C, and the holding time is 80 minutes to obtain a ceramic concentrating cavity.

The performance test was carried out with the same method as in Example 1, and the volume density of this ceramic concentrating cavity was 3.47 g/cm ³ . The relative density reaches 94.5%. The overall laser efficiency of the YAG laser is increased by 14.9% by using this ceramic concentrating cavity.

Claims (8)

1. A ceramic concentrating cavity material, characterized in that: it is made up of alumina powder, sintering aid and activator, wherein alumina powder accounts for 92.6-93.7wt% of the ceramic concentrating cavity material, and the rest is sintered auxiliary agent and activator; the sintering auxiliary agent is composed of at least one of calcium oxide, silicon oxide and magnesium oxide, wherein calcium oxide is added at 0-1.40wt%, silicon oxide at 1.95-4.88wt%, and magnesium oxide at 0 -1.29wt%, the activator is yttrium oxide, which accounts for 1.96-2.53wt% of the material of the ceramic concentrating cavity. 2. The ceramic light-gathering cavity material according to claim 1, characterized in that: the calcium oxide and the magnesium oxide are analytical reagents, and the yttrium oxide is industrial fluorescent grade. 3. The ceramic light concentrating cavity material according to claim 1 or 2, characterized in that: the alumina powder is an α phase, the purity is greater than or equal to 99.7%, and the particle size _D50 is 0.6 μm; the purity of the silicon oxide is It is greater than or equal to 99.5%, and the particle size D ₅₀ is 1.2 μm; the purity of the yttrium oxide is greater than or equal to 99.5%. 4. A ceramic concentrating cavity material, characterized in that it is composed of alumina powder doped with an activator and a sintering aid, and the weight ratio of the alumina powder doped with an activator and the sintering aid is 95.12 -95.73: 4.32-4.89; wherein, the activator is a rare earth oxide, and the rare earth oxide is yttrium oxide, and the weight ratio of yttrium oxide and alumina powder in the alumina powder doped with the activator is 2.03-2.66: 97.34-97.97; the sintering aid is composed of at least one of calcium oxide, silicon oxide and magnesium oxide, wherein calcium oxide is added at 0-1.40wt%, silicon oxide is 1.95-4.88wt%, and magnesium oxide is 0-1.29 wt%. 5. A method for manufacturing a ceramic light-focusing cavity from the ceramic light-gathering cavity material according to any one of claims 1-4, characterized in that: it comprises the steps of: 1) After mixing the alumina powder and yttrium oxide uniformly according to the stated ratio, place them in a crucible for calcination, the calcination temperature is 1200-1240°C, and form a solid solution after heat preservation; 2) Mix the solid solution obtained in step 1) with the sintering aid according to the stated ratio; 3) molding the mixture of step 2) into a green body through a mold; 4) The green body formed in step 3) is sintered at high temperature to form a ceramic concentrating cavity, and the sintering temperature is 1540-1570°C. 6. The method for manufacturing a ceramic light concentrating cavity according to claim 5, wherein the holding time in step 1) is 60 minutes, and the solid solution thereof is aluminum oxide and yttrium oxide compound. 7. The method for manufacturing a ceramic light concentrating cavity according to claim 5 or 6, characterized in that: the molding green body method of the step 3) is cold pressing, grouting, gel injection or isostatic pressing method One, wherein the molding pressure of the isostatic pressing method is 100-200MPa, and the holding time is 1-3 minutes; Step 4) heat preservation after sintering the green body, and the heat preservation time is 60-90 minutes. 8. A ceramic concentrating cavity, characterized in that it is formed by sintering 95.12-95.73wt% of alumina powder doped with an activator and 4.32-4.89wt% of a sintering aid, wherein the sintering aid is calcium oxide. -1.44wt%, silicon oxide 1.95-4.88wt%, magnesium oxide 0-1.29wt%, the alumina powder doped with the activator is 2.03-2.66: 97.34-97.97 yttrium oxide and alumina by weight ratio A solid solution obtained by mixing and calcining powders.

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