TW469176B - Processing of rain erosion resistant layer for aluminium phosphate ceramic base matrix composites - Google Patents

Abstract

This invention provides the processing of rain erosion resistant layer for aluminium phosphate ceramic base matrix composites. The raw materials are alumina, silicon oxide ceramic and alumina phosphate ceramic resin. The optimal composition of the raw materials is adjusted and mixed homogeneously. The mixture is coated onto the surface of the alumina phosphate base matrix composite. A dense layer with rain erosion resistance is then obtained after the coated composite is impregnated with silicone resin for resin sealing and thermally treated. This dense ceramic layer can reduce rain erosion rate at least for 100 times and, therefore, can improve the rain erosion resistance of aluminium phosphate base ceramic composite for the microwave application.

Description

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V. Description of the invention (1) (1), made by the background agent of the invention (reference material. The material that has an excellent surface through which the glue is stored in the gap will cause rain damage and the wall thickness of the stress. Chengzhi Ceramic composites based on the invention of the invention of the ceramic composites of the Republic of China have high strength, high toughness, aerospace, and airtightness of the national defense industry. The heat treatment of about 300 ° C will not only reduce the quality of ceramics. For example, On the one hand, the rain damage on the surface of the nose cone cover or radar material will cause aerospace to occur and reduce the structural strength and affect the microwave electrical properties. Phosphate ceramic glue is used as a bonding agent in China. Li No. 48197), a new type of composite material, is not only simple in process and reasonable in cost, but also can be used in microwave electrical properties. The main reason for the structural parts made of this kind of material is that the water evaporates out of the pores after the aluminum phosphate, which acts as a binder, evaporates. Porosity The sensitivity of the composite material will also affect the composite material with pores on the surface. After being made into a radome, it will be exposed to rain or rain damage. The surface of the product becomes rough, which affects the distribution of heat flow. At the same time, the rough surface will change the material. Although this problem was solved by the plasma method (piasma) on the surface of the compound material in order to achieve the effect of rain resistance, The residual thermal stress between the materials after the plasma method coating cannot be eliminated and the physical properties of alumina, such as thermal expansion and electrical properties, are significantly different from those of the base material, which may not match the properties of the original base material and increase its process variables. Therefore, it is an urgent task to develop a cladding material that can take into account the properties of its original materials and enhance its rain resistance.

Page 5 A6 91 76 ------ V. Description of the invention (2) (II), purpose of the invention The purpose of the invention is to develop a manufacturing technology of a rain-resistant layer coated on an aluminum phosphate ceramic-based composite material ^ In order to improve the rain erosion resistance of the aluminum phosphate ceramic composite material, it also has the characteristics of toughness and high temperature resistance. (III) Characteristics of the invention The present invention is based on the basic raw materials, such as acid base (such as A 1 P 〇 4-with silicon resin impregnated sealing material wealth and residual functions) aluminum phosphate glue mixed alumina powder and silicon oxide The powder is mixed in an appropriate ratio and sprayed on the surface of the substrate of glass fiber reinforced phosphorus (Ah 〇3). After the heat treatment, the holes are almost completely airtight, so the composite material can be greatly improved. (IV) Technical content The parameters that affect the material $ # = denseness, strong adhesion, and performance parameters include the hardness of the surface of the material, the weather resistance of the surface, and the coefficient of expansion and surface flatness. If you want to make the material yield, increase the surface smoothness of the sheet, increase the hardness of the material first, and reduce the porosity, you must also consider the heterogeneous coating on the right material surface. Force strength and coefficient of thermal expansion

Page 6 V. Description of the invention (3) The invention is based on alumina ceramics with extremely high hardness as the composition to enhance the hardness of the coating material; secondly, to obtain good thermal shock resistance , The formula is added with a very low thermal expansion coefficient of silicon oxide raw materials. In addition, considering the compatibility with the substrate, the adhesive is still selected from aluminum phosphate glue and supplemented with Miaoshuzhi sealing & infiltration treatment to improve the density and adhesion of the other coating materials. / 'The raw materials used in the present invention are alumina powder (Al203, 298%, average particle size $ 10. 0 // m), silicon oxide powder (Si 02 299%, average particle size $ 10 / zm) 、 Phosphate gelatin solution (specific gravity = 1.48 ± 0.02, dryness = 105 ± lOcps) 'The process used is shown in Figure 1' Including the mixing and milling of raw powder (Balliilling), spray-forming (Spray-forming ), Heat-treatment and Resin-seaiing: 1. Mix and grind three kinds of raw materials, such as alumina powder, silica powder, aluminum phosphate glue, etc. (the weight percentage range is 10 ~ 60: 0 ~ 60: 40 ~ 50) mixed into the alumina ball mill tank, and at the same time after adding pure water accounting for about 7% of the weight of the mixed powder, ball mill at a speed lower than 100 rpm for more than 1 hour to uniform Remove after mixing. 2. Spray coating Use spray paint to add a suitable amount of mixture and connect a high-pressure air pipe with an air pressure of 4 ~ 7kg / c π to start spray coating. Spray coating on aluminum phosphate

Page 7 4691 76 V. Description of the invention (4) The coating thickness of the ceramic-based composite material must be controlled below 0.5mm to avoid over-thickness and dryness. 3. Heat treatment After coating, the scaly acid-ceramic-based composite material needs to be fully dried for more than 2 hours in a ring of 60 ± 5 ° C to prevent cracks caused by water volatilization. After the drying is completed, it is transferred to a high temperature furnace for heat treatment. Conditions for heat treatment = temperature rise to 8 (rc at a temperature increase rate lt: / min, then change to 0 5 t: / min to 15 0 c, and then increase to 2 8 0 ° C at 1 ° c / mi η and keep warm After more than 2 hours, then the furnace is cooled to room temperature and taken out, so that the three raw materials can be fully reacted and sintered. 4. Knee infiltration and sealing treatment, in order to improve the compactness of the coating layer and the adhesion to the substrate, the present invention uses silicon Resin (Silicone Resin) is a sealing compound, under negative pressure ring ^ one atmosphere) 'Silicone resin penetrates into the coating layer and aluminum phosphate ceramic based hanging heat treatment conditions, the heating rate must be sufficient solvent Volatilization without residual stress = 2: heating up to 9 at a heating rate of 1-. . . Then the A " 0.5 C / min of the accompaniment -2 / 睥 rises to 130. . Then maintain the dish for 2 hours, and then warm it at a heating rate of 0.3t / min for 2 hours ... etc., each heating 30 ~ 50 ° C is one plus, the temperature rising rate of the gradient is lower than Kc / D] in, the heat preservation ^ hardening gradient 'is 350 until the final hardening gradient condition. . Incubation for 5 hours θ ′ ″ Π:: _ It takes more than 40 hours to process the program. Finally, the furnace is only used to cool down to room temperature. d6 91 76 V. Description of the invention (5) [Example 1] Select the content of aluminum phosphate glue solution as 40%, adjust the content ratio between alumina and oxidized stone powder Al2O3 = 60 ~ 20%, Si02 = 0 ～ 40%, put it into an oxidized sintered ball mill tank at 70 rpm for 16 hours, then take out an appropriate amount for use. Use lmm caliber spray paint to spray the mixture on the surface of phosphorous saucerite composite material with high pressure gas of 4kg / c m2, and control the thickness to 0.4mm. It was allowed to dry for 2 hours until it reached 60 ot. After the drying is completed, the composite material is transferred into a heat treatment furnace for heat treatment under the following conditions: first, the temperature is increased to 80 ° C at a heating rate of 10 c / min, and then 0.5. 〇 / 111 丨 11 warmed up to 15〇. (:, Then change to 1. (: / 1 ^ 11 is heated to 280 t and held for 4 hours. After the heat treatment is completed, the silicone resin is used for sealing and infiltration. The heat treatment program is to raise the temperature to 9 at a rate of it / min. 0 ° C for 6 hours, 0.5 t / min to 130 ° C for 2 hours, 0.3 C / mi η liter, dish to 15 ° C for 2 hours, 0 · 5 ° C / mi η The temperature was raised to 180 ° C for 2 hours, 0.5 ° C / min was elevated to 21 ° t for 2 hours, 0.5 t / min was used to incubate at 240 ° C for 2 hours, and 0.5 ° C / min was increased. Incubate at 270 ° C for 2 hours, 0. · 5 ° C / min. Warm to 300 0t for 4 hours, 0.6 $ to 35 0 t: Incubate for 5 hours, then cool down to room temperature by furnace cooling. After using the sowing process, rain erosion layers with different proportions can be prepared. Observe the existence of obvious micro-cracks on the surface of the coating layer 200 times with a scanning electron microscope (SEM). In addition, water is used. Knife mold ^ rain

4 ^ 91 76 V. Description of the invention (6) = Examination to verify the rain-resistant silver of the coating layer = The part uses a water jet with a hole diameter of 0. The water pressure is equal to: ㈣: The knife and the surface of the sample are 3 °. Angle, test distance is 3 centimeters, thickness of two centimeters of material loss per second; = time, converted into the test results as listed in Table-, the rain material with coating. The test rain erosion rates are all lower than 0.04mm / sec, and the oxide-based composite materials have better rain erosion properties. ‘The more the amount of 3, the more resistant

Select the above-mentioned eight-layer strips with coating layer :; glue = 3 ... sample for hot-shock; performance test table phosphorus J, and then quickly take out the static two ^; after the highest set temperature 'results found only two pieces # Health surface, collapse: to :: check the surface condition of the surface is maintained well, which proves the environment of the coating layer of the sample of moxibustion. The temperature of the dagger coating changed drastically [Comparative example]

A comparative sample was selected without any coating. The sample was treated as described in ##, + ,, and other materials, and was treated with silicone resin as described in [Example]. The test results of the conditions of the simulated water erosion test of the waterjet are described in the table—I know that the phosphoric acid inscription Tao Jifu has no coating.

-1 I 46 91 76 V. Description of the invention (7) The rain erosion rate of the material after water jet scouring is 1.03mm / sec, which is 16 to 550 times that of other coated layers, which proves [Example The coating described in] has significant rain erosion resistance. Rainfall composition ratio (weight ratio) Rainfall rate (mm / sec) Example 1 Al2〇3 Si〇2 aipo4 — sample 1 60 0 40 0.009 sample 2 40 20 40 0.011 sample 3 35 25 40 0.019 test Sample 4 30 25 40 0.019 Sample 5 27.5 32.5 40 0.025 Sample 6 25 35 40 0.032 Sample 7 20 40 40 0.033 Comparative Example 0 0 0 1.030 Table 1: Whether the aluminum phosphate ceramic-based composite rain-resistant layer is covered or not Waterjet simulation rain test results

Page 11 V. Description of the invention (8) Sample number Heating rate (° C / sec) Maximum temperature (° C) Test result 1 29 1000 Intact without crack 2 55 720 Incomplete without crack 3 56 730 Incomplete without crack 4 63 750 Intact and crackless 5 67 735 Intact and crackless 6 72 720 Intact and crackless 7 73 730 Intact and cracked 8 73 750 Intact and cracked 9 75 750 Cracking Table 2: Thermal shock test of aluminum phosphate ceramic-based composite material after rain-resistant coating ResultsΗ · 1 Page 12 4 6 917 6 ·

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Claims (1)

4 6 91 76 VI. Application scope of patent: A method for producing a rain-resistant layer on the surface of a ceramic acid-based ceramic composite material, the production process is as follows: (1), preparing a rain-resistant layer coating, and formulating Js ceramic, silica ceramic, and aluminum phosphate The weight percentage distribution ratio of ceramic glue is 10 ~ 60: 0 ~ 60: 40 ~ 50, and it is placed in a ceramic pot for mixing and grinding; (2) Spray coating directly sprays the rain-resistant coating on the phosphoric acid with spray paint The aluminum ceramic-based composite material is dried and formed on the surface, and the thickness must be controlled below 0.5mm; (3) Heat treatment The aluminum phosphate ceramic-based composite material covered with a rain-resistant layer is placed in a 60 ± 5 art environment. It is dried for more than 2 hours, and then moved into a high-temperature furnace to perform a reaction sintering heat treatment. The condition of the heat treatment is to raise the temperature to 80 at a heating rate of 1 it / m. . (:, Heating up to 150T: at 0.5t: / min, and then heating to 280 ° C at lt / min and keeping it for more than 2 hours, then take out the furnace to room temperature; (4), infiltration and sealing treatment using silicone resin For sealing compounds, under negative pressure environment (below one atmosphere pressure, the silicone resin is penetrated into the pores and gaps of the coating layer and the aluminum phosphate ceramic composite material. The silicone resin hardening condition after sealing is first ^ / The temperature of ηιίη is increased from 2 to 9 0 C 'for 16 hours, and the temperature will be changed to 30 ～ 50 0 inflammation shirt. υ L / Ma Yijia, Tianqu dagger section, the heating and hardening condition of each section is heating # The dish vd 'dish inversion rate is low. Mi η, the holding time is 2 ~ 5 hours, the final hardening is held for 5 hours, and finally the temperature is reduced to 35 ° t by the furnace cooling method: