Phosphorescence temperature measurement coating and preparation method thereof

Abstract

The invention provides a phosphorescence temperature measurement coating and a preparation method thereof, and belongs to the field of phosphorescence temperature measurement. The invention provides a preparation method of a phosphorescent temperature measurement coating, which comprises the following steps: coating a mixture of an adhesive containing ceramic, graphite and water and phosphorescent temperature measurement powder on the surface of a metal matrix, and curing to obtain the phosphorescent temperature measurement coating. According to the preparation method disclosed by the invention, the phosphorescent temperature measurement powder is adhered to the surface of the metal substrate by using the adhesive, the preparation of the phosphorescent temperature measurement coating can be realized without granulation, and the obtained coating has smaller influence on the luminous intensity of the original powder.

Description

Technical Field

[0001] The invention relates to the field of phosphorescence temperature measurement, and in particular to a phosphorescence temperature measurement coating and a preparation method thereof. Background Art

[0002] Turbine blades are the components with the worst working environment in the engine, bearing the highest pressure and temperature load in the aircraft engine. With the continuous increase in the thrust of aircraft engines, there are higher requirements for the high temperature resistance of turbine blades.

[0003] Thermal barrier coating technology is an active thermal protection technology used to reduce the heat exchange between turbine blades and external high-temperature airflow. Thermal barrier coatings are usually prepared using low thermal conductivity, high-temperature resistant zirconium oxide and yttrium oxide as basic materials. Due to their excellent high thermal resistance properties, they can isolate turbine alloy blades from direct contact with high-temperature combustion gases, thereby forming a large temperature gradient on the outer edge of the turbine blades. The temperature distribution on the surface of turbine blades can predict the failure of thermal barrier coatings and is also an important basis for turbine blade cooling design.

[0004] Phosphorescence temperature measurement technology is an emerging temperature testing technology. It forms a temperature-sensitive layer by spraying phosphorescent powder on the surface of turbine blades, which emits phosphorescence when irradiated by an external light source, thereby transmitting temperature information. Atmospheric plasma spraying (APS) is currently the most commonly used method for preparing the temperature-sensitive layer. In the atmospheric plasma spraying process, the phosphorescent powder needs to be granulated into a granulated powder with good fluidity so that it can be fed into the plasma flame. However, the luminescence intensity of the powder will be severely reduced after granulation, affecting the temperature measurement performance of the phosphorescence temperature measurement coating. Summary of the invention

[0005] The invention provides a phosphorescent temperature measuring coating and a preparation method thereof. The preparation method of the invention can realize the preparation of the phosphorescent temperature measuring coating without granulation, and the obtained coating has less influence on the luminescence intensity of the original powder.

[0006] The invention provides a method for preparing a phosphorescent temperature measuring coating. A mixture of an adhesive containing ceramic, graphite and water and phosphorescent temperature measuring powder is coated on the surface of a metal substrate and then cured to obtain the phosphorescent temperature measuring coating.

[0007] Preferably, the phosphorescent thermometric powder comprises yttria-stabilized zirconia doped with dysprosium and / or yttrium-aluminum garnet doped with dysprosium; and the average particle size of the phosphorescent thermometric powder is 25 to 100 nm.

[0008] Preferably, the preparation method of yttrium aluminum garnet doped with dysprosium comprises the following steps:

[0009] A solution containing dysprosium nitrate, yttrium nitrate and aluminum nitrate is mixed with a precipitant solution to perform a precipitation reaction to obtain a precipitate;

[0010] The precipitate is dried and then calcined to obtain the yttrium aluminum garnet doped with dysprosium.

[0011] Preferably, the ceramic comprises alumina;

[0012] The adhesive containing ceramic, graphite and water has a dynamic viscosity of 2500 to 80000 cP, a specific gravity of 1.8 to 2.15 g / cc, and an upper temperature resistance limit of 1650 to 1760°C.

[0013] Preferably, the adhesive containing ceramic, graphite and water includes 813-A, 670 or 671 from Aremco.

[0014] Preferably, the mass ratio of the adhesive containing ceramic, graphite and water to the phosphorescent temperature measuring powder is 3 to 4:1.

[0015] Preferably, the coating comprises air spraying.

[0016] Preferably, the nozzle diameter of the air spray gun during air spraying is 1.0-1.5 mm, the spraying distance is 150-200 mm, the spraying air pressure is 0.09-0.18 MPa, the air usage is 40-60 L / min, the spray material spray volume is 50-60 mL / min, and the spray width is 100-150 mm;

[0017] The air spray gun is the ANEST IWATA Japan IWATA spray gun W-71.

[0018] Preferably, the curing is performed by heating with an LED lamp, and the light intensity of the LED lamp heating curing is 1200-1500 mW / cm 2 , wavelength is 365~420nm, temperature is 150~200℃, and time is 0.5~2h.

[0019] The present invention also provides a phosphorescent temperature measuring coating prepared by the preparation method described in the above technical solution.

[0020] The preparation method of the present invention uses an adhesive to adhere the phosphorescent temperature measuring powder to the surface of a metal substrate, and the preparation of the phosphorescent temperature measuring coating can be achieved without granulation, and the obtained coating has less influence on the luminescence intensity of the original powder.

[0021] Furthermore, compared with the prior art, since the rotation angle of the spray gun used in atmospheric plasma spraying is limited, it is difficult to deposit a temperature-sensitive layer on the surface of special-shaped parts. In the air spraying of the present invention, the spraying angle of the air spray gun can be freely adjusted, so the phosphorescent temperature measuring coating can be better sprayed on the surface of the special-shaped parts.

[0022] The air spray gun selected by the present invention has the characteristics of wide spraying width, fine atomization, high nozzle hardness, etc., and is suitable for spraying high-viscosity slurry. The sprayed chemical adhesive coating has uniform thickness, smooth surface, and high coating bonding strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a process flow chart of an embodiment;

[0024] Figure 2 The temperature field diagram of the phosphorescent temperature measuring coating of Example 1 measured at 450°C;

[0025] Figure 3 This is the temperature field diagram of the phosphorescent temperature measuring coating of Example 1 measured at 900°C. DETAILED DESCRIPTION

[0026] The invention provides a method for preparing a phosphorescent temperature measuring coating. A mixture of an adhesive containing ceramic, graphite and water and phosphorescent temperature measuring powder is coated on the surface of a metal substrate and then cured to obtain the phosphorescent temperature measuring coating.

[0027] In the present invention, the coating preferably includes: immersing the metal substrate in acetone and then ultrasonically cleaning it, and then washing and drying the metal substrate after ultrasonic cleaning.

[0028] In the present invention, the soaking time is preferably 10 to 15 minutes; the frequency of the ultrasonic cleaning is preferably 40 kHz, and the time is preferably 5 minutes. Stubborn impurities can be completely removed after ultrasonic cleaning.

[0029] In the present invention, the detergent used for the washing preferably includes distilled water; the number of washings is preferably more than 2 times, and the time for each washing is preferably 2 minutes.

[0030] The present invention has no special limitation on the drying method, as long as no water stains are left. In a specific embodiment of the present invention, the drying method can be wiping with a dust-free cloth or blowing with an air gun.

[0031] In the present invention, the mass ratio of the adhesive to the phosphorescent temperature measuring powder is preferably 3 to 4:1; the ceramic in the adhesive preferably includes alumina; the dynamic viscosity of the adhesive is preferably 2500 to 80000 cP, the specific gravity is 1.8 to 2.15 g / cc, and the upper temperature limit is 1650 to 1760°C. In a specific embodiment of the present invention, the dynamic viscosity can be 2500 cP, 5000 cP, 10000 cP, 20000 cP, 30000 cP, 40000 cP, 50000 cP, 60000cP, 70000cP or 80000cP; the specific gravity is preferably 1.8-2.15g / cc, and in a specific embodiment of the present invention, the specific gravity may be 1.8, 1.9, 2, 2.1 or 2.15; the upper temperature resistance limit is preferably 1650-1760°C, and in a specific embodiment of the present invention, the upper temperature resistance limit may be 1650°C, 1700°C, 1750°C or 1760°C; the adhesive preferably includes 813-A, 670 or 670 of Aremco, and more preferably 813-A. Aremco's 813-A adhesive has the characteristics of good optical transmission properties, strong bonding force, high upper temperature resistance limit, and the coating is not easy to deform at high temperature, which can well meet the needs of phosphorescent temperature measurement coatings. The mass ratio of adhesive to phosphorescent powder will affect the luminescent properties of the coating. When the mass ratio is too high, the luminescent intensity of the coating is weak and the viscosity of the slurry is further increased, and it is difficult for the air spray gun to spray the suspension. When the mass ratio is too low, it is difficult for the phosphorescent powder to be completely suspended in the adhesive, and the temperature measurement performance of the coating decreases.

[0032] In the present invention, the phosphorescent temperature measuring powder preferably comprises yttria-stabilized zirconia doped with dysprosium and / or yttrium aluminum garnet doped with dysprosium; the average particle size of the phosphorescent temperature measuring powder is preferably 25 to 100 nm. In a specific embodiment of the present invention, the average particle size of the phosphorescent temperature measuring powder may be 25 nm, 50 nm, 75 nm or 100 nm; the chemical composition of the yttrium aluminum garnet doped with dysprosium preferably comprises Y3Al5O 12 : Dy, the crystal structure is preferably YAG phase.

[0033] In the present invention, the preparation method of yttrium aluminum garnet doped with dysprosium preferably comprises the following steps:

[0034] A solution containing dysprosium nitrate, yttrium nitrate and aluminum nitrate is mixed with a precipitant solution to perform a precipitation reaction to obtain a precipitate;

[0035] The precipitate is dried and then calcined to obtain the yttrium aluminum garnet doped with dysprosium.

[0036] The invention mixes a solution containing dysprosium nitrate, yttrium nitrate and aluminum nitrate with a precipitant solution to carry out precipitation reaction to obtain a precipitate.

[0037] In the present invention, the mixing preferably comprises dripping a solution containing dysprosium nitrate, yttrium nitrate and aluminum nitrate together with a precipitant solution into a reaction container.

[0038] In the present invention, in the solution containing dysprosium nitrate, yttrium nitrate and aluminum nitrate, the concentration of dysprosium nitrate is preferably 0.0012 mol / L, the concentration of yttrium nitrate is preferably 0.3 mol / L, and the concentration of aluminum nitrate is preferably 0.5 mol / L.

[0039] In the present invention, the volume ratio of the solution containing dysprosium nitrate, yttrium nitrate and aluminum nitrate to the precipitant solution is preferably 1:2; the precipitant in the precipitant solution preferably includes ammonium bicarbonate and ammonium nitrate; and the molar ratio of ammonium bicarbonate to ammonium sulfate is preferably 10:1.

[0040] In the present invention, the precipitation reaction time is preferably 24 hours.

[0041] After the precipitation reaction, the present invention preferably performs solid-liquid separation and washing on the obtained product to obtain the precipitate.

[0042] After obtaining the precipitate, the present invention preferably calcines the precipitate after drying to obtain the yttrium aluminum garnet doped with dysprosium.

[0043] In the present invention, the drying temperature is preferably 80° C. and the drying time is preferably 24 hours.

[0044] In the present invention, the calcination temperature is preferably 1100° C. and the calcination time is preferably 2 h.

[0045] After the calcination, the present invention preferably further performs ball milling on the obtained product to obtain the phosphorescence temperature measurement powder.

[0046] In the present invention, the coating preferably includes air spraying; during the air spraying, the nozzle diameter of the air spray gun is preferably 1.0-1.5 mm, the spraying distance is preferably 150-200 mm, the spraying air pressure is preferably 0.09-0.18 Mpa, the air usage is preferably 40-60 L / min, the spray material spray volume is preferably 50-60 mL / min, and the spray width is preferably 100-150 mm; in a specific embodiment of the present invention, the nozzle diameter can be 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm or 1.5 mm, the The spraying distance can be 150mm, 160mm, 170mm, 180mm, 190mm or 200mm, the spraying air pressure can be 0.09Mpa, 0.12Mpa, 0.15Mpa or 0.18Mpa, the air usage can be 40L / min, 50L / min or 60L / min, the spray material spray volume can be 50mL / min, 55mL / min or 60mL / min, and the spray width can be 100mm, 110mm, 120mm, 130mm, 140mm or 150mm.

[0047] In the present invention, the air spray gun is preferably Anest Iwata Japan Iwata spray gun W-71

[0048] In the present invention, the air spraying preferably includes repeated air spraying, the number of repetitions is preferably 2 to 3 times, and the interval time between two adjacent air sprayings is preferably 5 minutes.

[0049] In the present invention, the curing is preferably performed by heating with an LED lamp, and the light intensity of the LED lamp heating curing is preferably 1200 to 1500 mW / cm 2 In a specific embodiment of the present invention, the light intensity can be 1200 mW / cm 2 、1300mW / cm 2 、1400mW / cm 2 or 1500mW / cm 2 The wavelength is preferably 365-420nm, the temperature is preferably 200℃, and the time is preferably 2h. Compared with box furnace heating curing, LED lamp heating curing process is more controllable. Both curing temperature and curing time will affect the curing effect of the adhesive coating. If the curing time is too short, the adhesive coating will have insufficient adhesion and strength, and will fall off or blister and deform at high temperatures.

[0050] The present invention also provides a phosphorescent temperature measuring coating prepared by the preparation method described in the above technical solution.

[0051] Figure 1The process flow chart of the embodiment is as follows: the adhesive and the phosphorescent powder are mixed in a mass ratio of 3:1, and then air is sprayed on the surface to be tested after cleaning with acetone to form a phosphorescent coating, and then cured (heated to 200°C, 200 minutes) to obtain a hard phosphorescent coating.

[0052] The phosphorescent temperature measuring coating and the preparation method thereof provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0053] Adhesive used in the embodiment: 813-A from Aremco: dynamic viscosity 40000 cP, specific gravity 2 g / cc, upper temperature limit 1650°C;

[0054] Aremco's 670: dynamic viscosity is 2500cP, specific gravity is 1.80, and the upper temperature limit is 1650℃.

[0055] Aremco's 671: dynamic viscosity is 40,000 cP, specific gravity is 2.05, and the upper temperature limit is 1,760°C.

[0056] The preparation method of the phosphorescence temperature measuring powder in the embodiment is:

[0057] Dysprosium nitrate, yttrium nitrate and aluminum nitrate were added to deionized water to form a metal ion solution (dysprosium nitrate concentration was 0.0012 mol / L, yttrium nitrate was 0.3 mol / L, and aluminum nitrate was 0.5 mol / L). Ammonium bicarbonate and ammonium sulfate were mixed at a molar ratio of 10:1 to form a 2.5 mol / L precipitant solution. The two solutions (800 mL of metal ion solution and 1600 mL of precipitant solution) were dripped into a third beaker to form a suspension. The suspension was aged for 24 hours to separate the solid components. The separated solid components were washed with deionized water and ethanol, and dried in a drying oven at 80°C for 24 hours to form a precursor. The precursor was placed in a box furnace, calcined at 1100°C for 2 hours, and then placed in a ball mill for 6 hours at 450r / min to obtain yttrium aluminum garnet doped with dysprosium phosphorescence temperature measurement powder.

[0058] Example 1

[0059] Step 1: Immerse the metal substrate (sheet, high-temperature alloy GH4037) in acetone solution for 10 to 15 minutes. Use an ultrasonic cleaner with a frequency of 40kHz and a treatment time of 5 minutes to thoroughly remove stubborn impurities. After cleaning, rinse the metal substrate with high-purity distilled water at least twice, with each rinse time of 2 minutes. Use a dust-free cloth or air gun to blow dry the metal substrate to ensure that there is no water stain left.

[0060] Step 2: Take the adhesive 813-A and yttrium aluminum garnet doped dysprosium phosphorescent thermometric powder in a weight ratio of 3:1. Add the phosphorescent thermometric powder to the adhesive, stir with a mechanical stirrer at a speed of 500 rpm for 15 minutes to ensure full mixing and obtain a suspension.

[0061] Step 3: Pour the suspension into the feed tank of the air spray gun (Anest Iwata Japan Iwata spray gun W-71). The nozzle diameter of the air spray gun is 1.0mm, the spray distance is 200mm, the spray air pressure is 0.09Mpa, the air usage is 50L / min, the spray material spray volume is 55mL / min, and the spray width is 100mm. Move the spray gun evenly and quickly at a speed of 0.1m / s to ensure uniform coating, repeat the spraying 3 times, and leave 5min between each time to allow for slight drying.

[0062] Step 4: Place the sprayed metal substrate under a curing lamp for LED lamp heating and curing. The light intensity of the LED lamp heating and curing is 1200mW / cm 2 , wavelength of 365-420nm, temperature of 150℃, curing time of 30min, ensure the coating is completely cured. After curing, cool naturally to room temperature to avoid cracking of the coating caused by rapid cooling.

[0063] Example 2

[0064] Step 1: Immerse the metal substrate (sheet, high-temperature alloy GH4037) in acetone solution for 10 to 15 minutes. Use an ultrasonic cleaner with a frequency of 40kHz and a treatment time of 5 minutes to thoroughly remove stubborn impurities. After cleaning, rinse the metal substrate with high-purity distilled water at least twice, with each rinse time of 2 minutes. Use a dust-free cloth or air gun to blow dry the metal substrate to ensure that there is no water stain left.

[0065] Step 2: Take adhesive 813-A and yttria-stabilized zirconia-doped dysprosium phosphorescent thermometric powder (composition is yttria (8at%): zirconium oxide (92at%) and doped with Dy ions (1at%), chemical formula YSZ:Dy (1%)) in a weight ratio of 3:1. Add the phosphorescent thermometric powder to the adhesive, stir with a mechanical stirrer, set the stirring speed to 500 rpm, and last for 15 minutes to ensure full mixing to obtain a suspension.

[0066] Step 3: Pour the suspension into the feed tank of the air spray gun (Anest Iwata Japan Iwata spray gun W-71). The nozzle diameter of the air spray gun is 1.0mm, the spray distance is 200mm, the spray air pressure is 0.09Mpa, the air usage is 50L / min, the spray material spray volume is 55mL / min, and the spray width is 100mm. Move the spray gun evenly and quickly at a speed of 0.1m / s to ensure uniform coating, repeat the spraying 3 times, and leave 5min between each time to allow for slight drying.

[0067] Step 4: Place the sprayed metal substrate under a curing lamp for LED lamp heating and curing. The light intensity of the LED lamp heating and curing is 1200mW / cm 2 , wavelength of 365-420nm, temperature of 150℃, curing time of 30min, ensure the coating is completely cured. After curing, cool naturally to room temperature to avoid cracking of the coating caused by rapid cooling.

[0068] Performance Testing:

[0069] The phosphorescent temperature measuring coating of Example 1 was excited by 355 nm excitation light, the excitation frequency was 10 Hz, the phosphorescent light intensity at 448 nm and 494 nm was collected as a ratio, the relationship curve between the ratio and temperature was fitted, and the entire temperature field was obtained based on this. The data are as follows: Figure 2-3 As shown. Among them, Figure 2 This is the temperature field diagram of the phosphorescent temperature measurement coating measured at 450℃. Figure 3 This is the temperature field diagram of the phosphorescent thermometric coating measured at 900℃.

[0070] Depend on Figures 2-3 It can be seen that the coating temperature distribution measured at low temperature is uniform and the temperature measurement performance is good. The temperature distribution of the coating measured at high temperature increases, indicating that the light intensity of the two different wavelengths is very different, which may be caused by the inappropriate selection of the temperature measurement band. At the same time, the coating can still emit light signals at high temperatures, proving the feasibility of chemical adhesive phosphorescent temperature measurement coating at high temperatures.

[0071] Example 3

[0072] The only difference from Example 1 is that the adhesive used is 670 from Aremco.

[0073] Example 4

[0074] The only difference from Example 1 is that the adhesive used is 671 from Aremco.

[0075] The three coatings prepared in Examples 1, 3 and 4 were heated from room temperature to 1100 degrees. The 670 and 671 chemical adhesives fell off when the temperature was raised to about 1000 degrees, while the 813-A chemical adhesive did not fall off during the test.

[0076] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing a phosphorescent temperature measuring coating, characterized in that: The method comprises the following steps: coating a mixture of an adhesive containing ceramic, graphite and water and phosphorescent temperature measuring powder on the surface of a metal substrate and then curing the mixture to obtain the phosphorescent temperature measuring coating.

2. The preparation method according to claim 1, characterized in that: The phosphorescent temperature measuring powder comprises yttria-stabilized zirconia doped with dysprosium and / or yttrium-aluminum garnet doped with dysprosium; and the average particle size of the phosphorescent temperature measuring powder is 25-100 nm.

3. The preparation method according to claim 2, characterized in that: The preparation method of yttrium aluminum garnet doped with dysprosium comprises the following steps: A solution containing dysprosium nitrate, yttrium nitrate and aluminum nitrate is mixed with a precipitant solution to perform a precipitation reaction to obtain a precipitate; The precipitate is dried and then calcined to obtain the yttrium aluminum garnet doped with dysprosium.

4. The preparation method according to claim 1, characterized in that: The ceramic comprises aluminum oxide; The adhesive containing ceramic, graphite and water has a dynamic viscosity of 2500 to 80000 cP, a specific gravity of 1.8 to 2.15 g / cc, and an upper temperature resistance limit of 1650 to 1760°C.

5. The preparation method according to claim 1 or 4, characterized in that: The adhesive containing ceramic, graphite and water includes 813-A, 670 or 671 from Aremco.

6. The preparation method according to claim 5, characterized in that: The mass ratio of the adhesive containing ceramics, graphite and water to the phosphorescent temperature measuring powder is 3-4:

1.

7. The preparation method according to claim 1, characterized in that: The coating includes air spraying.

8. The preparation method according to claim 7, characterized in that: The nozzle diameter of the air spray gun during air spraying is 1.0-1.5 mm, the spraying distance is 150-200 mm, the spraying air pressure is 0.09-0.18 MPa, the air usage is 40-60 L / min, the spray material spraying volume is 50-60 mL / min, and the spray width is 100-150 mm; The air spray gun is the ANEST IWATA Japan IWATA spray gun W-71.

9. The preparation method according to claim 1, characterized in that: The curing is performed by heating with an LED lamp, and the light intensity of the LED lamp heating curing is 1200-1500 mW / cm 2 , wavelength is 365~420nm, temperature is 150~200℃, and time is 0.5~2h.

10. The phosphorescent temperature measuring coating prepared by the preparation method according to any one of claims 1 to 9.

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