A method and device for testing the wettability of ultra-high temperature CMAS

Abstract

The present application relates to the technical field of CMAS intrinsic property testing, and particularly to a super-high-temperature CMAS wettability testing method and device. The super-high-temperature CMAS wettability testing method of the present application innovatively applies the Joule heating technology to the CMAS wettability testing, and realizes rapid heating to the target temperature in the process of heating the CMAS test ash column, thereby avoiding the phenomenon that the CMAS test ash column has already melted and spread in the heating process, and further accurately obtaining the initial contact angle at the target temperature; the CMAS test ash column can be heated to a super-high temperature of 1600 DEG C-2500 DEG C, thereby simulating the real working temperature of the aero-engine and the hypersonic aircraft, and greatly promoting the research on the super-high-temperature CMAS wettability and corrosion behavior and mechanism, and accelerating the research and development process of the super-high-temperature thermal protection material.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of CMAS intrinsic property testing, and particularly relates to a super-high-temperature CMAS wettability testing method and device. BACKGROUND

[0002] The damage of atmospheric deposits (mainly composed of CaO-MgO-Al2O3-SiO2, referred to as CMAS) such as sand, dust and volcanic ash to the thermal protection system of aero-engines and hypersonic aircraft has become a key problem restricting their performance and service life. With the continuous improvement of the performance of aero-engines, the turbine inlet temperature has increased from 1200℃ to the current 1400℃. When the temperature of these deposits on the blade surface exceeds 1200℃, they will melt to form a CMAS melt with high fluidity, rapidly penetrate into the columnar crystal structure and pores of the thermal barrier coating, and undergo complex physical and chemical reactions with the thermal barrier coating material, thereby changing the phase composition and microstructure of the coating. Meanwhile, solidification and significant volume change occur during the cooling process, and these physical and chemical damages will lead to coating cracking, peeling and failure.

[0003] The flight speed of a hypersonic aircraft exceeds 5 Mach, and the aerodynamic heating makes the surface temperature of the thermal protection system reach above 1600℃, so the melting penetration and chemical corrosion of CMAS are more significant. The CMAS melt not only reduces the mechanical properties of the thermal protection material, but also accelerates the failure of the oxide protective coating, aggravates the oxidation, ablation and fatigue damage of the material, and seriously shortens the service life of the thermal protection system.

[0004] When the molten CMAS comes into contact with the high-temperature protective coating, the wettability behavior occurs between the molten silicate and the ceramic interface due to ion interaction, and its wettability behavior directly affects the adhesion penetration depth, diffusion rate and interface reaction degree of the molten CMAS and the coating, and thus dominates the material failure process.

[0005] Currently, the high-temperature wettability of CMAS is mainly tested by the sessile drop method to test the high-temperature contact angle of the CMAS melt. This method places a CMAS preform on the surface of the substrate material, heats it to the melting temperature in a high-temperature furnace, uses a high-speed CCD camera to record the morphology evolution of the melt drop in real time, and obtains the dynamic contact angle and spreading area through image analysis. However, this method still has the following shortcomings: first, there is a significant difference between the test conditions and the actual service conditions, especially the high-temperature furnace used in the existing test, the heating rate is usually ≤10℃ / min, it is difficult to achieve rapid heating, and the CMAS has already melted and spread during the heating process, so it is difficult to accurately obtain the initial contact angle at the target temperature; second, due to the heating mode of the existing high-temperature furnace, the test temperature is usually not higher than 1500℃, and it is difficult to realize the CMAS wettability test under super-high-temperature (≥1600℃) conditions.

[0006] Chinese invention patent CN110174331A discloses a method for determining the high-temperature wettability of iron ore sintering binder phase, which can improve the sample heating rate to a certain extent by manually feeding the sample into the heating furnace at a certain rate after the heating furnace is preheated to a specified temperature. However, this method cannot accurately control the heating rate, and the test temperature does not exceed 1600℃, which still cannot meet the conditions of super-high-temperature CMAS wettability test.

[0007] Therefore, with the continuous increase of the thrust-to-weight ratio of aircraft engines and the growing demand for hypersonic aircraft development, the service temperature continues to rise, and it is urgent to introduce new heating technology to develop a super-high-temperature CMAS wettability test method and device to realize rapid heating and test the wettability of CMAS under super-high-temperature conditions, reveal the wetting behavior and corrosion mechanism of CMAS under super-high-temperature conditions, and thus accelerate the research and development process of new thermal protection materials. SUMMARY

[0008] The technical problem to be solved by the present application is that the existing CMAS wettability test method and test device cannot realize rapid heating and test the wettability of CMAS under super-high-temperature conditions.

[0009] To solve the above technical problems, the technical solution provided by the present application is as follows: a super-high-temperature CMAS wettability test method, at least comprising the following steps:

[0010] S10, preparing a CMAS test column;

[0011] S20, polishing the ceramic substrate and placing the CMAS test column on the ceramic substrate;

[0012] S30, placing the ceramic substrate and the CMAS test column in the heating zone of the Joule heat heating structure in the heating furnace;

[0013] S40, setting the heating rate of the Joule heat heating body to 50℃ / s-150℃ / s, the peak temperature to 1600℃-2500℃, vacuumizing the heating furnace or vacuumizing and then introducing a protective atmosphere, and starting the heating furnace;

[0014] S50, recording the morphology change of the CMAS test column in the heating process in real time by a high-speed camera, and measuring the spreading baseline length, spreading area, droplet height and high-temperature contact angle of the CMAS melt on the ceramic substrate according to the photos of the CMAS melt spreading process.

[0015] In a preferred embodiment, the step of preparing a CMAS test column in step S10 comprises:

[0016] S11, grinding and sieving the CMAS particles, and taking a small amount of powder to press into a column preform with a special mold;

[0017] S12, placing the ash column preform in a muffle furnace for pre-burning treatment.

[0018] In a preferred embodiment, in step S11, the CMAS particles include natural sand, dust, volcanic ash, and artificially synthesized CMAS; the ash column preform has a diameter of 1-3 mm and a height of 2-3 mm.

[0019] In a preferred embodiment, in step S12, the pre-burning temperature is 500-800 ℃, and the pre-burning time is 10-30 min.

[0020] In a preferred embodiment, the Joule heat heating structure includes a pair of oppositely arranged heating bodies and graphite electrodes arranged at both ends of the heating bodies, and a heating interval for accommodating the ceramic substrate and the CMAS test ash column is arranged between the pair of heating bodies.

[0021] In a preferred embodiment, the test atmosphere in the heating furnace is vacuum, argon, or nitrogen.

[0022] In a preferred embodiment, the high-speed camera has a picture acquisition frequency of 1-30 pictures per second.

[0023] In a preferred embodiment, the high-temperature contact angle includes a left contact angle and a right contact angle of the CMAS melt on the ceramic substrate.

[0024] The application also discloses an ultrahigh-temperature CMAS wettability testing device for performing CMAS wettability testing by using the ultrahigh-temperature CMAS wettability testing method.

[0025] a heating furnace;

[0026] a Joule heat heating structure arranged in the heating furnace, the Joule heat heating structure including a pair of oppositely arranged heating bodies and graphite electrodes arranged at both ends of the heating bodies, and a heating interval with both sides open being arranged between the pair of heating bodies, and a temperature measurement opening being arranged at the bottom of the heating interval;

[0027] an infrared temperature measuring instrument arranged directly below the temperature measurement opening in the heating furnace;

[0028] a first window arranged on a side wall of one side of the heating furnace and directly opposite the heating interval;

[0029] a high-speed camera arranged outside the heating furnace and directly opposite the heating interval through the first window;

[0030] a second window arranged on a side wall of one side of the heating furnace and directly opposite the first window;

[0031] A light source is arranged outside the heating furnace and is used to illuminate the interior of the heating furnace through the second window.

[0032] In a preferred embodiment, the heating body is a carbon felt, graphite sheet or tungsten sheet that generates Joule heat using direct current.

[0033] In a preferred embodiment, the length of the heating body is 100-150 mm, the width is 20-50 mm, and the thickness is 3-10 mm.

[0034] The super-high-temperature CMAS wettability test method and device of the application have the following beneficial effects compared with the prior art:

[0035] (1) The Joule heat heating technology is innovatively applied to the CMAS wettability test. During the heating of the CMAS test ash column, the temperature rising rate is 50-150 ℃ / s, the target temperature is quickly reached, and the phenomenon of melting and spreading of the CMAS test ash column during the temperature rising process is avoided, so that the initial contact angle at the target temperature can be accurately obtained.

[0036] (2) The Joule heat heating technology is innovatively applied to the CMAS wettability test. The CMAS test ash column can be heated to a super-high temperature of 1600-2500 ℃, so as to simulate the real working temperature of an aero-engine and a hypersonic aircraft.

[0037] (3) The super-high-temperature CMAS wettability test device has a simple structure, low cost, simple operation and fast test speed, which can greatly promote the research on the super-high-temperature CMAS wettability and corrosion behavior and mechanism, and accelerate the research and development process of super-high-temperature thermal protection materials. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 FIG. 1 is a structural schematic diagram of the super-high-temperature CMAS wettability test device shown in Example 1;

[0039] Figure 2 FIG. 3 is a structural schematic diagram of the Joule heat heating structure in the super-high-temperature CMAS wettability test device shown in Example 1;

[0040] Figure 3 FIG. 5 is a physical schematic diagram of the super-high-temperature CMAS wettability test device shown in Example 1 during the super-high-temperature CMAS wettability test;

[0041] Figure 4 FIG. 7 is a physical diagram of the spreading of the CMAS melt on the surface of the ceramic substrate after the CMAS wettability test using the super-high-temperature CMAS wettability test method shown in Application Example 2;

[0042] Figure 5 SEM images of the cross-sectional microstructure of the CMAS wettability test sample after performing CMAS wettability testing using the ultra-high temperature CMAS wettability testing method shown in Example 2.

[0043] Figure 6 SEM images of the microstructure at the interface between the CMAS wettability test sample and the ceramic substrate after performing CMAS wettability testing using the ultra-high temperature CMAS wettability testing method shown in Example 2. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0045] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0046] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation", "connection" and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, an integral connection, or a detachable connection; they can refer to the internal connection of two components; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0047] Example 1

[0048] The ultra-high temperature CMAS wettability testing device in this embodiment, such as Figures 1-2 As shown, it includes a heating furnace 10, a Joule heating structure 20, a high-speed camera 30, a light source 40, and an infrared thermometer 50. The heating furnace has a sealable internal space.

[0049] As a particularity of the present embodiment, the Joule heat heating structure 20 is located in the inner space of the heating furnace 10. As a preference, in the present embodiment, the Joule heat heating structure 20 comprises a pair of oppositely arranged heating bodies, namely a first heating body 22 and a second heating body 23, and graphite electrodes 21 are arranged at both ends of the first heating body 22 and the second heating body 23, wherein the graphite electrodes 21 are used to conduct direct current to the heating bodies to generate Joule heat, and the material of the heating bodies can be selected from carbon felt, graphite sheet or tungsten sheet, and the heating bodies generate Joule heat to rapidly heat the sample after being passed through direct current. Generally, the direct current is 0-200 A, and the direct voltage is 0-40 V.

[0050] As a preference, in the present embodiment, the length of the heating body is 100-150 mm, the width is 20-50 mm, and the thickness is 3-10 mm.

[0051] In the present embodiment, a heating interval 24 with open two sides is arranged between the first heating body 22 and the second heating body 23, and the heating interval 24 is used to accommodate the sample to be heated.

[0052] As a preference, in the present embodiment, a temperature measuring opening 25 is arranged at the bottom of the heating interval 24, namely the bottom of the second heating body 23, and an infrared temperature measuring instrument 50 is located directly below the temperature measuring opening 25 in the heating furnace 10, which is used to measure the temperature of the sample in real time.

[0053] In the present embodiment, first and second view windows 11 and 12 are respectively arranged on the side walls of the heating furnace corresponding to the open two sides of the heating interval 24, and the first and second view windows 11 and 12 respectively face the heating interval 24.

[0054] In the present embodiment, a high-speed camera 30 is arranged outside the heating furnace 10 and faces the heating interval 24 through the first view window 11. The high-speed camera 30 is used to record the state of the sample in real time, and in the present embodiment, it is used to record the high-temperature melting and spreading process of the CMAS melt in real time. The frequency of collecting pictures by the high-speed camera 30 is generally 1-30 pictures per second, which can be set according to the needs.

[0055] In the present embodiment, a light source 40 is arranged outside the heating furnace 10 and is used to illuminate the inside of the heating furnace through the second view window 12, so as to facilitate the high-speed camera 30 to take pictures.

[0056] It should be understood by those skilled in the art that the ultrahigh-temperature CMAS wettability testing device of the present embodiment should also include a direct current power supply, a water chiller, a vacuum pump and a computer, which are not shown in the figure.

[0057] It should be noted that the ultrafast high-temperature sintering technology is a breakthrough material preparation technology in the field of inorganic material synthesis in recent years (reported in the cover article of Science in May 2020), which uses Joule heat generated by electric current through carbon felt or graphite paper to make the material reach a high temperature of 1000-3000℃ in tens of seconds, thereby realizing the rapid synthesis and densification of inorganic materials in a very short time. This Joule heat heating technology can achieve a heating and cooling rate of 20-200℃ / s and a temperature as high as 3000℃. However, this technology is currently only applied to material preparation, and no researchers have applied it to CMAS wettability testing and developed related testing devices. The ultra-high-temperature CMAS wettability testing device of the present embodiment innovatively applies the Joule heat heating technology to ultra-high-temperature CMAS wettability testing, which can effectively make up for the slow heating rate and low peak temperature of the traditional CMAS wettability testing method.

[0058] Embodiment Two

[0059] The ultra-high-temperature CMAS wettability testing method of the present embodiment applies the ultra-high-temperature CMAS wettability testing device shown in Embodiment One to CMAS wettability testing. The testing method of the present embodiment includes the following steps:

[0060] S10, preparing a CMAS test ash column, the preparation process of which includes the following steps:

[0061] S11, grinding typical artificial CMAS particles with a composition of 33CaO-9MgO-13AlO 1.5 -45SiO2(molar ratio) through a 200-mesh sieve, and introducing a small amount of powder into a cylindrical mold with a diameter of 2 mm and a height of 3 mm, and pressing the ash column preform under pressure.

[0062] S12, placing the ash column preform in a muffle furnace for pre-sintering treatment, heating to 600℃ at a heating rate of 10℃ / min, and keeping the temperature for 15 min to make the ash column preform have a certain strength, thereby obtaining a CMAS test ash column 100.

[0063] S20, polishing the ceramic substrate 200 with a composition of ZrC-20% MoSi2, and placing the CMAS test ash column on the ceramic substrate 200.

[0064] S30, placing the ceramic substrate 200 and the CMAS test ash column 100 in the heating zone 24 of the Joule heat heating structure 20 of the heating furnace, aligning the CMAS test ash column 100 with a high-speed camera as shown in Figure 3 , and adjusting the focal length to make the picture clear.

[0065] S40, set the heating program on the computer, set the temperature rising rate of the Joule heat heating body to 100℃ / s, the peak temperature to 1600℃, the holding time to 60s, and the temperature falling rate to 200℃ / s.

[0066] Next, the heating furnace is vacuumed to below 5 Pa, the vacuum pump is closed, high-purity argon is introduced, and then the heating program is started.

[0067] S50, the morphology change of the CMAS test column in the heating process is recorded in real time by a high-speed camera, and the spreading baseline length, spreading area, droplet height and high-temperature contact angle of the CMAS melt on the ceramic substrate are measured according to the photos of the CMAS melt spreading process, wherein the left contact angle, right contact angle, baseline length, spreading area and droplet height of the CMAS melt on the ceramic substrate are shown in Table 1.

[0068] S60, the CMAS test column after the wetting test is cut by a diamond wire cutting machine, and the cross-section microstructure and interface morphology of the sample are observed by a scanning electron microscope after polishing and polishing. Figure 4 The sample is cut, polished and polished, and the cross-section microstructure and interface morphology are observed by a scanning electron microscope, wherein, Figure 5 The SEM (scanning electron microscope) photo of the cross-section microstructure is shown in the figure, Figure 6 The SEM photo of the interface morphology is shown in the figure.

[0069] Example Three

[0070] The super-high-temperature CMAS wetting test method of the present embodiment is applied to the super-high-temperature CMAS wetting test device shown in Example One to test the CMAS wetting. The test method of the present embodiment includes the following steps:

[0071] S10, preparing a CMAS test column, the preparation process including the following steps:

[0072] S11, grinding the typical artificial CMAS particles with a composition of 33CaO-9MgO-13AlO 1.5 -45SiO2 (molar ratio) through a 200-mesh sieve, and introducing a small amount of powder into a cylindrical mold with a diameter of 2 mm and a height of 3 mm, and pressing the column preform under pressure.

[0073] S12, placing the column preform in a muffle furnace for pre-sintering, heating to 600℃ at a rate of 10℃ / min, and holding for 15 min to make the column preform have a certain strength, and obtaining the CMAS test column 100.

[0074] S20, polishing and polishing the ceramic substrate 200 with a composition of ZrC-20%SiC, and placing the CMAS test column on the ceramic substrate 200.

[0075] S30, the ceramic substrate 200 and the CMAS test ash column 100 are placed in the heating zone 24 of the Joule heat heating structure 20 in the heating furnace, as shown in Figure 3 The high-speed camera is aligned with the CMAS test ash column 100, and the focal length is adjusted to make the picture clear.

[0076] S40, a heating program is set on the computer, the temperature rising rate of the Joule heat heating body is set to 100℃ / s, the peak temperature is set to 1600℃, the holding time is set to 60s, and the temperature falling rate is set to 200℃ / s.

[0077] Then, the heating furnace is vacuumized to below 5Pa, the vacuum pump is closed, high-purity argon is introduced, and then the heating program is started.

[0078] S50, the morphology change of the CMAS test ash column in the heating process is recorded in real time by the high-speed camera, and according to the photos of the CMAS melt spreading process, the spreading baseline length, the spreading area, the droplet height and the high-temperature contact angle of the CMAS melt on the ceramic substrate are measured, wherein the left contact angle, the right contact angle, the baseline length, the spreading area and the droplet height of the CMAS melt on the ceramic substrate are shown in Table 1.

[0079] S60, the sample after the wetting test is cut by diamond wire cutting, and after polishing, the cross-sectional microstructure and interface morphology are observed by scanning electron microscope.

[0080] Example Four

[0081] The superhigh-temperature CMAS wetting test method of the present embodiment is applied to the superhigh-temperature CMAS wetting test device shown in Example One for CMAS wetting test. The test method of the present embodiment comprises the following steps:

[0082] S10, a CMAS test ash column is prepared, and the preparation process comprises the following steps:

[0083] S11, typical artificial CMAS particles with a composition of 33CaO-9MgO-13AlO 1.5 -45SiO2(molar ratio) are ground and passed through a 200-mesh sieve, and a small amount of powder is introduced into a cylindrical mold with a diameter of 2mm and a height of 3mm, and the ash column preform is pressed by applying pressure.

[0084] S12, the ash column preform is placed in a muffle furnace for pre-sintering treatment, and the temperature is raised to 600℃ at a temperature rising rate of 10℃ / min, and the ash column preform is kept at this temperature for 15min to have a certain strength, and the CMAS test ash column 100 is obtained.

[0085] S20, polishing the ceramic substrate 200 with a composition of ZrB2-20% MoSi2, and placing the CMAS test ash column on the ceramic substrate 200.

[0086] S30, placing the ceramic substrate 200 and the CMAS test ash column 100 in the heating interval 24 of the Joule heat heating structure 20 in the heating furnace, aligning the CMAS test ash column 100 using a high-speed camera, and adjusting the focal length to make the picture clear, as shown in Figure 3

[0087] S40, setting the heating program on the computer, setting the temperature rising rate of the Joule heat heating body to 100℃ / s, the peak temperature to 1800℃, the holding time to 60s, and the temperature falling rate to 200℃ / s.

[0088] Then, after the heating furnace is vacuumized to below 5Pa, the vacuum pump is closed, high-purity argon is introduced, and then the heating program is started.

[0089] S50, recording the morphology change of the CMAS test ash column in the heating process in real time through the high-speed camera, and measuring the spreading baseline length, spreading area, droplet height and high-temperature contact angle of the CMAS melt on the ceramic substrate according to the photos of the CMAS melt spreading process, wherein the left contact angle, right contact angle, baseline length, spreading area and droplet height of the CMAS melt on the ceramic substrate are shown in Table 1.

[0090] S60, cutting the sample after the wetting test with a diamond wire, polishing and observing the cross-sectional microstructure and interface morphology with a scanning electron microscope.

[0091] Example Five

[0092] The super-high-temperature CMAS wetting test method of the present embodiment is applied to the super-high-temperature CMAS wetting test device shown in Example One for CMAS wetting test. The test method of the present embodiment comprises the following steps:

[0093] S10, preparing the CMAS test ash column, which comprises the following steps:

[0094] S11, grinding the typical artificial CMAS particles with a composition of 33CaO-9MgO-13AlO 1.5 -45SiO2(molar ratio) through a 200-mesh sieve, and introducing a small amount of powder into a cylindrical mold with a diameter of 2mm and a height of 3mm, and pressing the ash column preform under pressure.

[0095] S12, placing the ash column preform in a muffle furnace for pre-sintering treatment, heating to 600℃ at a heating rate of 10℃ / min, and holding for 15min to make the ash column preform have a certain strength, thereby obtaining the CMAS test ash column 100.​

[0096] S20, polishing the ceramic substrate 200 with a composition of ZrB2-20% SiC, and placing the CMAS test ash column on the ceramic substrate 200.

[0097] S30, placing the ceramic substrate 200 and the CMAS test ash column 100 in the heating interval 24 of the Joule heat heating structure 20 in the heating furnace, aligning the CMAS test ash column 100 using a high-speed camera, and adjusting the focal length to make the picture clear, as shown in FIG. 3. Figure 3

[0098] S40, setting the heating program on the computer, setting the temperature rising rate of the Joule heat heating body to 100℃ / s, the peak temperature to 1800℃, the holding time to 60s, and the temperature falling rate to 200℃ / s.

[0099] Then, the heating furnace is vacuumized to below 5 Pa, the vacuum pump is closed, high-purity argon is introduced, and then the heating program is started.

[0100] S50, recording the morphology change of the CMAS test ash column in the heating process in real time by the high-speed camera, and measuring the spreading baseline length, spreading area, droplet height, and high-temperature contact angle of the CMAS melt on the ceramic substrate according to the photos of the CMAS melt spreading process, wherein the left contact angle, right contact angle, baseline length, spreading area, and droplet height of the CMAS melt on the ceramic substrate are shown in Table 1.

[0101] S60, cutting the sample after the wetting test with a diamond wire, polishing, and observing the cross-sectional microstructure and interface morphology with a scanning electron microscope.

[0102] Example Six

[0103] The super-high-temperature CMAS wetting test method of the present embodiment is applied to the super-high-temperature CMAS wetting test device shown in Example One to perform the CMAS wetting test. The test method of the present embodiment includes the following steps:

[0104] S10, preparing the CMAS test ash column, including the following steps:

[0105] S11, grinding the typical artificial CMAS particles with a composition of 33CaO-9MgO-13AlO 1.5 -45SiO2(molar ratio) through a 200-mesh sieve, introducing a small amount of powder into a cylindrical mold with a diameter of 2 mm and a height of 3 mm, and pressing the ash column preform under pressure.

[0106] ​S12, the ash column preform is placed in a muffle furnace for pre-burning treatment, and is heated to 600℃ at a heating rate of 10℃ / min, and is kept for 15min, so that the ash column preform has certain strength, and the CMAS test ash column 100 is obtained.

[0107] S20, the ceramic substrate 200 with a component of ZrB2-20%SiC is polished, and the CMAS test ash column is placed on the ceramic substrate 200.

[0108] S30, the ceramic substrate 200 and the CMAS test ash column 100 are placed in the heating zone 24 of the Joule heat heating structure 20 in the heating furnace, as shown in FIG. 4, the high-speed camera is aligned with the CMAS test ash column 100, and the focal length is adjusted to make the picture clear. Figure 3

[0109] S40, the heating program is set on the computer, the heating rate of the Joule heat heating body is set to 100℃ / s, the peak temperature is set to 2000℃, the holding time is set to 60s, and the cooling rate is set to 200℃ / s.

[0110] Then, the heating furnace is vacuumized to below 5Pa, the vacuum pump is closed, high-purity argon is introduced, and then the heating program is started.

[0111] S50, the morphology change of the CMAS test ash column in the heating process is recorded in real time by the high-speed camera, and according to the photos of the CMAS melt spreading process, the spreading baseline length, the spreading area, the droplet height and the high-temperature contact angle of the CMAS melt on the ceramic substrate are measured, wherein the left contact angle, the right contact angle, the baseline length, the spreading area and the droplet height of the CMAS melt on the ceramic substrate are shown in Table 1.

[0112] S60, the sample after the wetting test is cut by diamond wire cutting, and the cross-section microstructure and the interface morphology are observed by scanning electron microscope after polishing.

[0113] Table 1: The left contact angle, the right contact angle, the baseline length, the spreading area and the droplet height of the artificial CMAS melt on the ceramic substrate

[0114] Example Ceramic substrate class Test temperature / °C Left side contact angle / ° Right side contact angle / ° Baseline length / mm Spread area / mm 2 ]] Droplet height / mm 2 ZrC - 20% MoSi2 1600 8.6 5.5 9.74 74.5 0.29 3 ZrC-20% SiC 1600 10.6 6.9 8.96 63.15 0.32 4 ZrB2-20% MoSi2 1800 5.3 3.7 10.5 86.65 0.25 5 ZrB2-20% SiC 1800 8.9 6.5 9.5 70.95 0.3 6 ZrB2-20% SiC 2000 6.6 5.2 10.26 82.75 0.26

[0115] In summary, the above only describes the preferred embodiments of the present application, and does not limit the present application, any modification, equivalent replacement and improvement within the spirit and principle of the present application should be included in the protection scope of the present application.​

Claims

1. A method for testing the wettability of ultra-high temperature CMAS, characterized in that, At least the following steps are included: S10, prepare the gray column for the CMAS test; S20, polish the ceramic substrate and place the CMAS test gray column on the ceramic substrate; S30, place the ceramic substrate and the CMAS test gray column in the heating zone of the Joule heating structure in the heating furnace; The Joule heating structure includes a pair of oppositely arranged heating elements and graphite electrodes disposed at both ends of the heating elements, and a heating zone for accommodating the ceramic substrate and the CMAS test gray column is disposed between the pair of heating elements. S40: Set the heating / cooling rate of the Joule heating element to 50℃ / s-150℃ / s, and the peak temperature to 1600℃-2500℃. Evacuate the furnace or introduce a protective atmosphere after evacuation, and start the furnace. The S50 uses a high-speed camera to record the morphological changes of the CMAS test gray column during the heating process in real time. Based on the photos of the CMAS melt spreading process, the spreading baseline length, spreading area, droplet height and high temperature contact angle of the CMAS melt on the ceramic substrate are measured.

2. The ultra-high temperature CMAS wettability test method according to claim 1, characterized in that, Step S10, the step of preparing the CMAS test gray column includes: S11, grind and sieve the CMAS particles, take a small amount of powder and press it into gray column preforms using a special mold; S12, the gray column preform is placed in a muffle furnace for pre-firing.

3. The ultra-high temperature CMAS wettability test method according to claim 2, characterized in that, In step S11, the CMAS particles include natural sand, dust, volcanic ash, and synthetic CMAS; the diameter of the gray column preform is 1mm-3mm and the height is 2mm-3mm.

4. The ultra-high temperature CMAS wettability test method according to claim 2, characterized in that, In step S12, the pre-firing temperature is 500℃-800℃, and the pre-firing time is 10min-30min.

5. The ultra-high temperature CMAS wettability test method according to claim 1, characterized in that, The test atmosphere inside the heating furnace is vacuum, argon, or nitrogen.

6. The ultra-high temperature CMAS wettability test method according to claim 1, characterized in that, The high-speed camera captures images at a rate of 1-30 frames per second.

7. The ultra-high temperature CMAS wettability test method according to claim 1, characterized in that, The high-temperature contact angle includes the left and right contact angles of the CMAS melt on the ceramic substrate.

8. The ultra-high temperature CMAS wettability test method according to any one of claims 1-7, characterized in that, It also includes step S60, which involves cutting the sample after wetting test with diamond wire cutting, polishing it, and then observing its cross-sectional microstructure and interface morphology with a scanning electron microscope.

9. The ultra-high temperature CMAS wettability test method according to any one of claims 1-7, characterized in that, The testing apparatus for conducting ultra-high temperature CMAS wettability testing includes: Heating furnace; A Joule heating structure is provided inside the heating furnace. The Joule heating structure includes a pair of oppositely arranged heating elements and graphite electrodes disposed at both ends of the heating elements. A heating zone with open sides is provided between the pair of heating elements, and a temperature measuring opening is provided at the bottom of the heating zone. An infrared thermometer is positioned directly below the temperature measuring opening inside the heating furnace; The first viewing window is located on the side wall of one side of the heating furnace and faces the heating zone. A high-speed camera is mounted outside the heating furnace and faces the heating zone through the first viewing window; The second viewing window is located on the side wall of the heating furnace, directly opposite the first viewing window; A light source is located outside the heating furnace and is used to illuminate the interior of the heating furnace through a second viewing window.

10. The ultra-high temperature CMAS wettability test method according to claim 9, characterized in that, The heating element is a carbon felt, graphite sheet, or tungsten sheet that generates Joule heat using direct current.

11. The ultra-high temperature CMAS wettability test method according to claim 9, characterized in that, The heating element has a length of 100mm-150mm, a width of 20mm-50mm, and a thickness of 3mm-10mm.

Images