Ceramic matrix composite flame tube temperature difference thermal cycle device and reliability evaluation method

Abstract

The present invention discloses a ceramic matrix composite flame tube temperature difference thermal cycle device and reliability evaluation method, which includes a fully automatic electronic test control module, a circulating cooling module and a non-uniform temperature field loading module. After the CMC flame tube simulation part is assembled into the non-uniform temperature field loading module, the fully automatic electronic test control module collects the test data of the inner and outer wall temperatures of the CMC flame tube simulation part, and controls the circulating cooling module and the internal heating element of the non-uniform temperature field loading module through temperature feedback, dynamically adjusts the temperature field in the cavity of the non-uniform temperature field loading module, and maintains stable temperature difference thermal cycle loading conditions. The present invention can obtain the degradation of the residual mechanical properties of the CMC hot end components of an aircraft engine under different gradient ambient temperatures, which is of great significance to the structural design and life assessment of an aircraft engine.

Description

Technical Field

[0001] The invention belongs to the technical field of ceramic matrix composite material structure testing, and particularly relates to a ceramic matrix composite material flame tube temperature difference heat cycle device and a reliability evaluation method. Background Art

[0002] Fiber-reinforced ceramic matrix composites (Ceramic Matrix Composite, CMC) have many advantages such as high temperature resistance, light weight, high strength and good oxidation resistance. Its performance in high-temperature environments is better than that of traditional high-temperature alloy materials. It is an important material for high-temperature components of modern advanced aircraft engines. The flame tube is one of the important core hot end components in aircraft engines. As the place where combustion is organized in aircraft engines, it is subject to large thermal stress loads. Flame tubes made of CMC can significantly reduce the amount of cooling gas used, improve engine efficiency, and perform well in continuous high-temperature environments. They are currently being gradually applied to aircraft engines. However, in order to ensure the safety and reliability of CMC flame tubes in the service environment of aircraft engines, in-depth research and testing of the mechanical properties of the CMC flame tube structure under service conditions must also be carried out.

[0003] Since cooling air flows through the outer wall of the aircraft engine flame tube and high-temperature combustion gas flows through the inner wall, there is a large gradient in the temperature distribution of the inner and outer walls of the flame tube, and thermal stress damage will occur under long-term action. At present, most of the research work on the mechanical properties of ceramic-based composite materials in high-temperature environments only considers uniform ambient temperature (CN110686967A), and does not consider the damage caused by cyclic high-temperature shock. Therefore, it is difficult for existing technologies to simulate the complex temperature load distribution conditions of the aircraft engine CMC flame tube structure under working conditions, and the flame tube mechanical performance assessment test data obtained thereby deviates greatly from the actual situation. This type of data is difficult to correctly evaluate the service life of the flame tube in a complex temperature environment, which will have a serious impact on the service reliability of the aircraft engine.

[0004] Therefore, it is necessary to develop a testing system that can simulate the high-temperature thermal gradient environment experienced by aircraft engine flame tubes, as well as a method for evaluating flame tube reliability after thermal cycling tests. This invention accurately applies thermal gradient loads to CMC flame tube simulators and provides stable, long-term control of ambient temperature cycling. Ultimately, mechanical performance test data for CMC flame tube simulators is obtained, providing a reference for evaluating the service reliability of CMC flame tubes. Summary of the Invention

[0005] In response to the deficiencies in the prior art, the present invention provides a reliability assessment method for a CMC flame tube under a temperature difference thermal cycle service environment. First, the service operating temperature environment of the flame tube of an aircraft engine combustion chamber is simulated to obtain the residual performance of a CMC flame tube simulation under temperature difference thermal cycle conditions. This method controls the temperature field through temperature feedback regulation. The fully automatic electronic test control module synchronously collects the temperature field distribution inside the system and controls the heating elements at different positions separately. The stepper motor is controlled by a preset program to control the opening and closing of the cooling air path. The circulating cooling module is combined to adjust the temperature field inside the system to provide stable temperature difference thermal cycle test conditions for the CMC flame tube simulation. A temperature difference thermal cycle test is performed on the CMC flame tube simulation to obtain a CMC flame tube simulation with fully developed thermal stress damage.

[0006] This study conducted static strength tests on a CMC flame liner simulator with fully developed damage in a high-temperature environment. Simultaneously, static strength tests were conducted on a reference test piece in the same high-temperature environment, comparing the mechanical performance responses of the two. Based on these tests, the residual strength and residual stiffness of the CMC flame liner simulator were determined. The impact of thermal cycling tests on the CMC flame liner simulator's residual mechanical properties was determined, ultimately enabling a reliability assessment of the CMC flame liner under thermal cycling service conditions.

[0007] In order to achieve the above technical objectives, the technical solution adopted by the present invention is:

[0008] The temperature difference heat cycle device of the ceramic matrix composite flame tube includes a fully automatic electronic test control module, a circulating cooling module and a non-uniform temperature field loading module. The non-uniform temperature field loading module includes a furnace and a heating element. The heating element is installed in the furnace and can heat the furnace. There are several heating elements, and the power is not exactly the same. The circulating cooling module includes an air cooling channel and a cooling air pump. There is at least one air cooling channel. One end of the air cooling channel is connected to the cooling air pump and the other end is connected to the furnace. The heating element and the cooling air pump are both connected to the signal of the fully automatic electronic test control module. The ceramic matrix composite flame tube simulation piece can be placed It is positioned in the furnace, and the air outlet of the air-cooling channel is located at the predetermined position of the ceramic-based composite material flame tube simulation component, so that the cold air blown out by the air-cooling channel can produce a non-uniform temperature field on the ceramic-based composite material flame tube simulation component. A temperature sensor is installed in the furnace, and the temperature sensor is connected to the full-automatic electronic test control module signal. The temperature sensor is used to detect the surface temperature of the ceramic-based composite material flame tube simulation component and send the temperature information to the full-automatic electronic test control module. The full-automatic electronic test control module receives and records the temperature signal from the temperature sensor, and controls the heating temperature of the heating element and the cooling efficiency of the cooling air pump.

[0009] In order to achieve the above technical objectives, the technical solution adopted by the present invention is:

[0010] A reserved slot is provided in the furnace, and the heating element, the air cooling channel part located in the furnace and the temperature sensor are all positioned in the furnace through the reserved slot.

[0011] The heating element is connected to an electrode module, which is used to receive signals from the full-automatic electronic test control module and control the heating element to heat according to the signals. The electrode module is fixed on the outside of the furnace.

[0012] The circulating cooling module also includes a water cooling channel and a water cooler. The water cooler is connected to the automatic electronic test control module signal. The water cooling channel is arranged on the outside of the furnace. The water cooler is connected to the water cooling channel. The water cooler can input coolant into the water cooling channel. The water cooling channel cools the electrode module and the outer surface of the furnace through heat exchange. A temperature sensor is also installed on the outer surface of the furnace. The temperature sensor located on the outer surface of the furnace is also connected to the automatic electronic test control module signal.

[0013] The upper end of the furnace is open, and a lifting device is provided above the furnace. The lifting device includes a lifting device downward pressure platform, a limiting mechanism, a lifting device stepper motor, a guide rod and a mounting guide rail. A fixed platform is provided at the upper end of the mounting guide rail, and the lower end is fixedly connected to the upper end of the furnace. The lifting device stepper motor is fixedly mounted on the fixed platform, and the lower end of the lifting device stepper motor is connected to the lifting device downward pressure platform. The lifting device stepper motor can drive the lifting device downward pressure platform to seal the upper end opening of the furnace. The limiting mechanism is a flat plate with several vertical perforations. The limiting mechanism is fixed on the mounting guide rail, the guide rod passes through the vertical perforations on the limiting mechanism and slides with the limiting mechanism, and the lower end of the guide rod is fixedly connected to the lifting device downward pressure platform.

[0014] Both the air cooling channel and the water cooling channel pass through the lower pressure platform of the lifting device.

[0015] The bottom of the mounting guide rail is fixedly connected to the furnace through a connecting plate. A sealing slot is provided in the connecting plate, and a sealing ring is provided in the sealing slot. When the lower pressure platform of the lifting device is pressed on the upper opening of the furnace, the sealing ring is used to seal the gap between the lower pressure platform of the lifting device and the upper opening of the furnace.

[0016] The non-uniform temperature field loading module is installed on a bench, and rollers are provided at the bottom of the bench.

[0017] The lifting device also includes a limiter, which includes an infrared limit sensor, a fixing ring and an infrared limit rod. The fixing ring is detachably fixed at a predetermined height of the mounting guide rail, the infrared limit sensor is fixed on the fixing ring, and the infrared limit rod is fixed on the lifting device's downward pressure platform or guide rod. The infrared limit sensor is connected to the lifting device stepper motor signal. When the lifting device stepper motor drives the lifting device's downward pressure platform to move to a predetermined position, the infrared limit sensor can just sense the infrared limit rod, and the infrared limit sensor sends a signal to the lifting device stepper motor, and the lifting device stepper motor stops operating.

[0018] The thermal cycle reliability evaluation method of a ceramic matrix composite flame tube is based on the thermal cycle device of the ceramic matrix composite flame tube. The specific evaluation method includes the following steps:

[0019] Step 1: Install a predetermined number of temperature sensors and heating elements at predetermined positions in the furnace, and calculate whether the temperature field and temperature gradient can meet the experimental requirements. If so, proceed to step 2. If not, reconfigure the positions and quantities of temperature sensors and heating elements until the experimental requirements are met.

[0020] Step 2: Assemble the ceramic-based composite flame tube simulation into the furnace, lower the lifting device above the furnace, seal the furnace, connect the fully automatic electronic test control module to each temperature sensor and heating element, connect the air cooling channel and water cooling channel to the circulating cooling module, and test the airtightness; enter the preset test program into the fully automatic electronic test control module, start the device to start the test and record the parameters;

[0021] Step 3. The fully automatic electronic test control module controls the temperature rise of the heating element. The fully automatic electronic test control module controls the cold air blown out of the air cooling channel. Since the power of different heating elements in the temperature field is different, the size of the cold air blown out of the air cooling channel is controllable. Therefore, the inside of the furnace presents a non-uniform temperature field. The fully automatic electronic test control module collects the temperature field signal in the non-uniform temperature field loading module through the temperature measuring sensor, and determines whether the temperature gradient of the temperature field meets the experimental requirements. If so, the operation of the heating element and the air cooling channel is maintained. If not, the temperature of the heating element and the cold air blown out of the air cooling channel are adjusted to make the temperature gradient of the temperature field meet the experimental requirements, and then the operation of the heating element and the air cooling channel is maintained.

[0022] Step 4: After the predetermined test time, the fully automatic electronic test control module stops heating the heating element, lowers the temperature in the furnace to room temperature, raises the lifting device, and removes the ceramic matrix composite flame tube simulation from the furnace to evaluate the reliability of the ceramic matrix composite flame tube simulation. The specific evaluation method is as follows:

[0023] γ1 is used to represent the initial modulus degradation coefficient of the ceramic matrix composite flame tube simulation after the temperature difference thermal cycle test, and γ2 is used to represent the tensile failure strength degradation coefficient of the ceramic matrix composite flame tube simulation after the temperature difference thermal cycle test:

[0024]

[0025]

[0026] Among them E s 、S s It represents the initial modulus and failure strength of the ceramic matrix composite flame tube simulation after the temperature difference thermal cycle test, E r 、S r It represents the initial modulus and failure strength of the ceramic matrix composite flame tube simulation before the temperature difference thermal cycle test. Both γ1 and γ2 are less than . The closer γ1 and γ2 are to 1, the higher the reliability.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. The test method of the present invention can be applied to different types of aero-engine CMC hot-end components. Based on this test method, the degradation of the residual mechanical properties of aero-engine CMC hot-end components under different gradient ambient temperatures can be obtained, which is of great significance for aero-engine structural design and life assessment.

[0029] 2. The present invention proposes a temperature difference thermal cycle test scheme for a ceramic-based composite flame tube simulation component of an aircraft engine under complex ambient temperatures, and has the capability of fully automated unattended testing, which saves test manpower, reduces human control errors, and improves test efficiency and test accuracy.

[0030] 3. The system has a wide test range and strong robustness. The test temperature can reach up to 1200°C, the maximum temperature difference range can reach 400°C, and the maximum test duration can reach 1 month. The system can perform temperature self-calibration during the heating process, with a temperature control error of ±10°C.

[0031] 4. The present invention has flexible scalability and versatility. It can realize complex temperature field testing of various high-temperature components of aircraft engines such as aircraft engine turbine blades, tail nozzle adjustment plates, etc. by simply modifying the internal shape of the furnace, the layout of the heating elements, the position of the cooling slots, and the position of the temperature sensors. The modular improvement cost of the system device is low, and the efficiency of carrying out the same type of tests is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 Schematic diagram of the overall system structure;

[0033] Figure 2This is a schematic diagram of the lifting device structure of the fully automatic electronic test control module;

[0034] Figure 3 This is a schematic diagram of the limit mechanism structure of the fully automatic electronic test control module;

[0035] Figure 4 It is a flow chart of temperature field control and regulation of temperature difference thermal cycle;

[0036] Figure 5 This is a schematic diagram of removing the cambered surface test piece from the CMC flame tube simulation and clamping it in the fixture;

[0037] Figure 6 It is the real-time temperature data of the inner and outer walls of the CMC flame tube simulation part collected by the temperature sensor;

[0038] Figure 7 This is a comparison chart of the mechanical responses of the CMC flame tube simulation component before and after the temperature difference thermal cycle.

[0039] The accompanying drawings are marked as follows: 1-test bench, 2-lifting device, 3-limiting mechanism, 4-furnace, 5-heating element, 6-temperature sensor, 7-air cooling channel, 8-water cooling channel, 9-electrode module, 10-circulating cooling module, 11-full-automatic electronic test control module, 12-lifting device lower pressure platform, 13-lifting device stepper motor, 14-sealing slot, 15-guide rod, 16-mounting guide rail, 17-infrared limit sensor, 18-fixing ring, 19-infrared limit rod, 20-ceramic matrix composite material flame tube simulation part, 21-ceramic matrix composite material flame tube simulation part arc surface test piece, 22-high temperature alloy fixture, 23-arc surface matching clamp. DETAILED DESCRIPTION

[0040] The embodiments of the present invention are described in further detail below with reference to the accompanying drawings.

[0041] It should be noted that the terms such as "upper", "lower", "left", "right", "front", "back", etc. cited in the invention are only for the convenience of description and are not used to limit the scope of implementation of the present invention. Changes or adjustments to their relative relationships should be regarded as the scope of implementation of the present invention without substantially changing the technical content.

[0042] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments:

[0043] like Figure 1As shown, the apparatus of the present invention comprises a fully automatic electronic test control module 11, a circulating cooling module 10, and a non-uniform temperature field loading module. After the ceramic matrix composite flame tube simulator 20 is assembled and placed in the non-uniform temperature field loading module, the fully automatic electronic test control module 11 collects temperature data of the inner and outer walls of the ceramic matrix composite flame tube simulator 20. It then dynamically adjusts the temperature field within the furnace 4 of the non-uniform temperature field loading module through feedback control of the circulating cooling module 10 and the heating element 5 in the non-uniform temperature field loading module, maintaining a stable high-temperature temperature field and a non-uniform temperature gradient load, and performing cyclic loading.

[0044] The non-uniform temperature field loading module includes a stand 1, a lifting device 2, a limiting mechanism 3, a furnace 4, a heating element 5, a temperature sensor 6, an air cooling channel 7 and a water cooling channel 8.

[0045] The stand 1 is the main body of the device, providing assembly space for the entire device and its accessories. The base is equipped with a counterweight block for a stable structure and rollers for easy movement.

[0046] The lifting device 2 is installed above the furnace 4 and is used to control the opening and closing of the upper part of the furnace 4;

[0047] The limit mechanism 3 is mounted on the mounting guide rail 16 and is used to limit the guide rod 15 so that the guide rod 15 can only move vertically up and down. The limiter is mounted on the movement axis of the lifting device and is used to adjust the stroke of the lifting device. It is used to verify whether the lifting device has reached the specified position and feedback the corresponding signal to the lifting device stepper motor 13 or the fully automatic electronic test control module 11. The fully automatic electronic test control module 11 controls the operation of the lifting device stepper motor 13 according to the feedback signal.

[0048] The furnace 4 serves as the installation space for the test piece and the high-temperature environment thermal gradient space. It has slots for the temperature sensor 6, the heating element 5, the air cooling channel 7, and the water cooling channel 8. These slots can be customized according to the test method and the shape of the test piece.

[0049] The heating element 5 is installed in the furnace 4 through the slot reserved by the device and the furnace 4. It is connected to the electrode module 9 on the outer side of the furnace 4 and heats the ambient temperature by receiving the heating signal from the full-automatic electronic test control module 11. The number and installation position of the heating element 5 are related to the shape of the test piece, the test environment layout and the test purpose. In this embodiment, a total of 6 1000W heating elements 5 and 1 2000W heating element 5 are arranged for the ceramic-based composite flame tube simulation piece 20;

[0050] The number and installation position of the temperature sensors 6 are related to the shape of the test piece, the test environment layout and the test purpose. In this embodiment, three temperature sensors 6 are installed on the inner wall of the ceramic matrix composite flame tube simulation piece 20, and three temperature sensors 6 are installed on the outer wall;

[0051] The air cooling channel 7 and the water cooling channel 8 are both connected to the circulating cooling module and are controlled by signals sent by the fully automatic electronic test control module 11. The water cooling channel 8 is arranged inside the device and is used to cool the outer wall of the device and non-high temperature resistant components such as the electrode module 9. The air cooling channel 7 is arranged inside the furnace and is used to adjust the temperature field temperature inside the device. This embodiment reserves three compressed air cooling channels 7 and one water cooling channel 8;

[0052] The circulating cooling module 10 includes a water chiller and a cooling air pump, both of which are directly controlled by the fully automatic electronic test control module 11. The power of the cooling air and coolant input into the device is adjusted by obtaining the cooling adjustment signal of the temperature control system;

[0053] The fully automatic electronic test control module 11 sets the ambient temperature and duration in the furnace, receives the temperature signal transmitted by the temperature sensor 6, and sends signals to the circulating cooling module 10 and the heating element 5 through feedback adjustment to control the internal temperature field of the device and record the temperature and time test data.

[0054] like Figure 2 Figure 2 shows a detailed schematic diagram of the structure of lifting device 2. The lifting device's stepper motor 13 is directly controlled by the fully automatic electronic test control module 11, which uses feedback signals to control the position of the lifting device's downward pressure platform 12. The lifting device's stepper motor 13 drives the guide rod 15 to move, with the direction of movement calibrated by the limit mechanism 3.

[0055] like Figure 3 The figure shows a detailed schematic diagram of the structure of the limit mechanism 3. When the lifter stepper motor 13 drives the lifter's downward pressure platform 12, it also moves the infrared limit rod 19. Upon receiving the signal from the infrared limit rod 19, the infrared limit sensor 17 sends a signal to the fully automatic electronic test control module 11. The control system then transmits the signal to the lifter stepper motor 13, causing the lifter's downward pressure platform 12 to stop and reach the designated position. The fixed ring 18 adjusts the position of the infrared limit sensor 17 and arranges the position of the lifter's downward pressure platform 12 according to the test requirements, furnace structure, and heat dissipation channels.

[0056] The following is a detailed test process and Figure 4 The temperature control and regulation flow chart of the temperature difference thermal fatigue system further illustrates the present invention:

[0057] A furnace 4 is designed for the ceramic-based composite flame tube simulation part 20 to be tested as needed, the number and installation positions of the temperature sensors 6 and the heating elements 5 are designed, and whether the temperature gradient of the temperature field meets the requirements is calculated. In this embodiment, a total of 6 1000w heating elements 5 and 1 2000w heating element 5 are arranged for the ceramic-based composite flame tube simulation part 20, 3 temperature sensors 6 are installed on the inner wall of the ceramic-based composite flame tube simulation part 20, and 3 temperature sensors 6 are installed on the outer wall, and 3 compressed air cooling channels 7 and 1 water cooling channel 8 are reserved; the ceramic-based composite flame tube simulation part 20 is assembled into the furnace 4, the lifting device 2 is installed and sealed, and the fully automatic electronic test control module 11 is connected to each component; the air cooling channel 7 and the water cooling channel 8 are connected to the circulating cooling module 10, and the airtightness is tested; the preset test program is input into the fully automatic electronic test control module 11, the device is started to start the test and record the parameters.

[0058] The setting control program of the test requirements is input into the fully automatic electronic test control module 11, and the module immediately sends out a temperature control signal and a cooling control signal, wherein the temperature control signal is sent to the heating element 5, and the power of different heating elements 5 in the temperature field is different; on the one hand, the cooling control signal sends the cooling signal to the circulating cooling module 10 to adjust the cooling power of the water cooling device and the air cooling device; at the same time, the fully automatic electronic test control module 11 collects the temperature field signal in the non-uniform temperature field loading module through the temperature sensor 6, and the internal program determines whether the temperature field and its temperature gradient meet the experimental requirements and the preset value, and the above process is repeated and finally reaches a stable state. Therefore, the fully automatic electronic test control module 11 realizes comprehensive control of the non-uniform temperature field by outputting signals to the non-uniform temperature field loading module and the circulating cooling module 10, and collecting the non-uniform temperature field signal through the temperature sensor 6, such as Figure 6 Shown is the real-time temperature data of the inner and outer walls of the ceramic-based composite flame tube simulation component 20 collected by the temperature sensor 6.

[0059] The present invention is further described below by describing the assembly of the ceramic matrix composite flame tube simulation arc surface test piece 21 in the high temperature alloy fixture 22 and the residual strength test:

[0060] like Figure 5As shown, the ceramic-based composite flame tube simulator 20 is divided into eight equal parts by water jet cutting to obtain a ceramic-based composite flame tube simulator curved surface test piece 21. This step can also be completed by high-precision diamond wire cutting and laser cutting. The ceramic-based composite flame tube simulator curved surface test piece 21 is installed in a high-temperature alloy fixture 22, wherein the curved surface mating clamp 23 fully mates with the ceramic-based composite flame tube simulator curved surface test piece 21. The clamp is machined with horizontal grooves to increase friction. The tightening force of the screws on the fixture cover is 7N·m. This clamping method ensures that the test piece does not slip and fall off before tensile fracture. This step can be adjusted by changing the size of the curved surface mating clamp 23 to accommodate test pieces of different sizes.

[0061] The assembled ceramic matrix composite flame tube simulation arc surface test piece 21 and high temperature alloy fixture 22 were installed on the testing machine. The fixture was connected to water cooling, the high temperature furnace of the testing machine was heated, and the preload force of the testing machine was set to 100N. The strain of the ceramic matrix composite flame tube simulation arc surface test piece 21 in a high temperature environment was obtained by non-contact strain field measurement. The above steps were repeated to carry out high temperature static tensile test on the reference test piece. The residual strength test of the CMC flame tube simulation piece and the reference test piece was carried out to obtain the residual mechanical properties of the CMC flame tube simulation piece before and after the temperature difference thermal cycle test.

[0062] The following is an explanation of the test results of the specific embodiments of the present invention Figure 7 To further illustrate the present invention, the following steps can be used to calculate the effect of the thermal cycle test on the mechanical properties of the ceramic matrix composite flame tube simulation 20, thereby evaluating the service reliability of the CMC flame tube under thermal cycle loads:

[0063] like Figure 7Figure 2 shows a comparison of the mechanical properties of the ceramic matrix composite flame tube simulator 20 before and after thermal cycling. This shows that the nonlinear characteristics of the stress-strain response of the ceramic matrix composite flame tube simulator 20 before thermal cycling are quite evident. Before thermal cycling, the ceramic matrix composite flame tube simulator 20 had an initial linear modulus of 230.02 GPa. When the tensile stress reached 170.89 MPa, it entered a second linear modulus of 38.52 GPa, a failure strength of 253.63 MPa, and a failure strain of 0.00288. After thermal cycling, the ceramic matrix composite flame tube simulator 20 exhibited a significant decrease in both initial modulus and failure strength compared to before the thermal cycling test. After thermal cycling, the ceramic matrix composite flame tube simulator 20 had an initial modulus of 23.17 GPa, a final failure strength of 217.41 MPa, and a failure strain of 0.00867. The test results show that the residual mechanical properties of the ceramic matrix composite flame tube simulation 20 have been significantly reduced after the temperature differential thermal cycling test. During the temperature differential thermal cycling test, the repeated application of thermal loads caused many cracks in the SiC matrix of the CMC, and degradation phenomena such as debonding and cracking occurred at the interface, resulting in a particularly significant decrease in the initial modulus. γ1 is used to represent the initial modulus degradation coefficient of the CMC flame tube simulation after the temperature differential thermal cycling test, and γ2 is used to represent the tensile failure strength degradation coefficient:

[0064]

[0065] Among them E s 、S s It represents the initial modulus and failure strength of the CMC flame tube simulation after temperature difference thermal cycle, E r 、S r The initial modulus and failure strength of the CMC flame tube simulation before the thermal cycle are shown in Table 1. The degradation of mechanical properties before and after the thermal cycle test is shown in Table 1.

[0066] Table 1 Comparison of mechanical properties before and after cyclic temperature gradient loading test

[0067]

[0068]

[0069] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present application.

[0070] Obviously, those skilled in the art may make various changes and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application is intended to include these modifications and variations.

Claims

1. A ceramic matrix composite flame tube temperature difference heat cycle device, characterized in that: The invention comprises a fully automatic electronic test control module (11), a circulating cooling module (10) and a non-uniform temperature field loading module, wherein the non-uniform temperature field loading module comprises a furnace (4) and a heating element (5), wherein the heating element (5) is installed in the furnace (4) and can heat the furnace (4), wherein there are several heating elements (5) and the power is not completely the same, wherein the circulating cooling module (10) comprises an air cooling channel (7) and a cooling air pump, wherein there is at least one air cooling channel (7), wherein one end of the air cooling channel (7) is connected to the cooling air pump and the other end is connected to the furnace (4), wherein the heating element (5) and the cooling air pump are both connected to the fully automatic electronic test control module (11), wherein the non-uniform temperature field loading module comprises a furnace (4) and a heating element (5), wherein the heating element (5) and the cooling air pump are ... The ceramic matrix composite flame tube simulation part (20) can be positioned in the furnace (4), and the air outlet of the air cooling channel (7) is located at a predetermined position of the ceramic matrix composite flame tube simulation part (20), so that the cold wind blown out by the air cooling channel (7) can generate a non-uniform temperature field for the ceramic matrix composite flame tube simulation part (20). A temperature sensor (6) is installed in the furnace (4), and the temperature sensor (6) is connected to the full-automatic electronic test control module (11) by signal. The temperature sensor (6) is used to detect the surface temperature of the ceramic matrix composite flame tube simulation part (20) and transmit the temperature signal to the temperature sensor. The information is sent to a fully automatic electronic test control module (11), and the fully automatic electronic test control module (11) receives and records the temperature signal from the temperature sensor (6), and controls the heating temperature of the heating element (5) and the cooling efficiency of the cooling air pump; the upper end of the furnace (4) is open, and a lifting device (2) is provided above the furnace (4), and the lifting device (2) includes a lifting device pressing platform (12), a limiting mechanism (3), a lifting device stepping motor (13), a guide rod (15) and a mounting rail (16), and the upper end of the mounting rail (16) is provided with a fixed platform, and the lower end is fixedly connected to the upper end of the furnace (4), and the lifting device A stepper motor (13) is fixedly mounted on a fixed platform, a lower end of the lifting device stepper motor (13) is connected to the lifting device downward pressure platform (12), the lifting device stepper motor (13) can drive the lifting device downward pressure platform (12) to move downward, so that the lifting device downward pressure platform (12) seals the upper end opening of the furnace (4), the limiting mechanism (3) is a flat plate with a plurality of vertical through holes, the limiting mechanism (3) is fixed on the mounting guide rail (16), the guide rod (15) passes through the vertical through holes on the limiting mechanism (3) and is slidably matched with the limiting mechanism (3), and the lower end of the guide rod (15) is fixedly connected to the lifting device downward pressure platform (12);The lifting device (2) further comprises a limiter, the limiter comprising an infrared limit sensor (17), a fixing ring (18) and an infrared limit rod (19), the fixing ring (18) being detachably fixed at a predetermined height of the mounting guide rail (16), the infrared limit sensor (17) being fixed on the fixing ring (18), the infrared limit rod (19) being fixed on the lifting device pressing platform (12) or the guide rod (15), the infrared limit sensor (17) being connected to the lifting device stepping motor (13) by signal, when the lifting device stepping motor (13) drives the lifting device pressing platform (12) to move to a predetermined position, the infrared limit sensor (17) can just sense the infrared limit rod (19), the infrared limit sensor (17) sends a signal to the lifting device stepping motor (13), and the lifting device stepping motor (13) stops operating.

2. The ceramic matrix composite flame tube temperature difference heat cycle device according to claim 1, characterized in that: A reserved slot is provided in the furnace (4), and the heating element (5), the air cooling channel (7) portion located in the furnace (4), and the temperature sensor (6) are all positioned in the furnace (4) through the reserved slot.

3. The ceramic matrix composite flame tube temperature difference heat cycle device according to claim 1, characterized in that: The heating element (5) is connected to an electrode module (9), and the electrode module (9) is used to receive a signal from a full-automatic electronic test control module (11) and control the heating element (5) to heat according to the signal. The electrode module (9) is fixed on the outside of the furnace (4).

4. The ceramic matrix composite flame tube temperature difference heat cycle device according to claim 3, characterized in that: The circulating cooling module (10) further includes a water cooling channel (8) and a water cooling machine, the water cooling machine is connected to the full-automatic electronic test control module (11) by signal, the water cooling channel (8) is arranged outside the furnace (4), the water cooling machine is connected to the water cooling channel (8), the water cooling machine can input cooling liquid into the water cooling channel (8), the water cooling channel (8) cools the electrode module (9) and the outer surface of the furnace (4) through heat exchange, and the outer surface of the furnace (4) is also installed with a temperature sensor (6), and the temperature sensor (6) located on the outer surface of the furnace (4) is also connected to the full-automatic electronic test control module (11) by signal.

5. The ceramic matrix composite flame tube temperature difference heat cycle device according to claim 4, characterized in that: The air cooling channel (7) and the water cooling channel (8) both pass through the lifting device lowering platform (12).

6. The ceramic matrix composite flame tube temperature difference heat cycle device according to claim 4, characterized in that: The bottom of the mounting guide rail (16) is fixedly connected to the furnace (4) via a connecting plate, a sealing slot (14) is provided in the connecting plate, a sealing ring is provided in the sealing slot (14), and when the lifting device pressing down platform (12) is pressed on the upper end opening of the furnace (4), the sealing ring is used to seal the gap between the lifting device pressing down platform (12) and the upper end opening of the furnace (4).

7. The ceramic matrix composite flame tube temperature difference heat cycle device according to claim 1, characterized in that: The non-uniform temperature field loading module is installed on a stand (1), and a roller is provided at the bottom of the stand (1).

8. A method for evaluating the thermal cycle reliability of a ceramic matrix composite flame tube, characterized in that: The ceramic matrix composite flame tube temperature difference thermal cycle device according to claim 4 is used, and the specific evaluation method includes the following steps: Step 1: Install a predetermined number of temperature measuring sensors (6) and heating elements (5) at predetermined positions of the furnace (4), and calculate whether the temperature field temperature gradient can meet the experimental requirements. If the experimental requirements are met, proceed to step 2. If the experimental requirements cannot be met, reconfigure the positions and numbers of the temperature measuring sensors (6) and heating elements (5) until the experimental requirements are met. Step 2: Assemble the ceramic-based composite flame tube simulation part (20) into the interior of the furnace (4), lower the lifting device (2) above the furnace (4), close the furnace (4), connect the fully automatic electronic test control module (11) to each temperature sensor (6) and the heating element (5), connect the air cooling channel (7) and the water cooling channel (8) to the circulating cooling module (10), and test the airtightness; input the preset test program into the fully automatic electronic test control module (11), start the device to start the test and record the parameters; Step 3, the fully automatic electronic test control module (11) controls the heating element (5) to heat up, and the fully automatic electronic test control module (11) controls the cold air blown out of the air cooling channel (7). Since the power of different heating elements (5) in the temperature field is different, the size of the cold air blown out of the air cooling channel (7) is controllable, so the inside of the furnace (4) presents a non-uniform temperature field. The fully automatic electronic test control module (11) collects the temperature field signal in the non-uniform temperature field loading module through the temperature sensor (6) to determine whether the temperature gradient of the temperature field meets the experimental requirements. If the experimental requirements are met, the operation of the heating element (5) and the air cooling channel (7) is maintained. If the experimental requirements are not met, the temperature of the heating element (5) and the cold air blown out of the air cooling channel (7) are adjusted so that the temperature gradient of the temperature field meets the experimental requirements, and then the operation of the heating element (5) and the air cooling channel (7) is maintained. Step 4: After the predetermined experimental time, the fully automatic electronic test control module (11) stops the heating of the heating element (5), reduces the temperature in the furnace (4) to room temperature, raises the lifting device (2), takes the ceramic matrix composite material flame tube simulation part (20) out of the furnace (4), and evaluates the reliability of the ceramic matrix composite material flame tube simulation part (20). The specific evaluation method is as follows: adopt represents the initial modulus degradation coefficient of the ceramic matrix composite flame tube simulation part (20) after the temperature difference thermal cycle test, It represents the degradation coefficient of tensile failure strength of ceramic matrix composite flame tube simulation (20) after temperature difference thermal cycle test: ; ;in 、 represents the initial modulus and failure strength of the ceramic matrix composite flame tube simulation part (20) after the temperature difference thermal cycle test, 、 represents the initial modulus and failure strength of the ceramic matrix composite flame tube simulation part (20) before the temperature difference thermal cycle test, 、 are all less than 1, 、 The closer it is to 1, the higher the reliability.

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