A Thermomechanical Fatigue Test System Based on Quartz Lamp Radiant Heating

Abstract

A thermal mechanical fatigue test system based on quartz lamp radiation heating comprises a heating module, a fixture, a control module, an air cooling submodule, a water cooling submodule and a fatigue testing machine. The fatigue testing machine can simulate the fatigue load of a metal or non-metallic specimen in a service environment, and can also simulate the mechanical fatigue-high temperature creep fatigue of the metal or non-metallic specimen. A U-shaped quartz lamp tube is used to uniformly radiate heat on the surface of the test piece, so that the surface of the test piece forms a temperature field similar to that borne during operation. At the same time, the lamp power is adjusted by a control system to simulate the surface temperature field in the service environment. The cooling module can cool down the ceramic end of the quartz lamp tube of the heating module to extend the service life of the lamp tube, and can also cool down the test piece to achieve a temperature gradient, which is more in line with the assessment requirements of a real extreme service environment and solves the problem that the currently commonly used heating methods are difficult to truly simulate the service temperature field.

Description

Technical Field

[0001] The invention relates to a thermomechanical fatigue test system, in particular to a thermomechanical fatigue test system based on quartz lamp radiation heating, which is suitable for thermomechanical fatigue assessment of metal or non-metal hot end components of aircraft engines and has a good thermal environment simulation effect. Background Art

[0002] Thermomechanical fatigue (TMF) failure of aircraft engine turbine blades and other hot end components is the main failure mode during the service of aircraft engines, which seriously affects the safe and reliable operation of aircraft engines. Testing the thermomechanical fatigue resistance and service life of aircraft engine turbine blades through thermomechanical fatigue tests, updating and improving the blades and evaluating their life according to the test results are important tasks in the design and service of aircraft engine turbine blades.

[0003] Most existing methods for thermomechanical fatigue testing of high-temperature alloy turbine blades use gas thermal shock, high-frequency electromagnetic induction heating, etc. on coated single crystal specimens, and use fatigue testing machines to clamp the specimens to simulate the centrifugal force loads for thermomechanical fatigue testing. However, it is difficult to accurately control the temperature of the specimens with high-temperature gas, and it is difficult to achieve uniform heating of the specimens; high-frequency electromagnetic induction heating is a method of using electromagnetic induction to heat electrical conductors (usually metals), which will generate eddy currents in the metal and cause Joule heating of the metal due to resistance. This heating method is only applicable to metal specimens and does not conform to the actual service conditions of turbine blades, especially for turbine blades with ceramic coatings, whose heat transfer method is quite different from the actual situation.

[0004] The Chinese invention patent application with application number 201110460131 discloses a thermomechanical fatigue test system for hollow air-cooled turbine blades. The test system clamps the blades with a high-temperature fixture under static conditions, and the fatigue load is provided by a fatigue testing machine and the temperature load is provided by a high-frequency electromagnetic induction heating furnace to conduct a thermomechanical fatigue test on the blades. The problem with this test system is that it uses high-frequency electromagnetic induction heating to generate eddy currents inside the blades, and Joule heat is generated due to resistance to achieve the purpose of heating the test piece. However, in reality, the heat of the coated blades is gradually transferred from the outer surface to the inside, and the outer coating is heated first and the temperature rises. The existence of the coating is to prevent the metal substrate from being directly exposed to a high temperature environment, which causes accelerated damage. Therefore, the use of induction heating is inconsistent with the actual service conditions, affecting the accuracy of the experimental results.

[0005] Chinese invention patent application with application number 200910237475 discloses a device and method for thermomechanical fatigue testing. The heating method of the device is a laser heat source and a focusing lens, or an AC power supply and an induction coil. The problem with this test system is that the heating cost using a laser heat source and a focusing lens is high, and it is difficult to achieve large-area heating of the blades; the heating method using an AC power supply and an induction coil is the same as that of Chinese invention patent application number 201110460131, which does not conform to the actual service conditions of the blades and also affects the accuracy of the test results. Summary of the invention

[0006] In view of the problems and shortcomings of the prior art, the purpose of the present invention is to provide a thermomechanical fatigue test system based on quartz lamp radiation heating, which can truly simulate the thermomechanical fatigue test system to which metal or non-metallic specimens of aircraft engine hot end components are actually in service, so as to improve the accuracy and reliability of thermomechanical fatigue test data of metal or non-metallic specimens.

[0007] In order to achieve the above purpose, the technical solution of the present invention is:

[0008] A thermal mechanical fatigue test system based on quartz lamp radiation heating, comprising a heating module 1, a fixture 3, a control module 4, an air cooling submodule 5, a water cooling submodule 6 and a fatigue testing machine 7;

[0009] The heating module 1 comprises a left and a right furnace 1-1, 1-2 connected; aviation plugs 1-7 are installed on both sides of the left and right furnaces 1-1, 1-2; U-shaped quartz lamps 1-3 and thermocouples 1-4 are installed in the left and right furnaces 1-1, 1-2; through holes 1-5 are opened on the upper and lower surfaces of the left and right furnaces 1-1, 1-2 for placing the test piece 2; the sides of the left and right furnaces 1-1, 1-2 are respectively provided with an observation window 1-6, a cooling water inlet 1-10, a cooling water outlet 1-11 and a furnace air cooling channel 1-8 for cooling the test piece;

[0010] The fixture 3 is installed on the fatigue testing machine 7, and a cooling water channel 3-2 and a cooling air channel 3-1 are provided on the fixture 3; the test piece 2 is fixed on the fixture 3;

[0011] The air cooling submodule 5 includes an air compressor 5-5, a dryer 5-6 and a filter 5-7 connected in sequence. The outlet of the filter 5-7 is connected to the cooling air channel 3-1 and the furnace air cooling channel 1-8 through two A and B air cooling channels 5-8 and 5-9 respectively. The A air cooling channel 5-8 is provided with an A air cooling solenoid valve 5-1 and an A air cooling pressure gauge 5-3 in sequence; the B air cooling channel 5-9 is provided with a B air cooling solenoid valve 5-2 and an A air cooling pressure gauge 5-4 in sequence;

[0012] The control module 4 includes a temperature controller 4-2 for controlling the power of the U-shaped quartz lamp 1-3 through an aviation plug 1-7; A and B pressure controllers 4-4 and 4-5 for controlling the air pressure of the A and B air-cooling solenoid valves 5-1 and 5-2 of the air-cooling submodule; the signal ends of the temperature controller 4-2 and the A and B pressure controllers 4-4 and 4-5 are all connected to the computer control unit 4-1, the computer control unit 4-1 is connected to the power supply and the data acquisition card 4-3, and the signal input end of the data acquisition card 4-3 is respectively connected to the load signal of the fatigue testing machine 7, the temperature signal of the thermocouple 1-4, and the pressure signals of the A air-cooling pressure gauge 5-3 and the B air-cooling pressure gauge 5-4;

[0013] The water cooling submodule 6 includes two A and B cooling water channels 6-3 and 6-4 equipped with A and B water cooling pressure gauges 6-5 and 6-6. The A and B cooling water channels 6-3 and 6-4 connect the water tank 6-1 with the inlet of the cooling water channel 3-2 of the fixture 3 through the water pump 6-2, and the outlet of the cooling water channel 3-2 of the fixture 3 is then connected to the water tank; that is, the cooling water is transferred from the water tank 6-1 to the cooling water channel 3-2 inside the fixture 3 through the water pump 6-2, and finally flows back to the cooling water tank 6-1 for circulation cooling.

[0014] The test piece 2 is provided with a centrally-through air-cooling channel 2-1; both ends are provided with external threads 2-2, and the test piece 2 passes through the through hole 1-5 and is fixed on the fixture 3 via the external threads 2-2.

[0015] The center of the fixture 3 is provided with a central cooling water channel 3 - 2 , and the fixture 3 is also circumferentially provided with an annular fixture cooling layer 3 - 7 which is connected with the cooling air channel 3 - 1 on the surface of the fixture 3 .

[0016] Beneficial effects of the present invention:

[0017] 1. The present invention uses a fatigue testing machine to simulate the fatigue load of a metal or non-metallic specimen in a service environment, and can also simulate the mechanical fatigue-high temperature creep fatigue of a metal or non-metallic specimen.

[0018] 2. The present invention adopts a U-shaped quartz lamp tube, which can uniformly radiate heat on the surface of a metal or non-metallic specimen, so that the surface of the specimen forms a temperature field similar to that it is subjected to during operation. At the same time, the power of the lamp tube is adjusted by the control system to simulate the surface temperature field in the service environment, thereby solving the problem that the currently commonly used heating methods are difficult to truly simulate the service temperature field.

[0019] 3. The cooling module of the present invention can not only cool down the ceramic end of the quartz lamp tube of the heating module to extend the service life of the lamp tube, but also cool down the test piece to achieve a temperature gradient, which is more in line with the assessment requirements of a real extreme service environment.

[0020] 4. The present invention is used to perform thermomechanical fatigue tests on metal or non-metal specimens, and the test results are more accurate and reliable than those of the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawing is a schematic diagram of an embodiment of a thermomechanical fatigue test system based on quartz lamp radiation heating according to the present invention, wherein:

[0022] Figure 1 It is the overall structural block diagram of the present invention.

[0023] Figure 2 It is a schematic diagram of the connection between the modules of the present invention.

[0024] Figure 3 It is a schematic diagram of the structure of the heating module 1; wherein, Figure 3 (a) is a cross-sectional view of section AA; (b) is a top view.

[0025] Figure 4 It is a structural diagram of the control module 4.

[0026] Figure 5 It is a structural schematic diagram of the air cooling submodule 5.

[0027] Figure 6 It is a schematic diagram of the structure of the water cooling submodule 6.

[0028] Figure 7 It is a schematic diagram of the installation of the test sample 2 and the heating module 1.

[0029] Figure 8 is a schematic diagram of the structure of the test sample 2, wherein: Figure 8 (a) is the front view and (b) is the axonometric view.

[0030] Fig. 9 is a schematic diagram of the structure of the fixture 3, wherein: Fig. 9 (a) is the axonometric view, (b) is the axonometric view after (a) is rotated, and (c) is the sectional view.

[0031] Explanation of symbols in the figure:

[0032] 1: Heating module; 1-1: Left furnace; 1-2: Right furnace; 1-3: U-shaped quartz lamp; 1-4: Thermocouple; 1-5: Specimen hole; 1-6: Observation window; 1-7: Aviation plug; 1-8: Furnace air cooling channel; 1-9: Hinge; 1-10: Cooling water inlet; 1-11: Cooling water outlet; 2: Test sample; 2-1: Air cooling channel; 2-2: External thread; 3: Fixture; 3-1: Air channel; 3-2: Cooling water channel; 3-3: Internal thread hole; 3-4: Clamping end; 3-5: Fixture cooling outer wall; 3-6: Fixture cooling inner wall; 3-7: Fixture cooling layer; 4: Control module; 4-1: Computer control Control unit; 4-2: Temperature controller; 4-3: Data acquisition card; 4-4: A pressure controller 1; 4-5: B pressure controller 2; 5: Air cooling submodule: 5-1: A air cooling solenoid valve; 5-2: B air cooling solenoid valve; 5-3: A air cooling pressure gauge 1; 5-4: B air cooling pressure gauge; 5-5: Air compressor; 5-6: Dryer; 5-7: Filter; 5-8: A air cooling channel 1; 5-9: B air cooling channel; 6: Water cooling submodule; 6-1: Water tank; 6-2: Water pump; 6-3: A cooling water circuit: 6-4: B cooling water circuit; 6-5: A water cooling pressure gauge; 6-6: B water cooling pressure gauge; 7: Fatigue testing machine. DETAILED DESCRIPTION

[0033] The present invention is further described below in conjunction with embodiments and drawings.

[0034] like Figure 2 As shown, a thermomechanical fatigue test system based on quartz lamp radiation heating includes a heating module 1, a fixture 3, a control module 4, an air cooling submodule 5, a water cooling submodule 6 and a fatigue testing machine 7;

[0035] Combination Figure 2 , Figure 3 , Figure 7 The heating module 1 includes a left furnace 1-1 and a right furnace 1-2 connected by a hinge 1-9; aviation plugs 1-7 are installed on both sides of the left furnace 1-1 and the right furnace 1-2; U-shaped quartz lamps 1-3 and thermocouples 1-4 are installed in the left furnace 1-1 and the right furnace 1-2; through holes 1-5 are opened on the upper and lower surfaces of the left and right furnaces 1-1 and 1-2 for placing the test piece 2, and the surface temperature of the test piece 2 is detected by the thermocouple; the sides of the left and right furnaces 1-1 and 1-2 are respectively provided with observation windows 1-6, cooling water inlets 1-10, cooling water outlets 1-11 and air cooling channels 1-8 for cooling the test pieces.

[0036] Combination Figure 2 and Figure 8The test piece 2 is provided with a centrally-through air-cooling channel 2-1; both ends are provided with external threads 2-2; the test piece 2 passes through the through hole 1-5 and is fixed on a fixture 3 with a cooling water channel 3-2 and a cooling air channel 3-1 through the external threads 2-2; the cooling water channel 3-2 and the cooling air channel 3-1 are used to cool the fixture 3 to prevent the fixture from softening and being damaged in a high temperature environment, which may affect the test accuracy.

[0037] Reference Figure 2 , the fixture 3 is installed on the fatigue testing machine 7; refer to Figure 7 , Fig. 9 A cooling water channel 3-2 is provided in the center of the fixture 3, which is used to cool the fixture to prevent the fixture from softening and being damaged in a high temperature environment, which may affect the test accuracy. The fixture 3 is also circumferentially provided with an annular fixture cooling layer 3-7, which is connected to the cooling air channel 3-1 on the surface of the fixture 3, forming a fixture cooling outer wall 3-5, a fixture cooling inner part 3-6 and a fixture cooling layer 3-7, which are used to cool the inside of the round tube specimen and realize the thermal gradient distribution of the specimen from the outside to the inside.

[0038] Reference Figure 5 The air cooling submodule 5 includes an air compressor 5-5, a dryer 5-6 and a filter 5-7 connected in sequence. The outlet of the filter 5-7 is connected to the cooling air channel 3-1 and the furnace air cooling channel 1-8 through two A and B air cooling channels 5-8 and 5-9 respectively. The A air cooling channel 5-8 is provided with an A air cooling solenoid valve 5-1 and an A air cooling pressure gauge 5-3 in sequence; the B air cooling channel 5-9 is provided with a B air cooling solenoid valve 5-2 and an A air cooling pressure gauge 5-4 in sequence. The A air cooling solenoid valve 5-1 is used to control the internal cooling channel of the sample; the B air cooling solenoid valve 5-2 is used to control the surface cooling channel of the sample; the A air cooling pressure gauge 5-3 detects the cooling channel flow of the A air cooling solenoid valve 5-1; the B air cooling solenoid valve 5-2 detects the cooling channel flow of the B air cooling solenoid valve 5-1. The filter 5-7 is used to filter solid particles in the cooling gas, and the filtering accuracy is not less than 0.1mm.

[0039] Reference Figure 6 The water cooling submodule 6 includes two A and B cooling water channels 6-3 and 6-4 equipped with A and B water cooling pressure gauges 6-5 and 6-6. The A and B cooling water channels 6-3 and 6-4 connect the water tank 6-1 with the inlet of the cooling water channel 3-2 of the fixture 3 through the water pump 6-2, and the outlet of the cooling water channel 3-2 of the fixture 3 is then connected to the water tank; that is, the cooling water is transferred from the water tank 6-1 to the cooling water channel 3-2 inside the fixture 3 through the water pump 6-2, and finally flows back to the cooling water tank 6-1 for circulating cooling. The A water cooling pressure gauge 6-5 is used to detect whether the water path of the cooling fixture is normal; the B water cooling pressure gauge 6-6 is used to detect whether the water path of the cooling and heating module is normal.

[0040] Reference Figure 4 The control module 4 includes a temperature controller 4-2 for controlling the power of the U-shaped quartz lamp 1-3 through an aviation plug 1-7; A and B pressure controllers 4-4 and 4-5 for controlling the air pressure of the A and B air-cooling solenoid valves 5-1 and 5-2 of the air-cooling submodule; the signal ends of the temperature controller 4-2 and the A and B pressure controllers 4-4 and 4-5 are all connected to the computer control unit 4-1, the computer control unit 4-1 is connected to the power supply and the data acquisition card 4-3, and the signal input end of the data acquisition card 4-3 is respectively connected to the load signal of the fatigue testing machine 7, the temperature signal of the thermocouple 1-4, and the pressure signals of the A air-cooling pressure gauge 5-3 and the B air-cooling pressure gauge 5-4. The data acquisition card 4-3 transmits the temperature signal, the load signal and the pressure signal of the fatigue testing machine 7 to the PC control unit 4-1. The PC control unit 4-1 controls the power and air pressure of the U-shaped quartz lamp 1-3 through programming, thereby controlling the temperature of the specimen. By controlling the power of the U-shaped quartz lamp 1-3 and the air pressure of the air cooling submodule 5, the specimen can be quickly heated / cooled, and the temperature loading of the sample temperature in the form of sine wave, triangle wave, trapezoidal wave and other curve waveforms can be realized.

[0041] like Figure 1 As shown, the thermocouple 1-4 in the heating module 1 detects the surface temperature of the test piece 2 through the thermocouple, and transmits the temperature data to the PC control unit 4-1 through the data collector 4-3. The temperature controller 4-2 controls the temperature of the test piece within the allowable range by adjusting the power of the power controller.

[0042] Specifically, the test piece 2 is selected from but not limited to a coated round tube sample.

[0043] Specifically, the observation windows 1-6 are made of quartz glass.

[0044] Specifically, the thermocouples 1-4 are paste-type thermocouples.

[0045] Combination Figure 1 , the working principle of the present invention is:

[0046] The fixture 3 holds the test piece 2 through the test piece hole 1-5 to ensure that the test part of the test piece 2 is completely placed inside the heating module 1. The heating module 1 has a U-shaped quartz lamp 1-3 inside to heat the surface of the test piece 2. The side of the heating module 1 has an observation window 1-6 to monitor the state of the test piece at any time. A cooling water channel 3-2 is provided in the center of the fixture 3; the cooling air channel 3-1 is used to cool the inside of the round tube test piece to achieve a thermal gradient distribution from the outside to the inside of the test piece. The data acquisition card 4-3 transmits the temperature signal, the load signal and the pressure signal of the fatigue testing machine 7 to the PC control unit 4-1. The PC control unit 4-1 controls the power and air pressure of the U-shaped quartz lamp 1-3 through programming, and then controls the temperature of the specimen. By controlling the power of the U-shaped quartz lamp 1-3 and the air pressure of the air cooling submodule 5, the specimen can be quickly heated up / cooled down, and the temperature loading of the sample temperature in the form of sine wave, triangle wave, trapezoidal wave and other curve waveforms can be realized. The heating rate can reach 100℃ / s, the cooling rate can reach 50℃ / s, the maximum temperature is not less than 1100℃, and the error is less than ±5℃ when the steady-state temperature is maintained.

[0047] The heating module 1 of the present invention is based on the quartz lamp radiation heating principle, and adopts a quartz lamp tube to perform radiation heating on the metal or non-metallic test piece. The module can achieve the effect of rapid temperature rise / lowering and high temperature maintenance (>1100℃) of the metal or non-metallic test piece; the control module 4 performs fixed-point temperature control, and the temperature control accuracy is less than ±5℃. At the same time, the temperature gradient heating control can be used to achieve non-uniform heating of the test piece, which is more in line with the ground test of the hot end components of the aircraft engine; the water cooling submodule 5 and the air cooling submodule 6 form a cooling module, and the water cooling submodule 5 is to pump out the cold water of the cooling water tank through the water pump 6-2 and transmit it to the high-temperature fixture 3, and then the heat is brought to the high temperature fixture 3 through the built-in pipeline system of the fixture 3. In order to reduce the temperature of the fixture and prevent the fixture from being softened by heat and thus affecting the test accuracy, the air cooling submodule 5 inhales air from the outside through the air compressor 5-5, compresses it, and then transmits it to the surface of the test sample 2 or the inside of the round tube specimen through the dryer 5-6 and the filter 5-7 to cool it. On the one hand, the surface temperature of the test sample 2 is accurately controlled, and on the other hand, the inside of the specimen is cooled to achieve a thermal gradient distribution of the specimen from the outside to the inside; through the precise control of the heating module 1 and the air cooling submodule 5, the temperature field changes of metal or non-metal specimens in the service environment can be more realistically simulated, so that the thermal mechanical fatigue test results of the specimens are more in line with the actual service conditions than the existing technology.

Claims

1. A thermomechanical fatigue test system based on quartz lamp radiation heating, characterized in that: A heating module (1), a fixture (3), a control module (4), an air cooling submodule (5), a water cooling submodule (6) and a fatigue testing machine (7); The heating module (1) comprises a left and a right furnace (1-1, 1-2) connected to each other; aviation plugs (1-7) are installed on both sides of the left and the right furnaces (1-1, 1-2); U-shaped quartz lamps (1-3) and thermocouples (1-4) are installed in the left and the right furnaces (1-1, 1-2); through holes (1-5) are opened on the upper and lower surfaces of the left and the right furnaces (1-1, 1-2) for placing the test piece (2); the sides of the left and the right furnaces (1-1, 1-2) are respectively provided with an observation window (1-6), a cooling water inlet (1-10), a cooling water outlet (1-11) and a furnace air cooling channel (1-8) for cooling the test piece; The fixture (3) is installed on a fatigue testing machine (7), and a cooling water channel (3-2) and a cooling air channel (3-1) are provided on the fixture (3); the test piece (2) is fixed on the fixture (3); The air cooling submodule (5) comprises an air compressor (5-5), a dryer (5-6) and a filter (5-7) which are connected in sequence; the outlet of the filter (5-7) is respectively connected to the cooling air channel (3-1) and the furnace air cooling channel (1-8) through two A and B air cooling channels (5-8, 5-9); the A air cooling channel (5-8) is provided with an A air cooling solenoid valve (5-1) and an A air cooling pressure gauge (5-3); the B air cooling channel (5-9) is provided with a B air cooling solenoid valve (5-2) and an A air cooling pressure gauge (5-4); The control module (4) comprises a temperature controller (4-2) for controlling the power of a U-shaped quartz lamp (1-3) through an aviation plug (1-7); and A and B pressure controllers (4-4, 4-5) for controlling the air pressure of A and B air-cooling solenoid valves (5-1, 5-2) of the air-cooling submodule; the signal ends of the temperature controller (4-2) and the A and B pressure controllers (4-4, 4-5) are connected to a computer control unit (4-1); the computer control unit (4-1) is connected to a power supply and a data acquisition card (4-3); and the signal input end of the data acquisition card (4-3) is respectively connected to a load signal of a fatigue testing machine (7), a temperature signal of a thermocouple (1-4), and pressure signals of an A air-cooling pressure gauge (5-3) and a B air-cooling pressure gauge (5-4); The water cooling submodule (6) comprises two A and B cooling water channels (6-3, 6-4) equipped with A and B water cooling pressure gauges (6-5, 6-6); the A and B cooling water channels (6-3, 6-4) connect the water tank (6-1) and the inlet of the cooling water channel (3-2) of the fixture (3) through a water pump (6-2); and the outlet of the cooling water channel (3-2) of the fixture (3) is connected to the water tank; that is, the cooling water is transferred from the water tank (6-1) to the cooling water channel (3-2) inside the fixture (3) through the water pump (6-2), and finally flows back to the cooling water tank (6-1) for circulation cooling.

2. A thermomechanical fatigue test system based on quartz lamp radiation heating according to claim 1, characterized in that: The test piece (2) is provided with a centrally-through air cooling channel (2-1); both ends are provided with external threads (2-2); the test piece (2) passes through the through hole (1-5) and is fixed on the fixture (3) via the external threads (2-2).

3. A thermomechanical fatigue test system based on quartz lamp radiation heating according to claim 1, characterized in that: The center of the clamp (3) is provided with a centrally-through cooling water channel (3-2), and the clamp (3) is also circumferentially provided with an annular clamp cooling layer (3-7) which is connected to the cooling air channel (3-1) on the surface of the clamp (3).

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