CN110715862B

CN110715862B - Instrument and method for testing mechanical properties of materials under tension-torsion compound-force thermal coupling working condition

Info

Publication number: CN110715862B
Application number: CN201911104819.1A
Authority: CN
Inventors: 赵宏伟; 方宇明; 李世超; 张晗; 赵久成; 牟禹安
Original assignee: Jilin University
Current assignee: Jilin University
Priority date: 2019-11-13
Filing date: 2019-11-13
Publication date: 2024-06-04
Anticipated expiration: 2039-11-13
Also published as: CN110715862A

Abstract

The invention relates to a device and a method for testing mechanical properties of materials under a tension-torsion compound-force thermal coupling working condition, and belongs to the field of precision instrument equipment. The device comprises a supporting module, a stretching loading module, a torsion loading module, a high-temperature loading module and an in-situ monitoring module, wherein a stretching motor of the stretching loading module is fixed on one side of a first helical gear reducer, and the other side of the first helical gear reducer is fixed on an upper base of the supporting module through a first fixing bolt to realize bidirectional synchronous stretching loading of a tested sample. The invention can carry out loading and testing of a stretching-torsion composite load on a tested sample in a high-temperature environment, dynamically tests the mechanical behavior and performance evolution rule of a material under the action of high-temperature and stretching-torsion complex mechanical load, and has the characteristics of stable structure of the whole machine, abundant compatible modules, high testing precision, high environment complexity of load loading and the like. Providing important foundation and support for material research and development preparation, optimal design of mechanical equipment, life prediction and reliability evaluation.

Description

Instrument and method for testing mechanical properties of materials under tension-torsion compound-force thermal coupling working condition

Technical Field

The invention relates to the field of precision instrument equipment, in particular to precision instrument equipment for testing and representing mechanical properties of materials, and particularly relates to a device and a method for testing mechanical properties of materials under a tension-torsion compound-force thermal coupling working condition. The instrument device can realize the composite loading of the tensile/compression-torsion load of the tested sample in a high-temperature environment, and integrates an in-situ monitoring module to dynamically observe the mechanical behavior and the performance evolution rule of the material under the action of complex mechanical load in real time. The invention provides a new testing method and thought for researching the service performance of the material in complex static and dynamic mechanical load and extreme physical fields; and simultaneously, an important foundation and support are provided for material research and development preparation, optimal design of mechanical equipment, life prediction and reliability evaluation.

Background

The development and application of the material are development foundation stones of the national industry, the material innovation of mechanical parts is small, and the light material selection of plane missiles and warships is large, so that the important position of the material in the national life is highlighted, and the mechanical property test research of the material can promote the parallel development of a plurality of fields. The mechanical property test technology of the material can be divided into macroscopic, mesoscopic and microscopic tests, and common stretching, compression, torsion, bending, fatigue test and the like are to apply mechanical load to a sample; the physical fields such as an electric field, a magnetic field, a temperature field and the like can be coupled with mechanical loads to realize the composite loading of multiple physical fields and multiple mechanical loads, and simulate the working condition of a material in a complex service environment, but the test is generally an off-site test, and the internal structure morphology of the material, the metallographic structure changes of fracture and defect positions can not be dynamically observed in real time. With the continuous innovation of technology, micro-electro-mechanical systems (MEMS) and the rapid development of microscopic imaging technology, the material testing equipment can be provided with microscopic imaging equipment such as a high-depth microscope, an atomic force microscope and the like, observe the microstructure change of the material in real time, develop the research work of combining the inherent mechanism of the microstructure change of the material with the macroscopic mechanical property, and comprehensively characterize each property of the material.

Starting from the 80 s of the last century, some western countries are devoted to researching internal strain of materials, residual stress of defects and the like, have obtained a series of achievements, develop test instruments for testing various loads, start later in the research and development field of domestic test machines, and have certain differences in the precision, load size and stability of material testing equipment. The conventional test technology for stretching, twisting, bending and fatigue of the sample mostly adopts a single load loading mode, and the microstructure change of the sample cannot be monitored in real time in the test process, so that the conventional mechanical property test equipment cannot simulate the working condition of the material in the actual environment. The solid sample in the complex environment is affected by various factors, such as physical fields of high and low temperature, strong and weak magnetic fields, electric fields and the like, and complex mechanical loads of tension, compression, bending, torsion and the like. At present, compound load test equipment has been developed internationally and put into mass production, but the compound load test equipment is expensive and can only realize single loading or sequential loading; furthermore, the evolution rule of mechanical behavior and performance of the research material in the high-temperature physical field and variable-temperature loading process is a focus of attention of researchers at home and abroad, and in the existing research, in-situ test equipment for static and dynamic mechanical load composite loading in a high-temperature environment is rarely available. I.e. the search and research of new materials by humans is limited to a large extent.

Disclosure of Invention

The invention aims to provide a tension-torsion composite-force thermal coupling working condition material mechanical property testing instrument and method, which solve the problems that a testing machine in the prior art is single in loading load type, has no external physical field, cannot couple in-situ observation and mechanical load loading with physical field loading into a whole and the like. The invention relates to a method for carrying out multi-load preloading and multi-load composite loading on a solid sample in a high-temperature environment, wherein a tensile loading module, a torsion loading module and a high-temperature loading module can be independently loaded or combined loaded, and the modules are mutually independent, so that the modular design idea of multi-factor coupling is satisfied. The test equipment integrates data acquisition and a visual window, an in-situ monitoring module is carried to monitor the characteristic deformation and microstructure morphology change of the material in the composite loading process of the tensile load and the torsional load in real time, and image information is fed back to a terminal control unit in time, so that the whole test system forms a closed-loop network.

The above object of the present invention is achieved by the following technical solutions:

the tension-torsion composite-force thermal coupling material mechanical property testing instrument comprises a supporting module 1, a tension loading module 2, a torsion loading module 3, a high-temperature loading module 4 and an in-situ monitoring module, wherein a tension motor 13 of the tension loading module 2 is fixed on one side of a helical gear reducer I14, and the other side of the helical gear reducer 14 is fixed on an upper base 12 of the supporting module 1 through a fixing bolt I22 to realize bidirectional synchronous tension loading on a tested sample 72;

The torsion loading module 3 is coupled with a screw nut pair mechanism of the tension loading module 2 through a flange nut seat 27 on a torsion supporting seat 25, and a torsion motor 53 and a helical gear reducer II 52 are rigidly connected with a torsion supporting plate 42 through a motor seat 50, so that synchronous loading of double-end static torsion load of a tested sample 72 is realized;

the high temperature loading module 4 is rigidly connected with the support plate 7 of the support module 1 through the X-shaped support 63, and is rigidly connected with the upper flange connector 70 and the lower flange connector 73 of the torsion loading module 3 through the upper dynamic seal bellows 57 and the lower dynamic seal bellows 58 respectively, so as to form a vacuum environment or fill inert gas to isolate oxygen, and prevent the oxidation reaction of the tested sample 72 in the high temperature loading process, and influence the experimental result.

The supporting module 1 adopts a vertical four-column layout mode, the upper base 12, the lower base 10 and the supporting plate 7 are rigidly connected with the four columns 11 through locking nuts 5, a bushing 32 is arranged between the first guide plate 6 and the second guide plate 8 and between the second guide plate 11, the bushing 32 is fixed on the second guide plate 8 through M6 screws 33, the bushing 32 is fixed with the retainer ring 30 through M5 screws 29, a dust ring 31 is arranged between the retainer ring 30 and the bushing 32, and the lower base 10 is fixed on the vibration isolation table 9.

The stretching motor 13 of the stretching loading module 2 is rigidly connected with the first helical gear reducer 14, and an output shaft of the first helical gear reducer 14 is matched with the upper end of the connecting shaft sleeve 16 in a key connection mode; the connecting shaft sleeve 16 is provided with three angular contact ball bearings 21 in pairs at the position between shafts, the three angular contact ball bearings 21 bear radial and axial bidirectional combined loads, limit the axial displacement of the connecting shaft sleeve 16 in one direction, transmit the axial force to the upper base 12 of the supporting module 1, and bear the shearing force by the lock nut 5 matched with the upright post 11; the lower end of the connecting shaft sleeve 16 is fixed with a screw rod 19, and the screw rod 19 converts the rotary motion of the output shaft of the stretching motor 13 into the linear motion of the nut 18; the rolling elements between the screw 19 and the nut 18 are uniformly distributed threaded rollers 17.

The torsion loading module 3 comprises a helical gear speed reducer II 52 and a torsion motor 53, the torsion motor 53 is fixedly connected with the helical gear speed reducer II 52, the other end of the helical gear speed reducer II 52 is fixed on a motor base 50, an output shaft of the helical gear speed reducer II 52 is matched with a torsion shaft 51 through key connection, a deep groove ball bearing I43 is arranged at the position between the other end shaft of the torsion shaft 51, and a small end cover 44 of the bearing matched with the deep groove ball bearing I43 is fixed on a bearing seat 45.

After the speed and torque of the helical gear reducer II 52 of the torsion loading module 3 are reduced, power is transmitted to the torsion shaft 51 through the output shaft of the helical gear reducer II 52, the torsion shaft 51 is transmitted to the central shaft 39 through the synchronous belt 47, the small belt pulley 48 and the large belt pulley 37, one end of the central shaft 39 is connected with the circular grating encoder 24, the other end of the central shaft is connected with the clamp assembly through the intermediate connecting piece I69, the torsion supporting plate 42 is fixedly connected to the torsion supporting seat 25 through a bolt, and the angular contact ball bearing I36 in the torsion supporting seat 25 is matched with the central shaft 39 to limit the radial displacement of the central shaft 39; the second angular contact ball bearings 41 are installed in pairs between the other side shafts of the central shaft 39, the outer diameters of the second angular contact ball bearings 41 are matched with the inner holes of the torsion supporting seats 25, the torsion supporting plates 42 and the torsion supporting seats 25 are transmission bases of the whole torsion loading module 3, the freedom degree of the central shaft 39 can be limited, and only rotation around the axis can be achieved, so that torsion load loading is completed.

The high-temperature loading module 4 adopts a heating mode of a high-temperature furnace, the furnace body is of a vertical square structure, the furnace body is rigidly connected with the supporting plate 7 of the supporting module 1 through the X-shaped supporting seat 63, the X-shaped supporting seat 63 moves on the guide rail 62 through the sliding block 60, the height of the high-temperature furnace can be adjusted, and the movement of the high-temperature loading module 4 in the Z direction is realized; the front furnace door 65 of the high-temperature loading module 4 is provided with a quartz glass observation window 64 and a high-temperature colorimeter observation hole 67; the double-layer quartz glass observation window 64 is inlaid at the central observation hole of the front furnace door 65, the outer layer quartz glass is pressed by the pressing plate and fixed on the outer wall of the front furnace door 65, and the quartz glass observation window 64 and the high-temperature furnace body 59 are mutually independent modules and can be installed and detached according to working conditions.

The furnace chamber material of the high-temperature heat furnace of the high-temperature loading module 4 is alumina ceramic fiber material, the surface of the furnace chamber is coated with a high-temperature alumina coating, the high-temperature loading module 4 adopts a three-gradient heat preservation layer 55 structure, and the furnace lining, the cellucotton and the fiber furnace chamber are made of polycrystalline mullite ceramic fiber material and alumina fiber material.

The heating element of the high-temperature loading module 4 is a U-shaped silicon molybdenum rod 54, the U-shaped silicon molybdenum rod 54 is vertically hung in a ceramic fiber furnace chamber 56, the single-side door opening mode is designed in the high-temperature furnace, three groups of U-shaped silicon molybdenum rods 54 are respectively hung and installed on three planes of the furnace body, and the three groups of U-shaped silicon molybdenum rods 54 are connected in series.

The front furnace door 65 of the high-temperature loading module 4 is provided with a high Wen Bise measuring observation hole 67, and the colorimetric heat metering probe is matched with the high Wen Bise measuring observation hole 67 to measure the ambient temperature of a sample.

The invention further aims to provide a method for testing mechanical properties of materials under the tension-torsion compound-force thermal coupling working condition, which comprises the following steps:

step one: each sub-module of the test equipment is inspected and the test specimen 72 is mounted. The test purpose, load type, load size and the required temperature environment were analyzed. Checking whether each sub-module and connecting piece of the test equipment are normal, starting a stretching motor 13 of the stretching loading module 2 and a helical gear reducer 14 matched with the stretching motor, adjusting a high-temperature clamp assembly and an intermediate connecting piece to proper height, opening a front furnace door 65 of the high-temperature furnace, installing a tested sample 72 into the high-temperature clamp assembly, adjusting the clamp to tighten the clamp, and closing the front furnace door 65.

Step two: and clearing the sensor data and providing a high-temperature environment. And when a loading experiment starts, synchronously clearing data of the grating ruler displacement sensor, the circular grating angular displacement sensor, the tension-torsion compound force sensor and possible data of an extensometer, a temperature sensor and the like. The loading of the tested sample 72 under different temperature environments is provided by the high temperature loading module 4, and the air in the furnace chamber of the high temperature furnace is extracted by using external equipment until the vacuum degree required by the experiment is reached. The temperature controller introduces voltages with different magnitudes into the three sections of U-shaped silicon-molybdenum rods 54 in the furnace chamber of the high-temperature furnace to heat the three sections of U-shaped silicon-molybdenum rods, the heating mode is thermal radiation heating, the tested sample 72 is in different temperature environments, and the temperature of the gauge length section of the tested sample 72 is dynamically monitored in real time through a high Wen Bise meter.

Step three: the test specimen 72 is subjected to a constant velocity double-sided tensile-torsional load. The upper and lower symmetrical tensile loading modules 2 apply constant-rate tensile load loading to the test specimen 72, and the upper and lower symmetrical torsional loading modules 3 apply equal-rate torsional load loading to the test specimen 72. The bilateral synchronous stretching and twisting can ensure that the absolute position of the center point of the tested sample 72 is unchanged in the experimental process, so that in-situ observation and in-situ tracking on the microscopic scale can be performed.

Step four: and (5) collecting sensor data. In the experimental process, the mechanical load is acquired in real time by the stretching and torsion compound sensor, the experimental environment temperature is acquired in real time by the temperature sensor, the stretching displacement is acquired in real time by the grating ruler displacement sensor, the torsion angle displacement is acquired in real time by the circular grating angular displacement sensor, and the data can be calculated by the matched software of the instrument to output curves in real time, including but not limited to a stretching force-stretching displacement curve, a torque-torsion angle curve, a temperature-time curve and the like.

Step five: in situ observation and in situ tracking on a microscopic scale. The adjustment platform 82 of the in-situ monitoring module realizes the switching use of the microstructure morphology observation device 80 and the characterization deformation observation device 81 and the tiny displacement adjustment of the microstructure morphology observation device and the characterization deformation observation device in the axial direction and the radial direction. The real-time dynamic monitoring of the microstructure morphology and the characterization deformation of the gauge length section of the tested sample 72 is realized.

Step six: unloading the tested sample 72 after the test is finished, taking out the tested sample 72 after the temperature reduction treatment is carried out on the heating cavity, guiding out experimental data and closing the testing instrument.

Compared with the prior art, the invention has the beneficial effects that: the novel tension-torsion load loading mode comprises a transmission mechanism of a tension and torsion loading module and a tension and torsion coupling piece; the high-temperature loading module is integrated, and the internal structure of the high-temperature heat furnace is innovatively provided, and the internal structure comprises three gradient heat-insulating layers, a ceramic fiber furnace chamber and the like; the test equipment provided by the invention adopts a vertical structure, has good centering, higher coaxiality, high machine body rigidity and compact structure, and each sub-module is mutually independent, so that the modular design idea of multi-factor coupling is satisfied; the single load loading or the multiple load composite loading can be carried out on the sample in the temperature range of room temperature to 1500 ℃. The in-situ monitoring module is integrated in the supporting module and comprises microstructure morphology observing equipment, deformation characterizing observing equipment and the like, so that microstructure morphology and metallographic structure change of fracture defects of the material under the action of stretching-torsion load can be monitored in real time in a high-temperature environment, and a constitutive relation and a coupling mathematical model under the action of complex load can be established according to data fed back by the sensor and other data acquisition modules, so that the macroscopic mechanical properties of the material are researched.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate and explain the application and together with the description serve to explain the application.

FIG. 1 is a schematic view of the overall structure of the present invention;

FIG. 2 is a schematic diagram of a load in-situ monitoring module according to the present invention;

FIG. 3 is a single load/compound load coupled loading schematic diagram of the present invention;

FIG. 4 is a schematic view of the support module structure of the present invention;

FIG. 5 is a cross-sectional view of a tension loading module of the present invention;

FIG. 6 is a cross-sectional view of the torsion loading module of the present invention;

FIGS. 7 and 8 are schematic views of the high temperature loading module structure of the present invention;

fig. 9 is a schematic diagram of the mechanical loading mode of the present invention.

In the figure: 1. a support module; 2. a stretch loading module; 3. a torsion loading module; 4. a high-temperature loading module; 5. a lock nut; 6. a first guide plate; 7. a support plate; 8. a second guide plate; 9. a shock isolation table; 10. a lower base; 11. a column; 12. an upper base; 13. stretching a motor; 14. a helical gear speed reducer I; 15. m14 inner hexagon bolts; 16. a connecting shaft sleeve; 17. a threaded roller; 18. a nut; 19. a screw rod; 20. a bearing end cap; 21. angular contact ball bearings three; 22. a first fixing bolt; 23. a second fixing bolt; 24. a circular grating encoder; 25. twisting the supporting seat; 26. a set screw; 27. a flange nut seat; 28. an inner hexagon bolt; 29. m5 screws; 30. a retainer ring; 31. a dust ring; 32. a bushing; 33. m6 screw; 34. a first sealing ring; 35. adjusting the gasket; 36. angular contact ball bearing I; 37. a large belt wheel; 38. a second sealing ring; 39. a central shaft; 40. a large end cover of the bearing; 41. angular contact ball bearing II; 42. twisting the support plate; 43. a deep groove ball bearing I; 44. a small end cover of the bearing; 45. a bearing seat; 46. a sleeve; 47. a synchronous belt; 48. a small belt wheel; 49. a deep groove ball bearing II; 50. a motor base; 51. a torsion shaft; 52. a helical gear speed reducer II; 53. a torsion motor; 54. a U-shaped silicon molybdenum rod; 55. three gradient heat preservation layers; 56. a ceramic fiber furnace chamber; 57. an upper dynamic seal bellows; 58. a lower dynamic seal bellows; 59. a high temperature furnace box; 60. a slide block; 61. a positioning seat; 62. a guide rail; 63. an X-shaped bracket; 64. quartz glass observation window; 65. a front oven door; 66. a furnace door handle; 67. a photoelectric colorimeter observation hole; 68. an upper torsion box; 69. an intermediate connecting piece I; 70. an upper flange connection; 71. a fixing screw; 72. a sample to be tested; 73. a lower flange connection; 74. a lower torsion box body, 75 and a second middle connecting piece; 76. a pull-down force sensor; 77. a lower high-temperature clamp; 78. a high-temperature clamp is arranged; 79. a pull-up force sensor; 80. a microstructure morphology observation device; 81. characterizing a deformation observation device; 82. and adjusting the platform.

Detailed Description

The details of the present invention and its specific embodiments are further described below with reference to the accompanying drawings.

Referring to fig. 1 to 9, the apparatus and the method for testing mechanical properties of materials under the pull-torsion compound-force thermal coupling working condition mainly comprise: a support module 1, a tensile loading module 2, a torsion loading module 3, a high temperature loading module 4 and an in-situ monitoring module. The support module 1 is a structural support of the whole test equipment, adopts a layout scheme of vertical four upright posts, is convenient for clamping and positioning, is convenient for carrying an in-situ monitoring module to test under complex working conditions, and accords with the modular design idea of multi-factor coupling; the stretching loading module 2 is driven by an electric power source, and a roller screw nut pair mechanism is used for transmission, so that bidirectional synchronous stretching load can be applied to a sample; the torsion loading module 3 is coupled with the tension loading module through a coupling piece, so that bidirectional synchronous torsion load can be applied to the sample; the high-temperature loading module 4 adopts a heating mode of a high-temperature heat furnace and is used for applying a high-temperature physical field to the sample and providing a temperature-changing environment with the room temperature of 1500 ℃. The test sample 72 can be loaded and tested under a high-temperature environment, the mechanical behavior and the performance evolution rule of the material under the action of high-temperature and stretching-torsion complex mechanical loads can be dynamically tested, and the test sample has the characteristics of stable whole structure, abundant compatible modules, high testing precision, high environment complexity of load loading and the like. Providing important foundation and support for material research and development preparation, optimal design of mechanical equipment, life prediction and reliability evaluation.

Referring to fig. 1 and 2, the tension-torsion composite-force thermal coupling material mechanical property testing instrument comprises a supporting module 1, a tensile loading module 2, a torsion loading module 3, a high-temperature loading module 4 and an in-situ monitoring module, wherein the supporting module 1 is a structural support of the whole testing instrument, adopts a vertical four-column layout mode, is convenient for clamping and positioning, and has a vibration reduction effect; the stretching motor 13 of the stretching loading module 2 is driven by a commercial alternating current servo motor and a helical gear reducer 14 matched with the commercial alternating current servo motor, the stretching motor 13 is fixed on one side of the helical gear reducer 14 through a fixing bolt II 23, and the other side of the helical gear reducer 14 is fixed on the upper base 12 of the supporting module 1 through a fixing bolt I22 and is used for realizing bidirectional synchronous stretching loading on a tested sample 72;

The torsion loading module 3 is coupled with a screw nut pair mechanism of the tension loading module 2 through a flange nut seat 27 on a torsion supporting seat 25, a commercial torsion motor 53 and a helical gear reducer II 52 matched with the commercial torsion motor are selected to be rigidly connected with a torsion supporting plate 42 through a motor seat 50, and a synchronous pulley is selected to transmit torque for realizing synchronous loading of static torsion loads at two ends of a tested sample 72;

The high temperature loading module 4 is rigidly connected with the support plate 7 of the support module 1 through the X-shaped support 63, and is rigidly connected with the upper flange connection 70 and the lower flange connection 73 of the torsion loading module 3 through the upper dynamic seal bellows 57 and the lower dynamic seal bellows 58 respectively, so that a vacuum environment can be formed or inert gas can be filled to isolate oxygen, and the oxidation reaction of the tested sample 72 in the high temperature loading process can be prevented, thereby influencing the experimental result.

Referring to fig. 3 and 6, the supporting module 1 includes a lock nut 5, a first guide plate 6, a support plate 7, a second guide plate 8, a vibration isolation table 9, a lower base 10, a column 11, an upper base 12, and the like, and the supporting module 1 is a structural support of a tensile loading module 2, a torsional loading module 3, a high temperature loading module 4, and an in-situ monitoring module, so that each sub-module is independent of each other, and has a vibration isolation effect. Adopt the overall arrangement mode of vertical four stand, go up base 12, lower base 10 and backup pad 7 and pass through lock nut 5 and four stand 11 rigid connection, be equipped with bush 32 between deflector one 6 and deflector two 8 and the stand 11, bush 32 passes through M6 screw 33 to be fixed on deflector two 8, bush 32 passes through M5 screw 29 and retaining ring 30 to be fixed, be equipped with dust ring 31 between retaining ring 30 and the bush 32, prevent deflector two 8 in the in-process of moving on stand 11, dust and granule in the air get into guiding mechanism in, influence experimental precision. The four upright posts 11 are made of 45 steel, and a layer of chromium can be plated on the surfaces of the four upright posts 11 in order to prevent the upright posts 11 from generating oxidation reaction with air to cause rust. 10M 14 screws are used for fixing the lower base 10 on the vibration isolation table 9, so that the test instrument is prevented from generating larger vibration in the working process.

Referring to fig. 5, the tensile loading module 2 is driven by an electric power source, and is decelerated by a first helical gear reducer 14, and a roller screw nut pair mechanism converts rotary motion into linear motion, so that quasi-static tensile loading is realized; the bidirectional synchronous tensile load loading device comprises a tensile motor 13, a first helical gear reducer 14, an inner hexagon bolt 15 of an M14, a connecting shaft sleeve 16, a threaded roller 17, a nut 18, a lead screw 19, a bearing end cover 20, a third angular contact ball bearing 21, a first fixing bolt 22, a second fixing bolt 23 and the like, and can realize bidirectional synchronous tensile load loading on a tested sample 72. The stretching motor 13 is rigidly connected with the first helical gear reducer 14 through a second fixing bolt 23, and an output shaft of the first helical gear reducer 14 is matched with the upper end of the self-made connecting shaft sleeve 16 in a key connection mode; the connecting shaft sleeves 16 are provided with three angular contact ball bearings 21 in pairs at the positions between shafts, and the bearing end covers 20 are fixed on the lower surface of the upper base 12 of the support module 1 through the inner hexagon bolts 15 of M14. The angular contact ball bearing three 21 can bear radial and axial bidirectional combined loads, and the loads born by the bearings with different contact angles are different. The angular contact ball bearing 21 can also limit the axial displacement of the connecting shaft sleeve 16 in one direction, and can transmit the axial force to the upper base 12 of the support module 1, and the locking nut 5 matched with the upright 11 bears the shearing force; the lower end of the connecting shaft sleeve 16 is fixedly connected with a screw rod 19 through a bolt, and the screw rod 19 converts the rotary motion of the output shaft of the stretching motor 13 into the linear motion of a nut 18; according to comprehensive analysis and calculation, the roller screw 19 is preferably used for transmission, and compared with the traditional ball screw, the roller screw 19 is adopted for transmission, and the biggest advantage of the roller screw 19 is that rolling elements between the screw 19 and the nut 18 are uniformly distributed threaded rollers 17.

Referring to fig. 6, the torsion loading module 3 includes a circular grating encoder 24, a torsion supporting seat 25, a positioning screw 26, a flange nut seat 27, an inner hexagonal bolt 28, an M5 screw 29, a retainer ring 30, a dust ring 31, a bushing 32, an M6 screw 33, a first seal ring 34, an adjusting gasket 35, a first angular ball bearing 36, a large belt pulley 37, a second seal ring 38, a central shaft 39, a large bearing cover 40, a second angular ball bearing 41, a torsion supporting plate 42, a first deep groove ball bearing 43, a small bearing cover 44, a bearing seat 45, a sleeve 46, a synchronous belt 47, a small belt pulley 48, a second deep groove ball bearing 49, a motor seat 50, a torsion shaft 51, a second helical gear reducer 52, and a torsion motor 53, and can realize bidirectional synchronous torsion load loading on a sample 72 to be tested. The coupling piece of the stretching loading module 2 and the torsion loading module 3 is a flange nut seat 27, and the flange nut seat 27 is fixed on the torsion supporting seat 25 through a positioning screw 26; the second guide plate 8 is rigidly connected with the torsion support seat 25 through a socket head cap bolt 28. The torsion motor 53 is fixedly connected with the second helical gear reducer 52 through a bolt connection, the other end of the second helical gear reducer 52 is fixed on the motor base 50, an output shaft of the second helical gear reducer 52 is matched with the torsion shaft 51 through a key connection, a second 6004 deep groove ball bearing 49 is arranged at the inter-shaft position of one end of the torsion shaft 51, a first 6004 deep groove ball bearing 43 is arranged at the inter-shaft position of the other end of the torsion shaft 51, a small bearing end cover 44 matched with the first deep groove ball bearing 43 is fixed on the bearing base 45 through a bolt connection, and the motor base 50 and the bearing base 45 serve as a foundation and a support of the whole driving unit to play roles of limiting and guiding.

After the second helical gear speed reducer 52 of the torsion loading module 3 is used for reducing speed and increasing torque, power is transmitted to the torsion shaft 51 through the output shaft of the second helical gear speed reducer 52, the torsion shaft 51 and the central shaft 39 are driven through the synchronous belt 47, the small belt pulley 48 and the large belt pulley 37, the small belt pulley 48 is matched with the torsion shaft 51 through key connection, and the sleeve 46 is arranged outside the torsion shaft 51 to play a role in connection and support. One end of the central shaft 39 is connected with the circular grating encoder 24, the other end of the central shaft is connected with the clamp assembly through a first intermediate connecting piece 69, the torsion supporting plate 42 is fixedly connected to the torsion supporting seat 25 through a bolt, an angular contact ball bearing 36 in the torsion supporting seat 25 is matched with the central shaft 39 to limit radial displacement of the central shaft 39, a first sealing ring 34 is arranged in a bearing end cover matched with the angular contact ball bearing 36, and an adjusting gasket 35 is arranged between the bearing end cover and the torsion supporting seat 25; an angular contact ball bearing II 41 of 7316B is arranged in pairs at the position between the other side shafts of the central shaft 39, the outer diameter of the angular contact ball bearing II 41 is matched with the inner hole of the torsion supporting seat 25, the angular contact ball bearing II 41 is matched with a bearing large end cover 40, and a sealing ring II 38 is arranged in the bearing large end cover 40; the torsion support plate 42 and the torsion support seat 25 are transmission bases of the whole torsion loading module 3, and can limit the freedom degree of the central shaft 39, so that the central shaft can only rotate around the axis, thereby completing torsion load loading.

Referring to fig. 7 and 8, the high temperature loading module 4 includes a silicon molybdenum rod 54, a three-gradient heat insulation layer 55, a ceramic fiber furnace chamber 56, an upper dynamic seal bellows 57, a lower dynamic seal bellows 58, a high temperature furnace box 59, a slide block 60, a positioning seat 61, a guide rail 62, an X-shaped support 63, a quartz glass observation window 64, a front furnace door 65, a furnace door handle 66, a photoelectric colorimeter observation hole 67, and the like, and adopts a heating mode of a high temperature furnace, wherein a heating element is the silicon molybdenum rod 54, and can provide a temperature changing environment of room temperature to 1500 ℃ for a tested sample 72. The high-temperature loading module 4 adopts a heating mode of a high-temperature furnace, the furnace body is of a vertical square structure, the furnace body is rigidly connected with the supporting plate 7 of the supporting module 1 through an X-shaped supporting seat 63, the X-shaped supporting seat 63 moves on a guide rail 62 through a sliding block 60, the height of the high-temperature furnace can be adjusted, the high-temperature loading module 4 can move in the Z direction, the guide rail 62 is welded with a positioning seat 61, and the positioning seat 61 is rigidly connected with the supporting plate 7 of the supporting module 1 through a bolt; the front furnace door 65 of the high-temperature loading module 4 is provided with a quartz glass observation window 64 and a high-temperature colorimeter observation hole 67; the in-situ observation window is made of double-layer quartz glass, the linear expansion coefficient of the quartz glass is extremely small, the inner-layer quartz glass can bear the high-temperature environment under the set working condition due to the extremely high heat resistance and chemical stability, the double-layer quartz glass observation window 64 is inlaid at the central observation hole of the front furnace door 65, the outer-layer quartz glass is tightly pressed by a pressing plate, and the inner-layer quartz glass can bear the high-temperature environment under the set working conditionThe quartz glass observation window 64 and the high-temperature furnace body 59 are mutually independent modules and can be installed and detached according to working conditions; the outer wall of the front furnace door 65 is provided with a furnace door handle 66, and the two are welded together.

The furnace chamber material of the high-temperature heating furnace of the high-temperature loading module 4 is alumina ceramic fiber material, the melting point of the ceramic material is higher and generally higher than 2000 ℃ under the set working condition, and compared with other materials with high melting points, the ceramic material has extremely high chemical stability in a high-temperature environment, has small heat conductivity coefficient, has high hardness and high tensile strength and meets the design requirement of test equipment, and the hardness is generally higher than 1500 HV; the surface of the furnace chamber can be coated with a high-temperature alumina coating, the melting point of alumina is 2054 ℃, and the heating efficiency and the service life of the furnace chamber can be improved; the high-temperature loading module 4 adopts a three-gradient heat preservation layer 55 structure, the furnace lining, the cellucotton and the fiber furnace chamber are adopted, the heat preservation material is polycrystalline mullite ceramic fiber material and alumina fiber material, the heat preservation effect is excellent, and the heat energy loss is less.

The heating element of the high temperature loading module 4 is a U-shaped silicon molybdenum rod 54, the U-shaped silicon molybdenum rod 54 is similar to ceramics, and is made of high temperature resistant and oxidation resistant materials, the U-shaped silicon molybdenum rod 54 is made of brittle materials at normal temperature, and is easy to generate cracking phenomenon, if the temperature is continuously increased, the U-shaped silicon molybdenum rod 54 can be changed into plastic materials, and the texture is softened, so the U-shaped silicon molybdenum rod 54 is vertically hung in a ceramic fiber furnace chamber 56, the single side door opening mode of the high temperature furnace is designed, three groups of U-shaped silicon molybdenum rods 54 are respectively hung and installed on other three planes of the furnace body, the heating temperature of the rod body can reach 1800 ℃, and the three groups of U-shaped silicon molybdenum rods 54 are connected in series, and aluminum foils are used as lead materials. The front furnace door 65 of the high-temperature loading module 4 is provided with a high Wen Bise meter observation hole 67, the colorimeter heat probe is matched with the high Wen Bise meter observation hole 67, the ambient temperature of a sample is measured, and the temperature is fed back to the intelligent temperature control instrument.

Referring to fig. 2, the in-situ monitoring module comprises a microstructure morphology observation device 80, a characterization deformation observation device 81 and an adjustment platform 82. The in-situ monitoring module is rigidly connected with the supporting plate 7 of the supporting module 1 through screws, the microstructure morphology observing device 80 and the characterization deformation observing device 81 are installed on the adjusting platform 82 in front of the high-temperature loading module 4, and can be used simultaneously or in a switching mode, and the mechanical behavior and the performance evolution rule of the tested sample 72 under the complex mechanical load action are dynamically observed in real time through the quartz glass observing window 64 of the high-temperature loading module 4. The adjustment stage 82 can adjust the movement of the microstructure morphology observation apparatus 80 and the characterization deformation observation apparatus 81 in the axial direction and the radial direction of the sample 72 to be tested.

Referring to fig. 6 to 9, the central shaft 39 in the upper torsion box 68 of the torsion loading module 3 is rigidly connected to the upper tension sensor 79 through the first intermediate connecting member 69, and the central shaft 39 of the lower torsion box 74 is rigidly connected to the lower tension sensor 76 through the second intermediate connecting member 75. The tensile force applied by the tensile loading module 2 to the tested sample 72 measured by the upward tension sensor 79 is an important data material for drawing a stress-strain curve, and various tensile performance indexes are obtained on the basis of the important data material; one end of the upper flange connecting piece 70 is fixed with an upper tension sensor 79, and the other end is arranged on an upper high-temperature clamp 78, the upper part and the lower part of the clamp group are respectively provided with the same threaded holes, and the upper part and the lower part of the clamp group are fixed by fixing screws 71 with the same model; the upper dynamic seal bellows 57 and the lower dynamic seal bellows 58 of the high-temperature loading module 4 are respectively provided with screw holes of the same type, and the flange structures of the upper flange connector 70 and the lower flange connector 74 are rigidly connected by bolts of the same type.

The invention relates to a method and an instrument for testing mechanical properties of materials under a tension-torsion compound-force thermal coupling working condition, which can load tensile load and torsion load in a high-temperature physical field at the same time, and can also independently separate two sub-modules to apply the tensile load and the torsion load to a sample respectively. The test equipment is integrated with a quartz visual window port, and can be provided with an in-situ test instrument to monitor the mechanical property change of the sample in the load applying process in real time. The stretching loading module 2 adopts an alternating current servo motor and a helical gear reducer which is matched with the alternating current servo motor to be used as a power source, an output shaft of the helical gear reducer is matched with the upper end of a self-made connecting shaft sleeve 16 through key connection, the other end of the connecting shaft sleeve 16 is matched and connected with one end of a ball screw 19 through a bolt group, a transmission component is a screw nut pair mechanism, the rotation motion output by a motor shaft is converted into the linear motion of a nut, the quasi-static stretching loading is realized, the greatest advantage of adopting the roller screw transmission is that rolling elements between the screw 19 and the nut 18 are uniformly distributed threaded rollers 17, and the threaded rollers 17 have more contact points for supporting the stretching load compared with rolling bodies of the ball screw, so that the whole transmission component has higher shock resistance; the torsion loading module 3 is driven by an electric power source, power is transmitted to a torsion shaft through an output shaft of a motor, and torsion load loading is realized through synchronous pulley transmission between the torsion shaft 51 and the central shaft 39; the high-temperature loading module 4 adopts a heating mode of a high-temperature heat furnace, the heating element is a U-shaped silicon-molybdenum rod 54, the furnace is vacuumized or inert gas is introduced, so that the sample is prevented from being oxidized and deformed under the high-temperature environment, and the experimental result is prevented from being influenced; the high-temperature furnace is rigidly connected with the supporting plate 7 of the supporting module 1 through the X-shaped supporting seat 63, and the height of the X-shaped supporting seat 63 is adjustable, so that the in-situ observation module or other functional modules can be conveniently carried.

Referring to fig. 3, the correlation formula of the present invention is as follows:

(1) In the stretching process, a relation curve of engineering stress sigma and engineering strain epsilon, namely a stress-strain curve for short, is important data for representing the stretching behavior of a material sample, and the engineering stress sigma can be expressed as:

Where F is the tensile load to which the specimen is subjected and A ₀ is the original cross-sectional area of the specimen when not stretched.

The engineering strain is as follows:

Where l ₀ is the original gauge length of the sample and Δl is the elongation during stretching.

However, the engineering strain cannot fully reflect the real condition of the sample in the stretching process, because the cross-sectional area and the length of the sample are continuously changed along with the increase of the stretching force, namely the instantaneous real stress is

When the tensile force F has an increment DeltaF, the sample has an increment Deltal based on the instantaneous length l, so that the differential increment of strain should beThe true strain is after the sample is increased from l ₀ to l

The relation between engineering strain and real strain is that

This means that the true strain is always greater than the engineering strain when the test specimen is subjected to a tensile test.

The relation between engineering stress and real stress is that

S＝σ(1+ε)

This means that the true stress is always greater than the engineering stress when the test specimen is subjected to a tensile test.

(2) The torsion test of the invention generally selects a cylindrical sample, applies a torque M to the sample, and measures the torsion angle between two sections of the tested sample gauge length section through a circular grating angular displacement sensorObtain torsion diagramCurve to obtain torsion ratio limit tau _p

Wherein W is the section coefficient for a cylindrical sample of diameter d ₀

In the torsion test process, if the plastic stage is entered, the relative residual shear strain of torsion is as follows

Wherein,Is the residual torsion angle after the sample breaks.

(3) The invention relates to the relative knowledge of tensile/compression-torsion composite stress, and a third theory and a fourth intensity theory are applied to obtain a calculation formula

If a bidirectional stretching and bidirectional torsion load is applied to a cylindrical sample, the elastic modulus E and the Poisson ratio mu of the material are known, and the linear strain epsilon _x、ε_y、ε_z in the x, y and z directions respectively are as follows according to the generalized Hooke's law

(4) The invention relates to the thermal property of a material, the material absorbs or emits heat when the temperature rises or falls, and if the phase change and chemical reaction are not considered, the heat Q absorbed by the material sample when the temperature rises by 1k is the heat capacity C of the material sample, and the calculation formula is that

However, the heat capacity is not a parameter of the pure material, the heat capacity of the material per unit mass m can be defined as the specific heat capacity c by considering the amount of the material, and the calculation formula is as follows

(5) The general trend of the mechanical properties of the material related by the invention at high temperature is as follows: the strength is reduced, the plasticity is increased, the deformation and fracture are related to the load acting time, and the creep phenomenon is obvious. The relation calculation formula of creep rate and temperature is

Wherein Q _c is creep manifestation activation energy. The steady state creep rate is linear with the double logarithm of the stress, and at lower stress is expressed in the form of the following power law

Where n is the creep rate stress index. At higher stresses, the power law creep law fails, expressed as an exponential function

The influence of the comprehensive temperature and stress is that

Or (b)

Where D is the diffusion coefficient, G is the shear modulus, b is the dislocation Boltzmann vector, and k is the Boltzmann constant.

The theoretical knowledge related to the thermal coupling of force, namely the relation between creep rate and stress and temperature, is called a creep constitutive equation or a creep equation.

The above description is only a preferred example of the present invention and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. of the present invention should be included in the protection scope of the present invention.

Claims

1. A tension-torsion compound-force thermal coupling material mechanical property testing instrument is characterized in that: the device comprises a supporting module (1), a stretching loading module (2), a torsion loading module (3), a high-temperature loading module (4) and an in-situ monitoring module, wherein a stretching motor (13) of the stretching loading module (2) is fixed on one side of a first helical gear reducer (14), and the other side of the first helical gear reducer (14) is fixed on an upper base (12) of the supporting module (1) through a first fixing bolt (22) to realize bidirectional synchronous stretching loading on a tested sample (72);

The torsion loading module (3) is coupled with a screw nut pair mechanism of the tension loading module (2) through a flange nut seat (27) on a torsion supporting seat (25), and a torsion motor (53) and a helical gear reducer II (52) are rigidly connected with a torsion supporting plate (42) through a motor seat (50) so as to realize synchronous loading of static torsion loads at two ends of a tested sample (72);

The high-temperature loading module (4) is rigidly connected with a supporting plate (7) of the supporting module (1) through an X-shaped supporting seat (63), and is rigidly connected with an upper flange connecting piece (70) and a lower flange connecting piece (73) of the torsion loading module (3) through an upper dynamic sealing corrugated pipe (57) and a lower dynamic sealing corrugated pipe (58) respectively, so that a vacuum environment is formed or inert gas is filled for isolating oxygen, and oxidation reaction of a tested sample (72) in the high-temperature loading process is prevented, and experimental results are influenced;

The torsion motor (53) of the torsion loading module (3) is fixedly connected with a second helical gear reducer (52), the other end of the second helical gear reducer (52) is fixed on a motor base (50), an output shaft of the second helical gear reducer (52) is matched with the torsion shaft (51) through key connection, a first deep groove ball bearing (43) is arranged at the position between the other end shafts of the torsion shaft (51), and a small bearing end cover (44) matched with the first deep groove ball bearing (43) is fixed on a bearing base (45);

After the speed and torque of a helical gear reducer II (52) of the torsion loading module (3) are reduced, power is transmitted to a torsion shaft (51) through an output shaft of the helical gear reducer II (52), the torsion shaft (51) is transmitted to a central shaft (39) through a synchronous belt (47), a small belt pulley (48) and a large belt pulley (37), one end of the central shaft (39) is connected with a circular grating encoder (24), the other end of the central shaft is connected with a clamp assembly through a middle connecting piece I (69), a torsion supporting plate (42) is fixed on a torsion supporting seat (25) through a bolt connection, and an angular contact ball bearing I (36) in the torsion supporting seat (25) is matched with the central shaft (39) to limit radial displacement of the central shaft (39); the two angular contact ball bearings (41) are arranged in pairs at the other side of the central shaft (39), the outer diameters of the two angular contact ball bearings (41) are matched with the inner holes of the torsion supporting seat (25), the torsion supporting plate (42) and the torsion supporting seat (25) are transmission foundations of the whole torsion loading module (3), and the freedom degree of the central shaft (39) can be limited, so that the central shaft can only rotate around an axis, and torsion load loading is completed.

2. The tension-torsion composite-force thermal coupling working condition material mechanical property testing instrument according to claim 1, wherein the instrument is characterized in that: the supporting module (1) adopts the overall arrangement mode of vertical four stand, goes up base (12), lower base (10) and backup pad (7) through lock nut (5) and four stand (11) rigid connection, is equipped with bush (32) between deflector one (6) and deflector two (8) and stand (11), bush (32) are fixed on deflector two (8) through M6 screw (33), bush (32) are fixed with retaining ring (30) through M5 screw (29), be equipped with dust ring (31) between retaining ring (30) and bush (32), lower base (10) are fixed on vibration isolation platform (9).

3. The tension-torsion composite-force thermal coupling working condition material mechanical property testing instrument according to claim 1, wherein the instrument is characterized in that: the stretching motor (13) of the stretching loading module (2) is rigidly connected with the first helical gear reducer (14), and an output shaft of the first helical gear reducer (14) is matched with the upper end of the connecting shaft sleeve (16) in a key connection mode; the connecting shaft sleeves (16) are provided with three angular contact ball bearings (21) in pairs at the positions between shafts, the three angular contact ball bearings (21) bear radial and axial bidirectional combined loads, the axial displacement of the connecting shaft sleeves (16) in one direction is limited, axial force is transmitted to the upper base (12) of the supporting module (1), and the locking nuts (5) matched with the upright posts (11) bear shearing force; the lower end of the connecting shaft sleeve (16) is fixed with a screw rod (19), and the screw rod (19) converts the rotation motion of the output shaft of the stretching motor (13) into the linear motion of the nut (18); the rolling elements between the screw rod (19) and the nut (18) are uniformly distributed threaded rollers (17).

4. The tension-torsion composite-force thermal coupling working condition material mechanical property testing instrument according to claim 1, wherein the instrument is characterized in that: the high-temperature loading module (4) adopts a heating mode of a high-temperature heat furnace, the furnace body is of a vertical square structure, the furnace body is rigidly connected with a supporting plate (7) of the supporting module (1) through an X-shaped supporting seat (63), the X-shaped supporting seat (63) moves on a guide rail (62) through a sliding block (60), the height of the high-temperature heat furnace is adjusted, and the movement of the high-temperature loading module (4) in the Z direction is realized; a front furnace door (65) of the high-temperature loading module (4) is provided with a quartz glass observation window (64) and a high-temperature colorimeter observation hole (67); the double-layer quartz glass observation window (64) is inlaid at the central observation hole of the front furnace door (65), the outer layer quartz glass is tightly pressed by the pressing plate and fixed on the outer wall of the front furnace door (65), and the quartz glass observation window (64) and the high-temperature furnace body (59) are mutually independent modules and can be installed and detached according to working conditions.

5. The tension-torsion composite-force thermal coupling working condition material mechanical property testing instrument according to claim 1, wherein the instrument is characterized in that: the furnace chamber material of the high-temperature heat furnace of the high-temperature loading module (4) is alumina ceramic fiber material, the surface of the furnace chamber is coated with a high-temperature alumina coating, the high-temperature loading module (4) adopts a three-gradient heat preservation layer (55) structure, and the furnace lining, the fiber cotton and the fiber furnace chamber are polycrystalline mullite ceramic fiber material and alumina fiber material.

6. The tension-torsion composite-force thermal coupling working condition material mechanical property testing instrument according to claim 1, wherein the instrument is characterized in that: the heating element of the high-temperature loading module (4) is a U-shaped silicon molybdenum rod (54), the U-shaped silicon molybdenum rod (54) is vertically hung in a ceramic fiber furnace chamber (56), the single-side door opening mode is designed into a high-temperature heat furnace, three groups of U-shaped silicon molybdenum rods (54) are respectively hung and installed on three planes of a furnace body, and the three groups of U-shaped silicon molybdenum rods (54) are connected in series.

7. The tension-torsion composite-force thermal coupling working condition material mechanical property testing instrument according to claim 1, wherein the instrument is characterized in that: the front furnace door (65) of the high-temperature loading module (4) is provided with a high Wen Bise meter observation hole (67), and the calorimeter heat probe is matched with the high Wen Bise meter observation hole (67) to measure the ambient temperature of a sample.

8. A method for testing mechanical properties of a material under a pull-torsion composite-force thermal coupling condition by using the pull-torsion composite-force thermal coupling condition material mechanical property testing instrument according to any one of claims 1 to 7, which is characterized in that: the method comprises the following steps:

Step one, each sub-module of the test equipment is checked and a tested sample (72) is installed: starting a stretching motor (13) of the stretching loading module (2) and a helical gear reducer I (14) matched with the stretching motor, adjusting the high-temperature clamp assembly and the intermediate connecting piece to a proper height, opening a front furnace door (65) of the high-temperature furnace, installing a tested sample (72) into the high-temperature clamp assembly, adjusting the clamp to tighten the clamp, and closing the front furnace door (65);

Step two, resetting sensor data and providing a high-temperature environment: when a loading experiment starts, synchronously clearing data of a grating ruler displacement sensor, a circular grating angular displacement sensor, a stretching torsion composite sensor, an extensometer and a temperature sensor; the loading of the tested sample (72) under different temperature environments is provided by a high temperature loading module (4), and the air in the furnace chamber of the high temperature furnace is extracted by using external equipment until the vacuum degree required by the experiment is reached; the temperature controller is used for introducing voltages with different sizes into three sections of U-shaped silicon-molybdenum rods (54) in the furnace chamber of the high-temperature furnace to heat the three sections of U-shaped silicon-molybdenum rods, the heating mode is thermal radiation heating, the tested sample (72) is in different temperature environments, and the temperature of the gauge length section of the tested sample (72) is dynamically monitored in real time through a high Wen Bise meter;

Step three, loading the test sample (72) with constant-speed double-side stretching-torsion load: the upper and lower symmetrical stretching loading modules (2) apply constant-speed stretching load loading to the tested sample (72), and the upper and lower symmetrical torsion loading modules (3) apply constant-speed torsion load loading to the tested sample (72); the bilateral synchronous stretching and torsion ensures that the absolute position of the central point of the tested sample (72) is not changed in the experimental process so as to carry out in-situ observation and in-situ tracking on the microscopic scale;

Step four, sensor data acquisition: in the experimental process, the mechanical load is acquired in real time by a stretching and torsion composite sensor, the experimental environment temperature is acquired in real time by a temperature sensor, the stretching displacement is acquired in real time by a grating ruler displacement sensor, the torsion angle displacement is acquired in real time by a circular grating angular displacement sensor, and the data can output curves in real time, including but not limited to a stretching force-stretching displacement curve, a torque-torsion angle curve and a temperature-time curve;

Step five, in-situ observation and in-situ tracking on a microscopic scale: an adjusting platform (82) of the in-situ monitoring module realizes the switching use of the microstructure morphology observation equipment (80) and the characterization deformation observation equipment (81) and the tiny displacement adjustment of the microstructure morphology observation equipment and the characterization deformation observation equipment in the axial direction and the radial direction; realizing the real-time dynamic monitoring of the microstructure morphology and the characterization deformation of the gauge length section of the tested sample (72);

And step six, unloading the tested sample (72) after the test is finished, taking out the tested sample (72) after the temperature reduction treatment is carried out on the heating cavity, leading out experimental data, and closing the test instrument.