CN114544654A - Tiny crack growth in-situ test and observation device - Google Patents
Tiny crack growth in-situ test and observation device Download PDFInfo
- Publication number
- CN114544654A CN114544654A CN202210207097.8A CN202210207097A CN114544654A CN 114544654 A CN114544654 A CN 114544654A CN 202210207097 A CN202210207097 A CN 202210207097A CN 114544654 A CN114544654 A CN 114544654A
- Authority
- CN
- China
- Prior art keywords
- micro
- sample
- crack
- situ
- lens
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000012360 testing method Methods 0.000 title claims abstract description 58
- 238000011065 in-situ storage Methods 0.000 title claims abstract description 32
- 238000012544 monitoring process Methods 0.000 claims abstract description 30
- 238000012634 optical imaging Methods 0.000 claims abstract description 21
- 238000011068 loading method Methods 0.000 claims abstract description 11
- 230000005855 radiation Effects 0.000 claims abstract description 8
- 238000001914 filtration Methods 0.000 claims abstract description 7
- 238000010438 heat treatment Methods 0.000 claims description 50
- 230000003287 optical effect Effects 0.000 claims description 32
- 230000007547 defect Effects 0.000 claims description 26
- 238000009661 fatigue test Methods 0.000 claims description 24
- 238000002955 isolation Methods 0.000 claims description 21
- 238000013519 translation Methods 0.000 claims description 13
- 235000008429 bread Nutrition 0.000 claims description 10
- 229920001971 elastomer Polymers 0.000 claims description 8
- 238000001816 cooling Methods 0.000 claims description 7
- 238000005286 illumination Methods 0.000 claims description 7
- 238000013016 damping Methods 0.000 claims description 6
- HMDDXIMCDZRSNE-UHFFFAOYSA-N [C].[Si] Chemical compound [C].[Si] HMDDXIMCDZRSNE-UHFFFAOYSA-N 0.000 claims description 5
- 238000005188 flotation Methods 0.000 claims description 5
- 230000015572 biosynthetic process Effects 0.000 claims description 4
- 230000010354 integration Effects 0.000 claims description 4
- 238000004891 communication Methods 0.000 claims description 3
- 230000007246 mechanism Effects 0.000 claims description 3
- 208000037656 Respiratory Sounds Diseases 0.000 claims description 2
- 230000000977 initiatory effect Effects 0.000 abstract description 9
- 239000007769 metal material Substances 0.000 abstract description 8
- 239000002184 metal Substances 0.000 abstract description 6
- 238000000034 method Methods 0.000 description 14
- 238000003384 imaging method Methods 0.000 description 11
- 230000008569 process Effects 0.000 description 6
- 238000006073 displacement reaction Methods 0.000 description 5
- 239000000956 alloy Substances 0.000 description 4
- 230000005540 biological transmission Effects 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 4
- 238000002474 experimental method Methods 0.000 description 4
- 229910045601 alloy Inorganic materials 0.000 description 3
- 238000013461 design Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 239000007888 film coating Substances 0.000 description 3
- 238000009501 film coating Methods 0.000 description 3
- 238000002360 preparation method Methods 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 238000005520 cutting process Methods 0.000 description 2
- 238000009792 diffusion process Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 239000003921 oil Substances 0.000 description 2
- 238000003860 storage Methods 0.000 description 2
- 238000010998 test method Methods 0.000 description 2
- 230000000007 visual effect Effects 0.000 description 2
- 239000010965 430 stainless steel Substances 0.000 description 1
- 239000010425 asbestos Substances 0.000 description 1
- 229920005549 butyl rubber Polymers 0.000 description 1
- 230000001413 cellular effect Effects 0.000 description 1
- 229920002301 cellulose acetate Polymers 0.000 description 1
- 235000013339 cereals Nutrition 0.000 description 1
- 238000012512 characterization method Methods 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 230000001808 coupling effect Effects 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000008030 elimination Effects 0.000 description 1
- 238000003379 elimination reaction Methods 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 239000003365 glass fiber Substances 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 238000005498 polishing Methods 0.000 description 1
- 238000009417 prefabrication Methods 0.000 description 1
- 230000000644 propagated effect Effects 0.000 description 1
- 230000010076 replication Effects 0.000 description 1
- 229910052895 riebeckite Inorganic materials 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 229910000601 superalloy Inorganic materials 0.000 description 1
- 238000004154 testing of material Methods 0.000 description 1
- 238000012876 topography Methods 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/84—Systems specially adapted for particular applications
- G01N21/88—Investigating the presence of flaws or contamination
- G01N21/90—Investigating the presence of flaws or contamination in a container or its contents
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/01—Arrangements or apparatus for facilitating the optical investigation
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/02—Details
- G01N3/04—Chucks
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/0058—Kind of property studied
- G01N2203/006—Crack, flaws, fracture or rupture
- G01N2203/0062—Crack or flaws
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/02—Details not specific for a particular testing method
- G01N2203/022—Environment of the test
- G01N2203/0222—Temperature
- G01N2203/0226—High temperature; Heating means
Landscapes
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
Abstract
The invention discloses a micro-crack propagation in-situ test and observation device, which comprises a fatigue loading system, a temperature control system and a micro-optical imaging and monitoring system. The device has a simple and reasonable structure, can perform in-situ online test and observation on the initiation and the expansion of the micro cracks of the metal material in the high-temperature atmospheric environment by using the fatigue loading system, the temperature control system and the micro-optical imaging and monitoring system, does not need to suspend the testing machine to disassemble and reprocess the sample, and thus effectively solves the problem that the metal micro crack expansion behavior test in the high-temperature atmospheric environment can not be continuously performed online in the prior art. Meanwhile, the invention innovatively utilizes the band-pass filtering principle to cut off the high-temperature heat radiation and visible light (mainly red light section) of the sample and the temperature control system at high temperature, thereby eliminating the interference of the high temperature on crack observation.
Description
Technical Field
The invention relates to the field of metal material testing, in particular to a tiny crack propagation in-situ test and observation device.
Background
Defects such as gaps and non-metallic inclusions introduced in the manufacturing process of a metal material are often crack sources which cause catastrophic failure of the material in a loaded process. These defect sizes tend to be between tens of microns and 200 microns. The crack is initiated from the defects and then enters a small crack propagation stage, so that the propagation behavior and mechanism of the metal material micro crack are proved, and the design significance on the safe work, the service and the damage tolerance of the bearing structure is very important.
But are difficult to observe and measure by conventional means due to the size and small size of the cracks initiated at the manufacturing defect. Especially in high temperature environment, the development of the small crack propagation test brings many difficulties due to the oxidation of the material and the atmosphere. Although the advanced in-situ fatigue test technology based on the scanning electron microscope can be used for observing the initiation and the propagation conditions of the micro cracks on line, the use price is high, the test can be only carried out in a vacuum environment, and the coupling effect of the atmosphere and a high-temperature environment cannot be reflected.
Patent application No. CN201810060994.4 discloses a test method for obtaining fatigue small cracks of a metal plate by using cellulose acetate film replication, but the test method needs to stop the film coating record in the middle of the test, and cannot continuously observe, and only can record a small amount of information, which results in that key information is easily lost, and the real behavior of small crack propagation cannot be reproduced. Meanwhile, the film covering process is complicated, the covering success rate is greatly influenced by experience and technology of testers, and a large amount of labor cost is consumed.
In summary, how to provide a device with low cost and capable of continuously conducting an online metal micro crack propagation behavior test in room temperature and high temperature atmospheric environments is a problem to be solved urgently at present.
Disclosure of Invention
The invention aims to provide a micro-crack propagation in-situ test and observation device, which can perform in-situ on-line test and observation on the initiation and propagation of a micro crack of a metal material in a high-temperature atmospheric environment so as to solve the problem that the metal micro-crack propagation behavior test in the high-temperature atmospheric environment cannot be continuously performed on line in the prior art.
In order to achieve the purpose, the invention provides the following scheme:
the invention provides a tiny crack propagation in-situ test and observation device, which comprises:
the fatigue loading system comprises a fatigue testing machine and a sample clamp, the sample clamp is connected with the fatigue testing machine and used for clamping a small crack sample, and defects are prefabricated on the small crack sample; the fatigue testing machine is used for applying fatigue load to the small crack sample;
the temperature control system comprises a heating chamber and a heating element, the heating chamber is used for accommodating the small crack sample, and the heating element is arranged in the heating chamber and used for heating the small crack sample; an observation window is arranged on one side of the heating chamber, and the observation window can expose the prefabricated defects on the small crack sample;
micro-optics formation of image and monitoring system, micro-optics formation of image and monitoring system include micro-optical lens, band pass filter and image acquisition device, just observation window micro-optical lens band pass filter with image acquisition device aligns in proper order and arranges, band pass filter is used for the filtering heating element and the thermal radiation and the visible light that the crazing sample is heated and is sent, image acquisition device is used for observing and recording the crackle emergence and the expansion condition of the prefabricated defect department of crazing sample.
Optionally, the micro-optical imaging and monitoring system further comprises an illumination system; the lighting system includes:
the LED blue coaxial light source with the wavelength range of 425 nm-500 nm is positioned above the micro optical lens;
the light path integration component comprises a reflector and a convex lens, the convex lens is arranged between the observation window and the micro optical lens, the reflector is obliquely arranged between the convex lens and the micro optical lens and positioned below the blue coaxial light source of the LED, and the reflector can receive the light emitted by the blue coaxial light source of the LED and face the light reflected by the observation window.
Optionally, the micro-optical imaging and monitoring system further includes a cooling fan, and the cooling fan is disposed between the observation window and the micro-optical lens and is configured to cool the micro-optical imaging and monitoring system.
Optionally, the micro-optical imaging and monitoring system further includes an image recording and storing system, the image recording and storing system includes a graphic workstation, and the graphic workstation is configured with image monitoring and storing software and a hard disk; the graphic workstation is in communication connection with the image acquisition device.
Optionally, the image acquisition device is a CCD camera.
Optionally, the temperature control system further comprises a temperature thermocouple; the heating element comprises a pair of carbon silicon heating elements.
Optionally, the apparatus further includes a lens adjusting system, where the lens adjusting system includes:
a lifting platform;
the three-axis translation table is arranged on the lifting table;
the rotating table is rotatably arranged on the three-axis translation table;
and the micro lens holder is arranged above the rotating platform and is used for mounting the micro optical lens.
Optionally, the microlens holder includes:
the device comprises an annular bracket, a plurality of thread tightening devices and a plurality of thread tightening mechanisms, wherein the thread tightening devices are arranged on the annular bracket at intervals along the circumferential direction of the annular bracket and are used for fixing the micro optical lens;
the step pitching platform of the annular support is installed on the rotating platform, the step pitching platform of the annular support is installed on the step pitching platform of the annular support, and the step pitching platform of the annular support is used for adjusting the pitching angle of the microscopic optical lens.
Optionally, a thread tightening device is arranged on the annular bracket at intervals of 120 degrees along the circumferential direction of the annular bracket; the screw thread jacking device is a bolt in threaded connection with the annular support.
Optionally, the air floatation vibration isolation platform further comprises a vibration isolation system, wherein the vibration isolation system comprises a vibration isolation rubber block, an air floatation vibration isolation platform and a honeycomb bread board which are sequentially arranged from bottom to top; the lens adjusting system is arranged on the honeycomb bread board.
Optionally, the small crack sample is a rod-shaped sample, the cross section of the middle section of the rod-shaped sample is rectangular, and two ends of the middle section are both connected with a cylindrical section with a circular cross section; the middle section is used for prefabricating the defect; the cylindrical section is used for being in threaded connection with the sample clamp.
Compared with the prior art, the invention has the following technical effects:
the in-situ test and observation device for the tiny crack propagation provided by the invention has a simple and reasonable structure, can perform in-situ online test and observation on the tiny crack initiation and propagation of a metal material in a high-temperature atmospheric environment by using the fatigue loading system, the temperature control system and the micro-optical imaging and monitoring system, does not need to suspend the test machine to disassemble and reprocess a sample, and thus effectively solves the problem that the test of the metal tiny crack propagation behavior in the high-temperature atmospheric environment can not be continuously performed online in the prior art. Meanwhile, the invention innovatively utilizes the band-pass filtering principle to cut off the high-temperature heat radiation and visible light (mainly red light section) of the sample and the temperature control system at high temperature, and eliminates the interference of the high temperature to crack observation.
Compared with the prior art, the in-situ test and observation device for the tiny crack propagation can perform the in-situ test and observation of the tiny crack propagation on line at low cost and high efficiency, can acquire more abundant crack propagation and mesoscopic information compared with the experimental technology of a film coating method, breaks through the key technical problems of visible, clear and online viewing of the tiny crack propagation in a high-temperature atmospheric environment, can adapt to the working conditions from room temperature to high-temperature wide temperature, and has better universality.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.
FIG. 1 is a schematic structural diagram of a micro crack propagation in-situ testing and observing device disclosed in an embodiment of the present invention;
FIG. 2 is a schematic structural diagram of a small crack sample disclosed in an embodiment of the present invention;
FIG. 3 is a schematic view of a microscope imaging and monitoring system according to an embodiment of the present invention;
FIG. 4 is a schematic structural diagram of a prefabricated defect on a small-crack test specimen disclosed by an embodiment of the invention;
FIG. 5 is an image of a propagation path of a pre-formed defect on a small crack test specimen as disclosed in an embodiment of the present invention;
FIG. 6 is a graph of the disclosed FGH96 alloy high temperature microcrack propagation rate.
Wherein the reference numerals are: 100. a tiny crack propagation in-situ test and observation device;
1. a fatigue testing machine; 2. a tester control system; 3. a sample clamp; 4. heating furnace; 5. a temperature thermocouple; 6. a temperature control system; 7. a cooling fan; 8. an LED blue coaxial light source; 81. a mirror; 82. a convex lens; 83. a diffusion sheet; 9. a band-pass filter; 10. a microscopic optical lens; 11. a CCD camera; 12. an image recording and storage system; 13. a microlens holder; 131. a ring-shaped scaffold; 14. a rotating table; 15. a three-axis translation stage; 16. a lifting platform; 17. a vibration isolation rubber block; 18. an air-flotation vibration isolation platform; 19. a honeycomb bread board; 20. a small crack sample; 201. a middle section; 202. a cylindrical section.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The invention aims to provide a micro-crack propagation in-situ test and observation device, which can perform in-situ on-line test and observation on the initiation and propagation of a micro crack of a metal material in a high-temperature atmospheric environment so as to solve the problem that the metal micro-crack propagation behavior test in the high-temperature atmospheric environment cannot be continuously performed on line in the prior art.
In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.
Example one
As shown in fig. 1, the present embodiment provides an in-situ testing and observing apparatus 100 for micro crack propagation, which mainly includes a fatigue loading system, a temperature control system, and a micro-optical imaging and monitoring system. The fatigue loading system comprises a fatigue testing machine 1 and a sample clamp 3, wherein the sample clamp 3 is connected with the fatigue testing machine 1 and used for clamping a small crack sample 20, and defects (such as black spots shown in figure 4) are prefabricated on the small crack sample 20; the fatigue testing machine 1 applies a fatigue load to the small crack specimen 20. The temperature control system comprises a heating chamber and a heating element, wherein the heating chamber is used for accommodating the small crack sample 20, and the heating element is arranged in the heating chamber and used for heating the small crack sample 20; one side of the heating chamber is provided with an observation window capable of exposing the defects pre-fabricated on the small crack specimen 20. The microscopic optical imaging and monitoring system comprises a microscopic optical lens 10, a band-pass filter 9 and an image acquisition device, wherein an observation window, the microscopic optical lens 10, the band-pass filter 9 and the image acquisition device are sequentially arranged in an aligned mode, the band-pass filter 9 is used for filtering heat radiation and visible light emitted by heating of a heating element and a small crack sample 20, and the image acquisition device is used for observing and recording crack initiation and expansion conditions of a prefabricated defect of the small crack sample 20.
In this embodiment, as a preferable mode, the fatigue testing machine is provided with a fatigue testing machine load displacement sensor, the fatigue testing machine load displacement sensor is connected with a test control system, and the test control system is used for setting and feeding back fatigue load displacement data and controlling the operation and the stop of the fatigue testing machine 1. The fatigue testing machine, the fatigue testing machine load displacement sensor and the test control system are all existing devices, and are not described herein again.
In this embodiment, the sample holder 3 is specifically a high temperature alloy holder, one end of which is provided with a coaxial internal threaded hole to be coaxially connected with the small crack sample 20, and the other end of which is connected with the fatigue testing machine 1, thereby ensuring that the loading direction has a higher coaxiality with the axial direction of the small crack sample 20. The small crack sample 20 is preferably rod-shaped, as shown in fig. 2, the cross section of the middle section 201 (the middle section is also called "gauge length section") of the small crack sample 20 is rectangular, and both ends of the middle section 201 are connected to the cylindrical section 202 with a circular cross section; the intermediate section 201 is used for prefabrication defects; the outer ends of the two cylindrical sections 202 (i.e. the ends far away from the middle section 201) are provided with external thread sections matched with the coaxial internal thread holes for being coaxially connected with the sample clamp 3 in a threaded manner, so that fatigue load can be applied conveniently.
In the embodiment, the temperature control system comprises a heating furnace 4, an upper heating chamber and a lower heating chamber are arranged in the heating furnace 4, and each heating chamber is internally provided with a pair of carbon-silicon heating elements and a temperature thermocouple 5; the observation window is arranged on the surface of the hearth of the heating furnace 4, the observation window is preferably a circular window with the diameter of 5cm, and the surface of the circular window is covered with high-temperature-resistant quartz glass. Wherein, two carbon-silicon heating elements in any pair of carbon-silicon heating elements are symmetrically arranged at two sides of the small crack sample 20 for providing a stable high-temperature environment. The temperature thermocouple 5 is preferably a K-type thermocouple coated with high-temperature-resistant glass fiber, and the temperature point is in direct contact with the surface of the working section (namely the middle section 201) of the small crack sample 20 and is used for measuring the temperature of the working section (namely the middle section 201) of the small crack sample 20; the temperature thermocouple 5 is electrically connected with a temperature control system 6 outside the cavity of the heating furnace 4 through a thermocouple lead, and the temperature control system 6 is provided with a temperature display.
In this embodiment, as shown in fig. 1, the micro-optical imaging and monitoring system further includes an illumination system for providing high quality brightness conditions for micro-imaging of the small crack sample 20, so that the micro-optical imaging and monitoring system captures and captures the micro-crack information under suitable illumination conditions. The illumination system mainly comprises an LED blue coaxial light source 8 with the wavelength range of 425 nm-500 nm and a light path integration component, wherein the LED blue coaxial light source 8 is positioned above the micro optical lens 10, and the LED blue coaxial light source 8 can provide a coaxial light source with high parallelism, so that the elimination of shadows generated by uneven surface of an observed object is facilitated; while the emitting end of the LED blue coaxial light source 8 is provided with a diffuser 83, the diffuser 83 is an existing optical element that presents a lambertian distribution of transmitted light through solid light diffusion for creating uniform lighting conditions to provide stable, uniform and near monochromatic bright field lighting conditions. The light path integration component comprises a reflector 81 and a convex lens 82, the convex lens 82 is arranged between the observation window and the micro optical lens 10, the reflector 81 is obliquely arranged between the convex lens 82 and the micro optical lens 10 and is positioned below the LED blue coaxial light source 8, and the reflector 81 can receive light emitted by the LED blue coaxial light source 8 and reflects the light towards the observation window. Preferably, the LED blue coaxial light source 8 is arranged perpendicular to the micro optical lens 10, and the reflector 81 is arranged at an angle of 45 degrees, and is capable of receiving the vertical light source emitted by the LED blue coaxial light source 8 and reflecting a horizontal light ray coaxial with the micro optical lens 10, so as to form a parallel light path; at the same time, the mirror 81 is capable of transmitting part of the light towards the image acquisition device, which is also coaxial with the micro-optical lens 10. The convex lens 82 has an amplifying function, and can expand light spots of the reflected light of the reflector 81, which are irradiated on the observation window, expand an illumination area, and further improve illumination conditions.
In a high-temperature experiment, the heating element in the heating furnace 4 and the surface of the small crack sample 20 are heated, and the wavelength of the electromagnetic wave radiated outwards is in a visible light band and close to one side of an infrared band. According to the band-pass filtering principle, the transmission band of the band-pass filter 9 is surrounded by two cut-off bands, which allow only part of the wavelengths in the spectrum to pass. The technical scheme is innovatively characterized in that the pass-band pass filter 9 is arranged in a parallel light path and used for cutting off heat radiation, so that the influence of the heat radiation on the imaging quality is reduced; in this embodiment, the band pass filter 9 transmits light having a band wavelength that coincides with the wavelength range of the light emitted from the LED blue coaxial light source 8, thereby cutting off the visible light emitted from the small crack sample 20 and the heating element.
In this embodiment, the micro-optical lens 10 is preferably a micro-lens suitable for both room temperature and high temperature, and is a conventional lens structure. Specifically, the microscopic optical lens 10 used in the room temperature experiment is preferably a microscopic optical lens with a continuous zooming function, and the magnification range is 1.16-66.63; the microscopic optical lens 10 used in the high temperature experiment is preferably a long working distance microscope with a magnification in the range of 1-34.
In this embodiment, the image capturing device is preferably a CCD camera 11 (the CCD camera is collectively referred to as a "CCD image sensor camera"), the size of the CCD camera 11 is 2/3 inches, the number of pixels is 2448 × 2050, and the CCD camera 11 is connected to the image recording and storing system 12 through a camera lead for online transmission of information on the micro-cracks captured by the microscope lens. The image recording and storing system 12 mainly comprises a graphic workstation, wherein the graphic workstation is provided with image monitoring and storing software and a hard disk; the graphics workstation is in communication with the aforementioned image capture device (i.e., the CCD camera 11). The graphic workstation is a generic name of a high-grade special computer which professionally engages in graphic, image (static), image (dynamic) and video work, belongs to the existing equipment, and is not described herein again, wherein the image monitoring and storing software is preferably high-speed image monitoring and storing software, and the hard disk is preferably a high-speed hard disk, which are the prior art, and the specific structure and function are not described herein again.
In this embodiment, as shown in fig. 1, the micro-optical imaging and monitoring system further includes a cooling fan 7, and the cooling fan 7 is disposed between the observation window and the micro-optical lens 10, and is used for providing a stable air flow field to cool the micro-optical imaging and monitoring system.
In this embodiment, as shown in fig. 1, the apparatus further includes a lens adjusting system, where the lens adjusting system includes a lifting table 16, a three-axis translation table 15, a rotation table 14, and a micro-lens holder 13; the three-axis translation stage 15 is arranged on the lifting stage 16, the rotating stage 14 is rotatably arranged on the three-axis translation stage 15, and the microscope lens holder 13 is arranged above the rotating stage 14 and used for mounting the microscope optical lens 10. The micro lens holder 13 comprises an annular bracket 131 and an annular bracket ground-step pitching table, wherein a plurality of thread tightening devices are arranged on the annular bracket 131 at intervals along the circumferential direction of the annular bracket, and the thread tightening devices are used for fixing the micro optical lens 10; the ring-shaped stand ground step pitching stage is mounted on the rotating stage 14, and the ring-shaped stand 131 is mounted on the ring-shaped stand ground step pitching stage for adjusting the pitching angle of the microscopic optical lens 10. Preferably, a screw thread jacking device is arranged on the annular bracket 131 at intervals of 120 degrees along the circumferential direction of the annular bracket; the screw tightening means is preferably a bolt screwed with the ring bracket 131.
In this embodiment, the lifting table 16, the three-axis translation table 15, the rotating table 14 and the annular frame ground step pitching table are all existing devices. Wherein, a ball bearing guide rail is arranged in the rotating table 14 for adjusting the 360-degree rotation angle of the micro-optical lens 10 on the horizontal plane (the horizontal plane corresponds to the XY plane in the three-axis translation table 15). The three-axis translation stage 15 is an existing three-dimensional adjustment platform, for example, an existing HT111WM25M precision translation stage laboratory displacement stage sliding table, which has a thread pair along the height (Z axis), front-back (Y axis) and left-right (X axis) directions, and can provide a space macro motion function for the micro-optical lens 10 by matching with the micro-lens holder 13 and the rotation stage 14, so as to improve the focusing and imaging quality of the micro-optical lens 10. The lifting platform 16 is preferably a conventional scissor-type lifting platform, and the lifting (in the lifting direction parallel to the aforementioned Z-axis) is driven by a lead screw and is mainly used for coarse height adjustment of the microscopic optical lens 10. In the actual test process, the CCD camera 11 is also mounted on the turntable 14.
Because a plurality of vibration sources exist in the actual test environment, such as mechanical vibration of an oil pump in the fatigue testing machine 1, vibration caused by external street traffic, and the like, the vibration is transmitted to the micro-optical imaging and monitoring system and the fatigue testing machine 1, so that motion blur exists in imaging. To this end the embodiment is also provided with a damping system. The damping system comprises a vibration isolation rubber block 17, an air floatation vibration isolation platform 18 and a honeycomb bread board 19 which are arranged from bottom to top in sequence; the lens adjustment system is disposed on the cellular bread board 19. The vibration isolation rubber block 17, the air flotation vibration isolation platform 18 and the honeycomb bread board 19 form a combined type vibration isolation and damping device which is used for isolating and reducing the interference of external vibration on a microscopic optical imaging and monitoring system. Wherein, the vibration isolation rubber block 17 is arranged at the bottommost layer and is contacted with the ground, and absorbs the vibration transmitted from the ground by the outside by means of self deformation; further, the upper air-flotation vibration isolation platform 18 adopts compressed air to absorb vibration transmitted by the vibration isolation rubber block 17; the honeycomb bread board 19 mainly functions to provide a rigid platform without relative deformation, and when a vibration source is transmitted to the table top, the vibration deformation of the optical platform can be effectively weakened by the damping of the honeycomb structure. Preferably, the air pressure of the air flotation vibration isolation platform 18 is 2.2bar, the vibration isolation rubber block 17 is made of butyl rubber, and the honeycomb bread board 19 is made of 430 stainless steel.
During the test, part of the sample holder 3 is heated in the heating furnace 4 together with the small crack sample 20, so that the sample holder 3 is preferably made of high temperature alloy material (DZ125) to ensure normal operation at a high temperature of 1000 ℃. The advantages and implementation methods of the in-situ microcrack propagation test and observation apparatus 100 of this embodiment are further illustrated and described below in connection with the microcrack propagation test of the FGH96 superalloy, using the FGH96 alloy as an example for the microcrack specimen 20.
The method comprises the following steps: preparation of small crack specimen 20.
The small crack sample 20 is processed according to the design drawing size (as shown in fig. 2), and in order to obtain the crack initiation and propagation conditions at the micro-defect, the defect needs to be prefabricated on the surface of the sample. Preferably, the defect preparation method is femtosecond laser, and the size of the prepared surface defect (the defect is approximately rectangular) is not more than 100 μm x 60 μm.
In order to form a better finish and imaging environment on the surface of the small crack sample 20, the surface of the small crack sample 20 is ground by using sandpaper with different meshes, and then the sample is polished to a mirror surface by using a mechanical polishing method.
And corroding the surface of the small crack sample 20 by using a metallographic corrosive liquid so as to observe microscopic information of the small crack sample 20, such as grain morphology, twin crystals and the like in the test process.
After the small crack sample 20 is prepared, the surface is covered with an electrostatic film to protect the surface of the sample and prevent the surface from being scratched and oil from adhering to influence imaging.
The preparation form of the small crack sample 20 is only an implementation case of the technical scheme, and a practitioner can design the sample and the high-temperature clamp form according to the requirements of the practitioner, so as to ensure that the loading shaft of the load testing machine and the sample have enough coaxiality.
Step two: and clamping and heating the small crack sample 20.
The prepared small crack sample 20 is connected with the built-in threaded hole of the sample clamp 3 through the external threads on the upper and lower cylindrical sections 202, so that the connection between the small crack sample 20 and the fatigue testing machine 1 and the sample clamp 3 is more compact, the loose structure caused by simple pin connection is overcome, and the small crack sample 20 can be simultaneously suitable for tensile, tensile and compressive, tensile and torsional, compressive and other fatigue tests.
One end of an assembly formed by connecting the small crack sample 20 and the sample clamp 3 is fixed at the upper end of the fatigue testing machine 1, one side of the small crack sample 20 containing surface prefabricated defects is aligned to a high-temperature resistant quartz glass observation window (namely an observation window) on the heating furnace 4 through a visual observation method, and the surface of the small crack sample 20 is parallel to the glass surface of the observation window.
Fixing a temperature thermocouple 5 connected with a temperature control system 6 on the small crack sample 20 through asbestos threads, opening the temperature control system 6 to set the temperature to be a specified test temperature, and preserving the temperature for 30min when the temperature rises to the specified temperature to ensure that the small crack sample 20 is in a uniform temperature field.
Step three: and adjusting a micro-optical imaging and monitoring system.
An optical imaging system is installed and built according to the sequence shown in fig. 3, a micro-optical lens 10 is fixed on a micro-lens holder 13 by a screw thread tightening device, an LED blue coaxial light source 8 is arranged at the front end (left end of the visual angle shown in fig. 3) of the micro-optical lens 10, and a light source control switch is turned on.
A band-pass filter 9 and a CCD camera 11 are sequentially installed at the end of the micro-optical lens 10 (the right end of the viewing angle shown in fig. 3), a data transmission line of the CCD camera 11 is connected to an image recording and storing system 12, and digital image processing software on the image recording and storing system 12 is opened to obtain a preliminary imaging picture.
Checking whether the air internal pressure of the air floatation vibration isolation platform 18 is a rated value or not, and if the air internal pressure is lower than the set rated value, pressurizing to the rated 2.2bar by using a special inflator.
And adjusting a screw device on the lifting platform 16 to enable the height of the micro-optical lens 10 to be basically consistent with the height of an observation window on the heating furnace 4 and ensure that the micro-optical lens 10 is coaxially aligned with the observation window of the heating furnace 4, and at the moment, adjusting a focusing knob of the micro-optical lens 10 can observe the image of the small crack sample 20 on the image recording and storing system 12 but has low imaging quality.
Further adjusting the knobs on the three spatial directions (i.e., X-axis, Y-axis, and Z-axis) of the combined three-axis translation stage 15 enables the prefabricated micro defects on the small crack sample 20 to be observed on the image recording and storing system 12, and simultaneously adjusting the fixing knob on the micro lens holder 13, the focal length adjusting knob on the micro optical lens 10, and the like in a matching manner until clear defects and the micro topography of the sample surface can be observed in the center of the field of view as shown in fig. 4.
Step four: and (5) carrying out a micro crack propagation test.
And starting the control system 2 of the testing machine, and starting to circularly load the small crack sample 20 after setting the loading condition and overload protection.
After a certain cycle number is loaded, the fatigue testing machine 1 is suspended at the position with 80% of peak load, the crack initiation and propagation conditions at the position with the preformed notch on the surface are observed and image acquisition is carried out on the image recording and storing system 12, and the acquired crack morphology picture is named according to the current cycle number.
After the crack at the pre-formed defect has propagated for a certain period of time, an image of the micro crack propagation path may be observed on the image recording and storage system 12 as shown in FIG. 5.
The collected Crack morphology picture is processed according to the standard ASTM E647-15E1 Standard for measuring method of Fatigue Crack Growth Rates, so that the expansion rule of the Fatigue Crack under the micro scale can be obtained, as shown in FIG. 6.
When the crack is expanded to a specified length (generally, the long crack is 1mm as reference) but the sample is not broken, stopping loading, closing the temperature control system 6, opening the heating furnace 4 after the temperature is reduced to room temperature to take out the small crack sample 20, and further analyzing the micro crack expansion process by using advanced characterization means such as a scanning electron microscope.
Therefore, the in-situ test and observation device for the micro crack propagation in the high-temperature atmospheric environment can realize the direct online observation of the micro crack propagation path, length and microscopic appearance by using optical observation and digital transmission display equipment, and does not need to suspend the test machine to disassemble and process the test sample; meanwhile, the band-pass filtering principle is innovatively utilized to cut off high-temperature heat radiation and visible light of the sample and the heating system at high temperature, and interference on crack observation caused by high temperature is eliminated.
According to the technical scheme, the composite vibration isolation device is utilized to block the influence of external environment vibration on the imaging quality of the optical system, and the microscopic imaging system can still capture clear crack information under a micro scale.
Compared with the prior art, the technical scheme provides an online, low-cost and efficient in-situ observation and test device for tiny crack propagation, in particular to in-situ online test and observation of tiny crack initiation and propagation of a metal material in a high-temperature atmospheric environment, and compared with a film coating method experiment technology, the device can acquire more abundant crack propagation and microscopic information, breaks through the key technical problems of visible tiny crack propagation, clear sight and online sight in the high-temperature atmospheric environment, can adapt to the working conditions from room temperature to high-temperature wide temperature, has better universality, and is convenient for technicians in the field to develop tiny crack propagation tests in the room temperature and the high-temperature atmospheric environment in a low-cost and continuous online mode.
It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein, and any reference signs in the claims are not intended to be construed as limiting the claim concerned.
The principle and the implementation mode of the invention are explained by applying a specific example, and the description of the embodiment is only used for helping to understand the method and the core idea of the invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In view of the above, the present disclosure should not be construed as limiting the invention.
Claims (10)
1. A tiny crack propagation in-situ test and observation device is characterized by comprising:
the fatigue loading system comprises a fatigue testing machine and a sample clamp, the sample clamp is connected with the fatigue testing machine and used for clamping a small crack sample, and defects are prefabricated on the small crack sample; the fatigue testing machine is used for applying fatigue load to the small crack sample;
the temperature control system comprises a heating chamber and a heating element, the heating chamber is used for accommodating the small crack sample, and the heating element is arranged in the heating chamber and used for heating the small crack sample; an observation window is arranged on one side of the heating chamber, and the observation window can expose the prefabricated defects on the small crack sample;
micro-optics formation of image and monitoring system, micro-optics formation of image and monitoring system include micro-optical lens, band pass filter and image acquisition device, just observation window micro-optical lens band pass filter with image acquisition device aligns in proper order and arranges, band pass filter is used for the filtering heating element and the thermal radiation and the visible light that the crazing sample is heated and is sent, image acquisition device is used for observing and recording the crackle emergence and the expansion condition of the prefabricated defect department of crazing sample.
2. The micro-crack propagation in-situ test and observation apparatus according to claim 1, wherein the micro-optical imaging and monitoring system further comprises an illumination system; the lighting system includes:
the LED blue coaxial light source with the wavelength range of 425 nm-500 nm is positioned above the micro optical lens;
the light path integration component comprises a reflector and a convex lens, the convex lens is arranged between the observation window and the micro optical lens, the reflector is obliquely arranged between the convex lens and the micro optical lens and positioned below the blue coaxial light source of the LED, and the reflector can receive the light emitted by the blue coaxial light source of the LED and face the light reflected by the observation window.
3. The in-situ testing and observing device for the propagation of micro cracks of claim 1, wherein the micro-optical imaging and monitoring system further comprises a cooling fan disposed between the observation window and the micro-optical lens for cooling the micro-optical imaging and monitoring system.
4. The in-situ micro-crack propagation testing and observing device of claim 1, wherein the micro-optical imaging and monitoring system further comprises an image recording and storing system comprising a graphic workstation configured with image monitoring and storing software and a hard disk; the graphic workstation is in communication connection with the image acquisition device.
5. The in-situ micro-crack propagation testing and observing device of any one of claims 1 to 4, wherein the image capturing device is a CCD camera.
6. The microcrack propagation in-situ testing and observing apparatus according to claim 1, wherein the temperature control system further comprises a temperature thermocouple; the heating element comprises a pair of carbon silicon heating elements.
7. The in-situ micro-crack propagation testing and observing device of any one of claims 1 to 4, further comprising a lens adjusting system, wherein the lens adjusting system comprises:
a lifting platform;
the three-axis translation table is arranged on the lifting table;
the rotating table is rotatably arranged on the three-axis translation table;
and the micro lens holder is arranged above the rotating platform and is used for mounting the micro optical lens.
8. The micro crack propagation in-situ test and observation apparatus of claim 7, wherein the micro lens holder comprises:
the device comprises an annular bracket, a plurality of thread tightening devices and a plurality of thread tightening mechanisms, wherein the thread tightening devices are arranged on the annular bracket at intervals along the circumferential direction of the annular bracket and are used for fixing the micro optical lens;
the step pitching platform of the annular support is installed on the rotating platform, the step pitching platform of the annular support is installed on the step pitching platform of the annular support, and the step pitching platform of the annular support is used for adjusting the pitching angle of the microscopic optical lens.
9. The in-situ testing and observing device for the propagation of the micro-crack as claimed in claim 7, further comprising a damping system, wherein the damping system comprises a vibration isolation rubber block, an air flotation vibration isolation platform and a honeycomb bread board which are arranged from bottom to top in sequence; the lens adjusting system is arranged on the honeycomb bread board.
10. The in-situ test and observation device for the propagation of microcracks according to any one of claims 1 to 4, wherein the small crack sample is a rod-shaped sample, the cross section of the middle section of the rod-shaped sample is rectangular, and both ends of the middle section are connected with cylindrical sections with circular cross sections; the middle section is used for prefabricating the defect; the cylindrical section is used for being in threaded connection with the sample clamp.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210207097.8A CN114544654A (en) | 2022-03-04 | 2022-03-04 | Tiny crack growth in-situ test and observation device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210207097.8A CN114544654A (en) | 2022-03-04 | 2022-03-04 | Tiny crack growth in-situ test and observation device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114544654A true CN114544654A (en) | 2022-05-27 |
Family
ID=81661078
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210207097.8A Pending CN114544654A (en) | 2022-03-04 | 2022-03-04 | Tiny crack growth in-situ test and observation device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114544654A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115128788A (en) * | 2022-05-30 | 2022-09-30 | 中国人民解放军国防科技大学 | Horizontally arranged microscope parallel to observation object |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103454165A (en) * | 2013-08-19 | 2013-12-18 | 北京航空航天大学 | Testing system for fatigue crack propagation test under high/low temperature environment |
| CN104034600A (en) * | 2014-05-20 | 2014-09-10 | 北京航空航天大学 | Fatigue crack propagation experiment testing system under extremely high temperature environment |
| CN208651505U (en) * | 2018-03-29 | 2019-03-26 | 勤威(天津)工业有限公司 | A kind of roundness measuring equipment air bearing vibration absorber |
| CN209606222U (en) * | 2019-01-11 | 2019-11-08 | 华东理工大学 | A kind of Fracture of Metal Material toughness specimen crack length on-Line Monitor Device |
| CN110672441A (en) * | 2019-10-21 | 2020-01-10 | 江苏理工学院 | Characterization method of crack tip state in fatigue crack propagation process |
| CN112255113A (en) * | 2020-10-09 | 2021-01-22 | 中国航发北京航空材料研究院 | High-temperature elastic constant measuring method for thin strip |
| US20220065739A1 (en) * | 2020-09-03 | 2022-03-03 | University Of South Carolina | Vibration Test-Cell with Axial Load and In-Situ Microscopy |
-
2022
- 2022-03-04 CN CN202210207097.8A patent/CN114544654A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103454165A (en) * | 2013-08-19 | 2013-12-18 | 北京航空航天大学 | Testing system for fatigue crack propagation test under high/low temperature environment |
| CN104034600A (en) * | 2014-05-20 | 2014-09-10 | 北京航空航天大学 | Fatigue crack propagation experiment testing system under extremely high temperature environment |
| CN208651505U (en) * | 2018-03-29 | 2019-03-26 | 勤威(天津)工业有限公司 | A kind of roundness measuring equipment air bearing vibration absorber |
| CN209606222U (en) * | 2019-01-11 | 2019-11-08 | 华东理工大学 | A kind of Fracture of Metal Material toughness specimen crack length on-Line Monitor Device |
| CN110672441A (en) * | 2019-10-21 | 2020-01-10 | 江苏理工学院 | Characterization method of crack tip state in fatigue crack propagation process |
| US20220065739A1 (en) * | 2020-09-03 | 2022-03-03 | University Of South Carolina | Vibration Test-Cell with Axial Load and In-Situ Microscopy |
| CN112255113A (en) * | 2020-10-09 | 2021-01-22 | 中国航发北京航空材料研究院 | High-temperature elastic constant measuring method for thin strip |
Non-Patent Citations (3)
| Title |
|---|
| 郑欢斌;刘辉;刘欢;朱亚伦;齐子诚;: "疲劳裂纹扩展试验裂纹图像采集系统", 轻工机械, no. 06, 20 December 2015 (2015-12-20) * |
| 高红俐 等: "基于图像处理的疲劳裂纹扩展长度在线测量方法", 中国机械工程, no. 07, 15 April 2016 (2016-04-15) * |
| 龚明, 刘云平, 赵建华, 董本涵, 高鹏飞: "45CrNiMoVA钢的低周疲劳特性和表面疲劳裂纹的在位观测", 实验力学, no. 01, 30 March 2001 (2001-03-30) * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115128788A (en) * | 2022-05-30 | 2022-09-30 | 中国人民解放军国防科技大学 | Horizontally arranged microscope parallel to observation object |
| CN115128788B (en) * | 2022-05-30 | 2023-11-28 | 中国人民解放军国防科技大学 | Horizontally placed microscopic device parallel to observed object |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101900691B (en) | Glass inspection systems | |
| EP1001460B1 (en) | Method and apparatus for detecting, monitoring and characterizing edge defects on semiconductor wafers | |
| KR101944962B1 (en) | Inspection system for a combustor of a turbine engine | |
| US6937754B1 (en) | Inspection equipment | |
| CN100419410C (en) | Defect inspection data processing system | |
| JP2008502929A (en) | Inspection apparatus or inspection method for fine structure by reflected or transmitted infrared light | |
| WO2006059647A1 (en) | Surface inspection device and surface inspection method | |
| CN114544654A (en) | Tiny crack growth in-situ test and observation device | |
| US3884585A (en) | Fiber break detection methods for cables using multi-fiber optical bundles | |
| Thompson et al. | Optics damage inspection for the NIF | |
| CN208366872U (en) | A kind of device of detection and identification glass defect | |
| CN114813327B (en) | Tenon structure fretting fatigue test system and fretting fatigue crack detection method | |
| JPS61102505A (en) | Lighting device | |
| JPH10311811A (en) | Method and device for detecting defect of ceramic main body | |
| CN114157793B (en) | System and method for coupling optical fiber image sensing element with photosensitive surface of image sensor | |
| US7911618B2 (en) | Holographic interferometry for non-destructive testing of power sources | |
| CN114858080A (en) | Collaborative characterization detection system and method for material surface deformation and internal defects | |
| CN210894158U (en) | Chemical fiber spinneret hole-shaped precision detection device based on machine vision | |
| US6069693A (en) | Process for inspecting bonding of a laser amplifier disc | |
| KR20130099539A (en) | Illumination device for vision inspector of solar cell wafer | |
| CN112924472A (en) | Mini LED wafer appearance defect detection system and method | |
| CN220207467U (en) | Portable photo-thermal-acoustic multisource fusion imaging nondestructive testing device | |
| CN210401255U (en) | Machine vision high-resolution coaxial light illumination inspection device | |
| TW202009476A (en) | An apparatus for infrared inspection of an electronic component and method thereof | |
| CN215599027U (en) | Crack detection device for chromium coating layer on excircle of piston ring |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |