CN115436189A - In-situ high-temperature tensile test method and test system - Google Patents
In-situ high-temperature tensile test method and test system Download PDFInfo
- Publication number
- CN115436189A CN115436189A CN202211067593.4A CN202211067593A CN115436189A CN 115436189 A CN115436189 A CN 115436189A CN 202211067593 A CN202211067593 A CN 202211067593A CN 115436189 A CN115436189 A CN 115436189A
- Authority
- CN
- China
- Prior art keywords
- sample
- tensile
- ebsd
- situ
- polishing
- 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
- 238000011065 in-situ storage Methods 0.000 title claims abstract description 76
- 238000000034 method Methods 0.000 title claims abstract description 55
- 238000009864 tensile test Methods 0.000 title claims abstract description 47
- 238000012360 testing method Methods 0.000 title abstract description 23
- 239000000523 sample Substances 0.000 claims abstract description 170
- 238000005498 polishing Methods 0.000 claims abstract description 54
- 238000002474 experimental method Methods 0.000 claims abstract description 28
- 238000000227 grinding Methods 0.000 claims abstract description 17
- 238000001887 electron backscatter diffraction Methods 0.000 claims abstract 11
- 238000010438 heat treatment Methods 0.000 claims description 17
- 239000002245 particle Substances 0.000 claims description 8
- 244000137852 Petrea volubilis Species 0.000 claims description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 3
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims description 3
- 229910052814 silicon oxide Inorganic materials 0.000 claims description 3
- 239000000463 material Substances 0.000 abstract description 51
- 238000004458 analytical method Methods 0.000 abstract description 10
- 238000012512 characterization method Methods 0.000 abstract description 9
- 230000008569 process Effects 0.000 description 19
- 238000011160 research Methods 0.000 description 11
- 229910045601 alloy Inorganic materials 0.000 description 10
- 239000000956 alloy Substances 0.000 description 10
- 239000013078 crystal Substances 0.000 description 10
- 238000006073 displacement reaction Methods 0.000 description 8
- 238000005520 cutting process Methods 0.000 description 6
- 238000005516 engineering process Methods 0.000 description 6
- 238000003384 imaging method Methods 0.000 description 6
- 238000012545 processing Methods 0.000 description 5
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 4
- 239000000654 additive Substances 0.000 description 4
- 230000000996 additive effect Effects 0.000 description 4
- 230000008859 change Effects 0.000 description 4
- 238000002050 diffraction method Methods 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 238000009826 distribution Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 230000007246 mechanism Effects 0.000 description 3
- 238000001878 scanning electron micrograph Methods 0.000 description 3
- 238000004088 simulation Methods 0.000 description 3
- 238000005482 strain hardening Methods 0.000 description 3
- 238000011282 treatment Methods 0.000 description 3
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 2
- 238000009529 body temperature measurement Methods 0.000 description 2
- ORTQZVOHEJQUHG-UHFFFAOYSA-L copper(II) chloride Chemical compound Cl[Cu]Cl ORTQZVOHEJQUHG-UHFFFAOYSA-L 0.000 description 2
- 230000007797 corrosion Effects 0.000 description 2
- 238000005260 corrosion Methods 0.000 description 2
- 230000008878 coupling Effects 0.000 description 2
- 238000010168 coupling process Methods 0.000 description 2
- 238000005859 coupling reaction Methods 0.000 description 2
- 238000012613 in situ experiment Methods 0.000 description 2
- 239000007769 metal material Substances 0.000 description 2
- 229910052759 nickel Inorganic materials 0.000 description 2
- 230000009466 transformation Effects 0.000 description 2
- 239000004831 Hot glue Substances 0.000 description 1
- 229910000861 Mg alloy Inorganic materials 0.000 description 1
- 239000011825 aerospace material Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000005253 cladding Methods 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 230000001808 coupling effect Effects 0.000 description 1
- 229960003280 cupric chloride Drugs 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010892 electric spark Methods 0.000 description 1
- 238000010894 electron beam technology Methods 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 238000003754 machining Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 230000000877 morphologic effect Effects 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 238000004321 preservation Methods 0.000 description 1
- 230000000750 progressive effect Effects 0.000 description 1
- 230000005476 size effect Effects 0.000 description 1
- 229910000601 superalloy Inorganic materials 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- 238000009763 wire-cut EDM Methods 0.000 description 1
Images
Classifications
-
- 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
- G01N3/08—Investigating strength properties of solid materials by application of mechanical stress by applying steady tensile or compressive forces
- G01N3/18—Performing tests at high or low temperatures
-
- 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
- G01N3/06—Special adaptations of indicating or recording means
-
- 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
- G01N2203/0001—Type of application of the stress
- G01N2203/0003—Steady
-
- 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
- G01N2203/0014—Type of force applied
- G01N2203/0016—Tensile or compressive
- G01N2203/0017—Tensile
-
- 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
- G01N2203/0069—Fatigue, creep, strain-stress relations or elastic constants
- G01N2203/0075—Strain-stress relations or elastic constants
-
- 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
-
- 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
- G01N2203/06—Indicating or recording means; Sensing means
- G01N2203/0641—Indicating or recording means; Sensing means using optical, X-ray, ultraviolet, infrared or similar detectors
- G01N2203/0647—Image analysis
-
- 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
- G01N2203/06—Indicating or recording means; Sensing means
- G01N2203/067—Parameter measured for estimating the property
- G01N2203/0676—Force, weight, load, energy, speed or acceleration
-
- 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
- G01N2203/06—Indicating or recording means; Sensing means
- G01N2203/067—Parameter measured for estimating the property
- G01N2203/0682—Spatial dimension, e.g. length, area, angle
-
- 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
- G01N2203/06—Indicating or recording means; Sensing means
- G01N2203/067—Parameter measured for estimating the property
- G01N2203/0694—Temperature
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)
- Sampling And Sample Adjustment (AREA)
- Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
Abstract
The invention relates to an in-situ high-temperature tensile test method and a test system, which relate to the field of microscopic characterization and analysis of materials, and the method comprises the following steps: mechanically grinding and polishing the sample to obtain a tensile sample; the sample comprises a data acquisition area and two clamping areas; the data acquisition area is arranged between the two clamping areas; clamping a tensile sample by using a sample clamp of a tensile table, and placing the tensile table in a cavity of a scanning electron microscope; performing a high-temperature in-situ tensile test experiment on the tensile sample; acquiring an EBSD image of the tensile sample by using an EBSD probe; collecting a secondary electron morphology image of the tensile sample by using a scanning electron microscope; and determining deformation information of the tensile sample according to the EBSD image and the secondary electron morphology image. The method can simulate the actual high-temperature service environment, and obtain the crystallographic EBSD data of each stage of the material tensile deformation under the near-service condition.
Description
Technical Field
The invention relates to the field of microscopic characterization and analysis of materials, in particular to an in-situ high-temperature tensile test method and a test system.
Background
The tensile property of the material is the most basic and important mechanical property affecting the use condition of the material, the material generally suffers from external effects such as force, heat, atmosphere and the like in the specific use process, when the damage tolerance of the material is reached, fracture failure is generated, and the tensile fracture is a common failure mode. The tensile mechanical property of the material is tested and analyzed in a near-service environment, which is an important content in material research, and the research on the essential reason of tensile deformation of the material is more difficult.
The conventional off-position tensile experiment can obtain important parameters such as yield strength, tensile strength, elongation and the like representing the mechanical property of the material under the conditions of force and thermal coupling. However, the more essential microstructure structure evolution process which affects the mechanical property of the material cannot be captured, so that the research on the essential reason of the tensile deformation of the material under the near-service condition is difficult to develop.
An Electron backscattering Diffraction (EBSD) is a material characterization and analysis means used in combination with a scanning Electron microscope, and a plurality of crystallographic information such as material crystallographic orientation, grain boundary type, grain size, twin type and the like can be obtained by using a daisy-chain pattern formed by backscattering Electron signals excited by an Electron beam on a sample surface, so that the EBSD is a common and important characterization and analysis means in polycrystalline material research.
The EBSD technology and the material stretching deformation process are combined, an in-situ stretching experiment based on the EBSD technology is carried out, and accurate crystallographic information at different stages in the material deformation process is dynamically obtained in real time. The method can further analyze information such as crystal orientation change, crystal boundary type evolution, slip system starting and the like in the material stretching deformation process, and is favorable for analyzing essential reasons of the material stretching deformation.
The existing in-situ tensile test method based on a scanning electron microscope under high temperature condition is difficult to achieve micro-nano-scale microscopic imaging and is more difficult to combine the EBSD technology. At present, no research means for carrying out in-situ high-temperature stretching EBSD test under the high-temperature condition of simulating the near-service condition exists. Therefore, a testing method capable of acquiring EBSD data in a material stretching deformation process in situ at a high temperature in real time is needed to research the evolution rule of crystallographic information in the material high temperature stretching deformation and further analyze the essential cause of the material stretching deformation.
Disclosure of Invention
The invention aims to provide an in-situ high-temperature tensile test method and a test system, which are used for simulating an actual high-temperature service environment and obtaining crystallography EBSD data of each stage of material tensile deformation under a near-service condition.
In order to achieve the purpose, the invention provides the following scheme:
an in-situ high temperature tensile test method comprising:
mechanically grinding and polishing the sample to obtain a tensile sample; the sample comprises a data acquisition area and two clamping areas; the data acquisition area is arranged between the two clamping areas;
clamping the tensile sample by using a sample clamp of a tensile table, and placing the tensile table in a cavity of a scanning electron microscope; the scanning electron microscope cavity is provided with an EBSD probe and a scanning electron microscope;
carrying out a high-temperature in-situ tensile test experiment on the tensile sample;
acquiring an EBSD image of the tensile sample by using the EBSD probe;
collecting a secondary electron morphology image of the tensile sample by using the scanning electron microscope;
and determining deformation information of the tensile sample according to the EBSD image and the secondary electron morphology image.
Optionally, the mechanical grinding and polishing of the sample is performed to obtain a tensile sample, and the method specifically includes:
sequentially and mechanically grinding the sample by using 400-mesh, 600-mesh, 800-mesh and 1200-mesh sand paper by using mechanical grinding and polishing to obtain a ground sample;
and carrying out rough polishing and fine polishing on the polished sample by using a vibration polishing machine in sequence to obtain a tensile sample.
Optionally, the polishing solution for rough polishing is a silicon oxide polishing solution with a particle diameter of 0.3 μm, and the time for rough polishing is 4 hours; the polishing solution for fine polishing is alumina polishing solution with the particle diameter of 0.06nm, and the time for fine polishing is 4 hours.
Optionally the width of the clamping zone is 6mm and the length of the clamping zone is 8mm; the data acquisition area is square.
Optionally, the data acquisition region has a side length of 1.5mm.
The invention also provides an in-situ high-temperature tensile test system, which applies any one of the in-situ high-temperature tensile test methods, and comprises: the device comprises a tensile sample, an in-situ tensile device, a heating device and a scanning electron microscope chamber;
the in-situ stretching device comprises a stretching table and a stretching table base; the stretching table is arranged on the stretching table base; the tensile test sample is clamped on the tensile platform through a sample clamp of the tensile platform; the heating device is connected with the stretching table; the tensile sample and the in-situ tensile device are placed in the scanning electron microscope chamber; the scanning electron microscope cavity is provided with an EBSD probe and a scanning electron microscope; the EBSD probe acquires an EBSD image of the tensile sample; and the scanning electron microscope is used for collecting a secondary electron morphology image of the tensile sample.
Optionally, a plurality of positioning holes are arranged on the sample clamp; the positioning hole is used for adjusting the inclination angle of the sample clamp.
Optionally, the stretching table base comprises a fixed base and a supporting inclined plane; the supporting inclined plane is arranged on the fixed base; the included angle between the supporting inclined plane and the fixed base is 45 degrees; the tensile specimen is disposed on the support ramp.
According to the specific embodiment provided by the invention, the invention discloses the following technical effects:
mechanically grinding and polishing a sample to obtain a tensile sample; the sample comprises a data acquisition area and two clamping areas; the data acquisition area is arranged between the two clamping areas; clamping the tensile sample by using a sample clamp of a tensile table, and placing the tensile table in a cavity of a scanning electron microscope; the scanning electron microscope cavity is provided with an EBSD probe and a scanning electron microscope; carrying out a high-temperature in-situ tensile test experiment on the tensile sample; acquiring an EBSD image of the tensile sample by using the EBSD probe; collecting a secondary electron morphology image of the tensile sample by using the scanning electron microscope; and determining deformation information of the tensile sample according to the EBSD image and the secondary electron morphology image. The tensile sample can meet the requirements of EBSD imaging by mechanically grinding and polishing the sample, and a high-temperature in-situ tensile test experiment is carried out, so that the actual high-temperature service environment is simulated, and crystallography EBSD data of each stage of material tensile deformation are obtained under the near-service condition.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used 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 inventive exercise.
FIG. 1 is a flow chart of an in-situ high temperature tensile test method provided by the present invention;
FIG. 2 is a front view of a tensile specimen provided by the present invention;
FIG. 3 is a side view of a tensile specimen provided by the present invention;
FIG. 4 is a schematic view of a monofilament rod drawing station;
FIG. 5 is a schematic view of a base of a stretching table tilted 45 degrees;
FIG. 6 is a schematic view of a heating device;
FIG. 7 is a front view of an in situ high temperature tensile test;
FIG. 8 is a side view of an in situ high temperature tensile test;
FIG. 9 is a schematic diagram showing the position relationship of the EBSD signal acquisition system in the scanning electron microscope chamber;
FIG. 10 is a schematic view of a material viewing area and force displacement curves in a high temperature environment;
FIG. 11 is a schematic diagram of SEM morphology images and EBSD images of the material at various stages in an in-situ high temperature tensile test;
FIG. 12 is a schematic diagram of an in-situ high temperature tensile test method.
Description of the symbols:
1-sample clamp, 2-positioning hole, 3-conveying screw rod, 4-force displacement sensor, 5-motor, 6-stretching table base and 7-heating core.
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 obtained by a person skilled in the art without making any creative effort based on the embodiments in the present invention, belong to the protection scope of the present invention.
The invention aims to provide an in-situ high-temperature tensile test method and a test system, which are used for simulating an actual high-temperature service environment and obtaining crystallography EBSD data of each stage of material tensile deformation under a near-service condition.
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.
As shown in fig. 1 and 12, the in-situ high temperature tensile testing method provided by the present invention comprises:
step 101: mechanically grinding and polishing the sample to obtain a tensile sample; the sample comprises a data acquisition area and two clamping areas; the data acquisition area is arranged between the two clamping areas. Wherein the width of the clamping area is 6mm, and the length of the clamping area is 8mm; the data acquisition area is square. The side length of the data acquisition area is 1.5mm.
The shape and size of the sample can be placed in an electron microscope chamber for in-situ experiment, cannot be influenced by small size effect, and is designed into a plate-shaped test article with a small gauge length section structure, the total length is 50mm, and the thickness is 0.7mm; the width of the clamping part at the two ends is 6mm, and the length is 8mm; and a small square mark section with the side length of 1.5mm is reserved in the middle, the area is a data acquisition area, and the microstructure evolution information in the material deformation process comes from the area. And processing a proper tensile sample by using a wire cutting mode according to the designed shape and size of the sample. The following technical requirements need to be met in the processing: during linear cutting processing, wire feeding is carried out as slowly as possible, the cutting cladding layer on the surface is reduced, and no obvious sawtooth wave is generated on the cutting surface; the machined surface of the part cannot have the defects of scratches, grazes and the like which damage the surface of the sample.
and (3) mechanically grinding the sample by sequentially using 400-mesh, 600-mesh, 800-mesh and 1200-mesh sandpaper by using mechanical grinding and polishing to obtain a ground sample.
And carrying out rough polishing and fine polishing on the polished sample by using a vibration polishing machine in sequence to obtain a tensile sample. Wherein the polishing solution for rough polishing is an alumina polishing solution with the particle diameter of 0.3 mu m, and the time for rough polishing is 4 hours; the polishing solution for fine polishing is silicon oxide polishing solution with the particle diameter of 0.06nm, and the time for fine polishing is 4 hours.
Before a sample is placed in a stretching table to start an experiment, the sample needs to be preprocessed, a proper small-size sample is cut from a sample to be tested according to a designed sample drawing, a base material is processed into the sample convenient for observing a dynamic small area of a scanning electron microscope by adopting an electric spark machining process, and the sample is a plate-shaped test article with a small-gauge-length section structure. According to a specific sample pretreatment process, samples prepared by wire cutting are subjected to mechanical grinding, vibratory polishing and other treatments, so that the samples can achieve high quality of EBSD imaging in a short time, specifically, 400#, 800#, 1000#, 1200# abrasive paper are sequentially used for mechanical grinding, and when the samples are observed under a light mirror, small scratches in the same direction are formed on the surfaces of the samples after the samples are ground by the 1200-mesh abrasive paper. And then, polishing the sample in a vibration polishing machine, and selecting polishing solution with the particle diameter of 0.3 mu m and the particle diameter of 0.06nm to perform rough polishing for 4 hours and finish polishing for 4 hours respectively, wherein the polished sample has a flat and smooth surface and is in a mirror surface state, so that the requirement of high-quality EBSD imaging can be met, and corrosion treatment is not required. The material of the tensile sample includes, but is not limited to, nickel-based polycrystalline superalloy material, magnesium alloy, pure metal, as-cast, additive-fabricated printed, and the like.
Step 102: clamping the tensile sample by using a sample clamp of a tensile table, and placing the tensile table in a cavity of a scanning electron microscope; the scanning electron microscope cavity is provided with an EBSD probe and a scanning electron microscope.
The processed tensile sample is arranged at two ends of a clamp, 70-degree tilting is completed by means of a specially-made base and the clamp, the 70-degree tilting is realized by two-part structures, the specially-made clamp is of a positioning hole structure, and the sample clamp 1 can be fixed at the position to achieve the 25-degree tilting effect of the sample; the stretching table base 6 inclines by 45 degrees, and the stretching test sample is enabled to incline by 70 degrees in the in-situ high-temperature stretching test by combining the clamp and the stretching table base 6, so that the requirement of acquiring EBSD experimental data in situ is met.
The temperature of the in-situ tensile test can be controlled by matching with a heating device, and the EBSD rapid acquisition under high temperature can be met by combining a high-quality EBSD tensile test sample. The temperature of the whole tensile experiment is controllable, the experiment temperature can be accurately adjusted at 1200 ℃ according to different used materials, and the simulation experiment under different service conditions is met.
Step 103: and carrying out a high-temperature in-situ tensile test experiment on the tensile sample. After the device is installed, special stretching system control software is used for respectively testing the force displacement module, the heating device and the temperature measurement module, and the normal and stable operation of the modules is ensured. And the sample is pre-stressed to eliminate inaccurate stress condition in the initial stage. The EBSD probe uses a Bruker high-temperature probe and can accurately acquire EBSD data at the temperature below 900 ℃.
Step 104: acquiring an EBSD image of the tensile sample by using the EBSD probe.
Step 105: and collecting a secondary electron morphology image of the tensile sample by using the scanning electron microscope.
In a scanning electron microscope, the working distance of an electron gun is maintained to be about 25mm, and the image can be clearly formed under 5K times; under the high-temperature environment, the working distance of the EBSD probe is about 20mm, parameters such as exposure time, step length, resolution ratio and the like are adjusted, and an EBSD image can be acquired in situ in about 20 min.
And selecting a special area of the sample which is easy to deform and break, and observing a force displacement curve and a shape image. When no EBSD data acquisition is performed, the EBSD probe is retracted. During a characteristic phase in the stretch, such as the yield phase, the loading is stopped and the EBSD probe is extended to a specified distance for image acquisition.
And after the acquisition of the EBSD image is finished, continuing the high-temperature stretching experiment. Continuing the above acquisition process in the subsequent characterization phase, EBSD data can be recorded in situ during tensile deformation of the material while maintaining a high temperature environment.
Step 106: and determining deformation information of the tensile sample according to the EBSD image and the secondary electron morphology image.
And analyzing a plurality of crystallographic information transformation processes of the material, such as crystal orientation transformation, slip band starting condition, grain boundary type, KAM stress distribution evolution and the like by means of EBSD data in the in-situ high-temperature tensile test. The method can perform mechanical analysis on the essential reason of the high-temperature tensile deformation of the material, and provides an innovative and efficient characterization analysis means for the research of the material.
The in-situ stretching device is placed in a scanning electron microscope cavity with an EBSD probe, and the proper electron gun and the proper EBSD probe are adjusted, so that the requirement of rapidly acquiring an EBSD signal can be met; the limit height of the working distance of the electron gun is 25mm under the high-temperature condition, the limit of the working distance of the EBSD probe is 20mm under the high-temperature condition, and the distance can meet the requirement of high-temperature in-situ EBSD data acquisition. In the whole stretching experiment, the real-time loading and load maintaining of the load in the stretching process can be controlled, and the stable heating and heat preservation are realized. The force and thermal coupling effects can be well met, and meanwhile, EBSD data signals are rapidly acquired in real time under the high-temperature in-situ condition; according to different materials and attention points selected by experiments, observation stages can be freely determined, and EBSD data of different deformation stages can be acquired. In the whole in-situ tensile experiment, the accurate control of the load can be realized, and the accurate loading, load protection and recording of the load below 5000N are met; the temperature is controlled stably and accurately below 1200 ℃, the simulation of various force-heat coupling service conditions is met, and EBSD data are rapidly acquired.
The method can be used for obtaining a series of change processes of crystallographic information in the material deformation process in situ and in real time under the high-temperature environment by combining a scanning electron microscope and an EBSD technology in the tensile test of metal materials such as high-temperature alloy and the like. The method can further analyze the real change conditions of information such as crystal orientation, crystal boundary type, strain distribution, slip system and the like, and provides a powerful characterization analysis means for the essential reasons of the tensile deformation of the material in a high-temperature service environment. The technical problem that the EBSD technology cannot be combined in the existing high-temperature tensile test, and the evolution process of the crystallographic information can be obtained in situ is solved.
The beneficial effects of the invention are:
the testing method is based on a scanning electron microscope and an EBSD technology, and EBSD data of different stages of material deformation are acquired in situ in the high-temperature tensile experiment process. The method simulates the actual high-temperature service environment, can obtain crystallography EBSD data of each stage of the material stretching deformation in situ under the near service condition, and provides a powerful characterization means for researching the deformation essential reason of the material under the most real service condition. The processing mode of the tensile sample can prepare a large amount of high-quality EBSD test samples efficiently, greatly improves the EBSD data measurement efficiency, and provides great help for both off-position and in-situ EBSD tests; the EBSD experiment sample prepared by the method provided by the invention has higher quality, can obtain a high-quality diffraction pattern, greatly shortens the EBSD imaging time, can generate an EBSD image within about 20min, and meets the imaging requirement of a high-temperature in-situ EBSD experiment; the method provided by the invention has extremely wide application range, the temperature in the experiment is controllable, the simulation of the service environment of various materials can be met, the method not only can be applied to common metal materials, but also is extremely suitable for the research of high-performance nickel-based high-temperature alloy, and great help is provided for the research of aerospace materials; the whole testing method is simple to operate, practical and efficient, can be implemented by means of existing commercial instrument software, and is simple and convenient to use by a corresponding in-situ experimental instrument and high in acquisition efficiency; the method can also be combined with a non-contact Digital Image Correlation (DIC), and a quantitative relation of strain in the material deformation process is analyzed by utilizing a secondary electron morphology image acquired by a scanning electron microscope, so that a more effective analysis means is provided for a material deformation mechanism.
The invention also provides an in-situ high-temperature tensile test system, which applies any one of the in-situ high-temperature tensile test methods, and the in-situ high-temperature tensile test system comprises: the device comprises a tensile sample, an in-situ tensile device, a heating device and a scanning electron microscope chamber.
The in-situ stretching device comprises a stretching table and a stretching table base 6; the stretching table is arranged on the stretching table base 6; the tensile sample is clamped on the tensile platform through a sample clamp 1 of the tensile platform; the heating device is connected with the stretching table; the tensile sample and the in-situ tensile device are placed in the scanning electron microscope chamber; the scanning electron microscope cavity is provided with an EBSD probe and a scanning electron microscope; the EBSD probe acquires an EBSD image of the tensile sample; and the scanning electron microscope is used for collecting a secondary electron morphology image of the tensile sample. The tensile test sample is clamped on clamps at two ends of a tensile platform, the base is arranged in a cavity of a scanning electron microscope, the tensile platform is placed on the base, and the tensile platform is connected with four interfaces of a motor 5, a force displacement sensor 4, a heating device and a temperature measurement module.
In practical application, a plurality of positioning holes 2 are arranged on the sample clamp 1, the positions of the positioning holes 2 are shown in the right side of fig. 4, and are side views of the stretching table, which show the positioning holes 2 when the clamp is installed; the positioning hole 2 is used for adjusting the inclination angle of the sample clamp 1. The sample holder 1 can be adjusted in the tilting angle through the positioning hole 2, and the extension holder is installed in the positioning hole 2 in the vertical direction under the observation condition of a Scanning Electron Microscope (SEM), and the sample is 90 ° to the electron gun. When the EBSD tensile test was performed, the sample was tilted by 25 ° by being attached to positioning hole 2 at 25 ° from the vertical direction. The inclination of the clamp is matched with the 45-degree inclination of the stretching table base 6, so that the condition that the sample is inclined by 70 degrees in the EBSD data acquisition can be realized.
In practical application, the stretching table base 6 is shown in fig. 5 and comprises a fixed base and a supporting inclined plane; the supporting inclined plane is arranged on the fixed base; the included angle between the supporting inclined plane and the fixed base is 45 degrees; the tensile specimen is disposed on the support ramp.
During high temperature experiments, the heating device shown in fig. 6 is installed at a fixed position, the position relationship after connection is completed is shown in fig. 7, the heater is fixed at the middle position of the clamp through a fastening bolt, the samples are clamped at two ends of the sample clamp 1 at the moment, the data acquisition area of the samples is placed on the heating core 7, and the heating core 7 is also a sample which is matched and inclined at 25 degrees.
After the test system is installed, the overall situation is as shown in fig. 7. When in-situ stretching is carried out, the motor 5 controls the sample clamp 1 to carry out a stretching experiment of a sample through the transmission screw rod. In a particular deformation phase, a data acquisition of the observation region is carried out.
The invention also provides a more specific working mode in practical application.
As-cast IN718 samples suitable for high temperature IN situ tensile EBSD data acquisition were prepared.
As shown in FIGS. 2 and 3, the in-situ tensile specimen has a dog-bone shape, a length of 50mm, and an observation mark segment having a length and a width of 1.5mm. The as-cast IN718 alloy was cut into appropriate test specimens according to sample size using wire electrical discharge machining. The wire is slowly moved in the wire cutting process, so that the surface of the material is prevented from being damaged, and an oxide layer is prevented from being formed. Additive manufacturing of the IN718 alloy may also be used.
Adhering the cut sample on a special clamp by using hot melt adhesive, and mechanically grinding by using 400-mesh, 600-mesh, 800-mesh and 1200-mesh sand paper in sequence; then, respectively carrying out 4-hour coarse polishing and 4-hour fine polishing by using a vibration polishing machine according to the thickness of the polishing powder, and finally cleaning the sample by using an acetone solution; the EBSD test can be used for in-situ high-temperature stretching EBSD experiments only by focusing on EBSD data and simple secondary electron morphology phase without carrying out corrosion treatment on the sample. If it is desired to focus on the morphological phase at the same time, the polished sample can be etched using a cupric chloride solution.
After pretreatment, the sample is subjected to an etching operation, the structure of a molten pool of the additive manufacturing process can be seen, and the temperature is controlled in a medium-temperature environment of 450 ℃.
Early preparation work of the IN718 alloy IN-situ high-temperature stretching EBSD acquisition experiment.
The prepared sample is clamped at two ends of a sample clamp 1, the sample clamp 1 is not a fixed and unchangeable part, angle selection can be carried out by using a positioning hole 2 according to needs, and the positioning hole 2 with the angle of 25 degrees is selected in an EBSD experiment. In the stretching experiment, the motor 5 provides power, and the power of the motor 5 controls the stretching and compressing process of the sample through the transmission screw rod 3. The force displacement sensor 4 can record the accurate change condition of force and displacement in the whole tensile test very precisely.
After the sample is mounted on the stretching table, the stretching table is assembled on the EBSD test base shown in fig. 5, the 45 ° inclination is realized by the component 7, and the 45 ° inclination of the base is combined with the 25 ° sample inclination realized by the sample clamp 1 of the stretching table, so that the whole body forms a sample 70 ° inclination required for EBSD data acquisition.
The temperature loading is realized by a heater, the heating core 7 is also designed to be inclined by 25 degrees and is matched with a sample inclined by 25 degrees on the stretching table for use, and meanwhile, the reserved opening meets the requirement of the EBSD probe on signal acquisition. The high-temperature tensile of the IN718 alloy IN the embodiment reaches the IN718 limit service temperature of 650 ℃, and the whole test method can achieve IN-situ high-temperature EBSD data acquisition of 900 ℃.
EBSD data were collected IN situ for the IN718 alloy during high temperature stretching at 650 ℃.
The assembled in-situ high temperature tensile EBSD test system is shown in FIGS. 7 and 8, and FIG. 9 shows the position relationship of the system in the SEM chamber. In the experiment at the temperature of 650 ℃, the working distance of the electron microscope probe is about 25mm, and the acquisition distance of the EBSD probe is about 20mm, wherein the working distance meets the requirements of the whole experiment.
The intermediate special area which is most suitable for in-situ observation and is easy to generate phenomena is selected as shown in (a) in figure 10, a force displacement curve shown in (b) in figure 10 and a secondary electron morphology phase of a scanning electron microscope are observed, and a characteristic stage in stretching is determined. The yield stage, work-hardening stage and tensile strength location are selected in this example. And keeping a high-temperature environment, extending the EBSD probe to a position of 20mm, acquiring EBSD data in situ for about 16min, and meeting the requirements of in-situ experiments.
And after the acquisition of the EBSD data is finished, continuing the high-temperature stretching. Stopping the stretching in a specific characteristic stage, and acquiring EBSD data, so as to obtain specific EBSD data, as shown in FIG. 11, wherein (a) in FIG. 11 is an SEM image of the sample at the yield strength, (b) in FIG. 11 is an SEM image of the sample at the work hardening stage, and (c) in FIG. 11 is an SEM image of the sample at the tensile strength; fig. 11 (d) is an EBSD image at the yield strength of the sample, fig. 11 (e) is an EBSD image at the work hardening stage of the sample, and fig. 11 (f) is an EBSD image at the tensile strength of the sample. And subsequently processing the EBSD data to obtain the evolution conditions of the IN718 alloy such as crystal orientation, crystal boundary type, slip system starting and the like IN the deformation process at 650 ℃, and further performing essential research and analysis on the high-temperature tensile deformation mechanism of the IN718 alloy.
Aiming at the special case of the anisotropy of the additive manufacturing, the research on the intrinsic connection between the medium-temperature brittleness and the anisotropy of the IN718 alloy IN the additive manufacturing is carried out by combining dynamic EBSD data. The method realizes the variable and controllable material and temperature, can obtain better experimental data, and proves that the method can be stably and widely applied.
The method can use a commercial in-situ stretching device, a heating table and a scanning electron microscope provided with an EBSD probe to jointly form a test system for a high-temperature stretching experiment, can couple force, heat and other factors, and meets the requirement of acquiring EBSD data. The method can be efficiently and accurately realized, EBSD data signals of different materials are recorded in the stretching process under different high temperature conditions, and secondary electron morphology images are acquired by combining scanning electron microscope acquisition. The crystallographic information of the material in each deformation stage, such as crystal structure, crystal orientation, crystal boundary type, strain distribution and the like, is accurately mastered, and a powerful characterization analysis means is provided for researching and analyzing a high-temperature stretching deformation mechanism of the material.
The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other.
The principle and the embodiment of the present invention are explained by applying specific examples, and the above description of the embodiments is only used to help understanding the method and the core idea of the present 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 (8)
1. An in-situ high temperature tensile test method, comprising:
mechanically grinding and polishing a sample to obtain a tensile sample; the sample comprises a data acquisition area and two clamping areas; the data acquisition area is arranged between the two clamping areas;
clamping the tensile sample by using a sample clamp of a tensile table, and placing the tensile table in a scanning electron microscope chamber; the scanning electron microscope cavity is provided with an EBSD probe and a scanning electron microscope;
carrying out a high-temperature in-situ tensile test experiment on the tensile sample;
acquiring an EBSD image of the tensile sample by using the EBSD probe;
collecting a secondary electron morphology image of the tensile sample by using the scanning electron microscope;
and determining deformation information of the tensile sample according to the EBSD image and the secondary electron morphology image.
2. The in-situ high-temperature tensile test method according to claim 1, wherein the mechanical grinding and polishing of the sample to obtain the tensile test specimen specifically comprises:
sequentially and mechanically grinding the sample by using 400-mesh, 600-mesh, 800-mesh and 1200-mesh sand paper by using mechanical grinding and polishing to obtain a ground sample;
and carrying out rough polishing and fine polishing on the polished sample by using a vibration polishing machine in sequence to obtain a tensile sample.
3. The in-situ high-temperature tensile test method according to claim 2, wherein the polishing solution for rough polishing is a silicon oxide polishing solution with a particle diameter of 0.3 μm, and the time for rough polishing is 4 hours; the polishing solution for fine polishing is alumina polishing solution with the particle diameter of 0.06nm, and the time for fine polishing is 4 hours.
4. The in situ high temperature tensile test method of claim 1, wherein the width of the clamping zone is 6mm and the length of the clamping zone is 8mm; the data acquisition area is square.
5. The in situ high temperature tensile test method of claim 4, wherein said data acquisition region has a side length of 1.5mm.
6. An in-situ high temperature tensile test system, wherein the in-situ high temperature tensile test system applies the in-situ high temperature tensile test method of any one of claims 1 to 5, and the in-situ high temperature tensile test system comprises: the device comprises a tensile sample, an in-situ tensile device, a heating device and a scanning electron microscope chamber;
the in-situ stretching device comprises a stretching table and a stretching table base; the stretching table is arranged on the stretching table base; the tensile test sample is clamped on the tensile platform through a sample clamp of the tensile platform; the heating device is connected with the stretching table; the tensile sample and the in-situ tensile device are placed in the scanning electron microscope chamber; the scanning electron microscope cavity is provided with an EBSD probe and a scanning electron microscope; the EBSD probe is used for acquiring an EBSD image of the tensile sample; and the scanning electron microscope is used for collecting a secondary electron morphology image of the tensile sample.
7. The in-situ high temperature tensile test system of claim 6, wherein the sample holder is provided with a plurality of positioning holes; the positioning hole is used for adjusting the inclination angle of the sample clamp.
8. The in situ high temperature tensile test system of claim 6, wherein the tensile stage base comprises a fixed base and a support ramp; the supporting inclined plane is arranged on the fixed base; the included angle between the supporting inclined plane and the fixed base is 45 degrees; the tensile specimen is disposed on the support ramp.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211067593.4A CN115436189A (en) | 2022-09-01 | 2022-09-01 | In-situ high-temperature tensile test method and test system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211067593.4A CN115436189A (en) | 2022-09-01 | 2022-09-01 | In-situ high-temperature tensile test method and test system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115436189A true CN115436189A (en) | 2022-12-06 |
Family
ID=84246697
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211067593.4A Pending CN115436189A (en) | 2022-09-01 | 2022-09-01 | In-situ high-temperature tensile test method and test system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115436189A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116893092A (en) * | 2023-07-25 | 2023-10-17 | 东北大学 | Preparation method of EBSD (electron beam diffraction) sample suitable for central longitudinal surface of tensile fracture with diameter below 3mm |
-
2022
- 2022-09-01 CN CN202211067593.4A patent/CN115436189A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116893092A (en) * | 2023-07-25 | 2023-10-17 | 东北大学 | Preparation method of EBSD (electron beam diffraction) sample suitable for central longitudinal surface of tensile fracture with diameter below 3mm |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109781516B (en) | Clamp for material strain in-situ EBSD observation test and test method | |
| Cuddalorepatta et al. | Viscoplastic creep response and microstructure of As-fabricated microscale Sn-3.0 Ag-0.5 Cu solder interconnects | |
| CN111982642B (en) | EBSD sample preparation method of fracture sample section | |
| CN110361404B (en) | Device and method for acquiring crystal microtexture orientation | |
| CN115436189A (en) | In-situ high-temperature tensile test method and test system | |
| CN108931544B (en) | Sample clamping device and test method for in-situ electron back scattering diffraction research | |
| CN111965205A (en) | Sample preparation method for nickel-based powder superalloy in-situ sample micro-area observation SEM + EBSD | |
| CN111735836A (en) | Preparation method of ultra-pure high-chromium ferrite stainless steel EBSD sample | |
| CN104777046A (en) | Fatigue crack propagation mechanism testing method based on small time scale | |
| Du et al. | A uni-axial nano-displacement micro-tensile test of individual constituents from bulk material | |
| CN109470560A (en) | A kind of Fine Texture of Material compression/bending property dynamic characterization method | |
| CN111579397A (en) | Fatigue life prediction method for laser additive manufacturing alloy steel component | |
| Wu et al. | Duality of the fatigue behavior and failure mechanism in notched specimens of Ti-7Mo-3Nb-3Cr-3Al alloy | |
| Wang et al. | Dissimilar friction stir welding of 2219-T8 and 2195-T8 aluminum alloys: part I—microstructure evolution and mechanical properties | |
| CN110940582B (en) | Method for predicting fatigue strength of metal material through tensile test | |
| CN106525584A (en) | Preparation method for in-situ mechanic loading tool under transmission electron microscope | |
| CN113777270B (en) | Characterization method of high-temperature alloy powder hot cracking sensitivity and hot cracking sensitivity temperature | |
| CN116296781A (en) | Method and system for determining critical strain value of I-type crack tip fracture process zone | |
| CN113695596B (en) | Method for measuring temperature of heat affected zone in metal powder additive manufacturing process in high flux | |
| CN209342508U (en) | A kind of material strain original position EBSD observation test fixture | |
| CN115372166A (en) | Long-term creep testing method based on scanning electron microscope | |
| KR100534977B1 (en) | Method and apparatus for characterizing in-situ tensile of metallic meterial | |
| Holdermann et al. | Dynamic recrystallization of Sn3. 0Ag0. 5Cu Pb-free solder alloy | |
| CN115372135B (en) | Method for measuring rotation angle of high-temperature alloy crystal grain | |
| Abu-Farha et al. | On the development of viable cruciform-shaped specimens: towards accurate elevated temperature biaxial testing of lightweight materials |
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 |