CN114878301B - A coating long-term high-temperature bending test device and method - Google Patents
A coating long-term high-temperature bending test device and method Download PDFInfo
- Publication number
- CN114878301B CN114878301B CN202210397690.3A CN202210397690A CN114878301B CN 114878301 B CN114878301 B CN 114878301B CN 202210397690 A CN202210397690 A CN 202210397690A CN 114878301 B CN114878301 B CN 114878301B
- Authority
- CN
- China
- Prior art keywords
- contact
- coating
- tested
- coating sample
- long
- 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.)
- Active
Links
- 238000000576 coating method Methods 0.000 title claims abstract description 179
- 239000011248 coating agent Substances 0.000 title claims abstract description 175
- 238000005452 bending Methods 0.000 title claims abstract description 96
- 238000012360 testing method Methods 0.000 title claims abstract description 87
- 230000007774 longterm Effects 0.000 title claims description 39
- 238000000034 method Methods 0.000 title abstract description 30
- 238000011068 loading method Methods 0.000 claims abstract description 49
- 238000002474 experimental method Methods 0.000 claims abstract description 25
- 238000010438 heat treatment Methods 0.000 claims description 19
- 238000013001 point bending Methods 0.000 claims description 9
- 239000000919 ceramic Substances 0.000 claims description 8
- 229910052736 halogen Inorganic materials 0.000 claims description 7
- 150000002367 halogens Chemical class 0.000 claims description 7
- 238000005245 sintering Methods 0.000 claims description 6
- 238000010998 test method Methods 0.000 claims description 6
- 238000004519 manufacturing process Methods 0.000 claims description 5
- 239000000654 additive Substances 0.000 claims description 3
- 230000000996 additive effect Effects 0.000 claims description 3
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 claims description 3
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 claims description 3
- 229910010271 silicon carbide Inorganic materials 0.000 claims description 3
- 230000005484 gravity Effects 0.000 claims description 2
- 238000003825 pressing Methods 0.000 abstract description 18
- 238000004458 analytical method Methods 0.000 abstract description 3
- 238000013461 design Methods 0.000 abstract description 3
- 230000002349 favourable effect Effects 0.000 abstract description 2
- 239000011253 protective coating Substances 0.000 abstract description 2
- 238000010586 diagram Methods 0.000 description 8
- 230000008569 process Effects 0.000 description 8
- 230000006399 behavior Effects 0.000 description 6
- 230000002441 reversible effect Effects 0.000 description 6
- 230000009471 action Effects 0.000 description 5
- 230000004888 barrier function Effects 0.000 description 4
- 238000012512 characterization method Methods 0.000 description 4
- 230000009286 beneficial effect Effects 0.000 description 3
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 238000006073 displacement reaction Methods 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 238000007373 indentation Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 239000000758 substrate Substances 0.000 description 2
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000000227 grinding Methods 0.000 description 1
- 230000035876 healing Effects 0.000 description 1
- 230000006872 improvement Effects 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
- 239000000843 powder Substances 0.000 description 1
- 238000010248 power generation Methods 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 238000010008 shearing Methods 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 230000003746 surface roughness Effects 0.000 description 1
- 239000012720 thermal barrier coating Substances 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
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
- G01N3/02—Details
-
- 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
- G01N3/20—Investigating strength properties of solid materials by application of mechanical stress by applying steady bending forces
-
- 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
- G01N2203/025—Geometry of the test
- G01N2203/0252—Monoaxial, i.e. the forces being applied along a single axis of the specimen
-
- 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
- G01N2203/025—Geometry of the test
- G01N2203/0254—Biaxial, the forces being applied along two normal axes of the specimen
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/20—Hydro energy
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 long-time high-temperature bending experiment device and method for a coating, and belongs to the technical field of high-temperature mechanical experiments. The device comprises a stress loading device, wherein the stress loading device comprises a limiting support, a replaceable test bench, a replaceable pressure head and a counterweight module, the limiting support comprises a supporting rod, a top seat and a base, two ends of the supporting rod are respectively connected with the top seat and the base, the replaceable test bench is arranged on one side surface of the base, facing the top seat, of the base, the replaceable pressure head is used for applying pressure to a coating sample to be tested, which is placed on the replaceable test bench, and the counterweight module is arranged on the replaceable pressure head to counterweight the replaceable pressure head. The device and the corresponding method can solve the problem of long-time high-temperature mechanical loading with lower cost while expanding the high-temperature mechanical loading form of the coating, are favorable for researching long-time high-temperature evolution behavior under the gradient stress condition of the coating, and further provide basis and guidance for failure analysis and long-life design of the surface protective coating of the hot end component with complex configuration.
Description
Technical Field
The invention relates to the technical field of high-temperature mechanical experiments, in particular to a device and a method for long-time high-temperature bending experiments of a coating.
Background
Ceramic and metal coatings represented by thermal barrier and environmental barrier coatings are used as key heat protection technologies and widely applied to the surface protection of hot end components in the high technical fields of aerospace, energy power, ocean power generation and the like. The service working condition of the device not only has an extremely high-temperature environment, but also relates to complex mechanical conditions such as substrate constraint, inertial force, pneumatic load and the like. The ceramic and metal coatings which are in high temperature working conditions for a long time can generate structure or material evolution processes such as sintering, phase transformation, oxidation and the like, and the processes are sensitive to load conditions and stress states. The experimental study of the influence rule of stress on the long-term high-temperature evolution process of the coating is carried out, and the method has important significance for the failure analysis and long-life design of the surface protection coating of the hot end component with the complex configuration.
The heat load applying method in the technical field of high-temperature experiments is mature, and a uniform or gradient temperature field of the actual service working condition of the coating can be simulated through a plurality of devices such as a muffle furnace, a halogen lamp, a laser source and the like, and the average temperature and the temperature gradient can reach 1000 ℃ and 200 ℃ per mm respectively. However, since the coating thickness is generally small (several hundred micrometers to several millimeters), the mechanical loading method applicable to the high temperature environment of the coating is still limited.
The High temperature indentation (High-temperature Indentation) experimental equipment can apply short-time compressive stress on the micro-area of the surface of the sample, but is limited by the size and the material of the pressure head, so that the whole sample is difficult to be subjected to long-time High-temperature loading, and the thermal mechanical Analyzer (THERMAL MECHANICAL Analyzer) can apply three-point bending load on the coated sample, but is limited by the loading mode and the size of the clamp, and the maximum stress applied to the sample is usually smaller and the experimental cost is higher.
Therefore, it is necessary to develop a high temperature mechanical experimental device and method suitable for coating, so as to realize long-time low-cost experimental characterization of the high temperature evolution process in a larger load range.
In view of this, the present invention has been made.
Disclosure of Invention
The invention aims to provide a device and a method for long-time high-temperature bending experiment of a coating, so as to solve the technical problems.
The application can be realized as follows:
In a first aspect, the application provides a coating long-term high-temperature bending experimental device, which comprises a stress loading device, wherein the stress loading device comprises a limiting bracket, a replaceable test bench, a replaceable pressure head and a counterweight module;
the limiting support comprises a supporting rod, a top seat and a base which are oppositely arranged, and two ends of the supporting rod are respectively connected with the top seat and the base;
the replaceable test bench is arranged on one side surface of the base, facing the top seat;
the replaceable pressure head is used for applying pressure to a coating sample to be tested, which is placed on the replaceable test bench, and the counterweight module is additionally arranged on the replaceable pressure head and used for counterweight the replaceable pressure head.
In an alternative embodiment, the number of the supporting rods is multiple, the supporting rods are arranged along the edges of the top seat and the base, and the edges of the replaceable test bench are abutted against the supporting rods.
In an alternative embodiment, a plurality of support bars are equally spaced apart.
In an alternative embodiment, the replaceable test stand includes a test stand body and a contact;
The test bench body is positioned on one side surface of the base, which faces the top seat, and the edge of the test bench body is abutted against the supporting rod, and the contact piece is arranged on the upper surface of the test bench body to provide a contact site for a coating sample to be tested.
In an alternative embodiment, the contact member comprises a first contact bar and a second contact bar, and the first contact bar and the second contact bar are symmetrically arranged with the center of the test bench body as a symmetry axis;
or, the contact piece comprises a first contact ball, a second contact ball and a third contact ball, the first contact ball, the second contact ball and the third contact ball are arranged at equal intervals, and the distances from the center of the first contact ball, the center of the second contact ball and the center of the third contact ball to the center of the test bench body are equal.
In an alternative embodiment, the replaceable ram includes a pressing portion, a connecting rod, and a bearing portion;
The top seat is provided with a limit hole, the pressurizing part is used for contacting with the surface of a coating sample to be tested in the experimental process, one end of the connecting rod is connected with the pressurizing part, the other end of the connecting rod penetrates through the limit hole and extends out in a direction away from the base and is connected with the bearing part, and the counterweight module is borne on the bearing part.
In an alternative embodiment, the axis of the connecting rod, the center of the limiting hole, the center of the test stand body, the center of the bearing part and the center of the counterweight module are all collinear.
In an alternative embodiment, the pressurizing part is in a truncated cone shape;
When the contact piece comprises a first contact strip and a second contact strip, the pressurizing part is a forward round table with a small upper part and a large lower part, and the bottom of the pressurizing part is also provided with a third contact strip and a fourth contact strip which are matched with the first contact strip and the second contact strip to form four contact sites for a coating sample to be tested;
when the contact piece comprises a first contact ball, a second contact ball and a third contact ball, the pressurizing part is in a reverse round table shape with a big top and a small bottom.
In an alternative embodiment, the third contact strip and the fourth contact strip are symmetrically arranged with the center of the test bench body as an axis of symmetry.
In an alternative embodiment, the contact position between the lower end of the pressurizing part with a reverse truncated cone shape and the coating sample to be tested is the center position of the test bench body.
In an alternative embodiment, the counterweight module is ring-shaped, and the counterweight module passes through the connecting rod and is loaded on the bearing part.
In alternative embodiments, the stress-loading device is made from high temperature structural ceramics by sintering or additive manufacturing.
In alternative embodiments, the high temperature structural ceramic comprises aluminum oxide or silicon carbide.
In an alternative embodiment, the coating long-term high-temperature bending test device further comprises a heating device, and the heating device is used for heating the coating sample to be tested.
In alternative embodiments, the heating device comprises a muffle furnace, halogen lamp, or laser source.
In a second aspect, the application provides a long-term high-temperature bending test method for a coating, which comprises the following steps of adopting the long-term high-temperature bending test device for the coating of any one of the previous embodiments, applying a constant bending load to a coating sample to be tested through a stress loading device, and simultaneously heating the coating sample to be tested through a heating device, so that the coating sample to be tested forms a gradient stress field along the thickness direction in a high-temperature environment.
In an alternative embodiment, the stress loading device applies a constant bending load to the coating sample to be tested, wherein the constant bending load comprises a single-axis bending mode and a double-axis bending mode, and the single-axis bending mode corresponds to a four-point bending loading mode and the double-axis bending mode corresponds to a piston-three-ball loading mode.
In an alternative embodiment, when a four-point bending loading mode is adopted, the coating sample to be tested is in a long strip shape, the contact piece comprises a first contact strip and a second contact strip, the pressurizing part is in a forward round table shape with a small upper part and a large lower part, and the bottom of the pressurizing part is also provided with a third contact strip and a fourth contact strip which are matched with the first contact strip and the second contact strip to form four contact sites for the coating sample to be tested;
the corresponding extreme value of the tensile stress or the compressive stress is calculated in the following mode that 3PL/4wb 2, wherein P is the total weight of the replaceable pressure head and the counterweight module, L is the distance between the contact site of the first contact strip and the coating sample to be measured and the contact site of the second contact strip and the coating sample to be measured, w is the width of the coating sample to be measured, and b is the thickness of the coating sample to be measured.
In an alternative embodiment, the distance between the contact site of the third contact strip with the coating sample to be tested and the contact site of the second contact strip with the coating sample to be tested is half of L.
In an alternative embodiment, when a piston-three-ball loading mode is adopted, a coating sample to be tested is circular, the contact piece comprises a first contact ball, a second contact ball and a third contact ball, the first contact ball, the second contact ball and the third contact ball are equidistantly arranged, and the ball centers of the first contact ball, the second contact ball and the third contact ball are equidistant from the center of the test bench body;
The corresponding extreme value of tensile stress or compressive stress is calculated by 0.2387P (X-Y) b 2, wherein X and Y are (1+v) [1+ln (r 1/r3)2]+(1-v)(r1/r3)2 and (1+v) ln (r 2/r3)2+[(1-v)/2](r2/r3)2; P is the total weight of the replaceable pressure head and the counterweight module), b is the thickness of the coating sample to be measured, v is the Poisson's ratio of the coating sample to be measured, r 1 is the radius of the circle where the first contact ball, the second contact ball and the third contact ball are located together, r 2 is the radius of the contact surface between the lower end part of the pressing part and the coating sample to be measured, and r 3 is the radius of the coating sample to be measured.
The beneficial effects of the application include:
according to the coating long-time high-temperature bending experimental device provided by the application, the limit bracket, the replaceable test bench, the replaceable pressure head and the counterweight module are matched, the counterweight module is additionally arranged on the replaceable pressure head to counterweight the replaceable pressure head, and the replaceable pressure head is enabled to apply pressure (constant bending load) to a coating sample to be tested, which is placed on the replaceable test bench, so that a long-time stable gradient stress field can be formed in the thickness direction of the coating sample to be tested. The experimental device has a simple structure and low manufacturing and using cost, can characterize the influence of two different stress states of pulling and pressing on a sample on high-temperature evolution behaviors according to the needs, and is favorable for realizing high-flux characterization of complex stress action rules.
The corresponding experimental method is simple and easy to implement, and the single-shaft and double-shaft bending loading is beneficial to forming a large stress gradient in the small-size coating sample to be tested, and the coating sample can be heated by means of the existing muffle furnace, halogen lamp, laser source and other devices, so that the experimental hardware and the running cost are reduced. In addition, by adopting different replaceable test tables and replaceable pressure heads, different forms of high-temperature mechanical experiments such as single-axis and double-axis bending can be carried out, and the development of the high-temperature mechanical loading form of the coating is facilitated.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a schematic structural diagram of a long-term high-temperature bending experimental device for a coating in a uniaxial bending mode under a first view angle;
FIG. 2 is a schematic structural diagram of a long-term high-temperature bending experimental device for a coating with a uniaxial bending mode under a second view angle;
FIG. 3 is a schematic structural diagram of a long-term high-temperature bending experimental device for a coating with a uniaxial bending mode under a third view angle;
FIG. 4 is a schematic structural diagram of a long-term high-temperature bending experimental device for a coating with a uniaxial bending mode under a fourth view angle;
FIG. 5 is a schematic structural diagram of a coating long-term high-temperature bending experimental device with a biaxial bending mode under a first view angle;
FIG. 6 is a schematic structural diagram of a coating long-term high-temperature bending experimental device with a biaxial bending mode under a second view angle;
FIG. 7 is a schematic structural diagram of a coating long-term high-temperature bending experimental device with a biaxial bending mode under a third view angle;
FIG. 8 is a schematic structural diagram of a long-term high-temperature bending experimental device for a coating with a biaxial bending mode under a fourth view angle;
FIG. 9 is a cross-sectional microstructure of the upper portion of a coating specimen subjected to a long-term high-temperature bending test in an application example of the present application;
FIG. 10 is a cross-sectional microstructure of the lower part of a coating specimen subjected to a long-time high-temperature bending test in an application example of the present application.
The icons are 11-top seat, 111-limit hole, 12-base, 13-support bar, 21-test bench body, 221-first contact bar, 222-second contact bar, 223-first contact ball, 224-second contact ball, 225-third contact ball, 31-pressing part, 311-third contact bar, 312-fourth contact bar, 32-connection bar, 33-bearing part, 40-counterweight module and 5-coating sample to be tested.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below. The specific conditions are not noted in the examples and are carried out according to conventional conditions or conditions recommended by the manufacturer. The reagents or apparatus used were conventional products commercially available without the manufacturer's attention.
The device and the method for the long-term high-temperature bending experiment of the coating provided by the application are specifically described below.
Referring to fig. 1 to 8, the present application provides a long-term high-temperature bending experimental apparatus for coating, which includes a stress loading device, wherein the stress loading device includes a limiting bracket, a replaceable test stand, a replaceable pressure head and a counterweight module 40;
the limiting support comprises a supporting rod 13, a top seat 11 and a base 12 which are oppositely arranged, and two ends of the supporting rod 13 are respectively connected with the top seat 11 and the base 12;
the replaceable test bench is arranged on one side surface of the base 12 facing the top seat 11;
The replaceable press head is used for applying pressure to the coating sample 5 to be tested, which is placed on the replaceable test bench, and the counterweight module 40 is arranged on the replaceable press head and used for counterweight the replaceable press head.
For reference, the top seat 11 and the bottom seat 12 are identical in shape and size, and are circular in cross section. The top seat 11 and the bottom seat 12 are projected and overlapped in the vertical direction.
The number of the supporting rods 13 is multiple, the supporting rods 13 are arranged along the edges (also can be understood as the circumferential direction) of the top seat 11 and the base 12, and the edges of the replaceable test bench are abutted against the supporting rods 13. In a preferred embodiment, a plurality of support rods 13 are equally spaced.
The support rods 13 may provide support for the replaceable test bed, replaceable ram, counterweight module 40, etc., while the support rods 13 may also constrain in-plane displacement of the replaceable test bed.
Alternatively, the supporting rod 13 may be integrally formed with the top base 11 and the bottom base 12, or may be connected and fixed by a conventional connection method (such as a clamping connection, an adhesive connection, etc.).
In the present application, the replaceable test stand includes a test stand body 21 and a contact;
The test board body 21 is located on one side surface of the base 12 facing the top seat 11, the edge of the test board body 21 is abutted against the supporting rod 13, and the contact piece is arranged on the upper surface of the test board body 21 to provide a contact site for the coating sample 5 to be tested.
For reference, the cross section of the test bench body 21 may also be circular, and the center of the circle is collinear with the center of the base 12. The contact piece protrudes upward from the upper surface of the test bench body 21, and is brought into contact with the coating sample 5 to be tested placed on the test bench body 21 to support it.
In some embodiments, as shown in fig. 1 to 3, the contact includes a first contact bar 221 and a second contact bar 222, and the first contact bar 221 and the second contact bar 222 are symmetrically disposed with respect to the center of the test bench body 21 as an axis of symmetry and are disposed near an edge of the test bench body 21.
In other embodiments, as shown in fig. 5 to 7, the contact includes a first contact ball 223, a second contact ball 224, and a third contact ball 225, the first contact ball 223, the second contact ball 224, and the third contact ball 225 are equidistantly spaced apart and the centers of the first contact ball 223, the second contact ball 224, and the third contact ball 225 are equidistant from the center of the test stand body 21.
It is also understood that the circles of the first contact ball 223, the second contact ball 224, and the third contact ball 225 may collectively form a circle. The first contact ball 223, the second contact ball 224, and the third contact ball 225 are identical in size.
In the present application, the replaceable ram includes a pressing portion 31, a connecting rod 32, and a bearing portion 33;
The top seat 11 is provided with a limiting hole 111, the pressing part 31 is used for contacting with the surface of the coating sample 5 to be tested in the experimental process, one end of the connecting rod 32 is connected with the pressing part 31, the other end passes through the limiting hole 111 and is disbursed in a direction away from the base 12 and is connected with the bearing part 33, and the counterweight module 40 is borne on the bearing part 33.
The axis of the connecting rod, the center of the limiting hole 111, the center of the test bench body 21, the center of the bearing part 33, and the center of the weight module 40 are all collinear. Preferably, the centers of the circles where the plurality of support rods 13 are located coincide with the centers of the limiting holes 111. Through the arrangement, the replaceable pressure head and the replaceable test bench can be kept vertically centered all the time, and therefore single-axis or double-axis bending loading conditions are met.
In addition, the limiting aperture 111 may also be configured to constrain displacement in the plane (i.e., the horizontal direction) of the replaceable press head, allowing only movement in the vertical direction.
In the present application, the pressurizing part 31 is formed in a circular truncated cone shape as a whole, and the circular truncated cone shape is formed in a forward direction and a reverse direction according to different test requirements.
Specifically, when the contact member includes the first contact bar 221 and the second contact bar 222, the pressing portion 31 is a forward truncated cone with a smaller top and a larger bottom, and the bottom of the pressing portion 31 further includes the third contact bar 311 and the fourth contact bar 312 (as shown in fig. 1) to form four contact points with the first contact bar 221 and the second contact bar 222 to the coating sample 5 to be tested;
preferably, the third contact strip 311 and the fourth contact strip 312 are symmetrically disposed about the center of the test bench body 21 as an axis of symmetry. The third contact bar 311 and the fourth contact bar 312 protrude downward from the bottom of the pressing portion 31 to come into contact with the coating sample 5 to be measured located therebelow to apply a mechanical load.
When the contact includes the first contact ball 223, the second contact ball 224, and the third contact ball 225, the pressing portion 31 is in a reverse truncated cone shape with a large upper portion and a small lower portion.
Preferably, the contact position between the lower end of the pressurizing part 31 with the reverse truncated cone shape and the coating sample 5 to be tested is the center position of the test bench body 21.
It can also be understood that in the present application, the stress loading means applies a constant bending load to the coating specimen 5 to be tested, including a uniaxial bending mode corresponding to a four-point bending loading mode and a biaxial bending mode corresponding to a piston-three-ball loading mode. The contact corresponds to a four-point bending load mode (uniaxial bending mode) when the contact is a contact bar, and corresponds to a piston-three-ball load mode (biaxial bending mode) when the contact is a contact ball.
In the basic mechanical loading modes of pulling, pressing, bending, shearing and the like, the uniaxial and biaxial bending loads can form gradient stress fields in the thickness direction of the coating sample, and the influence of two different stress states of pulling and pressing on high-temperature evolution behaviors can be simultaneously represented through one sample, so that the high-flux representation of the complex stress action rule is facilitated.
Further, in the present application, the weight module 40 is circular, and the weight module 40 passes through the connecting rod 32 and is loaded on the bearing part 33.
Specifically, the counterweight module 40 may be formed by stacking a plurality of stackable unit annular blocks according to needs, that is, may be nested outside the connecting rod 32 and carried on the carrying portion 33 in a stacking manner. In a specific experiment, according to a single-axis experiment mode, a double-axis experiment mode and a required stress gradient, the total weight of the required weight module 40 is calculated through the following extreme value calculation formula of tensile stress or compressive stress, and the weight module 40 and the replaceable pressure head load the coating sample 5 to be tested together through gravity.
The stress loading device can be manufactured by sintering or additive manufacturing of high-temperature structural ceramics. The high temperature structural ceramic may include, among others, aluminum oxide or silicon carbide, for example.
The stress loading device can perform uniaxial or biaxial loading high-temperature bending mechanical experiments for hundreds of hours in a high-temperature environment with the temperature of more than 1000 ℃.
Further, the long-term high-temperature bending experimental device for the coating provided by the application further comprises a heating device (not shown), wherein the heating device is used for heating the coating sample 5 to be tested.
For reference, the heating means may comprise, for example, a muffle furnace, a halogen lamp or a laser source.
Correspondingly, the application also provides a long-term high-temperature bending experiment method for the coating, which comprises the following steps of applying a constant bending load to the coating sample 5 to be tested through a stress loading device and simultaneously heating the coating sample 5 to be tested through a heating device by adopting the long-term high-temperature bending experiment device for the coating, so that the coating sample 5 to be tested forms a gradient stress field along the thickness direction in a high-temperature environment.
The coating sample 5 to be measured can be, for example, a thermal barrier and an environmental barrier coating.
By way of reference, the stress loading means apply a constant bending load to the coating specimen 5 to be tested, including a uniaxial bending mode corresponding to a four-point bending loading mode and a biaxial bending mode corresponding to a piston-three-ball loading mode.
When the four-point bending loading mode is adopted, the coating sample 5 to be tested is in a strip shape, the contact piece comprises a first contact strip 221 and a second contact strip 222, the pressurizing part 31 is in a forward round table shape with a small upper part and a large lower part, the bottom of the pressurizing part 31 is also provided with a third contact strip 311 and a fourth contact strip 312 which are matched with the first contact strip 221 and the second contact strip 222 to form four contact sites for the coating sample 5 to be tested, and a gradient uniaxial stress field is formed along the thickness direction of the coating sample 5 to be tested.
The corresponding extremum of the tensile stress or compressive stress is calculated in such a way that 3PL/4wb 2, where P is the total weight of the replaceable indenter and the weight module 40, L is the distance between the contact site of the first contact bar 221 and the coating sample 5 to be measured and the contact site of the second contact bar 222 and the coating sample 5 to be measured, w is the width of the coating sample 5 to be measured, and b is the thickness of the coating sample 5 to be measured.
The distance between the contact point between the third contact strip 311 and the coating sample 5 to be tested and the contact point between the second contact strip 222 and the coating sample 5 to be tested is half of L (i.e., L/2). The length of the test piece 5 of the coating to be tested is > L.
When the piston-three-ball loading mode is adopted, the coating sample 5 to be tested is circular, the contact piece comprises a first contact ball 223, a second contact ball 224 and a third contact ball 225, the first contact ball 223, the second contact ball 224 and the third contact ball 225 are equidistantly arranged at intervals, the distances between the center of the first contact ball 223, the center of the second contact ball 224 and the center of the third contact ball 225 and the center of the test table body 21 are equal, the pressurizing part 31 is in a reverse round table shape with the upper part being large and the lower end part of the pressurizing part 31 and the contact position of the coating sample 5 to be tested are the center position of the test table body 21, the first contact ball 223, the second contact ball 224, the third contact ball 225 and the lower end part of the pressurizing part 31 are matched to form four contact sites on the coating sample 5 to be tested, and a gradient double-axis stress field is formed along the thickness direction of the coating sample 5 to be tested.
The corresponding extreme values of tensile stress or compressive stress are calculated by 0.2387P (X-Y) b 2, wherein X and Y are (1+v) [1+ln (r 1/r3)2]+(1-v)(r1/r3)2 and (1+v) ln (r 2/r3)2+[(1-v)/2](r2/r3)2; P is the total weight of the replaceable ram and the counterweight module 40), b is the thickness of the coating sample 5 to be measured, v is the Poisson's ratio of the coating sample 5 to be measured, r 1 is the radius of the circle where the first contact ball 223, the second contact ball 224 and the third contact ball 225 are located together, r 2 is the radius of the contact surface between the lower end of the pressing portion 31 and the coating sample 5 to be measured, and r 3 is the radius of the coating sample 5 to be measured.
The operation process of the long-term high-temperature bending experiment method for the coating can be referred to by referring to the method, firstly, a single-axis or double-axis mode is selected according to the required stress state of the coating sample 5 to be tested, then, a corresponding replaceable test bench and a replaceable pressure head are installed on a limiting support, the replaceable test bench and the replaceable pressure head are guaranteed to be centered through a limiting hole 111 on the limiting support and a supporting rod 13, then, according to the single-axis or double-axis mode, the strip-shaped or round coating sample 5 to be tested is placed on the replaceable test bench, the height of the replaceable pressure head is reduced until the strip-shaped or round coating sample contacts with the coating sample, the total weight of the required weight module 40 is calculated according to the single-axis or double-axis mode through a corresponding tensile stress extremum formula, the weight module 40 is placed on the replaceable pressure head, a constant bending load is applied to the coating sample 5 to be tested, a gradient stress field is formed along the thickness direction of the coating sample 5 to be tested, and devices including but not limited to muffle furnaces, halogen lamps, laser sources and the like are used for heating the coating sample 5 to be tested, so that long-term low-cost gradient stress loading of the coating sample 5 to be tested in a high-temperature environment is achieved.
The experimental device and the method for long-time high-temperature bending of the coating are simple in structure and low in manufacturing and using cost, a constant bending load is applied to form a long-time stable gradient stress field in the thickness direction of the coating sample 5 to be tested, influences of two different stress states of pulling and pressing on high-temperature evolution behaviors can be simultaneously represented on one sample, high-flux representation of a complex stress action rule is facilitated, the experimental method is simple and easy to implement, single-axis and double-axis bending loading is facilitated to form a large stress gradient in the small-size coating sample 5 to be tested, and the coating sample can be heated by means of devices such as a muffle furnace, a halogen lamp and a laser source, so that experimental hardware and running cost are facilitated to be reduced. In addition, by adopting different replaceable bases 12 and replaceable pressure heads, different forms of high-temperature mechanical experiments such as single-axis and double-axis bending can be carried out, and the development of the coating high-temperature mechanical loading form is facilitated.
Application example 1
The long-term high-temperature bending experiment device and method for the coating provided by the application are adopted to carry out long-term high-temperature bending experiment on the coating sample 5 to be tested, and the device and method are specifically as follows:
S1, pretreatment, namely preparing a thermal barrier coating by adopting melt broken powder of America 204NS through an F4 plasma spray gun under the atmospheric environment, and stripping a substrate after corrosion for 6 hours by 30% concentrated hydrochloric acid to obtain a coating sample (the thickness is 0.4mm, the width is 5mm and the length is 30 mm).
S2, selecting a mode, namely adopting the long-time high-temperature bending experimental device for the coating provided by the application to perform a single-axis mode, wherein the span (L) is 20mm.
S3, mechanical loading, namely placing the coating sample pretreated in the step S1 on a replaceable test bench of a long-time high-temperature bending test device for the coating in the step S2, reducing a replaceable pressure head until the replaceable pressure head contacts with the coating sample, and placing a counterweight module 40 on the replaceable pressure head, wherein the load is 1.6N.
S4, high-temperature experiment, namely placing the device and the coating sample into a muffle furnace integrally, heating to 1200 ℃ at the rate of 10 ℃ per minute, performing high-temperature experiment for 20 hours, and taking out the coating sample after cooling to room temperature at the rate of 10 ℃ per minute.
S5, sample characterization, namely metallographic sample preparation is carried out on the coating sample by a vacuum cooling inlay method, and the surface roughness is reduced to below 1 mu m according to a standard metallographic grinding and polishing flow to observe the microstructure and mechanical property evolution of the coating.
The microstructure of the coating cross section through the long-term high temperature bending test is shown in fig. 9 and 10. FIG. 9 shows that the upper portion of the coating sample is sintered and accelerated under the action of compressive stress, the porosity is lower, and the healing of the microcracks between the sheets is better, and FIG. 10 shows that the lower portion of the coating sample is sintered and slowed down under the action of tensile stress, the porosity is higher, and the majority of microcracks between the sheets remain open and unhealed.
The average porosity and elastic modulus results obtained by the image method and the nanoindentation method are shown in tables 1 and 2, respectively.
TABLE 1 section porosity of coating samples after high temperature bending experiments
TABLE 2 modulus of elasticity in section of coating samples after high temperature bending experiments
It can be seen from tables 1 and 2 that the gradient stress field formed by uniaxial bending load has remarkable influence on the high-temperature evolution behavior of the coating sample, and the gradient stress field has the advantages of slow sintering in a tensile stress region, higher porosity, lower elastic modulus, fast sintering in a compressive stress region, lower porosity and higher elastic modulus.
The results shown in the figures 9, 10, 1 and 2 are consistent with the theoretical results of the gradient stress field formed by the uniaxial bending load on the high-temperature evolution behavior of the coating sample, so that the long-time high-temperature bending experimental device and method for the coating provided by the application are accurate and feasible, and the long-time low-cost experimental characterization of the high-temperature evolution process can be realized in a larger load range.
In conclusion, the device and the method provided by the application can solve the problem of long-time high-temperature mechanical loading with lower cost while expanding the high-temperature mechanical loading form of the coating, are beneficial to researching long-time high-temperature evolution behavior under the gradient stress condition of the coating, and further provide basis and guidance for failure analysis and long-life design of the protective coating on the surface of the hot-end component with a complex configuration.
The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (16)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210397690.3A CN114878301B (en) | 2022-04-15 | 2022-04-15 | A coating long-term high-temperature bending test device and method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210397690.3A CN114878301B (en) | 2022-04-15 | 2022-04-15 | A coating long-term high-temperature bending test device and method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114878301A CN114878301A (en) | 2022-08-09 |
| CN114878301B true CN114878301B (en) | 2024-12-31 |
Family
ID=82669039
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210397690.3A Active CN114878301B (en) | 2022-04-15 | 2022-04-15 | A coating long-term high-temperature bending test device and method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114878301B (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110231234A (en) * | 2019-07-09 | 2019-09-13 | 中国科学院金属研究所 | Test the experimental provision of the two-way alternating bending of steel wire in high and low temperature environment |
| CN110715862A (en) * | 2019-11-13 | 2020-01-21 | 吉林大学 | Instrument and method for testing mechanical properties of materials under tension-torsion composite-mechanical-thermal coupling conditions |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8177953B2 (en) * | 2008-12-17 | 2012-05-15 | Hamilton Sundstrand Corporation | Method and apparatus for evaluation of coated parts |
| CN113588417A (en) * | 2021-06-24 | 2021-11-02 | 中国特种设备检测研究院 | Metal coating stress corrosion test method and device in corrosion environment |
-
2022
- 2022-04-15 CN CN202210397690.3A patent/CN114878301B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110231234A (en) * | 2019-07-09 | 2019-09-13 | 中国科学院金属研究所 | Test the experimental provision of the two-way alternating bending of steel wire in high and low temperature environment |
| CN110715862A (en) * | 2019-11-13 | 2020-01-21 | 吉林大学 | Instrument and method for testing mechanical properties of materials under tension-torsion composite-mechanical-thermal coupling conditions |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114878301A (en) | 2022-08-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108344642B (en) | Creep experiment device based on gravity loading three-point bending and testing method | |
| CN107421807B (en) | Compression clamp and method for measuring high-temperature compression yield strength of small-size plastic material | |
| CN107607409B (en) | Ultra-high temperature complex load biaxial stretching compression testing device | |
| CN109100242B (en) | Device and method for testing shearing creep property of brazed joint | |
| CN110940596A (en) | A rock high stress high temperature micro-nano indentation test system | |
| CN103335894A (en) | Titanium alloy stress relaxation test device and method based on V-type hot bending | |
| CN106116559B (en) | A kind of electric field-assisted ceramic low-temp quick-combustion device | |
| CN103940679B (en) | A kind of 3 overhanging bending creep parameter measuring apparatus and method of work thereof | |
| CN109060552B (en) | A kind of thermal environment rebound test equipment and test method | |
| CN110333137A (en) | A kind of thin-walled plate tube material compression performance test sample, fixture and method | |
| CN103926159B (en) | A kind of microbonding point device for testing creep resistance and using method | |
| CN114878301B (en) | A coating long-term high-temperature bending test device and method | |
| Sun et al. | Design and analysis of a large-range precision micromanipulator | |
| CN111499215A (en) | An intelligent manufacturing device for surface protection coating vacuum coating of optical glass | |
| Wereszczak et al. | Contact drying of printed sinterable-silver paste | |
| Alaca et al. | Biaxial testing of nanoscale films on compliant substrates: Fatigue and fracture | |
| CN111579384A (en) | A tensile test system for metal materials in high temperature environment | |
| Wereszczak et al. | Reflow-oven-processing of pressureless sintered-silver interconnects | |
| CN112067462A (en) | Method and device for prefabricating cracks on ultrathin brittle material | |
| CN104374361A (en) | Plate creep extensometer | |
| CN115791433A (en) | Loading device and loading method at high temperature | |
| CN110044721A (en) | High-precision ultra-temperature mechanical performance test macro | |
| PL et al. | Comparative mechanical behavior of Sn-Bi based low temperature solder alloys under different pretest aging conditions | |
| CN209432578U (en) | A test tool for mechanical properties of CVD diamond material | |
| CN111812023A (en) | Test method for wrinkling properties of sheet metal based on uniaxial tension of specimens with holes |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |