CN111272624A - Porosity detection method - Google Patents
Porosity detection method Download PDFInfo
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- CN111272624A CN111272624A CN201911198736.3A CN201911198736A CN111272624A CN 111272624 A CN111272624 A CN 111272624A CN 201911198736 A CN201911198736 A CN 201911198736A CN 111272624 A CN111272624 A CN 111272624A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume, or surface-area of porous materials
- G01N15/08—Investigating permeability, pore-volume, or surface area of porous materials
- G01N15/088—Investigating volume, surface area, size or distribution of pores; Porosimetry
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N23/00—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00
- G01N23/02—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by transmitting the radiation through the material
- G01N23/04—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by transmitting the radiation through the material and forming images of the material
- G01N23/046—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by transmitting the radiation through the material and forming images of the material using tomography, e.g. computed tomography [CT]
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2223/00—Investigating materials by wave or particle radiation
- G01N2223/03—Investigating materials by wave or particle radiation by transmission
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2223/00—Investigating materials by wave or particle radiation
- G01N2223/10—Different kinds of radiation or particles
- G01N2223/101—Different kinds of radiation or particles electromagnetic radiation
- G01N2223/1016—X-ray
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2223/00—Investigating materials by wave or particle radiation
- G01N2223/40—Imaging
- G01N2223/426—Imaging image comparing, unknown with known substance
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2223/00—Investigating materials by wave or particle radiation
- G01N2223/60—Specific applications or type of materials
- G01N2223/615—Specific applications or type of materials composite materials, multilayer laminates
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2223/00—Investigating materials by wave or particle radiation
- G01N2223/60—Specific applications or type of materials
- G01N2223/649—Specific applications or type of materials porosity
Abstract
The invention relates to the technical field of porosity detection, and particularly discloses a porosity detection method, which comprises the following steps: establishing an evaluation curve, wherein the abscissa of the evaluation curve is porosity, and the ordinate is the gray level of the negative film; carrying out ray scanning on a workpiece to be detected and obtaining a detection negative film; confirming the actual gray scale of the detection negative film; and searching the value of the abscissa matched with the actual gray scale from the evaluation curve to serve as the actual porosity of the workpiece to be detected. According to the detection method, the workpiece to be detected is scanned through rays, compared with ultrasonic waves in the related technology, the workpiece to be detected cannot be damaged, and the detection efficiency is high.
Description
Technical Field
The invention relates to the technical field of porosity detection, in particular to a porosity detection method.
Background
The pores are inevitable micro defects in the manufacturing process of the carbon fiber composite material, and the mechanical properties of the composite material are very sensitive to the pores. The parameter for assessing the effect of porosity on a composite material is porosity, which is the percentage of the volume of pores in the material relative to the total volume of the material in its natural state. The porosity detection method of the carbon fiber composite material mainly comprises two types: destructive testing and non-destructive testing. Destructive detection mainly comprises a density method and a photomicrograph method; nondestructive testing mainly refers to ultrasonic testing.
At present, ultrasonic detection is widely adopted for nondestructive detection of porosity of composite materials, but the method has low detection efficiency and low speed.
Disclosure of Invention
The invention aims to: a porosity detection method is provided to improve porosity detection efficiency.
The invention provides a porosity detection method, which comprises the following steps:
establishing an evaluation curve, wherein the abscissa of the evaluation curve is porosity, and the ordinate of the evaluation curve is the gray level of the negative film;
carrying out ray scanning on a workpiece to be detected and obtaining a detection negative film;
confirming the actual gray scale of the detection negative film;
and searching the value of the abscissa matched with the actual gray scale from the evaluation curve to serve as the actual porosity of the workpiece to be detected.
As a preferred technical solution of the porosity detection method, the method for establishing the evaluation curve includes:
manufacturing a sample combination, wherein the sample combination comprises a plurality of reference test blocks with the same thickness, the porosity of each reference test block is different, and the material of each reference test block is the same as that of the workpiece to be detected;
respectively carrying out ray scanning on each contrast test block of the sample combination, and obtaining a plurality of sample negative films;
confirming the gray scale of each sample negative film;
establishing a coordinate point of each reference block by taking the porosity of the reference block as an abscissa and the gray scale of the sample negative of the reference block as an ordinate in a coordinate system;
fitting each of the coordinate points to the evaluation curve.
As a preferred technical solution of the porosity detection method, the number of the sample combinations is multiple, the multiple sample combinations form a sample library, and the thicknesses of the reference blocks in the sample combinations are different;
and establishing the evaluation curves for the sample combinations respectively, wherein the vertical coordinates of the evaluation curves do not overlap.
As a preferable technical scheme of the porosity detection method, the ray is an X ray.
As a preferred technical scheme of the porosity detection method, the method further comprises the step of enabling the workpiece to be detected to be made of a carbon fiber composite material.
As a preferred technical scheme of the porosity detection method, the workpiece to be detected is subjected to ray scanning through a CT system, and the detection negative film is obtained.
The invention has the beneficial effects that:
the invention provides a porosity detection method, which comprises the following steps: establishing an evaluation curve, wherein the abscissa of the evaluation curve is porosity, and the ordinate is the gray level of the negative film; carrying out ray scanning on a workpiece to be detected and obtaining a detection negative film; confirming the actual gray scale of the detection negative film; and searching the value of the abscissa matched with the actual gray scale from the evaluation curve to serve as the actual porosity of the workpiece to be detected. According to the detection method, the workpiece to be detected is scanned through rays, compared with ultrasonic waves in the related technology, the workpiece to be detected cannot be damaged, and the detection efficiency is high.
Drawings
FIG. 1 is a flow chart of a method of porosity detection in an embodiment of the invention;
Detailed Description
The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. Where the terms "first position" and "second position" are two different positions, and where a first feature is "over", "above" and "on" a second feature, it is intended that the first feature is directly over and obliquely above the second feature, or simply means that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.
In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.
Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.
As shown in fig. 1, the present embodiment provides a porosity detection method, which includes the following steps:
s1: and establishing an evaluation curve, wherein the abscissa of the evaluation curve is porosity, and the ordinate is the gray scale of the negative film.
The method for establishing the evaluation curve comprises the following steps:
1) the sample combination comprises a plurality of comparison test blocks with the same thickness, the porosity of each comparison test block is different, and the material of each comparison test block is the same as that of the workpiece to be detected. It will be appreciated that the individual reference blocks of the sample combination can be used as a basis for comparison of the porosity measurement.
2) And respectively carrying out ray scanning on each comparison test block of the sample combination, and obtaining a plurality of sample negative films.
In this embodiment, the radiation is X-ray, and the scanning operation can be performed by a CT system.
3) And confirming the gray scale of each sample negative film.
The evaluation may be performed manually through experience, or may be performed by an image processing system.
4) And establishing coordinate points of the reference test blocks in a coordinate system by taking the porosity of the reference test blocks as an abscissa and taking the gray scale of the sample negative of the reference test blocks as an ordinate.
5) And fitting the coordinate points into an evaluation curve.
The coordinate points of each reference block can be fitted to an evaluation curve by software such as Matlab or Origin.
Optionally, the number of the sample combinations is multiple, the multiple sample combinations form a sample library, and the thicknesses of the reference blocks in the sample combinations are different; and respectively establishing an evaluation curve for each sample combination, wherein the vertical coordinates of the evaluation curves do not overlap. Thus, for a particular actual gray scale, there will be only one porosity corresponding to it.
S2: and carrying out ray scanning on the workpiece to be detected and obtaining a detection negative film.
During scanning, the CT system is used for scanning the workpiece to be detected in a full coverage mode.
S3: confirming the actual gray scale of the detection negative film;
s4: and searching the value of the abscissa matched with the actual gray scale from the evaluation curve to serve as the actual porosity of the workpiece to be detected.
According to the detection method, the workpiece to be detected is scanned through rays, compared with ultrasonic waves in the related technology, the workpiece to be detected cannot be damaged, and the detection efficiency is high.
It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.
Claims (6)
1. A method of porosity detection, comprising:
establishing an evaluation curve, wherein the abscissa of the evaluation curve is porosity, and the ordinate of the evaluation curve is the gray level of the negative film;
carrying out ray scanning on a workpiece to be detected and obtaining a detection negative film;
confirming the actual gray scale of the detection negative film;
and searching the value of the abscissa matched with the actual gray scale from the evaluation curve to serve as the actual porosity of the workpiece to be detected.
2. The porosity detection method according to claim 1, wherein the method of establishing the evaluation curve comprises:
manufacturing a sample combination, wherein the sample combination comprises a plurality of reference test blocks with the same thickness, the porosity of each reference test block is different, and the material of each reference test block is the same as that of the workpiece to be detected;
respectively carrying out ray scanning on each contrast test block of the sample combination, and obtaining a plurality of sample negative films;
confirming the gray scale of each sample negative film;
establishing a coordinate point of each reference block by taking the porosity of the reference block as an abscissa and the gray scale of the sample negative of the reference block as an ordinate in a coordinate system;
fitting each of the coordinate points to the evaluation curve.
3. The porosity detection method according to claim 2, wherein the number of the sample combinations is plural, the plural sample combinations form a sample library, and the thickness of the reference block in each sample combination is different;
and establishing the evaluation curves for the sample combinations respectively, wherein the vertical coordinates of the evaluation curves do not overlap.
4. The porosity detection method according to claim 1, wherein the radiation is X-ray.
5. The porosity detection method according to claim 1, further comprising the step of detecting whether the workpiece to be detected is made of a carbon fiber composite material.
6. The porosity detection method according to claim 1, wherein the workpiece to be detected is subjected to ray scanning by a CT system, and the detection negative is obtained.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911198736.3A CN111272624A (en) | 2019-11-29 | 2019-11-29 | Porosity detection method |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911198736.3A CN111272624A (en) | 2019-11-29 | 2019-11-29 | Porosity detection method |
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| CN111272624A true CN111272624A (en) | 2020-06-12 |
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| CN201911198736.3A Pending CN111272624A (en) | 2019-11-29 | 2019-11-29 | Porosity detection method |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113129259A (en) * | 2021-03-03 | 2021-07-16 | 中冶南方连铸技术工程有限责任公司 | Casting blank density detection method and system and electronic equipment |
| CN113155062A (en) * | 2021-03-03 | 2021-07-23 | 中冶南方连铸技术工程有限责任公司 | Method and system for testing deformation efficiency under continuous casting press and electronic equipment |
| CN113237809A (en) * | 2021-04-16 | 2021-08-10 | 贵州电网有限责任公司 | Composite insulator core rod porosity evaluation method |
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| SU1458770A1 (en) * | 1987-07-06 | 1989-02-15 | Kirovsk Polt Inst | Method of quantitative analysis of porosity of electroplated coating |
| CN106769770A (en) * | 2017-01-06 | 2017-05-31 | 佛山科学技术学院 | A kind of measuring method of nano-porous film closed-cell porosity |
| CN108562528A (en) * | 2018-06-19 | 2018-09-21 | 长沙理工大学 | A kind of composite material porosity evaluation method based on acoustic emission |
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2019
- 2019-11-29 CN CN201911198736.3A patent/CN111272624A/en active Pending
Patent Citations (5)
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| SU1458770A1 (en) * | 1987-07-06 | 1989-02-15 | Kirovsk Polt Inst | Method of quantitative analysis of porosity of electroplated coating |
| CN106769770A (en) * | 2017-01-06 | 2017-05-31 | 佛山科学技术学院 | A kind of measuring method of nano-porous film closed-cell porosity |
| CN108682020A (en) * | 2018-04-28 | 2018-10-19 | 中国石油大学(华东) | Rock core micron CT pore structure reconstructing methods |
| CN108562528A (en) * | 2018-06-19 | 2018-09-21 | 长沙理工大学 | A kind of composite material porosity evaluation method based on acoustic emission |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113129259A (en) * | 2021-03-03 | 2021-07-16 | 中冶南方连铸技术工程有限责任公司 | Casting blank density detection method and system and electronic equipment |
| CN113155062A (en) * | 2021-03-03 | 2021-07-23 | 中冶南方连铸技术工程有限责任公司 | Method and system for testing deformation efficiency under continuous casting press and electronic equipment |
| CN113237809A (en) * | 2021-04-16 | 2021-08-10 | 贵州电网有限责任公司 | Composite insulator core rod porosity evaluation method |
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