CN-122016119-A - Etching-based copper alloy strip internal stress inspection method

Abstract

The invention provides an etching-based copper alloy strip internal stress inspection method, and relates to the technical field of copper alloy strip inspection. The method for testing the internal stress of the copper alloy strip comprises the steps of firstly establishing an internal stress value-etching warpage degree comparison curve of a copper alloy with a specific grade and specification through a standard method, selectively attaching a film to a strip sample to be tested, accurately measuring the initial warpage height of the strip sample to be tested, using a ferric trichloride etching solution with a specific proportion to controllably spray and etch a sample reserved window until the copper alloy strip is penetrated, measuring the post-etching warpage height and calculating the warpage degree, and finally converting the measured warpage degree into an actual internal stress value based on the comparison curve. The invention combines the rapid macroscopic deformation of chemical etching with the accurate calibration of a standard method, discharges the interference of mechanical tapping on measurement accuracy, realizes the quantitative inspection of the internal stress of the copper alloy strip, and has the advantages of simple operation, low cost, accurate and reliable detection result, high efficiency and the like.

Inventors

• HU YUFENG
• Leng Meiyong
• ZHANG SHUPING
• QIU HUIFENG
• ZHAO ZHIYONG
• XU SI
• PAN FEI

Assignees

• 中铜华中铜业有限公司

Dates

Publication Date

20260512

Application Date

20260206

Claims (8)

1. 1. The method for testing the internal stress of the copper alloy strip based on etching is characterized by comprising the following steps of: S1, establishing a comparison curve of internal stress sigma of a copper alloy strip and sample warpage WD; s2, preparing a sample according to the size a multiplied by b; S3, sticking a film on the sample, reserving a window with a size of c multiplied by c at a designated position of the film, and then measuring the initial warping height h of the sample; S4, carrying out penetration etching on the window part of the sample, then measuring the final warping height H of the sample, and according to the formula Obtaining the warping degree WD of the sample; And S5, quantitatively obtaining the internal stress value of the copper alloy strip according to the comparison curve.
2. 2. The method for inspecting the internal stress of the copper alloy strip based on etching of claim 1, wherein in S1, a series of standard samples with different internal stress levels are prepared for the copper alloy strip with specific brands and specifications, the actual internal stress value sigma of the standard samples is measured by adopting a standard stress measurement method, then the corresponding warping degree WD is obtained according to the steps S2-S4, the actual internal stress value sigma is taken as an abscissa, the warping degree WD is taken as an ordinate, a scatter diagram is drawn, and linear regression fitting is carried out, so that a comparison curve of the copper alloy with the brands and specifications is obtained.
3. 3. The method for inspecting internal stress of copper alloy strip based on etching according to claim 2, wherein said standard stress measuring method is X-ray diffraction method.
4. 4. The method for inspecting the internal stress of the copper alloy strip based on etching according to claim 1, wherein in S2, a rectangular sample is cut along the rolling direction of the copper alloy strip, the size of the sample is trimmed, the long side a=300 mm, the wide side b=60 mm is ensured, in S3, the center of a window is positioned at the position of 250mm on the long side and 30mm on the wide side of the sample, and the side length c=5-10 mm of the window.
5. 5. The method for testing the internal stress of the copper alloy strip based on etching according to claim 1, wherein in S3, absolute ethyl alcohol is used for wiping the surface of a sample before film pasting, then drying is carried out, and after film pasting, a pressing roller or a pressing block with the pressure of 0.01-0.05MPa is used for pressing the film pasting, so that the film pasting is tightly attached to the surface of the sample.
6. 6. The method for inspecting the internal stress of the copper alloy strip based on etching according to claim 1, wherein in S4, etching solution is adopted to carry out penetration etching on a window part of a sample, and the etching solution is a mixed solution of ferric trichloride, deionized water and absolute ethyl alcohol, wherein the mass ratio of the ferric trichloride to the deionized water to the absolute ethyl alcohol=4:5:1.
7. 7. The method for inspecting internal stress of copper alloy strip based on etching according to claim 6, wherein the temperature of etching solution is 30-50 ℃, the spraying pressure is 0.2-0.4 bar, and the sample conveying speed is 10-80 mm/s.
8. 8. The method for inspecting the internal stress of a copper alloy strip by etching according to claim 1, wherein the initial warpage height H or the final warpage height H of the sample is measured, the sample is placed on a platform, one wide side of the sample is attached to the platform, and then the warpage height of the other wide side of the sample is measured, and at least 5 points are measured to take a maximum value.

Description

Etching-based copper alloy strip internal stress inspection method Technical Field The invention relates to the technical field of copper alloy strip detection, in particular to a copper alloy strip internal stress etching detection method which is simple and convenient to operate, accurate in detection and high in efficiency, and is suitable for production quality control and internal stress rapid quantitative detection of copper alloy strips (such as brass, bronze and cupronickel) used in the fields of electronics, electricity, automobiles, aerospace and the like. Background Copper and copper alloy strips are widely used in the fields of electronic information, electrical engineering, automobile manufacturing, aerospace and the like due to their excellent electrical conductivity, thermal conductivity, ductility and corrosion resistance. During production, rolling, cutting, bending and other processing steps inevitably introduce internal stresses within the material. Excessive internal stress can cause the strip to warp, twist and even crack in subsequent processing or use, and seriously affect the dimensional accuracy, assembly performance and service life of the product. Therefore, the method accurately and rapidly detects the internal stress level of the copper alloy strip, and is important for optimizing the production process and controlling the product quality. At present, a common internal stress detection method mainly comprises the following steps: 1. the X-ray diffraction method has high precision, but the equipment is expensive, the operation is complex, the requirements on the test environment and the sample surface are harsh, and the on-site rapid detection is difficult to realize. 2. The stress relaxation method calculates the stress by measuring the strain change after stress release, but has extremely long test period (up to tens of hours), low efficiency and is not suitable for quality control with fast production rhythm. 3. The drilling method is characterized in that strain gauges are required to be adhered to the periphery of a drilled hole, the operation is complex, the effect of a drilling adhesion process on the result is large, and the repeated measurement accuracy is poor. In addition, the drilling process introduces new machining stresses that interfere with the accuracy of the measurement. 4. The strip cutting method is to cut the strip into narrow strips, release the constraint in the length direction and characterize the size of the internal stress by measuring the warpage or the length change of the strip, and has the defects that the direction of releasing the constraint of the narrow strips is one-dimensional and the size of the internal stress cannot be obtained quantitatively. In addition, new processing stresses can be introduced during the slitting process, interfering with the accuracy of the measurement. The method is difficult to meet the requirements of rapid, low-cost and convenient detection of a large number of samples on a copper alloy strip production line, either due to high cost, low efficiency or complex operation. Therefore, development of a copper alloy strip internal stress detection method which is simple and convenient to operate, low in cost, high in efficiency and reliable in result has important practical significance. Disclosure of Invention In order to solve the problems in the background technology, the invention provides an etching-based copper alloy strip internal stress inspection method, which aims at: 1. the detection operation flow is simplified, and the requirements on the professional skills of operators are reduced; 2. The input cost of detection equipment is reduced, and expensive precise instruments are not needed; 3. The detection period is shortened, and the rapid detection of batch samples is realized; 4. The accuracy and the repeatability of the detection result are improved, and reliable data support is provided for the production process optimization. The method comprises the steps of establishing an internal stress value-etching warpage quantitative comparison curve in advance, enabling a sample to generate natural deformation without external force interference in a penetrating etching mode, measuring the warpage of the sample, and finally converting the internal stress value of the copper alloy strip according to the comparison curve. Specifically, the invention adopts the following technical scheme: An etching-based copper alloy strip internal stress inspection method comprises the following steps: S1, establishing a comparison curve of internal stress sigma of a copper alloy strip and sample warpage WD; s2, preparing a sample according to the size a multiplied by b; S3, sticking a film on the sample, reserving a window with a size of c multiplied by c at a designated position of the film, and then measuring the initial warping height h of the sample; S4, carrying out penetration etching on the window part of the sample, then m