Metallic and oxide coatings-Measurement of coating inckness-Microscopical method
Some standard content:
ICS25.220.20
National Standard of the People's Republic of China
GB/T6462—2005/IS01463.2003
Replaces GB/T64621986
Metallic and oxide coatings-Measurement of coating inckness-Microscopical method (ISO1463.2003.IDT)
2005-06-23 Issued
General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China Standardization Administration of China
2005-12-01 Implementation
Normative references
Terms and definitions
Factors affecting measurement uncertainty
Preparation of cross sections
Uncertainty in measurement
Test report
Appendix A (informative) Appendix B (Informative Appendix) Appendix C (Informative Appendix) References Guidelines for cross-section preparation and measurement Measurement of cross-section slope and tooth structure coating Typical corrosion inhibitors used at room temperature GB/T6462-2005/ISO1463-2003 This standard is equivalent to ISO1463:2008 4 Metallic and oxide coatings This standard is equivalent to TSO1463:2003. For ease of use, the following editorial changes have been made to this standard: a) The term "this international standard" has been changed to "this standard"; b) "the country" has been changed to "country"; tt|| The comma used as a decimal point has been replaced by a decimal point; e) The prefix "international standard" has been deleted.
GB/T6462-2005/1SO1463.2003
Thickness measurement
Microscopic method" (English version).
This standard replaces GB/T6462--1986 Metal and oxide coatings GB/T6462--1986. The main changes are as follows: The name of the standard is changed to "Measurement of the thickness of metal and oxide coatings--Added the scope of application of the measurement method (Chapter 1): Added normative references (Chapter 2): Added the definition of local thickness (Chapter 3): Added Appendix B,
Appendix A, Appendix B, and Appendix C of this standard are informative appendices. This standard is proposed by the China Machinery Industry Federation. Cross-sectional thickness microscope measurement method. With microscope method":
This standard is under the jurisdiction of the National Technical Committee for Standardization of Metal and Non-metallic Coatings (SAC/TC57). The responsible drafting units of this standard are: Wuhan Institute of Materials Protection and Ningbo Yongxin Optics Co., Ltd. The main drafters of this standard: Zhang Dehuan, Zeng Lizhu, Chen Xiaofan, Wang Bencheng The previous versions of the standard replaced by this standard are: GB/T6462-1986.
1 Scope
GB/T6462-2005/ISO1463:2003
Measurement of the thickness of metal and oxide coatings
Microscopic method
This standard specifies the method of measuring the local thickness of metal coatings, oxide films and shaft porcelain or glass porcelain coatings by using optical microscope to detect cross sections
Warning: The application of this standard may involve the use of hazardous materials, operations and devices. This standard does not raise any health hazards and safety issues during use. Before using this standard, users are responsible for formulating appropriate health and safety regulations according to national or local regulations and taking corresponding measures.
2 Normative references
The clauses in the following documents become clauses of this standard through reference in this standard. For dated references, all subsequent amendments (excluding errata) or revisions are not applicable to this standard. However, parties to agreements based on this standard are encouraged to study whether the latest versions of these documents can be used. For undated references, the latest versions apply to this standard. GB/T 12334 Definitions and general rules for thickness measurement of metals and other non-organic coatings (idt ISO 2064) 3 Terms and definitions
The terms and definitions established in GB/T 12334 and the following terms and definitions apply to this standard: Local thickness
The average value of the specified number of thickness measurements within the reference surface. 4 Principle
A specimen is cut from the piece to be tested and, after mounting, the cross section is ground, polished and etched using appropriate techniques. The thickness of the cross section of the overburden is measured using a calibrated ruler.
Advice: Experienced metallographers are familiar with these techniques. For less experienced operators, some guidance is given in Chapter 5 and Appendix A. 5 Factors Affecting Measurement Uncertainty
5.1 Surface Roughness
If the surface of the overburden or the overburden substrate is rough, one or both of the interface lines with the cross section of the overburden will be irregular and cannot be accurately measured (see A.57 5.2 Slope of Cross Section
If the cross section is perpendicular to the plane of the overburden to be measured, the measured thickness will be greater than the true thickness. For example, a deviation from perpendicularity of 10" will produce an error of 1.5%.
Note: Appendix B provides the BI D. Guidance on inclined cross-sections. 5.3 Deformation of overlays
During mounting of specimens and preparation of cross-sections, excessive temperatures and pressures will cause harmful deformation of soft or low-melting-point overlays. Excessive grinding will also cause deformation when preparing cross-sections of brittle materials. 5.4 Chamfering of overlay edges
If the edges of the cross-section of the overlay are chamfered, that is, the cross-section of the overlay is not completely flat with the edge, the true thickness cannot be obtained by microscopic measurement. Incorrect polishing, grinding, polishing and etching can all cause edge chamfers. Therefore, before mounting, test specimens are often additionally plated. This can minimize edge chamfers (see A.2). 5.5 Additional coatings
When preparing cross-sections, in order to protect the edges of the overlay to avoid measuring Disk error, often additional coating is added to the sample to be tested. During the surface preparation process before additional coating, the removal of the cover material will result in a lower thickness measurement value. 5.6 Diffuse etching
Appropriate etch can produce a thin and clear black line at the interface line of the two metals: Excessive etch will make the interface line unclear or the line wider + cause measurement errors:
5.7 Avoid covering
Improper polishing or additional plating of soft metals will cause one metal to cover the other metal, resulting in a blurred interface line between the coating and the substrate. In order to reduce the impact of continuous covering, the cross-section of the prepared metal coating can be replicated until the thickness measurement (see A, 3 and A5) appears reproducible. Or additionally plate a harder metal. 5.8 Magnification
For any coating thickness to be measured, the measurement error generally increases with decreasing magnification. When selecting magnification, the microscope field of view should be 1.5 to 3 times the thickness of the covering layer. 5.9 Calibration of the combined micrometer of the sample
The reading error during the calibration of the stage micrometer will be reflected in the measurement of the sample. The scale must be strictly calibrated or verified, otherwise an error of several percent will occur. The calibration method is to use the full scale length as the accurate value, and then use the linear micrometer to measure the length of each grid, and calculate the scale value of each grid according to the ratio. 5.10 Calibration of the micrometer eyepiece
The linear micrometer self-mirror can provide the most satisfactory thickness measurement method: after the self-mirror is calibrated, the measurement will be more accurate. Solid calibration is related to the operator's human factors, so the self-mirror should be calibrated by the measurement operator. Repeated calibration of the micrometer self-mirror can hope to obtain an error of less than 1%. The spacing between the two lines of the stage micrometer should be within the larger range of 0.2 or 0.1%. If the stage micrometer has not been verified for accuracy, it should be calibrated. Note: The measurement uncertainty of some stage micrometers is verified by the manufacturer. In addition, some stage micrometers have an error of 1am or 2rm when measuring a distance of 2. When measuring a distance of 0.1mm and 0.01mm, the error is 0.4m or more. Some micrometer eyepiece image magnification has nonlinear characteristics, so even short-distance measurements can have an error of 1%. 5.11 Alignment
The tooth wandering during the movement of the micrometer eyepiece can also cause measurement errors. To eliminate this error, ensure that the final movement of the alignment line is always in the same direction during the alignment process
5.12 Consistency of magnification
Errors will occur if the magnification is inconsistent throughout the field of view. Therefore, it is necessary to ensure that the interface to be measured is placed at the center of the optical axis and that calibration and measurement are performed at the same position in the field of view
5.13 Lens quality
Unclear images will cause measurement uncertainty, so ensure that high-quality lenses are used. Note: Sometimes, monochromatic light can be used to improve image clarity. 5.14 Eyepiece orientation
Ensure that the directrix of the heliostat is perpendicular to the interface line of the summer cover cross section during the movement of the alignment. Read her: a deviation of 10° has an error of 1.5%
5.15 Length of the tube
Changes in the tube length will cause changes in magnification. If this change occurs between calibration and measurement, the measurement will be inaccurate. When repositioning the otoscope in the tube, changing the focal length of the eyepiece, and making fine adjustments to the microscope, be careful to avoid changes in the length of the tube. 6 Preparation of cross sections
The requirements for preparation, mounting, grinding, polishing, and etching of samples are as follows: 2
The underlying section is perpendicular to the summer cover layer
GB/T6462-2005/1SO1463:2003
The cross-sectional surface is flat, and the entire width of the image should be focused simultaneously at the magnification taken during measurement: The deformed material caused by cutting and preparing the cross section should be removed: The interface line on the cross section of the covering layer can be clearly determined only by the appearance contrast or by a thin line that is easily distinguishable! d
Detailed guidance is given in Chapter 5 and Appendix A. Some typical reagents are listed in Appendix C. 7 Measurement
7.1 Due regard should be paid to the factors listed in Chapter 5 and Appendix A. The microscope and its measuring device should be calibrated with a verified or calibrated stage micrometer. 7.2
When measuring the width of the cross-sectional image of the coating, at least five points of the length of the microscopic section should be measured. 73
Note that Appendix B gives guidance on the measurement of the slope of the cross section and the serration of the coating. B
Uncertainty of measurement
The microscope and its accessories, the method of use and calibration of the microscope and its accessories, and the method of cross-section preparation should be selected so that the uncertainty of the measurement of the coating thickness to be measured is within the larger value of 1 μm or 10% of the true thickness. This method can obtain an absolute measurement uncertainty of 0.8 μm. When the thickness is greater than 25 μm, the reasonable measurement uncertainty should be 5% or less. cSee B.3. Under good conditions, carefully prepared specimens, and using appropriate instruments, this method can obtain a measurement uncertainty of 0.4m 9 Test report
The test report should include the following:
The number of this standard, i.e. GB/T6462-2005: a
The characteristics of the test specimen
The date of the measurement result:
The location of the section taken on the test specimen: The thickness measured at each point, in microns (if greater than 1mm, in millimeters> (7.3), the length of the distribution of the measuring points on the cross section: 2)
Local thickness, i.e. the arithmetic mean of the thickness measurements 3
Any deviation from the specified process!
Any abnormal characteristics (abnormal phenomena) observed during the test: The date of inspection.
GB/T6462—2005/1SO1463:2003
A Introduction
Appendix A
(Informative Appendix)
Guide to cross-section preparation and measurement
The preparation of the specimen and the measurement of the coating thickness depend to a large extent on personal skills, and there are many applicable techniques. It is unreasonable to prescribe only one technique, and it is unrealistic to include all applicable techniques. The techniques described in this appendix are used as a guide for inexperienced metallographers to refer to when measuring the coating thickness. A.2 Mounting
In order to prevent chamfering of the cross-section edges of the coating, the outer surface of the coating should be supported so that there is no gap between the coating and the support. The specimen is often plated with a metal with a hardness similar to that of the coating as an additional coating with a thickness of at least 10 μm. For hard, brittle coatings (such as oxide films or chrome coatings), the specimen can be tightly wrapped with a layer of soft aluminum foil before mounting. If the coating is soft, the addition of a softer metal coating will make polishing more difficult, because the softer the metal, the easier it is to polish away. Adding copper coatings to zinc and galvanized coatings will cause difficulties because the dissolved copper tends to deposit on the zinc and galvanized coatings during subsequent etching: adding coatings to zinc coatings is better. Vice versa
A.3 Grinding and polishing
It is extremely important to keep the cross-section of the mounting perpendicular to the coating. When plastic keys are embedded, clamping a few more metal sheets at the outer edge, changing the grinding direction regularly (rotating 90°), and maintaining the grinding time and minimum pressure are all conducive to maintaining the verticality of the cross section. Before grinding, if a reference mark is engraved on the edge of the embedded edge, it is easy to determine the inclination to the horizontal plane. The grinding of the embedded specimen should use suitable sandpaper, use lubricants such as water and anhydrous alcohol, and use the minimum pressure to prevent the surface from becoming tilted. At the beginning of grinding, 100 or 180 sandpaper should be used to make the real wheel of the specimen appear and remove the deformed parts. Then use 240, 320, 500, and 600 sandpapers for grinding in turn, and the time for each time should not exceed 305~405. Each time the sandpaper is changed, the grinding time should be changed by 9o. Finally, drag on the polishing wheel for 2min~3min to eliminate scratches. It is convenient for final observation. The polishing wheel should be coated with grinding oil and anhydrous alcohol lubricant with diamond grains of 4~8m. If the surface polishing level is particularly high, a grinding paste with diamond grains of about 1m can be used for polishing.
When preparing very soft metal specimens, grinding sand particles are easily embedded in the specimen surface during grinding. In this case, the paper should be completely immersed in lubricant during grinding, or a large amount of flowing lubricant should be used to minimize the embedding. If sand particles are embedded, the method of removal is: after grinding and before fine diamond polishing, use a short period of light manual polishing or one or more diffuse etching, and alternate polishing cycles. A.4 Diffuse etching
In order to improve the contrast between metal layers, remove metal cover marks, and show a clear thin line at the boundary of the coating layer, diffuse etching methods are usually appropriate. Some typical etching agents are listed in Appendix C. A.5 Measurement
The measuring instrument is generally a linear micrometer or a micrometer eyepiece, the latter of which is less accurate. The eyepiece magnifies the image and is conducive to the measurement of thin coatings on rough substrates. The measurement method of projecting the image onto a frosted glass plate is usually unsatisfactory because the clarity of the image and the scale reading is relatively poor when the projection is visible.
The measuring instrument should be calibrated at least once before and after the measurement, unless otherwise required by repeat experiments. Calibration and measurement should be performed by the same operator. The stage micrometer and the cover should be placed in the center of the field of view. Each measurement point should be measured at least twice and the average value should be taken.
GB/T6462-2005/IS01463.2003
For critical arbitration measurements, all steps in preparing cross sections and measuring the thickness of the cover, starting with grinding with 600 g or coarser sandpaper until the measurement, should be performed twice: advanced technology and precision instruments are used to prepare smooth cover and substrate surfaces with a reproducibility within 2% or 0,5um, whichever is greater. Some microscopes are prone to spontaneous movement of the stage relative to the objective lens. This may be caused by uneven thermal effects of the light source. This movement will cause measurement errors when high magnification is used during thickness measurements. Rapid measurements or two measurements per interval, once from left to right and once from right to left, can minimize errors. 5
GB/T6462-2005/1SO1463.2003
Appendix B
(Informative Appendix)
Measurement of the slope of the cross section and the toothed structure covering layer B.1 Slope of the cross section
If the orientation of the specimen deviates from the vertical plane (see Figure B.1), the measured value will be too high (see 5.2). The covering layer thickness d can be calculated according to formula (B.1): dd..cosa
Formula:
The covering layer thickness when 0=0!
Deviation of the cross section from the vertical plane of the overburden surface, expressed in degrees. The measured value of the overburden thickness at 0
Overburden surface:
Cross section:
Regular direction
Figure B.1 Deviation angle α of the cross section
B.2 Measurement of toothed overburden
B.2.1 Principle
This method can be used to measure the local thickness of toothed overburden, for example, nitrided overburden produced by thermochemical means B.1)||t t||The thickness of the covering layer is magnified 200 times and then measured using screens located 2 mm apart between the two boundary lines of the covering layer until it exceeds an appropriate total length, such as 100 mm (see Figure B.2).
B.2.2 Numerical calculation
The arithmetic mean of the toothed covering layer is calculated from the individual values. The standard deviation gives the interface irregularity (angle of the toothed structure). Method of expression
Coating layer:
GB/T6462—2005/ISO1463:2003
Figure B.2 Measurement of the thickness of the overburden with a toothed structure B.3 Empirical values of the standard deviation of the measurements obtained using a lightweight microscope Under repeatable conditions, the standard deviation (a) is 0.3 mm, while the standard deviation under comparative conditions is 0.8 m. For a given standard deviation, Table B.1 lists the reliable intervals for the local thickness of the overburden. The values calculated in the table according to formula (B2) (simplified form) have a statistical reliability of 95%: 0.1.96
Calculation of the number of measurements of the local thickness
Standard deviation
Therefore, 95% of the measurements are within the range of ±9 of the local thickness of the overburden (see reference 1). Table B.1 Relative error of local thickness of covering layer at 95% statistical reliability (%) Repeatable parts
Local thickness
Month=10
Comparison conditions
GB/T6462--2005/ISO1463:2003
Appendix C
(Informative Appendix)
Typical etchants used at room temperature
Some typical etchants used at room temperature are shown in Table CI Warning: Be careful when preparing, using, handling and discharging these etchants Table C.1
Etching agent
Acid drop to-1.42/mL: 5ml| |tt||Ethanol volume fraction 95%+95mL
Warning, this mixture is unstable and can explode, especially when heated. Hydrated iron trioxide (FeCl·6H2O), 10g hydrochloric acid solution (g=L: 16g/mL/: 2mL: ethanol liquid volume fraction 95%. 98mL
Nitric acid solution (g=1.42/mL) 50mL
Ice alcohol solution (g=116g/ml) 50mlbzxZ.net
Persulfate 10g:
Ammonium hydroxide solution (g=0.88g/mL) 2mL
Purple water 93m
Nitric acid solution (g=1. 42g/mL) 5mL
Hydrofluoric acid solution (p-1.14g/ml3t2mlt purple pot water: 93mL
Chromium (Cr0).20g:
Sulfuric acid 5ml:
Distilled water: 100ml
Hydrofluoric acid solution (p=1.14g/mL) 2mL
Distilled water.98mL
Use the nickel and chromium plating on steel by hand, without steel, this agent should be newly prepared
Use the gold, lead, silver, nickel and copper plating on steel, copper and copper alloys to etch steel, copper and copper alloys
Use for the single layer thickness measurement of nickel sensitive layer on steel and copper By showing the organization to distinguish each layer of brocade, nickel + over-fast steel and copper alloy
for copper and alloy on the silver and silver alloy chain layer to transfer the alloy,
the immersion agent must be newly prepared
for aluminum and aluminum alloy on the nickel and ketone bond layer to etch aluminum and aluminum alloy
for zinc alloy on the nickel and silver plating,
also suitable for copper iron on the zinc and pot plating, zinc, zinc alloy and aluminum
for anodized aluminum alloy!
etch aluminum and its alloys
reference
GB/T6462-2005/ISO1463:2003
1l BARGHOORN.H..Vergleichende Untersuehungen von Schichtdicke-MessverfahrenMetalloberflaehe.1955.7.pp.g-1l.L2] Ray. Gp,Thickness testing of electroplated and related coatings,Eleerochemical Publica.tions Ltd..Asahi House.1o Chureh Road,Port Erin+ UK,,1993,ISBN0 901150 2 741) Available from The Metal Finishing Institute, Exeter House + 48 Holleway Head, Birmingham B1 INQ, UK
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