Metallic and other inorganic coatings-Review of methods of measurement of thickness
Some standard content:
ICS 25.220.20
National Standard of the People's Republic of China
GB/T 6463---2005/1S0 3882:2003 replaces GB/T 6463—1986
Metallic and other inorganic coatings-Review of methodsof measurement of thickness
(ISO3882:2003(E),IDT)
2005-06-23 release
General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China Standardization Administration of China
2005-12-01 implementation
GB/T6463—2005/IS03882:2003
This standard is a revision of 3/T6463—1986 standard, equivalent to ISO3882:2003 (E) Gold flag and other inorganic coating thickness measurement method review".
This standard is redrafted according to the editing requirements of GB/T1.1 and ISO3882 standard. This standard makes the following modifications to ISO3882:
The foreword of JSO3882 is cancelled and the foreword of this standard is redrafted; - "and standard" is used instead of "this international standard" - for ease of use, some Chinese standards that adopt international standards are quoted. This standard is proposed by the China Machinery Industry Federation. This standard is under the jurisdiction of the National Technical Committee for the Promotion of Metal and Non-metallic Covering Standards. The drafting unit of this standard is the Quality Supervision and Inspection Center for Surface Covering Products of the Machinery Industry. The main drafters of this standard are: Zhong Lichang, Jiang Xinhua, and Song Zhiling. The version released is: -GB/T6463-1986.
GB/T6463--2005/IS03882:2003
This standard summarizes the various methods used to measure the thickness of the coating on the disc and describes their working principles. The methods for measuring the thickness of the coating on the disc can be destructive or non-destructive (see Table 1). The information given in Table 2 will help in measuring the thickness in selecting the method suitable for a specific purpose. For instruments that work with all methods, the manufacturer should indicate this in the instructions. Thickness measured using different methods The accuracy depends on the coating material, coating thickness, substrate and the instrument used (see Table 3). For example, although the X-ray spectrometry can measure the thickness of the chrome coating, if the thickness is less than 20um, the measurement is inaccurate. Similarly, the magnetic method can measure the thickness of the gold coating on the magnetic steel substrate, but most magnetic thickness gauges cannot accurately measure the gold coating with a thickness less than 2μm1. bzxZ.net
The arbitration method suitable for the coating thickness measurement should be necessary for commercial design. 1 Scope
GB/T6463—2005/IS03882. 2003
Metallic and other inorganic covering layers
Review of thickness measurement methods
This standard reviews the measurement methods of the thickness of metallic and other inorganic covering layers on metallic and non-metallic substrates (see Table 1, Table 2, Table 3). These methods are limited to the tests that have been specified or are to be specified in the national standards, and do not include tests for some special purposes. Table 1 Measurement methods for the thickness of the covering layer
Non-ring method
Double-beam microscope (light section) method (GB/T8015.2\) Magnetic method (GB/T4956 and GR/T 13744) Eddy current method (GB/T4957)
X-ray spectrometry method (GB/T16921)
Solar ray backscattering method (1S0) 3543) may be destructive in some applications,
may be non-destructive in some applications. Normative references
Dissolution method:
Wrinkle method
Microscope (optical) method (GB/T6462)
Pesso multi-beam F sand determination (1SO3868)
Profilometer (stylus) method (GB/T11378*) Scanning electron microscope method (TSO9220)
Xia Zui (shaving and weighing) method and heavy disk (analysis) method (IS010111) Coulometric method (GB/T455)
The clauses in the following documents become the clauses of this standard through reference in this standard. For all referenced documents with dates, all subsequent amendments (excluding errata) or revisions are not applicable to this standard. However, parties that reach an agreement based on this standard are encouraged to study whether the latest versions of these documents can be used. For all referenced documents without dates, the latest versions are applicable to this standard. GB/T4955 Measurement of thickness of metal coating - Coulometric method by anodic dissolution (idl.ISO2177) GB/T 4956 Measurement of thickness of non-magnetic coating on magnetic substrate - Magnetic method (ISO 2178,11)T) (R/T4957 Measurement of thickness of non-conductive coating on non-magnetic substrate - Eddy current method (ISO2360,11)T) GB/T6462 Measurement of thickness of metal and oxide coating - Microscope method (ISO1463, IDT) GB/T8015.2 Test method for thickness of anodic oxide film on aluminum and aluminum alloy - Beam microscope method (idl.ISO2128) GB/T 11378
GB/T 12334
GB/T 13744
GR/T 16921
Metallic coatings - Measurement of coating thickness - Profilometer method (ISO 4518, II)) Metal and other inorganic coatings - Definitions and general rules for thickness measurement (idt ISO 2064) Magnetic and magnetic substrates - Measurement of coating thickness by electron microscope (idt ISO 2361) Metallic coating thickness - Measurement of coating thickness by X-ray spectroscopy (e9VISC 3197) Metallic and non-metallic coatings - Measurement of coating thickness by beta-ray backscattering method ISO 3543
IS0 3868
I$O 9220
IS0 10111
3 Terms and definitions
Metallic and other inorganic coatings - Measurement of coating thickness - Persor multi-beam dry sand method - Metallic coating thickness - Scanning electron microscopy method - Measurement of mass per unit area of metallic and other inorganic coatings - Review of gravimetric and chemical analysis methods This standard adopts GB, T 12334. Terms and definitions specified in GB/T 64632005/1S0 3882:2003
4 Non-destructive method
4.1 Double beam microscope (light tree) method (GB/T 8015.2) This instrument was originally designed for measuring surface roughness, but it can now be used to measure the roughness of transparent and semi-opaque coatings, especially aluminum anodized films. A light beam is projected onto the surface at a 45-degree angle. Part of the beam is reflected from the surface of the coating, and the other part penetrates the coating and reflects from the interface between the coating and the base metal. Two separate images can be observed from the microscope eyepiece, and the distance between them is proportional to the thickness of the coating. This method is only suitable for coatings that can have sufficient light reflected back from the interface between the coating and the base metal and show a clear image in the microscope. For transparent or semi-transparent coatings, such as anodized films, this method is a non-destructive method. In order to measure the thickness of the most opaque coating, a small piece of the coating must be removed. Therefore, this method is destructive. It uses the refraction of the light beam generated by the step between the coating surface and the substrate metal to measure the absolute value of the coating thickness. This method is not suitable for measuring hard anodic coatings, very loose (<2um) or very thick (>100μm) coatings, and rough coatings. It is also not suitable for measuring coatings with excessive sandblasting on the substrate. In the case where the double-beam microscope thickness measurement method cannot be used, other methods can be used, such as: eddy current method (GB/T4957), interference microscope method (ISO3868) and microscope method (GB/T6462). The measurement uncertainty of this method is generally less than 10% of the thickness. 4.2 Magnetic method (GB/T 4956 and GB/T13744) The purpose of this method is to measure the change of the magnetic bow force between the magnet and the substrate metal affected by the coating, or to measure the magnetic resistance of the magnetic flux between the thin coating and the substrate metal.
All instruments used for magnetic methods are sensitive to magnetic conditions and sample characteristics such as surface curvature, surface cleanliness, surface roughness, thickness of base metal and absence of covering layers.
In practice, these methods are limited to measuring the thickness of non-magnetic coatings on magnetic substrates (see GB/T4956) and electroplated nickel layers on magnetic or non-magnetic substrates (see GB/T13744). The measurement uncertainty of this method is generally less than 10% of the thickness or 1.5rm, whichever is greater. 4.3 Eddy current method (GB/T4957)
This method describes a widely used method based on the difference in electrical conductivity between the coating and the substrate. This method is mainly used to measure the thickness of non-conductive coatings on non-magnetic metal substrates and single-layer metal coatings on non-conductors. If this method is used to measure the thickness of a coating on a substrate, special attention should be paid to the applicability of the results obtained. This method is an ideal and rapid method for determining the thickness of anodized films on aluminum and aluminum alloys, and can be well used for on-site measurements. For autocatalytic nickel coatings, the measurement instability presented by this method is caused by changes in the conductivity and phosphorus content of the metal coating. The measurement uncertainty of this method is generally less than 10% of the thickness or 0.5 μm, whichever is greater. 4.4 X-ray spectroscopy (GB/T16921)
This method uses an emission and absorption X-ray spectroscopy device to determine the thickness of a metal coating. X-rays are emitted to a fixed area on the surface of the coating, and the intensity of secondary rays emitted by the coating or the intensity of secondary rays emitted by the substrate and weakened by the coating is measured. The X-ray intensity has a certain relationship with the coating thickness, which is determined by the calibration standard. The accuracy of this method will be reduced in the following cases: ~ When the components of the coating exist in the base metal or the components of the base metal exist in the cover layer - when there are more than two cover layers;
When the chemical composition of the coating is greatly different from the chemical composition of the calibration standard. This method is not suitable for measuring the saturation thickness exceeding the atomic number and density of the relevant material. For autocatalytic nickel coating, this method is only recommended for deposits under electrochemical conditions. The phosphorus content in the coating must be known to calculate the thickness of the deposited layer. The distribution of groups in the coating will also affect the measurement uncertainty. The calibration standard must be made under the same production conditions. The measurement uncertainty of the thickness gauge available on the market is less than 10% of the thickness. 4.5 β-ray backscattering method (ISO3543) This method uses the effective isotopic emission of β-rays and measures the β-ray backscattering intensity reflected by the sample. The β-ray backscattering intensity GB/T 6463-2005/IS0 3882:2003 value should be between the backscattering intensity value of the coating layer and the backscattering intensity value of the base metal. It can only be measured when the atomic number of the coating material and the base metal differs sufficiently. The instrument is calibrated using a calibration standard with the same coating and base as the sample to be tested. The β-ray backscattering intensity measured by the sample is used to calculate the mass per unit area of the coating. If the density of the coating is uniform, the β-ray backscattering intensity value is proportional to the thickness.
This method can be used to measure thin coatings, whose maximum thickness is a function of the atomic number of the coating. The measurement uncertainty obtained by this method in a large range of degrees is less than 10% of the thickness. 5 Destructive method
5.1 Microscope (optical) method (CB/T6462) In this method, the coating thickness is measured on the enlarged image of the cross section of the coating. When there is a minimum error of 0.8μm, the measurement uncertainty of this method is less than 10% of the thickness. If the sample is carefully prepared and the appropriate instrument is used, the measurement uncertainty of this method can reach 0.4μm when repeated measurements are made. 5.2 Multi-beam immersion method (IS03868) Completely dissolve a small piece of coating without corroding the substrate or masking the substrate before electroplating, and form a step from the coating surface to the substrate. The height of the step is measured using a multi-beam x-ray analyzer. This method is particularly suitable for measuring the thickness of very thin opaque metal coatings. It is not suitable for measuring ceramic coatings. This method is a laboratory method used to measure the thickness of the coating on a standard sheet to calibrate non-destructive thickness gauges such as beta backscatter instruments and X-ray instruments. It is particularly suitable for measuring standard sheets of relatively thin (sub-micron) coatings. This method specifies the absolute value of the thickness of the coating layer in the range of 0.002 μm to 0.2 μm measured by a microscope perpendicular to the sample surface. The measurement uncertainty of this method is 20.001 μm. 5.3 Profilometer (Stylus) Method (GB/T11378) When preparing the coating, a small piece of the coating is masked or a small piece of the substrate is dissolved without etching the substrate, so that a step is formed between the substrate and the surface of the coating. The stylus passes through the step, and the electronic instrument tests and records the movement of the stylus to measure the height of the step. The measurement range allowed by the applicable commercial instrument is 0.00002 mm (20 nm) to 0.01 mm. The measurement uncertainty of this method is less than 10% of the thickness. 5.4 Scanning Electron Microscope Method (ISO9220) In this method, the coating thickness is measured on an enlarged image of the cross section of the coating using a scanning electron microscope. This measurement is carried out on a common image or a visual signal photo of a unidirectional scanning cross section. Image magnification may not be consistent across the entire field of view. If calibration and measurement are not performed on the inter-section field of view, errors may occur. In thickness measurement, the magnified image often changes over time, resulting in progressive measurement errors. The measurement uncertainty of this method is less than 10% of the thickness or 0.1um, whichever is greater. 5.5 Dissolution method 5.5.1 Coulometric method (GB/T4955) Under appropriate conditions, the specimen is used as the anode, and the coating is dissolved from a precisely defined area with an appropriate electrolyte. The thickness of the metal coating is determined by the consumed electric disk. The potential changes when dissolving to the underlying material, indicating the end point of dissolution. This method can be used to measure metal coatings on metal and non-metal substrates. The measurement uncertainty of this method is less than 10% of the thickness. 5.5.2 Mass (residue and weighing) method (ISO 10111) This method weighs the sample before and after dissolving the cover without attacking the substrate, or weighs the cover after dissolving the substrate without attacking the cover to determine the mass of the cover. The density of the cover should be uniform. The mass of the cover divided by the area and density of the cover gives the average thickness of the cover. The limitation of this method is that it cannot indicate the presence of exposed spots where the cover thickness is less than the specified minimum value. In addition, each measurement is the average value over the entire measurement area: no further mathematical processing, such as statistical control procedures, can be performed here. The measurement uncertainty of this method is less than 5% over a large thickness range. 5.5.3 Quantitative (analytical) method (1$010111) In this method, the content of dissolved gold in the overcoat is determined by chemical analysis, regardless of whether the matrix material is dissolved, to determine the mass of the overcoat. The mass of the overcoat is divided by the area and density of the overcoat to obtain the average value of the overcoat thickness. This method specifies the following:
- If the same metal exists in the coating and the underlying or base metal, this method is unreliable; it cannot be used to identify exposed points in the measurement area or areas where the coating thickness is less than the specified minimum value. Each measurement is the average value of the entire measurement area: no further mathematical processing, such as statistical control steps, can be performed here.
The measurement uncertainty of this method is generally less than 5% over a large thickness range. Table 3 Typical thickness ranges for coating thickness measurement Instrument type
Magnetic method (for non-magnetic coatings on steel) Magnetic method (for galvanized steel)
Eddy current method
X-ray spectroscopy
Beta-ray backscattering method
Double-beam microscopy
Coulometric method
Microscopy
Wheel separation instrument method
Scanning electron microscopy
Note 1: The specified thickness range represents the following: Standard model instrument for market warning!
-Use large, flat and smooth specimens; typical thickness range*/μm
5-7500
5~-2000
0.25 ~~25
0. 1～1000
0. 25~100
4～several hundred
0.002-100
1～several straight
Use ordinary electroplating, white secondary chemical plating, resistive oxidation or sugar porcelain covering layer; ...careful and meticulous operation.
Related standards
GB/T4956
GB/T13744
GB/T 4957
GB/T16921
1SO9543
GB/T 8015.2
GB/T4955
GB/T 6462
GB/T 11378
ISO9220
The actual range depends on the sample's base material, coating material, shape, size, and instrument manufacture and model. The specified range is often expanded due to the improvement of measurement technology and instruments. It is impossible for any instrument to include all the range values measured by various instruments. Note 2: Usually, when the thickness is 1/10 of the lower limit of the range, its measurement uncertainty can reach about 100%. Therefore, the measurement uncertainty of the microscopic method is 1/1G of 4 μm, that is, 0.4 μm. The values in the table are provided by the instrument manufacturer. The L thickness range contains an uncertainty of less than 10% of the thickness. Mukao Literature
GB/T6463—2005/ISO3882:2003
[1]CLARKE,M. and DUTTA,PK,Transacions of the Instilule of Metal Finishing,1966.44(1),9
[2J HARBUI.AK,EP,Simultaneous thickness and clcrtrochemical potential determinalion af inudividual layers in muitiplayer nickel deposits, Plating and surface finishing, Fehruary 198o, 67(2),49-54
[3] JOFFE,BB ,Plating and surface finishing, Septcmber L983,40[i] LATTER,IDT ,British journal of NDT, July 1989,3I(7),372E5] KOMATSU, H. ,Interierometry: Principles and applications of two-heam and ruultiple-beam interferometry, Sendai.Japan,Institute of Materials Research, Tohoku UnivcrsityRAY,CP,Thickness testing of electroplated and related coatings, Electrochcmical Publica-tions Ltd. +Asahi House,, 10 Church Road, Purt Erin, lsle of Man ,British lsles,3993,ISBV0901150274,Avail ablefromInstituteofMetal Finishing,Exeter[lousc,48HollawayHead,Birmingham Bi 1NQ,UK)
[7]BIKULCIUS,G.,Plating and surface finishing, August 1997,84(8),30
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