Some standard content:
GB/T 17461-1998 This standard is equivalent to ISO 758:1986. Introduction This standard makes the following modifications and supplements to ISO 7587: The guiding element "metal coating" is added to the standard name, and the original filler element "specification and test method" is omitted, so that the subject is clearer and more prominent than the original name; - The "introduction" is omitted, and its content is placed in the notes of the relevant chapters; - In Chapter 2, "[ISO 2859] cited in the original standard is omitted because the referenced standard is already included in the other standard IS01529 to avoid duplication; - In Chapter 3, the definition of "basic measuring surface" is added; - In Appendix A, the installation method of the protective gas generated by the Geiger funnel is taken as the main method, and the installation method of the protective gas in the cylinder is listed in the notes as an alternative method, and the connection method of the protective gas in the cylinder is supplemented. At the same time, the special provisions of the serpentine tube for the introduction of the protective gas are cancelled, so that the actual operation is more feasible: - In Appendix B, the calculation formula for the average thickness of the lead-aluminum coating with an alloy ratio other than 60/40 is supplemented: - In addition, some necessary supplements are made in Chapter 1, Chapter 5, 10.2, 10.5 and B0.2.1 to make the expression more complete and clear. The appendixes A, B and C of this standard are all standard appendices: Appendix D of this standard is a suggestive appendix.
This standard is proposed by the State Machinery Industry Bureau. This standard is under the jurisdiction of the National Technical Committee for Standardization of Metal and Non-metallic Coatings. The responsible drafting unit of this standard is Wuhan Material Protection Research Institute. The only drafting unit of this standard is Guangdong Dongjinhui Electroplating Factory. The main drafters of this standard are: Xie Ruibing, Lin Yunfeng, Pan Derong, Yang Ming'an, Qin Wei, GB/T17461-1998
ISO former ISO
ISO) is a worldwide federation of national standards bodies (ISO member bodies). The work of formulating international standards is generally carried out through ISO technical committees. If each member body is interested in a topic determined by a technical committee, it has the right to submit a statement to the committee. International organizations, both governmental and non-governmental, that have ties to ISO may also participate in this work. The draft international standard adopted by the technical committee shall be circulated to the member bodies for approval before it is adopted as an international standard by the [S( Council]. According to the ISO procedure, at least 75% of the member bodies participating in the voting shall approve it. International Standard ISO7587 was prepared by ISO/TC107 Technical Committee on Metallic and Other Non-Organic Coatings. Users should note that all international standards are subject to revision. Therefore, unless otherwise stated, the other international standards referenced in this international standard are their latest versions.
1 Scope
National Standard of the People's Republic of China
Metallic Coatings-Electroplated Coatings of Tin-Lead Alloys
Metallic Coatings-Electroplated Coatings of Tin-Lead AlloysGB/T 17461 -1998
eqvso7587.1986
This standard specifies the technical requirements and test methods for tin-lead plating layers with a tin content range of 50% to 70% (mass ratio) (see 10.3).
This standard applies to tin-cobalt alloy plating layers for preventing corrosion and improving welding performance of electronic, electrical and other metal products. This standard is also applicable to other compositions of lead-cobalt alloy plating layers, but when using them, it should be noted that the performance of these coatings may be different from that of tin-cobalt alloys with the above alloy composition range. The classification method in this standard specifies the type of base metal and the composition of the coating within a certain range of tin content to modify the provisions for hot melt coating and bright coating. This standard does not apply to: a) tin-lead alloy coating on threaded parts; b) tin-lead alloy coating on bearings; c) tin-lead alloy coating on unformed plates, strips or wires, or tin-lead alloy coating on parts formed from them; d) tin-lead alloy coating on steel with a tensile strength greater than 1U00 IMPa (or hardness), because such steel is susceptible to hydrogen embrittlement after electroplating (see 8.2). 2 Referenced standards The provisions contained in the following standards constitute the text of this standard through reference in this standard. When this standard is released, the versions shown are valid. All standards will be revised. The party using this standard should explore the possibility of using the latest versions of the following standards: GB/T2423.28-1982 Basic environmental testing procedures for electronic and electrical products Test T: Tin pot test method (cqv IEC 68-2-20:1979)
Metallic coatings - Measurement of coating thickness - Electrodeposition coulometry (IDT ISO2177:1985) GB/T 4965-1997 wwW.bzxz.Net
GH/T5270-1985 Metallic coatings (electrodeposited and chemically deposited) on metal substrates - Surface treatment method (EUV IS0 2810:1980)
G3/T 5931--1986
Method for thickness test of metal plating and chemically treated coatings on light industrial products - 3-ray backscattering method (IDT IS0 3543:1981)
GB/T6462-1986Method for measuring the thickness of metal and chloride coatings by microscope (cqIS0) 1163:1982) GB/T 9789-1988
Metal and other non-organic coatings - Sulfur diamine corrosion test under normal condensation (eqv 1S0 6988:1985)
GB/T10125-1997Salt spray test in human atmosphere (eIS0 9227:1990)
[）The resistance of the zinc-lead alloy layer to product growth and allotropic change is better than that of pure tin. Approved by the State Administration of Quality and Technical Supervision on August 12, 1998, and implemented on July 1, 1999
GB/T 17461 - 1998
GB/T10574.1—10859 Chemical analysis methods for lead solder - Determination of tin content by potassium iodate titration GL/T12334--3990 Definitions of thickness measurement for metals and other inorganic coatings - General rules (V1S0) 2064: 19903
GB/T 12609-1990
Sampling procedure for electrodeposited metal coatings and related finishes by counting (EV1504513: 1180) GB/T16921—1997 Measurement of thickness of metallic coatings - X-ray spectrometry (eqVIS0) 3497: 1900) 3 Definitions
This standard adopts the definitions in column F.
3.1 Significant surface Some surface on the workpiece that has been plated or is to be plated. The coating on this surface is of great importance to the appearance and (or) performance of the workpiece. It should meet all the requirements specified in the standard.
3.2 Reference area
An area on the main surface. A specified number of single wash measurements are required within this area. 3.3 Fluwinelting
A process that uses molten metal plating to improve the surface quality in order to obtain the desired properties such as brightness or brazeability (see Appendix (Suggested Appendix) D)
4 Information that the purchaser should provide to the electroplating manufacturer 4.1 Necessary information
The purchaser should provide the following information to the electroplating manufacturer: a) National standard number;
b) Properties of base metal (see Section 5); c) Use condition number (see 7.1) or coating grade number (see 7.2) and alloy composition requirements (see 10.3); d) Whether the coating quality needs to be inspected (see 10.3); e) Specify the main surface of the workpiece to be plated, such as marking with drawings or providing samples with appropriate markings;) Inspection requirements (see Chapter 6): g) Unavoidable contact marks and other acceptable coating defects on the workpiece (see 10.1): h) Applicable bonding strength test method (see 10.4); 1) Special post-plating treatment (see D3-1 in the Appendix): 4.2 Supplementary information
If necessary, the following supplementary information may also be required) Heat treatment requirements (see Chapter &):
b) Porosity test requirements (see 10.5);
c) Brazing test requirements and test methods and use conditions (see 10.6): d) Special requirements for the bottom coating (see Chapter): c) Samples that can show the appearance requirements of the bond layer (see 10.1): 1) Special pre-treatment requirements;
3) Special packaging requirements for plated parts.
Note: The party who does not provide the content specified in, and if necessary, also provide 4.2. The contents specified in the standard are not sufficient without the subscripted numbers.
5 Substrate
This standard does not make any requirements for the surface state, appearance or surface roughness of the substrate before electroplating (Appendix D111) 2.1) However, when the surface quality of the substrate is too poor to make the coating meet the requirements of appearance (or? performance requirements), it cannot be considered that the electroplating production quality does not meet the requirements. 6 Sampling
When it is necessary to check whether the tin-lead coating meets the requirements specified in Chapter 10 of this standard: the sampling method specified in (B/T12609) shall be used for sampling, and the acceptance level shall be agreed upon by both parties. 7 Classification
7.1 Use condition number
The parts are classified according to the following use environment and the use condition number is used to indicate the severity of the use conditions: 4 Special harsh products - such as those used in harsh corrosion conditions (see Appendix D+DI): 3 Severe - For use in typical temperature conditions outdoors, 2
such as for use in slightly condensing conditions indoors; 1 Light
Slight - For use in dry atmosphere conditions indoors, in this environment, soldering performance is the main requirement. Note
1 See 1.2. This gives a guide to the relationship between the application condition code and the minimum thickness. 2 When specifying the application condition code or coating grade code, it should be noted that tin-lead alloys are easily damaged in an environment with abrasives or certain organic volatile condensates (see Appendix
7.2 Coating grade code
The coating grade code is composed of four parts, and the first two parts should be separated by a short slash. For example, a/ved
represents the chemical symbol of the base metal (or the main component of the alloy base); H: a
h - indicates that the bottom coating will be (or alloy The chemical symbol of the main component of the bottom coating is followed by a number indicating the minimum thickness of the bottom coating, in units of 2 ml. If there is no bottom coating, it can be omitted (see 1.2d)): Indicates the coating composition and method with the chemical symbol S followed by the mass fraction of tin in the coating, followed by a short dash and the academic symbol Pb, and then a number indicating the minimum thickness of the tin-lead coating, in units of mil. Indicates the surface finishing state of the coating, the symbol m is matte coating, b is bright coating, and f is hot-melt coating. For example: Fe/NiSnG0-Fh10
This classification indicates that the base metal is steel, the bottom coating is a nickel coating of at least 5 mm thick, the nominal content of the nickel coating is 50% (mass ratio), at least 10 mm thick, and is treated with hot melt: 8 Heat treatment of steel
8.1 Stress relief before electroplating||tt ||Deeply cold-deformed and hardened parts should be heat-treated at 190~220℃ for 1h before electroplating. To eliminate stress, some steels that have been carburized, flame-hardened or high-frequency induction quenched and then ground will be damaged by the above conditions. Instead, a lower stress elimination temperature should be used, such as 130-150℃, and the treatment time should be not less than 5h. 8.2 Elimination of oxygen embrittlement after electroplating
Due to the slow diffusion of the structure through the plating room and the melting of the coating at the temperature required for hydrogen removal treatment, it is not suitable to perform heat treatment to eliminate hydrogen embrittlement.
9 Requirements for the bottom layer
For any of the following reasons, it is necessary to electroplate a bottom layer on some base materials: a) to prevent diffusion (see Appendix D2.2 and 2.3); b) to maintain welding performance (see Appendix D2.2, 2.3 and FD2.4) CB/T 174611998
c) Ensure bonding strength (see Appendix 1) [2.4 and [2.5) d) Improve corrosion resistance.
When selecting the bottom plating or bottom plating system, care should be taken that it does not bring about undesirable properties. For example, hydrogen embrittlement of the base material or the parts should be avoided.
If the base material is a zinc-containing copper alloy and welding performance is required, in addition to the specified tin-bond alloy bond layer (see 10.2>), the strip should have a lock or copper bottom plating with a minimum local thickness of 2.51μm. This bottom plating is also necessary to maintain good appearance and joint strength <see Appendix [1) 2.3.
If a base coating is specified, its properties (see Appendix D) and minimum local thickness (see 10.2) shall be specified by the purchaser. The thickness of a single base coating or multiple base coatings shall be measured by the appropriate force method specified in Appendix B (Appendix to the Standard). 10 Requirements for coatings
10.1 Appearance
When inspected visually, there shall be no visible defects such as blisters, pinholes, roughness, cracks or localized delamination on the main surface of the plated part, and there shall be no stains or discoloration.
The purchaser shall specify the acceptable contact marks to be avoided by optical method and the defects allowed on non-main surfaces. The surface of the workpiece after electroplating shall be clean, undamaged, uniform and free of nodules. No finger-wetting area shall appear at the fusion point. The mesh pattern that may appear on the surface shall not be considered unqualified.
When necessary, the purchaser shall provide or approve samples that can show the appearance requirements of the coating. 10.2 Thickness
The tin-lead coating is classified by thickness and the minimum thickness value corresponding to each use condition number (see.1) is specified in Table 1 (see Appendix 1). D8.2)
Coating thickness
Substrate material
Use condition number
(Partial damage
Sn.c.-Pbls
Sr.r*Ph $
Minimum thickness
: The requirements for the base layer on the copper alloy base material containing copper components are shown in Chapter 9; 2 See Appendix T) "General.4 and 1>2.5 for certain base materials with coatings; 3 The following are the nominal thickness of the key members:
Other benzene materials"
(Partial) classification number
Sur'i.-Pb12
Snzt.-Pb 5
Minimum thickness
On the basic measuring surface of the main surface, use the appropriate method given in Appendix B to measure the thickness of any part that can be touched by a 2mm diameter ball. The minimum thickness of the coating should meet the requirements specified in Chapter 1. In the case where the main surface of the workpiece is larger than 100mm, the minimum thickness in Table 10 should be regarded as the minimum local thickness. 1. In the case of a main surface area of less than 1umm, the minimum thickness in the table should be the minimum average thickness. For printed circuit boards with plated through holes, the minimum coating thickness requirement is not only applicable to any position on the main surface that can be touched by a 20mm diameter ball, but also applies to the surface inside the through hole (see Appendix B0.2, 5). The degree of hot melt coating is applicable to the bonded layer before hot baking (see Appendix 1) T13.2, I and Appendix B). When there is a dispute in the thickness measurement, the arbitration method specified in Appendix B0.2 should be used. 10.3 Composition
GB/T 17461-199E
This standard is based on coatings with a tin content of 50% to 70% (mass ratio). The nominal tin content should be indicated in the grade number, and the composition tolerance should be indicated in the information provided to the electroplating party (see Note). Appendix A (Standard Appendix) gives the analysis method of tin-lead coating, which should be used in case of dispute. Note: Appendix D gives the application guide of its component alloys. 10.4 Bonding strength
If the purchaser specifies the test of bonding strength, the test shall be carried out by one of the methods described in Appendix C (Standard Appendix). The coating shall not show any signs of separation from the pad body.
10.5 Porosity
If the purchaser specifies the determination of porosity, the coating with a minimum thickness of 10 μⅡ or greater than 10 Ⅱ shall be subjected to one of the following tests, and the number of test cycles shall be agreed upon by the supply and demand parties: a) Ferrous substrates shall be tested in accordance with GB/T 10125; b) Non-ferrous substrates shall be tested in accordance with GBT 9789. For both of the above cases, when the coating after the test is observed with a 3x magnifying glass, there shall be no signs of substrate corrosion (see Appendix [D1)
10.6 Welding performance (see Appendix D 1D2)
10.6.1 General materials and parts
If it is necessary to specify the test of welding performance, the welding performance test shall be carried out in accordance with the Ta test method 1 in GB/T2423.28-1982, using inactive flux.
If there is a requirement for accelerated aging before the test, the aging procedure shall be specified by the purchaser. 10.6.2 Printed circuit boards
If the purchaser specifies testing of soldering performance, the coating of printed circuit boards that comply with this standard shall be in accordance with GB/T2423.28-1982 Tc test for welding performance test,
If there is a requirement for accelerated aging before the test, the aging procedure should be specified by the purchaser. A General requirements
GB/T17461-1998
Appendix A
(Appendix to the standard)
Coating analysis
This method is not suitable for electroplated assemblies. It is difficult to ensure that the coating on the substrate is completely removed. Note: For the routine determination of the coating composition of electroplated assemblies, the 9-ray backscattering method is more appropriate. If arbitration analysis of the coating composition is required, it is necessary to electroplate a special sample under the process conditions that are different from those of the workpiece to be processed, and determine the tin content of this coating according to the method in 83. 12 Preparation of special specimens
A2.1 Hanging plating specimen
A 25~30mm tin-lead gold plating layer is applied on an austenitic stainless steel sheet of about 10mttm×80t1m×0.5mm. The coating should be easily scraped and peeled off. Specimens that cannot be peeled off should be filled and re-prepared. 42.2 Roller plating specimen
A2.2.1 Preparation of stripping solution: Add 50ml of 6% (mass ratio) hydrogen peroxide solution to 50ⅢL of 40% (mass ratio) boric acid solution. Fresh stripping solution should be prepared before use. A2.2.2 Prepare some steel specimens (about 12mm in diameter and 50mm in length) to be plated. A2.2.3 After electroplating, take a certain number of specimens to make sure that the plating mass reaches 0.5 area, weigh them to the nearest 0.01g. Then pour them into 50ml of stripping solution (A2.2.1) to remove the coating, rinse them clean, and Collect the rinse solution in another beaker, dry it and weigh the sample again. Combine the stripping solution and the rinse solution and determine their content according to the method in A3. A3
Determination
A3.1 Principle
Reducing tin to divalent tin and determining it by iodine ion method. A3.2 Range
Containing tin 10%-90% (mass ratio).
The allowable error of the tin determination result should be +0.5% (mass ratio). A3.3 Reagents
During the analysis process, only analytical reagents and fresh distilled water, or deionized water after boiling and cooling can be used. A3.3.1 Hot acid ±=1. 16--1.18g/mL.A3.3.2 Hydrogen peroxide, 6% (mass ratio) solution. A3.3.3 Sodium bicarbonate, saturated solution,
A3.3.4 Reduced iron powder, to reduction, light pot, 43.3.5 Starch indicator. 1!g/1, solution. Use 1g soluble starch and water to make a slurry, stir and add into 100tr boiling water, cool and set aside, 3.3.6 Potassium iodate standard solution, for alloys containing more than 25% (mass ratio) of tin. First dry potassium iodate at 105℃T, then dissolve 6.01g of dried potassium iodate in 400mL water containing 1B sodium hydroxide and 30% potassium iodide, and dilute to the scale in a 1000mL volumetric flask (see A3.8). 1mL of this solution is equivalent to 0.01n pot,
A3.4 Apparatus
GB/T 17461—1998
All volumetric glassware used must meet the Class A accuracy of the corresponding national standards, a 750mL conical flask with a rubber stopper, connected to an appropriate device for generating and maintaining an inert atmosphere, such as a Geiger funnel filled with saturated sodium bicarbonate solution or a double-ball safety funnel of similar principle. Inert protective gas (nitrogen, ammonia or carbon dioxide) in a cylinder with a pressure reducing valve and pipeline can also be used. A3.5 Preparation of test solution
A3. 5.1 Rack-plated sample
Weigh 0.5-0.8g of the analytical sample, accurate to 0.0018, and transfer it to a 750mL conical flask. Add 73ml of pad acid (A3.3.1) and heat it to dissolve it. At the same time, add a few drops of hydrogen peroxide solution (A3.3.2) intermittently to promote its dissolution. A3.5-2 Rolling key sample
Quantitatively transfer the stripping solution to a 750mL conical flask. And add 60ml of hydrochloric acid (A3.3.1). A3.6 Step
Add enough water to the test solution (A3.5) to make the solution volume 250mL, add 0.5 reduced iron powder (A3.3.4), and slowly boil until dissolved.
Use a rubber stopper with a Geiger funnel or a double ball cap to tighten the conical flask, add saturated sodium bicarbonate solution (A3.3.3) into the funnel, heat the solution to boiling, and continue boiling for 10 minutes. Move the flask to the radiator and cool it below 20°C. During the cooling process, pay attention to replenish saturated bicarbonate solution (A3.3.3) at any time to prevent air from being sucked into the bottle. Remove the rubber case and funnel and quickly add 2-3 ml starch solution (A3.3.5). Titrate with iodic acid standard solution (A3.3.6) until the light blue color remains unchanged.
Use the same amount of reagents, but do not use the test solution, and follow the same steps to conduct a one-time empty test. Proof: You can also use the method of passing inert gas. For the specific connection method, see GB/T10571.1--108. After adding the test solution (A3.b), water and reduced iron powder (43.3.4) into the flask, plug the rubber stopper, pass an appropriate amount of inert gas, heat the solution to boiling, and keep boiling for more than 30 minutes: while maintaining the inert gas, move the flask to the radiator. Cool to below 20 (, remove the rubber stopper, and quickly add about 20ml of saturated sodium ferric oxide solution (A3.3.3). Use 2~31:1 of starch solution A3.3.=, and titrate with potassium iodate standard solution (A3.3.6) until the light blue color remains unchanged. A3.7 The result indicates the tin content of the lead layer. It is expressed as mass percentage, and its calculation formula is as follows: c: -Vexm x 100
Wherein: V: Volume of potassium iodate standard solution used to titrate the white solution, mL; V, Volume of potassium iodate standard solution used to titrate the test solution, mL: Mass basis of the sample taken
I——1mi. Mass of tin equivalent to potassium iodate standard solution. A3.8 Explanation
Usually, for the accuracy required by this standard, the calibration of potassium iodate standard solution can be ignored: If the solution needs to be calibrated, weigh about 0.4g of casting powder with a purity of 99.9% (mass ratio) and weigh it to an accuracy of 0.001. Prepare the unit according to the method of rack plating sample (A3.5.1). Parallel determination.
B0-1 Conventional method
GB/T 17461—1998
Appendix B
(Standard Appendix)
Measurement of Friction of Coatings
As long as the specimens specified in the methods of this appendix are used correctly, all the methods given in this appendix can be considered to have sufficient accuracy. Taking into account factors such as coating thickness, part shape, part size, coating composition and base material, the selected conventional test method should be the method that can produce the most reliable results expected.
In individual cases, other methods that have been proven to be equivalent to or better than the test methods given in this appendix may also be used. BO.2 Arbitration Method
B0. 2. 1 General requirements
In case of dispute, the arbitration method shall be selected according to the specific circumstances in B0.2.2 to B0.2.6. When using the coulometric method and chemical stripping method, the method given in Appendix A shall also be used to determine the alloy composition, and the calculation formula given in B2.5 shall be used to obtain a more accurate thickness value. However, the thickness value calculated by the density of the ammonium layer may still be smaller than the actual thickness value. BO.2.2 Flat thickness greater than 9 μm
Use the microscope method specified in R1.1.
B0.2.3 Local thickness is less than 9um
If the coating surface is flat enough and the electrolyte does not leak from the electrolytic probe, the coulometric method specified in 1.2 shall be used for determination; otherwise, the microscope method specified in B1.1 shall be used for determination.
Note: When the bottom bond layer is measured by the coulometric method, the tin-lead alloy chain layer shall be removed first, and the short-lead alloy coating shall be removed by the coulometry method, or the stripping force method used for analyzing the sample in A2 shall be used.
B0.2.4 The average thickness of the copper, nickel or steel tin-lead intermetallic plating layer shall be determined by the chemical stripping method specified in B2.
B0.2-5 The average thickness of the bottom coating or the average thickness of the tin-lead alloy bond layer on other substrates or bottom coatings other than copper, nickel and steel. If the coating surface is smooth enough and the electrolyte does not leak from the electrolytic probe, the coulometric method specified in 1 and 2 shall be used; otherwise, the microscope method specified in B.1 shall be used, and the microscopic section shall pass through the center of the sample, and at least 5 points of equal distance shall be measured along the microscopic section. BO.2.6 The thickness of the tin-lead alloy bond layer in the printed stripping pedal shall be measured by B1.1 Specified microscope method: The microscopic section should be parallel to the axis of the hole and perpendicular to the surface of the base coating or bottom layer to be measured (see GB/T 6462).
B1 Local coulometric measurement
B1.1 Microscopic method
Use the method specified in B/T6462: This method includes the bottom protection procedure, that is, the copper protection with a thickness of not less than 101m1 is used.
The accuracy tolerance of this method is 0.8μm. Or when the thickness is greater than 25μm, the accuracy tolerance is 10% of the thickness. B1-2 Coulometric method
Use the method specified in G/T4955. This method generally has an accuracy of less than 10%. B1.3β-ray backscattering method
Use the method specified in GB/T5931. This method requires the instrument and operation accuracy to be able to measure the coating thickness within 10% of its true value; this accuracy depends on the unit area mass basis of the coating, the atomic number of the base metal and the change of the alloy content. .4X-ray spectrometry
CB/T 17461--1998
Use the method specified in GB/T16921. This method requires the instrument and operation accuracy to be able to measure the coating thickness within 10% of its true value.
B2 Measurement of average thickness
B2.1 Principle
Wash and weigh a suitable plated sample with a known surface area (if the sample is small, more samples can be taken), remove the coating by chemical dissolution method, and weigh it again.
This method is generally not suitable for small workpieces or coatings on certain metals (see D2.5 in Appendix D). It is necessary to take the average value of the microscope thickness measurement of several thousand sections as the strict average thickness measurement value (this GB/T12334). B2.2 Reagents
During the analysis process, only analytical reagents and distilled water or deionized water are allowed to be used. B2.2.1 Stripping of coatings on iron-based and nickel-based coatings Dissolve 20% antimony trioxide in 1000ml of cold concentrated acid (g=1.18g/m1). The workpiece stripped with this solution may not be suitable for electroplating again. B2.2.2 Stripping of coatings on copper and copper alloys Add 50mL of 6% (mass ratio) hydrogen peroxide solution to 40% (mass ratio) fluoroboric acid solution and 0mL of 0.5% (mass ratio) fluoroboric acid solution to prepare a stripping solution. A new stripping solution should be prepared before use. B2.3 Specimens
Use one or more specimens, the total surface area of which should be sufficient to obtain a weight loss of not less than 0.1, and the surface area should be measurable to an accuracy of 2%. Use appropriate organic solvents or vapor degreasing to remove all dirt on the specimens. R2.4 Procedure
B2.4.1 Plating on iron substrate and nickel base coating Weigh the cleaned specimen (B2.3) to an accuracy of 0.001 and immerse it in the stripping solution (B2.2.1). After the evaporation stops, keep it for another 2 minutes; remove the specimen from the solution, clean it with running water, scrape off the dirt, dry it, and weigh it after cooling to an accuracy of 0.001. B2.4.2 Copper and alloy 1 bond layer
Weigh the electro-cleaned specimen (B2.3) to an accuracy of 0.001, immerse it in the stripping solution (B2.2.2), and remove it immediately after the coating is completely dissolved. Rinse thoroughly with running water, dry and cool, weigh to the nearest 0.00? g: B2.5 Result Expression
B2.5.1 Average thickness of the coating with a nominal lead content of 60% (mass ratio), unit m, is calculated according to the following formula: (m2 - m2)
×117400
Wu: m——-mass of the sample before stripping; m2——mass of the sample after stripping + Service:
A----surface area of the sample, nm
117400----coefficient obtained based on the alloy ratio of 60/40 and the density of 8.52g/cm* of tin-lead alloy. B2.5.2 Average density of the coating with other alloy components, unit μm, is calculated according to the following formula: (m2) × 10
In: m1---mass of the sample before stripping + name: Mass of the sample after plating + name:
A——Surface area of the sample. mm\
Y—Density of the coating of other components, g/cm GB/T 17461: 1998
1000+553c
-Tin content of tin-aluminum coating. Mass fraction. Appendix
(Standard Appendix)
Bonding strength test
C1 Friction test
Use the method specified in (H/T5270) to test on a coating with an area not exceeding 600mm\ on the upper surface; a handle with a length of 1G10mm, a blade with a length of 30~5?mm, a blade with a length of 5~10mm, and a slightly ground scraper is used as a friction tool.
C2 Bending test
Place the sample on an appropriate instrument (or a plastic bag) that can make the sample bend to a radius of 4m, bend the sample through 90, and return it to its original position. Do this three times to check whether the sample coating has No separation phenomenon C3 thermal shock test
Note: This test may have an adverse effect on the mechanical properties of the test piece. Therefore, the sample shall not be used for other tests after the test. Use the method specified in GB/5270.
Appendix D
(Instructions)
Instructions
These instructions draw the user's attention to: \) If certain properties of the tin-lead alloy are not understood, it may lead to incorrect use of this bonding layer: b) The properties and preparation of the substrate;
c) Electroplating practice,
D1 Properties of the coating
Tin-lead coating is a soft and easy to wear coating. The melting point of the eutectic alloy coating composed of 62Sn/38Plb is as low as 183℃. This relatively low melting temperature of the tin-lead alloy can facilitate automatic welding. Under certain outdoor exposure conditions, especially under high humidity conditions, some corrosion may occur in the tin-lead coating. The thicknesses specified in Table 1 are all minimum values. In actual use, the thickness may require a greater than the standard value in Table 1. Under normal indoor exposure, if there is no organic vapor such as phenolic compounds and volatile organic acids, and the coating is not discontinuous and porous, then even-ortho-plating can protect most metals. The porosity of the coating is affected not only by its thickness, but also by factors such as the surface state of the substrate material and the actual electroplating process conditions. When specifying the porosity test (see 10.5), the following factors should be considered. Compared with pure tin coatings, tin-lead alloy coatings within the composition range specified in this standard can better prevent whisker growth or sprocket deformities at sub-zero temperatures.
Coatings that meet this national standard can be thinner or thicker than general hot-dip coatings.3 Specimens
Use one or more specimens, the total surface area of which should be sufficient to obtain a weight loss of not less than 0.1, and the surface area should be measurable to an accuracy of 2%. Use appropriate organic solvents or steam degreasing to remove all dirt on the specimens. R2.4 Procedure
B2.4.1 Plating on iron substrate and nickel base coating Weigh the cleaned specimen (B2.3) to an accuracy of 0.001 and immerse it in the stripping solution (B2.2.1). After the evaporation stops, keep it for another 2 minutes; remove the specimen from the solution, clean it with running water, scrape off the dirt, dry it, and weigh it after cooling to an accuracy of 0.001. B2.4.2 Copper and alloy 1 bond layer
Weigh the electro-cleaned specimen (B2.3) to an accuracy of 0.001, immerse it in the stripping solution (B2.2.2), and remove it immediately after the coating is completely dissolved. Rinse thoroughly with running water, dry and cool, weigh to the nearest 0.00? g: B2.5 Result Expression
B2.5.1 Average thickness of the coating with a nominal lead content of 60% (mass ratio), unit m, is calculated according to the following formula: (m2 - m2)
×117400
Wu: m——-mass of the sample before stripping; m2——mass of the sample after stripping + Service:
A----surface area of the sample, nm
117400----coefficient obtained based on the alloy ratio of 60/40 and the density of 8.52g/cm* of tin-lead alloy. B2.5.2 Average density of the coating with other alloy components, unit μm, is calculated according to the following formula: (m2) × 10
In: m1---mass of the sample before stripping + name: Mass of the sample after plating + name:
A——Surface area of the sample. mm\
Y—Density of the coating of other components, g/cm GB/T 17461: 1998
1000+553c
-Tin content of tin-aluminum coating. Mass fraction. Appendix
(Standard Appendix)
Bonding strength test
C1 Friction test
Use the method specified in (H/T5270) to test on a coating with an area not exceeding 600mm\ on the upper surface; a handle with a length of 1G10mm, a blade with a length of 30~5?mm, a blade with a length of 5~10mm, and a slightly ground scraper is used as a friction tool.
C2 Bending test
Place the sample on an appropriate instrument (or a plastic bag) that can make the sample bend to a radius of 4m, bend the sample through 90, and return it to its original position. Do this three times to check whether the sample coating has No separation phenomenon C3 thermal shock test
Note: This test may have an adverse effect on the mechanical properties of the test piece. Therefore, the sample shall not be used for other tests after the test. Use the method specified in GB/5270.
Appendix D
(Instructions)
Instructions
These instructions draw the user's attention to: \) If certain properties of the tin-lead alloy are not understood, it may lead to incorrect use of this bonding layer: b) The properties and preparation of the substrate;
c) Electroplating practice,
D1 Properties of the coating
Tin-lead coating is a soft and easy to wear coating. The melting point of the eutectic alloy coating composed of 62Sn/38Plb is as low as 183℃. This relatively low melting temperature of the tin-lead alloy can facilitate automatic welding. Under certain outdoor exposure conditions, especially under high humidity conditions, some corrosion may occur in the tin-lead coating. The thicknesses specified in Table 1 are all minimum values. In actual use, the thickness may require a greater than the standard value in Table 1. Under normal indoor exposure, if there is no organic vapor such as phenolic compounds and volatile organic acids, and the coating is not discontinuous and porous, then even-ortho-plating can protect most metals. The porosity of the coating is affected not only by its thickness, but also by factors such as the surface state of the substrate material and the actual electroplating process conditions. When specifying the porosity test (see 10.5), the following factors should be considered. Compared with pure tin coatings, tin-lead alloy coatings within the composition range specified in this standard can better prevent whisker growth or sprocket deformities at sub-zero temperatures.
Coatings that meet this national standard can be thinner or thicker than general hot-dip coatings.3 Specimens
Use one or more specimens, the total surface area of which should be sufficient to obtain a weight loss of not less than 0.1, and the surface area should be measurable to an accuracy of 2%. Use appropriate organic solvents or steam degreasing to remove all dirt on the specimens. R2.4 Procedure
B2.4.1 Plating on iron substrate and nickel base coating Weigh the cleaned specimen (B2.3) to an accuracy of 0.001 and immerse it in the stripping solution (B2.2.1). After the evaporation stops, keep it for another 2 minutes; remove the specimen from the solution, clean it with running water, scrape off the dirt, dry it, and weigh it after cooling to an accuracy of 0.001. B2.4.2 Copper and alloy 1 bond layer
Weigh the electro-cleaned specimen (B2.3) to an accuracy of 0.001, immerse it in the stripping solution (B2.2.2), and remove it immediately after the coating is completely dissolved. Rinse thoroughly with running water, dry and cool, weigh to the nearest 0.00? g: B2.5 Result Expression
B2.5.1 Average thickness of the coating with a nominal lead content of 60% (mass ratio), unit m, is calculated according to the following formula: (m2 - m2)
×117400
Wu: m——-mass of the sample before stripping; m2——mass of the sample after stripping + Service:
A----surface area of the sample, nm
117400----coefficient obtained based on the alloy ratio of 60/40 and the density of 8.52g/cm* of tin-lead alloy. B2.5.2 Average density of the coating with other alloy components, unit μm, is calculated according to the following formula: (m2) × 10
In: m1---mass of the sample before stripping + name: Mass of the sample after plating + name:
A——Surface area of the sample. mm\
Y—Density of the coating of other components, g/cm GB/T 17461: 1998
1000+553c
-Tin content of tin-aluminum coating. Mass fraction. Appendix
(Standard Appendix)
Bonding strength test
C1 Friction test
Use the method specified in (H/T5270) to test on a coating with an area not exceeding 600mm\ on the upper surface; a handle with a length of 1G10mm, a blade with a length of 30~5?mm, a blade with a length of 5~10mm, and a slightly ground scraper is used as a friction tool.
C2 Bending test
Place the sample on an appropriate instrument (or a plastic bag) that can make the sample bend to a radius of 4m, bend the sample through 90, and return it to its original position. Do this three times to check whether the sample coating has No separation phenomenon C3 thermal shock test
Note: This test may have an adverse effect on the mechanical properties of the test piece. Therefore, the sample shall not be used for other tests after the test. Use the method specified in GB/5270.
Appendix D
(Instructions)
Instructions
These instructions draw the user's attention to: \) If certain properties of the tin-lead alloy are not understood, it may lead to incorrect use of this bonding layer: b) The properties and preparation of the substrate;
c) Electroplating practice,
D1 Properties of the coating
Tin-lead coating is a soft and easy to wear coating. The melting point of the eutectic alloy coating composed of 62Sn/38Plb is as low as 183℃. This relatively low melting temperature of the tin-lead alloy can facilitate automatic welding. Under certain outdoor exposure conditions, especially under high humidity conditions, some corrosion may occur in the tin-lead coating. The thicknesses specified in Table 1 are all minimum values. In actual use, the thickness may require a greater than the standard value in Table 1. Under normal indoor exposure, if there is no organic vapor such as phenolic compounds and volatile organic acids, and the coating is not discontinuous and porous, then even-ortho-plating can protect most metals. The porosity of the coating is affected not only by its thickness, but also by factors such as the surface state of the substrate material and the actual electroplating process conditions. When specifying the porosity test (see 10.5), the following factors should be considered. Compared with pure tin coatings, tin-lead alloy coatings within the composition range specified in this standard can better prevent whisker growth or sprocket deformities at sub-zero temperatures.
Coatings that meet this national standard can be thinner or thicker than general hot-dip coatings.
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