Electroless nickel plating is an process that codeposits a nickel-phosphorous alloy without need for an externally applied electrical current. The electroless nickel plating process occurs from a chemical reduction of the nickel ions within the electroless nickel solution onto a metallic substrate rather than deposition of the ions from an applied current. As a result, the electroless nickel deposit is free of many of the problems associated with traditional electrolytic nickel including edge buildup and non-uniform coating. Electroless nickel deposits are extremely uniform, corrosion and erosion resistant and provide excellent lubricity. APT offers loose-piece barrel, rack and vibratory electroless nickel plating on nearly any metallic substrate including nearly any ferrous, cupreous and aluminum alloys as well as many exotic alloys.
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ASTM Fa ASTM B - standard Designation: B — 04 Standard Speci? A number in parentheses indicates the year of last reapproval. A superscript epsilon e indicates an editorial change since the last revision or reapproval. This standard has been approved for use by agencies of the Department of Defense. Scope 1. Because the deposited nickel alloy is a catalyst for the reaction, the process is self-sustaining. The chemical and physical properties of the deposit vary primarily with its phosphorus content and subsequent heat treatment.
The chemical makeup of the plating solution and the use of the solution can affect the porosity and corrosion resistance of the deposit. They are also used for the salvage of worn or mismachined parts. These coatings are used in applications requiring abrasion and wear resistance. These coatings are used in electronic applications providing solderability, bondability, increased electrical conductivity, and resistance to strong alkali solutions.
They are used on beryllium and titanium parts for low stress properties. Coatings with phosphorus contents greater than This standard does not purport to address all of the safety concerns, if any, associated with its use.
It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Referenced Documents 2. Current edition approved Aug. Published August Originally approved in Last previous edition approved in as B — Terminology 3. Coating Classi? NOTE 1—Due to the precision of some phosphorus analysis methods a deviation of 0.
Rounding of the test results due to the precision of the limits provides for an effective limit of 4. For example, coating with a test result for phosphorus of 9. Applications include requirements for diffusion barrier, undercoat, electrical conductivity and wear and corrosion protection in specialized environments. Typical environments include light-load lubricated wear, indoor corrosion protection to prevent rusting, and for soldering and mild abrasive wear. It is characterized by industrial atmosphere exposure on steel substrates in dry or oiled environments.
Typical environments would include acid solutions, elevated temperature and pressure, hydrogen sul? NOTE 2—The performance of the autocatalytic nickel coating depends to a large extent on the surface? Rough, non uniform surfaces require thicker coatings than smooth surfaces to achieve maximum corrosion resistance and minimum porosity.
Ordering Information 5. NOTE 4—The purchaser should furnish separate test specimens or coupons of the basis metal for test purposes to be plated concurrently with the articles to be plated see 8. Materials and Manufacture 6.
Any such defects on signi? The producer shall not be responsible for coatings defects resulting from surface conditions of the metal, if these conditions have been brought to the attention of the purchaser. An example is leaded steel which may exhibit liquid or solid embrittlement after heat treatment.
Careful selection of the pre and post heat treatments are recommended. The tensile strength of the material shall be supplied by the purchaser. See Supplementary Requirements. See S In this case, the part shall be heat treated as soon as possible.
In all cases, the duration of the heat treatment shall commence from the time at which the whole of each part attains the speci? Table 3 describes the heat treatment for maximum hardness. Avoid rapid heating and cooling of plated parts. Sufficient time must be allowed for large parts to reach oven temperature. NOTE 7—The length of time to reach maximum hardness varies with the phosphorus content of the deposit. High phosphorus deposits may require longer time or a higher temperature, or both.
Individual alloys should be tested for maximum hardness attainable, especially for conditions of lower temperatures and longer times. Do not use gas containing hydrogen with high-strength steel parts. The location of rack or wire marks in the coating shall be agreed upon between the producer and purchaser. The use of a statistical regimen to establish the control limits and frequency of analysis may be employed to ensure quality deposits are produced.
The tensile strength shall be supplied by the purchaser. Guide B contains a list of post treatments, procedures, limitations, and guidelines that are permitted to be used to reduce the effects of hydrogen embrittlement. Requirements 7. Also, discoloration due to heat treatment shall not be cause for rejection unless special heat treatment atmosphere is speci?
After coating and if speci? NOTE 9—The thickness of the coating cannot be controlled in blind or small diameter deep holes or where solution circulation is restricted.
The tests for these quali? The weight percent of phosphorus shall be in the range designated by type classi? For Class 2 coatings, the microhardness shall equal or exceed a minimum of HK or equivalent Vickers see 4. The conversion of Vickers to Knoop using Tables E is not recommended. Sampling 8. Properly performed this will ensure coated products of satisfactory quality and will reduce the amount of acceptance inspection. NOTE 10—Usually, when a collection of coated parts the inspection lot 8.
The inspection lot is then classi? The size of the sample and the criteria of compliance are determined by the application of statistics. The procedure is known as sampling inspection.
Three standards Test Method B , Guide B , and Test Method B contain sampling plans that are designed for the sampling inspection of coatings. Test Method B contains four sampling plans, three for use with tests that are nondestructive and one for use with tests that are destructive. The purchaser and producer may agree on the plan s to be used. If they do not, Test Method B identi? Guide B provides a large number of plans and also gives guidance on the selection of a plan.
When Guide B is speci? Test Method B can be used only for coating requirements that have a numerical limit, such as coating thickness. The last must yield a numerical value and certain statistical requirements must be met. Test Method B contains several plans and also gives instructions for calculating plans to meet special needs.
An inspection lot shall be de? NOTE 11—The autocatalytic nickel process is dynamic and a daily sampling is recommended. For coatings requiring alloy analysis and corrosion testing weekly sampling should be considered as an option. Test Methods 9. NOTE 12—Inductively coupled plasma techniques can determine the alloy to within 0.
The following analysis wavelength lines have been used with minimum interference to determine the alloy. Ni NOTE 14—To protect the edges, electroplate the specimens with a minimum of 5? The instrument shall be calibrated with deposits plated in the same solution under the same conditions on magnetic steel. The instrument must be calibrated with standards having the same composition as the coating.
Make sure that the surfaces measured are smooth, clean, and dry. The surface of the coating shall be cleaned prior to testing see Note NOTE 16—This method is only recommended for deposits in the as-plated condition. The phosphorus content of the coating must be known to calculate the thickness of the deposit. Matrix effect due to the distribution of phosphorus in layers of the coating also effect the measurement accuracy and require that calibration standards be made under the same conditions as the production process.
When required, one of the following tests can be used on the plated part or specimen. After rinsing and air drying, examine the part for blue spots, which form at pore sites. Apply heat to the beaker at such a rate that the water begins to boil in not less than 15 min, nor more than 20 min after the initial application of heat. Continue to boil the water for 30 min.
Then remove the part, air dry, and examine for rust spots, which indicate pores.
MIL-C-26074 E Electroless Nickel Plating
Active view current version of standard. Other Historical Standards. More B Because the deposited nickel alloy is a catalyst for the reaction, the process is self-sustaining. The chemical and physical properties of the deposit vary primarily with its phosphorus content and subsequent heat treatment. The chemical makeup of the plating solution and the use of the solution can affect the porosity and corrosion resistance of the deposit.
Electroless Nickel Coating
There are four 4 different classes and three 3 different grades of electroless nickel plating used throughout the industry to meet different specifications. The class of an electroless nickel plating refers to the post-plating heat treatment process that is used; the grade of an electroless nickel plating refers to its thickness. Heat treatment after electroless nickel plating provides evidence of proper adhesion and improves the crystalline structure of the amorphous deposit for greater hardness. Six heat-treat classes are available.
The thickness of the coating can vary from 2 micron up to 30 micron. The thickness of the coating and the treatments is displayed in the tables below:. In cases where there is demand for different qualities than the above, a different type of electroless nickel with a lower or a higher quantity of phosphorus can be ordered. The electroless nickel coating is not poisonous and authorized by the American Health Organization as the best coating for cutlery. The Electroless nickel processes in our plant are medium phosphorus electroless nickel and high phosphorus electroless nickel, where the main characters of this processes are:. Go to main content. Previous Next.
Electroless Nickel Plating
ASTM Fa ASTM B - standard Designation: B — 04 Standard Speci? A number in parentheses indicates the year of last reapproval. A superscript epsilon e indicates an editorial change since the last revision or reapproval. This standard has been approved for use by agencies of the Department of Defense. Scope 1.