Nickel electroplating

Surface coating

The company is the world’s best barrel nickel plating machine supplier. We are your one-stop shop for all needs. Our staff are highly-specialized and will help you find the product you need.

Nickel electroplating is a technique of electroplating a thin layer of nickel onto a metal object. The nickel layer can be decorative, provide corrosion resistance, wear resistance, or used to build up worn or undersized parts for salvage purposes.[1][2]

Overview

[

edit

]

Nickel electroplating is a process of depositing nickel onto a metal part. Parts to be plated must be clean and free of dirt, corrosion, and defects before plating can begin.[3] To clean and protect the part during the plating process, a combination of heat treating, cleaning, masking, pickling, and etching may be used.[1] Once the piece has been prepared it is immersed into an electrolyte solution and is used as the cathode. The nickel anode is dissolved into the electrolyte to form nickel ions (Ni2+). Just like in other electrodeposition processes, the ions travel through the solution and deposit on the cathode.[5]

The anode efficiency for nickel dissolution is close to 100%, unless due to problems with the process anode becomes passive (and its efficiency thus 0). The cathode efficiency depends on the process and varies between 90 and 97%. Due to this mismatch, during the plating the nickel concentration in the solution and the pH will slowly rise. The process takes minutes to hours depending on the current density and the intended thickness of the plating.

History

[

edit

]

Nickel electroplating was developed in the first half of the 19th century, with notable experiments made by Golding Bird (1837) and nickel nitrate patent by Joseph Shore (1840). The first practical recipe, an aqueous solution of nickel and ammonium sulfates, was invented by Böttger in 1843 and was in use for 70 years. The commercial success was achieved by Isaac Adams Jr., whose patent for a solution of nickel ammonium sulfate, while similar to Böttger's, had neutral pH that made the process easier to control. Adams enjoyed a near-monopoly in nickel plating from 1869 to 1886, when the consumption of nickel for plating reached 135 tons. In the US, Remington tried to use the nickel ammonium chloride solution (1868), in the process establishing the anode construction in the form of a platinum basket filled with nickel pieces, Edward Weston initiated the use of boric acid (patent issued in 1878), Bancroft figured out the role of chlorides in dissolving the anode (1906). Finally, Oliver P. Watts in 1916 established the Watts bath, variations of which are still widely used for decorative plating, with sulfamate solutions challenging it in the engineering applications.

Types and chemistry

[

edit

]

Watts baths

[

edit

]

A Watts bath, named for its inventor Oliver Patterson Watts, is an aqueous electrolyte solution for plating nickel from a nickel anode. It can deposit both bright and semi-bright nickel. Bright nickel is typically used for decorative purposes and corrosion protection. Semi-bright deposits are used for engineering applications where high corrosion resistance, ductility or electrical conductivity is important, and a high luster is not required.[2][11][12]

Bath composition

[

edit

]

Chemical Name Formula Bright[11] Semi-bright[11] Metric US Metric US Nickel sulfate NiSO4·6H2O 150–300 g/L 20–40 oz/gal 225–300 g/L 30–40 oz/gal Nickel chloride NiCl2·6H2O 60–150 g/L 8–20 oz/gal 30–45 g/L 4–6 oz/gal Boric acid H3BO3 37–52 g/L 5–7 oz/gal 37–52 g/L 5–7 oz/gal

Operating conditions

[

edit

]

• Temperature: 40-65 °C
• Cathode current density: 2-10 A/dm2
• pH: 4.5-5

Brighteners

[

edit

]

• Carrier brighteners (e.g. paratoluene sulfonamide, benzene sulphonic acid) in concentration 0.75-23 g/L. Carrier brighteners contain sulfur providing uniform fine grain structure of the nickel plating.[5]
• Levelers, second class brighteners (e.g. allyl sulfonic acid, formaldehyde chloral hydrate) in concentration 0.0045-0.15 g/L produce (in combination with carrier brighteners) brilliant deposit.[5]
• Auxiliary brighteners (e.g. sodium allyl sulfonate, pyridinium propyl sulfonate) in concentration 0.075-3.8 g/L.[5]
• Inorganic brighteners (e.g. cobalt, zinc) in concentration 0.075-3.8 g/L. Inorganic brighteners impart additional lustre to the coating.[5]

Type of the added brighteners and their concentrations determine the deposit appearance: brilliant, bright, semi-bright, satin.

Nickel sulfamate

[

edit

]

Sulfamate nickel plating is used for many engineering applications. It is deposited for dimensional corrections, abrasion and wear resistance, high efficiency coating and corrosion protection. It is also used as an undercoat for chromium.[2][13]

Bath composition

[

edit

]

Chemical name Formula Bath concentration[5] Metric US Nickel sulfamate Ni(SO3NH2)2 300-450 g/L 40–60 oz/gal Nickel chloride NiCl2·6H2O 0-30 g/L 0–4 oz/gal Boric acid H3BO3 30-45 g/L 4–6 oz/gal

Operating conditions

[

edit

]

All-chloride solutions allow for the deposition of thick nickel coatings. They do this because they run at low voltages. However, the deposition has high internal stresses.[2][5]

Chemical name Formula Bath concentration[5] Nickel chloride NiCl2·6H2O 30–40 oz/gal Boric acid H3BO3 4–4.7 oz/gal

A sulfate-chloride bath operates at lower voltages than a Watts bath and provide a higher rate of deposition. Although internal stresses are higher than the Watts bath, they are lower than that of an all-chloride bath.[2][5]

Chemical name Formula Bath concentration[5] Nickel sulfate NiSO4·6H2O 20–30 oz/gal Nickel chloride NiCl2·6H2O 20–30 oz/gal Boric acid H3BO3 4–6 oz/gal

An all-sulfate solution is used for electro-depositing nickel where the anodes are insoluble. For example, plating the insides of steel pipes and fittings may require an insoluble anode.[2][12]

Chemical name Formula Bath concentration[5] Nickel sulfate NiSO4·6H2O 30–53 oz/gal Boric acid H3BO3 4–6 oz/gal

Hard nickel

[

If you want to learn more, please visit our website Hot Dip Galvanizing Machine For Metal Product.

Featured content:
Industrial Air Compressors
6 Essential Safety Gears and Tools for Laser Cutting
Homemade Dog Food vs Store-Bought: Pros & Cons

edit

]

A hard nickel solution is used when a high tensile strength and hardness deposit is required.[2][5]

Chemical name Formula Bath concentration[5] Metric Nickel sulfate NiSO4·6H2O 24 oz/gal 179.7g/L Ammonium chloride NH4Cl 3.3 oz/gal 24.7 g/L Boric acid H3BO3 4 oz/gal 29.96 g/L

Black nickel

[

edit

]

"Black nickel" is a dark coating that consists primarily of nickel sulfide and metallic zinc and nickel.[14] It is typically plated on brass, bronze, or steel in order to produce a non-reflective surface.[15] This type of plating is used for decorative and military purposes and does not offer much protection.[1][2][15]

Chemical name Formula Bath concentration[15] Nickel ammonium sulfate NiSO4·(NH4)2SO4·6H2O 8 oz/gal Zinc sulfate ZnSO4 1.0 oz/gal Sodium thiocyanate NaCNS 2 oz/gal

Applications

[

edit

]

Decorative coating

[

edit

]

Decorative bright nickel is used in a wide range of applications. It offers a high luster finish, corrosion protection, and wear resistance. In the automotive industry bright nickel can be found on bumpers, rims, exhaust pipes and trim. It is also used for bright work on bicycles and motorcycles. Other applications include hand tools and household items such as lighting and plumbing fixtures, wire racks, firearms, and appliances.[11]

Modern coating technology makes deposited nickel to appear mirror-bright with no need of polishing, multi-layer applications are frequently used to improve the corrosion resistance of coated steel, zinc, copper, aluminum, and other metals. In order to prevent tarnishing, decorative electroplated nickel is typically coated with a thin layer of chromium.

Engineering applications

[

edit

]

Engineering nickel is used where brightness is not desired. Non decorative applications provide wear and corrosion protection as well as low-stress buildups for dimensional recovery,[11][16] nickel or its nickel alloys usually having matte or dull finish. The method can be used for making nanocomposite wear resistance coatings.[17][18]

Nickel electroforming has nickel plating applied for fabrication of nickel products. For example, nickel can be deposited onto a mandrel and then lifted off the latter, creating a nickel-only part.

See also

[

edit

]

References

[

edit

]

Sources

[

edit

]

Nickel electroplating is one of the oldest coating and plating processes known and offers several benefits to a broad variety of industries. Since it is an affordable option, it has become a popular due to its low cost and appealing benefits. Industries from aviation to telecommunications benefit from nickel electroplating.

History of Electroplating

Electroplating was invented by an Italian chemist named, Luigi Brugnatelli, in 1805. He was considered to be one of "The Fathers of Science" and performed electrodeposition of gold using the Voltaic Pile, which was discovered by his colleague Aliessandro Volta in 1800. His work with electroplating was published in the Belgian Journal of Physics and Chemistry. However, Luigi Brugnatelli's work was rebuffed by Napoleon Bonaparte, the dictator, causing him to suppress any further publications.

Nearly 40 years later, John Wright of Birmingham, England discovered that potassium cyanide was a suitable electrolyte for gold and silver electroplating. John Wright was the first one who showed that electroplated items could be immersed in a tank of silver held in a solution with an electric current passing through.

Henry and George Richard Elkington patented the rights to John Wright's electroplating process in 1840. While there were several other inventors vying for these rights, the Elkington brothers were the first to possess the patent. They held a monopoly on electroplating for many years thanks to the patent for an inexpensive method to electroplate.

Nickel electroplating can be used from industrial parts to telecommunications. The benefits and uses make it an appealing option for a lot of industries.

Nickel electroplating is a process of applying a nickel coating onto a metal surface by means of electrolytic deposition. In order for parts to be plated, they must be clean and free of dirt, corrosion, and defects so the plating can be applied. In order to prepare a product, it must be cleaned and protected before the plating process. To prepare a part, a combination of cleaning, masking, heat treating, pickling and etching are commonly used.

Preparing A Product for Electroplating:

• Masking is where a specific area of a surface can be covered to ensure that it is not exposed during the anodizing or electroplating process.
• Heat Treating is a process to soften the metal and improve formability. It makes parts harder to improve the strength.
• Pickling is a treatment that is used to remove impurities like stains, inorganic contaminants, rust of ferrous metals, which could potentially affect the usage of the product. Typically, an acid solution called "pickled liquor" is used to remove the impurities.
• Etching is a process of using strong acid or mordant (dye fixative) to cut into the unprotected parts of a metal surface to create a design in the metal.

After the part has been prepared, it is immersed in an electrolyte solution and is used as the cathode (an electrode from which a conventional current leaves a polarized electrical device). The nickel anode is dissolved into the electrolyte to form nickel ions. These ions move through the solution and deposit on the cathode.

Nickel electroplating requires a nickel strike process for adhesion and then a chromium finish is added to create a higher corrosion resistance and anti-tarnish property to the nickel deposit. A strike layer (or flash layer) adheres to a thin layer of high-quality nickel plating to the base material.

Nickel electroplating baths can deposit both bright and semi-bright nickel. In most instances, bright nickel is used for ornamental or decorative purposes as well as for corrosion protection. Typically, semi-bright deposits are used for engineering applications, where higher corrosion resistance, ductility, and electrical conductivity are necessary.

Nickel Plating Benefits

It is common for nickel plating to be used for a variety of reasons or uses including:

• Corrosion resistance: Nickel plating provides protection from oxidizing and rusting with a coating,which shields the base metal.
• Solder-ability: The plating allows you to solder difficult metals.
• Durability: Mechanical parts and tools often benefit from an increased hardness making them more durable and longer lasting. thicker platings can often make an object magnetic.
• Ornamental purposes: A variety of colors and finishes can give an aesthetically pleasing look to an object. From brushed stainless steel to metallic black, there is a broad range of options available making nickel appealing to lots of industries.

Nickel Plating

Nickel electroplating is an appealing option for all types of industries ranging from aerospace and aviation to automobile and telecommunications due to its versatility. There are also several types of nickel plating, which give it different appearances and durability attributes.

Types of Nickel Electroplating

Bright Nickel Plating-Due to high levelling properties, bright nickel plating hides polishing lines and other imperfections of the surface of a material, which makes it an appealing option. It produces a bright mirror like finish due to its elevated sulfur content and is also has good conductivity. However, it is not as corrosion resistant as other types of nickel plating. It is ideal for car parts like trim work, bumpers, rims, and exhaust pipes.

Electroless Nickel Plating– This process differs from other nickel plating in that it does not use an electric current application process, but rather uses an auto-catalytic reaction. Its even coating and ability to deposit on surfaces which are non-conductive is appealing to many. It is ideal for preventing corrosion and wear for anything needing an increased hardness.

Dull Nickel Plating-Producing this hard wearing dull, matte finish is a very similar process to bright nickel plating process. Dull nickel plating is extremely corrosion resistant and malleable. It is ideal for machine parts and springs since its coating can build thickness and is useful for abrasion and dimensional correction purposes for movement.

Professional companies like Asheville Metal Finishing can assist your business with finding the best option for your products. A professional can help ensure you find the best nickel plating choice as well as determine the most cost effective option for your products. Asheville Metal specializes in bright nickel plating. Since nickel electroplating is a science, you want to make sure you leave it up to a professional to determine the best solution for you.

If you are looking for more details, kindly visit Gold Plating Machine For Sale.