Black nickel electroplating is like black magic! The process transforms a metal part into a good-looking, durable product. As you know, people like more unique and efficient products, so new technologies are arising. Black nickel electroplating is one of the most premium technologies you may have ever seen. This article mainly discusses this technology and its making process.
Moreover, the article also discusses electroless black nickel plating. You will learn the significant differences between black nickel electroplating and electroless. Overall, this guide can help you understand black nickel electroplating better than before. It gives you technical details that you may not find on other websites. So, let’s get started.
What is Black Nickel Electroplating?
Black nickel electroplating is a unique electrochemical process. As the name implies, it deposits a thin layer of black nickel onto a metal substrate. A common question arises: “Why does nickel turn black?” The best answer is that nickel deposit decreases reflectivity.
This technique first immerses the metal item in a black nickel solution. Then, it applies an electric current. When the electrons pass through the cathode or your substrate, they attach nickel ions to combine with it. This way, the nickel ions deposit on the substrate surface, forming a black nickel layer. You can find the detailed manufacturing process in the later sections.
Black nickel electroplating is a premium technology in surface finishing. It generally offers many benefits, one of which is corrosion resistance. Because of its benefits, black electroplating nickel parts are widely used in many industries. In the car industry, you may find many car parts and accessories that are black nickel-plated. Similar applications can be observed in electronics, fashion and jewelry, home décor, and architecture.
Advantages of Black Nickel Electroplating
Black nickel electroplating typically offers many benefits. This premium technology improves the appearance and durability of metal objects. Here are some key benefits of black nickel electroplating.
Aesthetics
One of the main reasons why people prefer black nickel plating is its striking look. The deep, rich black finish adds a premium look to any metal part. People like to use it in fashion, jewelry, and car parts. The smooth and shiny surface creates a sleek and modern look.
Rust Resistance
Black nickel electroplating also resists rust, essential for more rust-prone metal parts. This technique is crucial for metal parts used in marine or exposed to moisture.
Long Life
In addition to rust resistance, black nickel electroplating is good against wear and tear. The process creates a tough surface on every metal part. Overall, objects with nickel plating have a longer lifespan. They generally remain functional and attractive for many years. As a result, you don’t need frequent replacements.
Low Upkeep
The metal parts with black electroplating nickel need a very low upkeep. As you know, they offer corrosion, wear, and tear resistance. Since they have a longer lifespan, they also require low maintenance. You can clean them by simply wiping them with a soft cloth. The low upkeep saves both time and effort.
How Does Black Nickel Electroplating Work?
Black nickel electroplating is practically a simple and quick process. All you need to do is follow the proper instructions. Following these instructions correctly is crucial for several reasons. First, it can achieve the best coat quality. Second, it significantly avoids costly mistakes. Third, it can give you consistent results. Fourth, it eliminates issues like peeling and uneven coating.
Moreover, safety is always crucial here. Wear safety gear, such as gloves and goggles. For your information, correct handling of chemicals and equipment reduces risks. Overall, precise instruction makes the process more efficient.
Step #1 Choosing the Right Material and Technique
Gather all the necessary items for the process correctly. First, select the correct substrate. As you know, black nickel electroplating works on any metal and its alloys. However, common metals are aluminum, steel, brass, copper, and titanium.
You can independently choose any shape but must know the correct surface area. The more surface area there is, the more time it takes to complete the electroplating of black nickel. Next, gather the following tools and equipment for the process. With everything ready, you can complete the task faster and more effectively.
1. A polishing device is optional. If you want an excellent mirror-like finish, you can get this item. It mainly smooths the substrate’s surface.
2. Soap/Degrease Powder can help you clean the substrate thoroughly. When choosing the degrease powder, check the compatibility with the substrate material.
3. Distilled water is mainly necessary for rinsing, which may need to be done several times during the process.
4. You will typically need two separate tanks: a degreasing tank and a black nickel electroplating tank.
5. A plastic spoon is necessary for stirring the black electroplating nickel powder. You can also use other types of spoons, but it’s better to choose non-reactive materials.
6. A small slit of anode plate is a must for the black nickel electroplating process.
7. For the cathode part, you will need a copper pipe. Note that you will place this copper pipe on top of the tank. You can connect your substrate to the copper pipe with a copper wire. You will generally need it for convenience.
8. An agitation pump typically helps keep the plating solution moving. You will need it for uniform nickel coating.
9. Finally, you will need a DC power supply, the heart of the black nickel electroplating.
Step #2 Polishing for Bright Plated Finish
You can polish your substrate for a bright and smooth finish. Polishing typically removes imperfections and ensures that your substrate is clean. You can use various polishing machines to do this, or you could also do manual scrubbing. Either way is acceptable as long as you get a good result. Using the machine typically makes the process faster and more effective.
Step #3 Cleaning the Substrate at an Appropriate Temperature
Once your substrate is ready, prepare the cleaning tank. Fill it with hot water. Remember, the temperature for the process should be 170 degrees Celsius. Now, add an appropriate amount of soap or degreasing powder. Stir it thoroughly to allow these chemicals to dissolve in the water. This mixture will typically help remove oil and contaminants.
You can also use other cleaning methods, such as chemical or ultrasonic cleaning. Concerning chemicals, you can use strong bases or acids to dissolve impurities in this case.
Properly cleaning the substrate ensures better adhesion for electroplating black nickel. Always handle the substrate gently during the cleaning process. Do not use abrasive chemicals or harsh chemicals that might damage your substrate.
Step #4 Rinsing in Distilled Water
Rinsing is typically necessary to remove the cleaning agents. It generally ensures 100% contamination-free.
Rinse the substrate thoroughly. In this case, use distilled water. Note that regular water may leave mineral deposits, which can cause contamination. Eventually, this may affect the plating quality. Therefore, we generally do not recommend regular water.
Step #5 Calculating Total Surface Area and Plating Time
This step is the most crucial part of black electroplating nickel. Based on your requirements, you must calculate the proper electroplating time. FYI: proper electroplating time creates the appropriate thickness for nickel plating.
We will calculate, for example, plating thickness and substrate. You can follow the similar steps to find out yours.
Let’s take a 20 cm x 10 cm substrate. Our desired nickel plating thickness is 15 microns, which is 0.0015 cm. We will use a 5cm x 5cm anode plate. And the other values are generally the same for all situations.
#1 Calculating the Nickel Plating Density and Weight
First, we calculate the density of the nickel plating, which is surface area x nickel plating thickness. The density of the nickel plating = 20cm x 10cm x 0.0015cm = 0.3 cm3.
Second, we calculate the total mass of the nickel. As you know, the density of nickel is 8.9g per cm3 or 58.71g/mol. So, in 0.3cm3, we need 2.67g of nickel. If we convert it into mol, we get 2.67g/58.71 = 0.055mol.
#2 Calculating the Ampere and Voltage for Power Supply
First, we calculate the total ampere needed for our process. To do this, we need the anode plate surface area. For example, a 5cm x 5cm anode plate can give 0.3A/cm2. So, a 25 cm2 can give 0.3 x 25 cm2 = 7.5A or 7.5C/s. Consider the fraction that reduces the nickel. Normally, it is 75%, which gives 5.625A.
Second, we calculate the voltage needed for the black nickel electroplating. Our standard equation is V = IR = 5.625 x 0.4 = 2.25V.
#3 Calculating the Black Nickel Electroplating Time
Calculate the total mole of electrons needed for plating. Typically, a nickel ion needs two electrons. Therefore, the total mole for electroplating is 0.055 x 2 = 0.11 mole.
Finally, total need time (t) = Q/I = 0.11 x 96485.3/6.625 = 1886.82s or 31.45 mins. Note that the charge for every mol is 96485.3C/mol. You know, this value is Faraday’s constant.
So, the ampere you need for the process is 5.625A, the voltage for the DC power supply is 2.25V, and the electroplating time is 31.45s.
Step #6 Setting up Black Nickel Electroplating Solution
First, place the plastic bucket or plating tank in a safe place. Then, add the distilled water. You can decide the size of the bucket and liquid quantity based on the number of parts and plating thickness.
Now, pour the black electroplating nickel powder into the water. Then, stir it gently using the plastic spoon. You could also use a wooden spoon or metal spoon. For pH control, you can use some white vinegar. You don’t typically need pH control for general-purpose black nickel electroplating.
Once your mixture is ready, place the copper pipe on the bracket or plating tank. Now, place the anode plate on one side of the bucket. Ensure the plate is immersed perfectly inside the solution. Attach the substrate to a copper wire and connect it to the copper pipe. Carefully immerse the substrate in the solution.
Take the DC power supply near the bucket. Connect the (-) negative wire with the copper pipe and the (+) positive wire to the anode plate. Set the parameters for voltage 2.25V and ampere 5.625A. Note these parameter values are only for the plate we took as an example. For your part, first calculate the voltage, ampere, and time and then set these parameters accordingly. Check step #5 for more information.
Next, ensure proper agitation for black nickel electroplating. Agitation ensures consistent plating on your metal part. Place the agitation pump in any corner inside the bucket.
Step #7 Black Nickel Electroplating
Once everything is ready, start the power supply. You will notice bubbles coming up, which means your process has already begun. Now, wait for 31.45 minutes for our example parts. The time may vary based on different surface area and anode plating size.
Continuously monitor the process. You will observe that your metal part is gradually getting black color. After the calculated time, you will see the magic! Your metal part has completely turned into a black, perfectly finished part.
If you still see some places that didn’t get the nickel plating, you can immerse the part again and wait a few minutes. But it’s not a good idea because the delayed ampere lowers the quality of the plating.
Step #8 Rinsing in Distilled Water
Once again, you will need to rinse the metal part. Immerse the plated item in distilled water. Then, agitate it thoroughly to remove all chemicals. Repeat the rinse to ensure every bit of residue is completely gone. Now, pat the item dry very carefully with a clean and soft cloth.
Step #9 Additional Surface Protection if Necessary
If necessary, you can also provide some additional protection. In this case, you can think of environmental factors and intended use. You can apply sealants or lacquers if necessary. Follow the instructions for each additional process.
What metals can be electroplated with nickel?
Black nickel electroplating is a versatile process. This means that you can use this technique on any conductive metal. You can choose the metals based on your project needs and give them an astonishing premium look. The following table details the metals that can be electroplated with black nickel. You can also find some examples there.
|
Metal |
Description |
Example Products |
|
Steel |
Good for strength and durability |
Car parts, tools, and fasteners |
|
Copper |
Excellent electrical and thermal conductivity |
Connectors, circuit boards, plumbing fixtures |
|
Brass |
An alloy of copper and zinc, known for decorative items |
Musical instruments, decorative hardware |
|
Aluminum |
Lightweight and corrosion resistant |
Bicycle frames, aircraft parts, packaging materials |
|
Zinc |
It can form a strong bond with nickel, mainly used for corrosion resistance. |
Hardware, bolts, nuts, die-cast parts |
|
Iron |
Strong and durable but more prone to rust |
Machinery parts, construction materials |
Electroless Nickel Plating vs Electrolytic Nickel Plating: What’s The Difference?
Both electroless and electroplating black nickel processes are popular in modern industries. Each technique has its unique benefits and limitations. In this section, you will know some of their significant differences. In the future, this comparison can help you choose the correct method for your project.
Electroless Plating vs Electroplating Black Nickel: Process Type
Electroless black nickel plating mainly depends on a chemical reduction reaction. It doesn’t need an electrical current to help deposit nickel ions. Instead, it uses a catalyst or reducing agent. Because of this, electroless plating is also known as auto-catalytic plating.
On the other hand, electroplating uses electric current to deposit nickel. In the previous section, we learned how black nickel electroplating works. When the current passes through the cell, the nickel ions gradually gather at the cathode side and create a deposit on the metal part. This is how black nickel electroplating works on metals.
Electroplating vs Electroless Plating: Substrate Type
Electroless black nickel plating works on both conductive and non-conductive substrates, which can be metals or non-metals. However, non-conductive metals need pre-treatment for the job.
In contrast, electroplating black nickel only works on conductive materials, primarily metals. Typical metals used in this case are steel, copper, brass, and aluminum. In electroplating, these metals do not need any pre-treatment. However, you must clean it and polish it if necessary.
Electroless vs Electrolytic Nickel Plating: Thickness Control
Electroless black nickel plating gives you uniform thickness. Controlling the nickel plating thickness is limited.
On the other hand, electroplating black nickel is the best here. You can control the thickness of the nickel plating in anything you want. In step #5, you learned how to calculate the plating time to get the desired deposit thickness. Based on your result, you can set the voltage and ampere of the power supply and wait for the calculated time. In the end, you can get the desired thickness.
Electroless vs Electroplating Black Nickel: Energy Cost
Electroless black nickel plating doesn’t need any external power source. It entirely depends on the chemical reaction. However, the process requires an additional catalyst for the chemical reaction, increasing the overall cost.
On the other hand, black nickel electroplating needs a power supply to run the process. As you know, you will need 0.3A/cm2 of electric current for the process. So, when you calculate the whole process, you will find a significant energy cost.
Electroless Nickel Plating vs Electrolytic Nickel Plating: Setup Complexity
Electroless black nickel plating doesn’t need an electrical setup. Once you have prepared the solution, you can immerse the metal part. The chemical reaction will work; you can wait until it’s finished.
On the other hand, the black electroplating nickel process requires an electrical setup. You must carefully place your anode and cathode parts, requiring a relatively complex setup. Again, you must calculate the exact voltage and ampere required. So, for beginners, it might be a troublesome process. However, black nickel electroplating is a precise and controlled process.
Frequently Asked Questions
Is Black Nickel Plating Conductive?
Yes, black nickel plating is highly conductive. It typically provides a high-conductive surface and is uniformly plated on complex shapes. Because of this, black nickel plating is used in many electronic applications. However, this plating reduces the reflectivity; thus, it is black.
What Is The Difference Between Nickel And Black Nickel Plating?
Nickel plating typically has a shiny, silvery look. On the other hand, black nickel plating has a dark, black tint on the surface. Sometimes, the black nickel finish maintains a reflective, mirror-like quality. This premium look is especially suitable for TVs, kettles, and toasters. The difference only lies in their aesthetic appeal.
What Is The Hardness Of Black Nickel Plating?
Black nickel electroplating typically has a hardness of approximately 54 to 56 RC. This level of hardness is suitable for resisting wear and tear. Because of this, black nickel electroplating parts are used in various industries. You can find its use in cars, electronics, and decorative industries.
Does Black Nickel Rust?
Black nickel electroplating is highly corrosion-resistant. It is even more durable than other types of finishes. Its protective coating maintains a shiny look for an extended period. Unlike other finishes, black nickel electroplating finishes are less prone to showing fingerprints. Besides, it is easy to maintain too.
What Is The Hardest Electroplating?
The hardest electroplating is chromium plating or chrome plating. The process creates a very thick and hard surface. Most industrial applications utilize chrome plating for metal parts. It improves wear resistance and helps reduce friction.
What Are The Disadvantages Of Nickel Plating?
There are a few limitations of nickel plating. One of the main reasons is that the process is only for conductive materials. Besides, the cost of black nickel may be higher than traditional nickel plating.
Summary
Black nickel electroplating is a popular type of electroplating. The process creates a layer of black nickel on the surface of the substrate. This black nickel layer gives a unique, premium look. Besides, it is corrosion-resistant and can withstand wear and tear.
The manufacturing process for electroplating black nickel is relatively simple. (1) Clean the substrate. (2) Prepare the electroplating black nickel solution. (3) set up the whole process. (4) Calculate the process’s time, voltage, and ampere. (5) Immerse the substrate and start the process. (6) Do additional protection if necessary.
You may get confused about electroless and electroplating black nickel. Well, they are both different processes. One needs electricity, while the other does not; thus, electroless and electrolyte are used. A catalyst mainly helps in chemical reactions for the electroless black nickel-making process.
Please go to black anodized aluminum page to know more about other surface finish, If you have any questions, feel free to contact us.