Important Facts About Metal Plating

• Metal plating is a very important and beneficial methodology to protect the metal from various problems like corrosion, rust, etc.
• There are several types of metal plating techniques in the market. Some techniques are traditional and some are advanced.
• Top popular metal plating techniques are named electroplating and electroless plating.
• Electroplating is most commonly used on very heavy metal materials.
• The industry has a set rule of standards and businesses have to follow these standards.   
• Many countries deal in metal plating but China has a very reputed name in the industry.
• China highly deals in zinc, copper, nickel, and chrome plating because they have a huge amount of resources.

Introduction

There are numerous types of metal in the market. Some of the top metals include chrome, nickel, zinc, etc. These metals are used for various purposes and one of them is product manufacturing such as electric appliances, electric wires, jewelry, and ornaments.

Since a metal part can experience various types of stress, plating plays a very vital role. It is a popular methodology used for metal finishing. Electroplating is another term widely used for metal plating.

In simple terms, plating helps to prevent metal from oxidation (such as rust), increases object wear resistance, adds shine for light reflection, prevents corrosion, adds aesthetic appeal, as well as elevates the thickness of the metal, etc. Electroplating is divided into copper, gold, silver, chromium, nickel, zinc plating, etc.

Many businesses, as well as individuals, often get confused about the difference between chrome, nickel and zinc plating. In case, you also have the same concern, then read on. We will walk you through the main differences between these metals and other important aspects of metal plating. Let’s get started!

Importance Of Metal Plating

Metals can anytime wear and disintegrate without plating. As a result, metals will have a very short life span. But thanks to the technology and innovation for inventing various types of plating for metals. When metals are covered with a protective metal plate or layer, the longevity of the metal increases. Since metal plating protects the metal against corrosion, improves solderability, hardens the component or part, increases strength against wear and tear, reduces friction, alters conductivity, shields against radiation, and chemical damage, etc. Additionally, there are several beneficial reasons to invest in metal plating.

For instance, plating is used to add the finishing, durability to the metal, etc. In fact, some metal plating is done for decoration and some to add functionality. The process of metal plating is very crucial and necessary, thus it is important for businesses to consider metal plating as a priority for great results.

Types of Metal Plating Methodology

No matter if you simply want to either turn a metal fixture in your home into something decorative or keep the rust away or harden a soft metal piece, metal plating is a must-to-follow step. Since there are 4 types of metal plating, every technique of plating offers different types of benefits. Thus, it is also necessary to opt for the right type of metal plating.

Types Of Metal Plating

There are 4 main types of metal plating.

1. Electroplating
2. Electroless Plating
3. Immersion Plating
4. Plasma Spray Coating

Electroplating – The most popular type of metal plating in the market. Electroplating can be used on any type of metal to either enlarge or strengthen metal items. Thus, the process works without bending the metal, as well as allowing better electrical conductivity. Jewelry is one type of metal that uses electroplating to keep them away from staining and also to strengthen the jewelry pieces.

The electroplating process involves placing the metal item in one place to be plated and a solution is used as the plating into an electrolyte solution. Then electricity passes through the solution causing the plating metal to shed a bit. Later, the small pieces flow via the solution and then adhere to the metal item for electroplating.

Electroless Plating – In case, you do not want to use electricity, then this process is the best. The electroless plating technique provides protection to metals against oxidation. Hence, metals plated with electroless methodology don’t rust. Moreover, electroless plating builds up a piece so that it fits properly in place.

In electroless metal plating methodology, chemicals are used in the electrolyte solution for plating to release some atoms instead of electricity to join the piece that needs to be coated. Although electroless protects the metal items from any electrical damage, the coating does not last as long as an electroplated coat.

Immersion Plating – As compared to other metal plating techniques, this process is slower. Also, the results of immersion plating don’t last long. But immersion plating improves conductivity, reduces corrosion, and increases metal hardness.

In this process, the noble metal is placed into an electrolyte solution where the metal sheds some ions. The pieces are then put into the solution. On the other hand, the loose ions from the noble metal are pulled towards the piece that needs to be plated, adhering to the piece.

Plasma Spray Coating – This method of metal plating is ideal when metal parts or items need to endure a very high temperature. In addition, plasma spray coating is a great option to prevent metal from corrosion.

While plasma spray coating, metal is heated to an extremely high temperature in a plasma flame. When the metal melts, it is quickly sprayed onto the piece that needs to be coated and lastly, it is left to cool down to normal temperature.

Purpose Of Metal Plating

Metal plating is a centuries-old process that permanently joins a metal to a conductive surface. This process not only affects the appearance of a metal but also hardness, electrical conductivity, coefficient of friction, and how it will withstand corrosion or wear resistance.

Metal often comes into contact with dissimilar metals that allow corrosion, as well as other problems. In fact, the smallest component can ruin the overall effectiveness of a metal or metal product, then cause significant challenges or problems. This in turn might determine either success or failure of the metal.

• Metals are extremely resistant to wear, tear, and corrosion.
• Metal finishing is used to shape components according to the needs.
• Metal plating helps to improve the electrical properties of a metal product.
• Metal finishing enhances the ability of a metal to bond with adhesives, coatings, or rubber.
• Metal plating enhances the look, feel, and presentation of metal products.

Some Common Metal Plating

• Chrome Plating – This is used to provide increased corrosion resistance, and surface hardness, to ease the maintenance process of the metal, or for completely decorative purposes.

• Nickel Plating – This provides a unique combination of corrosion and wears resistance. It can also add brightness, luster and appeal. Moreover, nickel plating provides excellent adhesion properties for subsequent coating layers. Thus, nickel is often used as an ‘undercoat’ for other coatings, such as chromium/chrome.

• Zinc Plating – This is used especially for screws and other small fasteners such as light switch plates, or various small parts. For use in moderate or severe environments, the materials must be chromate-conversion coated for additional corrosion protection and zinc plating is very helpful in such cases.

Benefits Of Metal Plating

Plating Adds More Properties to Metals – Metal plating offers various types of electrolytes, such as copper, nickel, silver, and gold-based. Therefore, electroplating makes the metal more desirable.

Improves Quality of the Manufacturing Processes – Electroplating offers so many important benefits, as well as features, as a result, improves the quality of the manufacturing processes.

Plating Enhances Appearance – Metal plating thoroughly enhances the appearance of metal. For e.g. Gold, silver, platinum, etc. are usually plated with a thin layer of precious metal to make them more beautiful and lustrous.

Another example is jewelry often tends to get tarnished when exposed to extreme acidic sweat. In such a scenario, electroplating can be a big help to prevent premature tarnishing. This also reduces abrasion, as well as scratches.

Affordable Solution for Business – There are many electroplating solutions under budget to help businesses find a cost-effective alternative to more expensive plating.

Reduces Friction – Many times plating can reduce friction build-up and help premature wear and tear. Plating is crucial and beneficial to preventing such problems. It also improves performance.

Conducts Electricity – For manufacturing electrical components, silver plating enhances electrical conductivity. In addition, plating is an efficient as well as cost-effective conductivity solution.

Absorbs Excess Hydrogen – During the manufacturing of automobile catalytic converters, palladium plating can absorb excess oxygen. The process is very beneficial to improve catalytic converter performance.

Increases Hardness – The electroplating process makes brittle materials more durable. Thus, plated surfaces will likely withstand damage caused by dropping or striking.

Additional Benefits Of Metal Plating

The metal plating technique caters to the following benefits to metal products: –

• Reduces Chances Of Corrosion
• Provides Aesthetic Decoration
• Enhances Solderability
• Increases Strength
• Changes Conductivity
• Increases Paint Adhesion
• Improves Magnetism

Procedure Of Metal Plating

The process of metal plating involves depositing metal on the substrates to coat and protect metals and other materials. The procedure can either follow electroplated or electroless plating or any other technique. The metal plating methodology involves adding layers of metal onto existing pieces/items. In addition, metal plating has a wide range of benefits depending on the specific plating technique. Plating can be done on almost all types of metal.

Stages of Metal Plating

Cleaning and Surface Preparation

• Oxide Removal
• Electro-Polishing
• Alkaline Cleaning

Metal Plating

• Electroless Plating (autocatalytic)
• Electroplating
• Immersion Plating

Finishing and Protection Treatments

• Phosphating
• Chromate Conversion
• Anodizing

Industrial Metal Plating Standards

• Limiting the impact of corrosion
• Serves as a primer coat to promote paint adhesion
• Strengthening the substrate and increasing wear resistance
• Reducing the effects of friction
• Improving the appearance of a part
• Increasing solderability
• Making a surface electrically conductive
• Enhancing chemical resistance
• Cleaning, polishing and removing surface defects

Explore the Difference Between Chrome Plating, Nickel Plating And Zinc Plating

Chrome Plating – A Small Brief

Chrome – a colloquial term generally used for chromium. It is popular because it is a naturally occurring element. Chrome is widely useful for plating over different materials such as steel, brass, aluminum, plastic, copper, or stainless steel rather than as a solid substance.

The chrome plating process is a method of applying a very thin layer of chrome/chromium onto a substrate (metal or alloy) through an electroplating procedure.

In simple terms, the electroplating technique is used to achieve an electric current between two electrodes that are immersed in an electrolyte bath composed of chromic acid. In this process, one of the electrodes is the substrate that is plated. During the flow of electricity in electroplating between the two electrodes, chromium atoms are deposited in a layer on the electrode to be plated.

Need Of Chrome Plating

Chrome plating has an abundance of benefits to offer. Not only does it make objects look new and aesthetically pleasing, but it is also highly useful in restorative work and the preservation of expensive engineering parts.

For example – to increase the hardness, durability, and corrosion resistance of a surface. In addition, chrome plating adds a shiny and smooth surface that is easier to clean.

For improved wear and corrosion resistance also chrome plating is an ideal choice as it’s tough to beat hard chrome plating. The hardness, as well as durability, of a chrome metal surface, adds finish to the metal to last longer even under severe mechanical contact and wear situations. Promotes use in harsh environments along with other plating materials that may wear exposing the substrate metal to corrosion attack.

Step-by-Step Chrome Plating Process

Chrome plating is offered through two main methods: hexavalent chromium plating and trivalent chromium plating.

Hexavalent chrome plating is a very traditional method of plating chrome. This is very popular and highly used for functional purposes.

Trivalent chromium plating is the most eco-friendly solution to traditional chrome plating. Because it uses chromium sulfate or chromium chloride as key ingredients and replaces the chromium trioxide.

Types of Chrome Plating

In general, there are two main types of chrome plating such as hard chrome plating and decorative chrome plating.

Preparation care & method – In this process a lot of steps are involved such as inspection, stripping, repair & restoration, polish, cleaning & plating preparation, etc. to prepare the metal for chrome plating.

Quality of plating solution – For quality plating on chrome a lot of options are available in the market. For example – copper plating & buffing to add shine to chrome metal plating.  

The thickness of the plating layer – For hard chrome plating as well as decorative plating, companies follow wiring, racking & recleaning along with nickel plating and chrome plating is done.

Nickel Plating – A Small Brief

Nickel plating refers to a technique or process that covers a metal object in a protective layer of nickel or nickel alloy.

Need For Nickel Plating

Nickel plating adds durability, hardness, conductivity, and heat resistance to the product. In addition, the nickel plating is incredible for corrosion protection and enhancing the aesthetic looks of metal.

Step-by-Step Nickel Plating Process

Pre-Treatment

The very first step is the pretreatment process for nickel plating. The metal is cleaned with a series of chemicals to remove greases and oils. In this process, each component is properly cleaned.

Surface Prepare

After cleaning, the substrate is activated with an acid etch or proprietary solution. This is done to prepare the surface for a deposit of nickel-phosphorus.

Rendering

Once the plating has been completed the electroless nickel process renders the component more resistant to corrosion, as well as friction.

Zinc Plating – A Small Brief

Zinc plating refers to the methodology or process of a surface treatment technology that coats a layer of zinc on the surface of the metal, alloy, or other materials to improve aesthetics, as well as for rust prevention.

Need For Zinc Plating

Although zinc plating has excellent corrosion properties, except against alkalis, sulfides, and acids. This metal has great mechanical strength. Thus, zinc is often used in humid and hot environments because of its stable metal form. Since metals are abundant, they can be very easily used for work at a very low cost and still render great profit. But zinc plating is not a good choice for parts that experience a very high amount of friction. So it is mostly used for applications to prevent parts from rusting instead of friction.

Step-by-Step Zinc Plating Process

Preparation and cleaning — It’s essential to thoroughly clean the surface of the substrate prior to the zinc plating process. This helps to remove every type of debris or contaminants on the surface. Further, prevents complete adhesion of the zinc coating. For zinc plating, the alkaline detergent solution is primarily used for surface cleaning. This is further followed by the application of an acid treatment to remove surface rust. The latter procedure is referred to as pickling which is also a part of the process of plating.

Preparation of the plating solution — Zinc plating requires the immersion of the substrate into a specially formulated electrolyte solution, which is referred to as the plating bath. The solution bath consists of the zinc metal ionic solution along with various chemicals that facilitate brilliant plating processes. This helps to produce the desired chemical and physical properties of the finished zinc metal product.

Some zinc electrolyte solutions include: –

Acid zinc — This technique is widely used for zinc plating. This technology is also known for its high efficiency, fast deposition and superior covering power. But the acid zinc provides a very poor throwing power, as well as thickness distribution.

Alkaline zinc — The alkaline zinc step in the plating process offers very less plating efficiency than acid zinc. Also, it has a very slow electrodeposition rate. But alkaline zinc provides better thickness distribution and ductility that’s why people prefer to use it.

Following the right procedure — Once the solution for zinc plating is prepared, the metal parts are ready for the plating process. This method could involve rack plating in which larger parts are affixed to metal racks. Further, these parts are placed inside the tank containing the plating solution bath. For the plating of smaller parts, barrel plating is generally used instead of a plating tank. Then, the parts are placed inside a barrel and rotated for a better layer of coating which provides a more uniform finish.

Electrical current — For this, the electroplating process is used. This is also known as the electrodeposition technique because an electrical current is used to pass metal ions onto the surface of the substrate.

In the process of zinc plating, the substrate serves as the cathode. A DC (direct current) current originates when the anode is introduced into the bath and flows to the substrate. Then, the zinc ions are deposited onto the outer surface. The current flows from the cathode back to the anode to complete the circuit and provide the desired results.

Post-treatment procedure — Once the electrodeposition process is completed, the metal parts are ready for post-treatment. This step involves rinsing the parts in water to remove any remaining contaminants and plating.

In cases, there is very heavy contamination, the metal parts may need to be rinsed off several times. But this is not a general scenario so you do not have to worry about it much.

The final step of zinc plating involves thoroughly drying the zinc-plated parts to ensure plating is done accurately. However, in case, extra corrosion protection is required, then the application of passivates and sealers is included in the post-treatment process.

Should You Opt For Metal Plating?

A metal can experience a number of stresses when gone under numerous conditions or temperatures. For e.g. corrosion from other components, chemical reactions, or even from the environment. In fact, metal can also wear or tear out before age or time due to many reasons like lack of lubrication, faded plating, friction, etc.

To overcome the failure of metal along with prolonging life, metal plating is a must-to-follow step. There are a number of metals available in the market. In addition, the type of plating solutions, as well as the process or method of metal plating are also numerous. Plating is a very helpful method to prevent metal from any type of wear and tear issues.

Basically, plating is a very common and traditional method of coating metal to prevent it from rust or other problems. In addition to protection, plating also enhances the look and feel of the metal. Still many people, as well as businesses, often encounter a situation where they face the question of whether to opt for metal plating or not. Well, the short answer is YES!