Rust on metallic components causes damages worth billions annually. To counter this challenge, various protective mechanisms have been developed, including surface finishing with zinc.
Zinc finishing is an electrochemical process of adding a layer of zinc to another metal. With the layer of zinc in place, elements cannot infiltrate so the metal underneath is protected from rust.
What is Zinc Plating?
The process of plating with zinc is also called zinc electroplating and galvanization. It takes place in an electrolyte solution fed with electric current. The process aims to form a protective sacrificial barrier on the base metal. The protective barrier protects the metal against corrosion and rusting.
Apart from protecting the base material, galvanic zinc coating adds aesthetic value. Furthermore, the best zinc plating services can create a range of surface finishing qualities and colors. Black, yellow, and other zinc plating colors decorate products.
Zinc plated Iron Sheets
Is zinc plating rust proof?
While zinc plating significantly slows down rust, it is not entirely rust-proof, particularly in the face of extreme conditions for years. When the base metal is exposed, it can rust. The plating is highly effective, but the potential for rust depends on the quality of the coating and the environmental conditions.
How does zinc plating work?
This section covers how the galvanization process works. The steps in plating with zinc are:
Surface Cleaning
The first step is to clean the base metal thoroughly to get rid of dirt and oxides. Removing these impurities ensures that the coating sticks to the surface.
Electroplating Bath Setup
The core of the zinc finishing process is the bath and its contents. Preparation involves getting the required chemicals (salt and additives) and adding them to the container. The amount and concentration will depend on the specific requirements of the process.
Power Terminals
Zinc is connected to the anode and the base metal to the cathode. The two share a single power source. A direct current connects to the setup.
The Plating Process
When the system is powered, the current flow is visible in the electrolyte solution. Zinc ions move from the anode to the base metal. Electrons merge with the ions to create the protective barrier on the metal.
Parts in a zinc plating bath
Process Control
As the plating process proceeds, monitor process parameters, particularly the duration. The longer the process lasts, the thicker the zinc coating will be.
Rinsing and Post-treating
Following the zinc electroplating step is the post-treatment step. This stage is as essential as the plating process. It is the point where you remove any residue and enhance the corrosion resistance even further.
Quality Control
Quality control is an irreplaceable step in plating because it ensures consistency and durability. It is done throughout the process, encompassing surface preparation, bath composition, adhesion, plating thickness, and microscopic inspections when the process is complete.
The Different Types of Zinc Plating
Notable categories of this process are barrel plating, alkaline non-cyanide, or rack.
Barrel Plating
Small parts are placed in a barrel and rotated within an electrolyte solution to affect the plating process.
Alkaline Non-cyanide Zinc Plating
The zinc deposition process is based on alkaline-based solutions.
Rack Plating
As the name suggests, this method is characterized by irregularly shaped parts placed on the rack being lowered into the electrolyte solution.
What are the advantages of zinc plating?
If you are wondering why plating with zinc is considered a critical process in the different applications, consider these benefits:
Improved Corrosion Resistance
Zinc has a natural ability to resist rust. Corrosion resistance is one of the prominent properties of this non-ferrous metal. Once it creates a protective layer on the substrate, environmental factors cannot breach it to strike the material underneath.
Zinc plated metal pipes
Enhanced Surface Appearance
Another reason why plating with zinc makes sense is the method’s aesthetic appeal when applied on a component’s surface. The surface can play two functions: Protect the substrate metal and visually appeal to people.
For instance, chromate options provide a shiny appearance suitable for some products. Expert plating providers have different options for these visually appealing zinc plating colors like black and silver.
Compatible with Complementary Processes
If you consider improving the surface of a zinc-plated item, no problem. One of the advantages of zinc plating is that it offers room for more processes.
Alodine coating, also called chromate conversion coating, is one such process. Another option would be passivation to make the product even more corrosion-resistant.
How long does zinc plating last?
Many factors contribute to the lifespan of the surface finish. These include environmental conditions, plate thickness, and surface finish quality.
The best galvanic zinc coating providers provide a protective finish that can serve for many years. This coating can withstand rust and other elements for years if the application technique and general care are right.
How much does it cost to get something zinc-plated?
The cost of zinc plating something depends on many factors, from the complexity to the size of the part. Generally, this method is affordable compared to alternatives. The cost of nickel plating is usually higher.
What is zinc plating used for?
The formation of a zinc plate affects the substrate metal in three ways: Improved visual appeal, enhanced corrosion protection, and increased conductivity. Several industries benefit from these improvements, including the following:
Automotive Industry
Metallic zinc coating is a popular treatment method in the automotive industry for metal parts like gears and fasteners. The protective zinc layer protects the metal underneath against rust for enhanced part durability. The combined effect of the plating is better performance for the whole car.
Defense Industry
Reliability in the face of difficult conditions is the hallmark of defense products. Treating weapons and vehicle components with zinc electrocoating promotes rust resistance and overall performance.
Despite the harsh conditions, the items remain unaffected, thus adhering to stringent performance standards.
Construction Applications
Construction engineers use zinc-plated metal products across commercial, residential, and industrial sectors. Zinc electroplating fundamentally keeps off corrosion, a phenomenon that can affect the strength of materials.
Zinc plated screws
For architects, metallic zinc coating has even more meaning – The visual appeal of the materials. Zinc deposition is an attractive element for interior and exterior applications.
Electronics
The surface finishing process enhances the electrical conductivity in electronic products. Like in other products, it also optimizes corrosion resistance.
This capability is evident in related products such as connectors and switches.
Aerospace
The aerospace industry requires reliable and durable components. Whether the conditions are saline or humid, zinc-plated aerospace parts can withstand the dangers of corrosion. Using this surface treatment method ensures the functionality and dependable performance of parts.
Which is better, nickel or zinc plating
At this juncture, you might wonder, is nickel plating better than zinc plating or chrome plating? These three processes are notable in surface finishing in many industries.
The table below highlights this comparison.
| Property | Zinc finish | Nickel finish | Chrome finish |
| Process features | A silver-white appearance
Low-cost process Simple process |
More decorative
Yellow and silver white appearance Relatively pricey Complicated process |
Two process categories – for hardness and visual appeal
Bright appearance
|
| Benefits | Rust prevention visual appeal | Decorative
Corrosion resistance Wear resistance |
Part decoration
Increase hardness Increase wear resistance |
| Applications | Electronics
General industries Automotive Aerospace Construction |
Hardware
Coins Lamps |
Faucets
Tools Electronics |
Conclusion
Different industries treat their products with zinc to protect the base metal against destructive elements. Manufacturers in the aerospace, automotive, electronics, and other industries use the method to enhance product shelf life and general performance.
For more on zinc coating basics and its capability to add value to your products, contact specialists at ProleanTech. The team will help you crown your products right.
