Manufacturers use different metal coatings for customized products. Most of these metal coatings improve the aesthetics of products, while others improve functionality, and some provide both.
Metallic plating remains a practical post-production finishing option and an important aspect of modern technology, making it an excellent choice for many applications. This article examines metallization surface finishing and its principle, describing in detail the essential elements of this technique and how you can make the most of it.
What is metal cladding?
Metal plating involves applying an outer layer of chromium, copper, nickel, or other metal to a component to improve its aesthetics and corrosion resistance. Coating offers numerous benefits for parts made of metal and other materials.
Helps improve the surface roughness of machined parts. This finishing technique provides an aesthetically pleasing appearance, reduced friction, greater hardness, better paint adhesion and weldability.
Metal coating process steps
The metal coating process includes several steps, from pre-treatment to post-treatment. There are several coating techniques; However, this aspect focuses on the basic electroplating procedures:
Step 1: Pretreatment
Pre-treatment helps remove any harmful contaminants from the substrate that could hinder the coating process. It may include cleaning, rinsing and other pre-treatments that remove contaminants from the coating surface.
Step 2: Determine the effectiveness of the cleaning process
The requirements of your parts often determine the ideal coating process. This also determines how clean your substrate needs to be before coating. For example, some CAD coating techniques only require the removal of coarse dirt particles, while others require the removal of oil and grease.
Step 3: Setting up the coating station
Since the focus here is electroplating, you will need materials such as anode, cathode, rectifier, tank and a suitable electroplating solution to set up your electroplating station.
Step 4: Coating Process
The deposition process begins as soon as you turn on the electricity. In cases where a thicker coating is required, it will be necessary to expose the components to electricity for longer periods. However, you may need to consider variables such as temperature, voltage level, soaking time, etc.
Step 5: Post-Treatment Process
Once you have the desired coating on your product, post-treatment cleaning is necessary. Therefore, electrolytic polishing is an effective means of improving the corrosion resistance of manufactured components.
Step 6: Waste disposal
Metallic plating produces heavy metals, which are generally dangerous due to their high toxicity. An efficient way to dispose of these wastes is therefore to pre-treat the coating wastewater before disposal.
Different types of metal coatings
There are several standard coatings available to the industry. Here are some of them:
1. Galvanization
Zinc remains one of the most economical materials for producing galvanized metal on metal substrates. Manufacturers use zinc by dipping and spraying it in molten baths. The substrate takes the position of the cathode, while the metallic zinc takes the place of the anode in an electrolysis bath with soluble zinc salt. The galvanizing technique forms a very ductile coating on the clad metal, allowing better control of thickness and uniformity.
2. Chrome plating
Alodine chrome plating or finishing generally uses chromic acid and trivalent chromium baths to create a top coat on metal components. The main objective of chrome plating is to improve the aesthetics of the material.
However, chrome plating increases the hardness of the material, making it more resistant to corrosion. Chrome plating can restore tolerances to worn parts. These chrome-plated components are generally suitable for industrial applications.
3. Nickel plating
Nickel is another commonly used and valuable plating metal in chemical plating method. Nickel plating creates a protective layer on household products such as door handles, shower taps, cutlery, etc. and helps improve its aesthetics and wear resistance. This coating method is suitable for aluminum and copper. However, it also works well on other metals and serves as a base coat for chromium.
4. Copper plating
Copper is the most economical metal coating with high conductivity. Copper plating is standard for electronic products such as circuit boards and is often chosen because it offers high plating efficiency and low material costs.
5. Cadmium plating
Cadmium plating is a soft silver metallic coating applied to various base metals such as aluminum, steel, copper and iron. This process is suitable for coating bolts and nuts for submarines and military parachute buckles. Furthermore, it is very malleable, resistant to corrosion, easily weldable and resistant to chemicals.
6. Silver Plating
Silver plating is identical to gold plating in that it improves the aesthetics of the material used. It is an excellent metallic surface if electrical conductivity is a factor you need to consider. Many manufacturers use silver plating due to its cost-effectiveness as it is a better alternative to gold. It is also effective for coating copper parts.
7. Gilding
This metal is known for its resistance to oxidation and high electrical conductivity. Gold plating allows these remarkable properties to be effectively transferred to metals such as copper and silver. It is often used to improve the conductivity of electronic parts such as electrical connectors.
8. Tinning
This industrial refinement uses electrical current to apply a solderable layer of tin to the surface of a material. Electrotinning is a very economical process as tin is readily available and costs less than metals such as gold, palladium or platinum.
9. Rhodium plating
Rhodium plating is another standard metal plating that involves applying a thin layer of rhodium to the surface of a piece of jewelry. This process is the same as rhodium plating or rhodium plating. Helps improve a piece of jewelry's shine, durability and light reflection.
Metallization techniques for customized products
Different metal coating techniques are used in different industries. Here are some of them:
Electroplating
Electroplating is a metal galvanizing technique in which a metal or metal alloy is deposited on the surface of a workpiece. It is a typical metal plating process that uses electrical currents in an electrolyte solution to dissolve charged metal particles (ions).
Charged (positive) metal ions adhere to the workpiece, in which case the workpiece has a negative charge in the circuit. Dissolved metal particles rise to the surface of the material when you place the part in the chemical solution.
Electroplating improves the chemical, mechanical and physical properties of a workpiece. Ensures a smooth, fast and uniform coating of clad metal. This thin coating gives the metal part a protective and aesthetic appearance.
Chemical coating (autocatalytic)
Electroplating is the ideal alternative to electroplating and represents a much simpler and cheaper option. It is also known as autocatalytic or chemical coating because it does not require external electrical current.
Electroplating involves the deposition of metals such as copper, gold, nickel and silver onto the surface of various materials using a reducing chemical bath. This creates catalytic reduction because it is a chemical process that does not require machines or electricity.
Electrolytic coating is suitable for components with hard surfaces and excellent corrosion resistance. Therefore, this process is used in the oil and naval industries to produce its components. Some common components, such as pumps or valves, which are often subject to corrosion, are manufactured using electrolyte-free coating technology.
Dip coating
The metal dip coating process involves dipping a metal into a chemical compound that contains metal ions of a noble metal. The ion present in the precious metal is generally stable.
This creates a natural suction that separates the metal ions from the parent metal and forms a thin layer of noble metal ions. This process is slightly slower than galvanic and current-free processes. Furthermore, it is only suitable for precious metals such as platinum, silver and gold.
Carburization
Carburizing is a metal coating process that solidifies the surface of a metal while leaving the underlying metal soft. This technique is the same as carburizing, surface hardening or surface hardening and results in the formation of a thinner and stronger metal layer called the surface layer.
Manufacturers carburize a part after it has been given its final shape because this helps to make the element contents harder, as in standard welding. Carburizing is an ideal metal coating technique that product designers use to prevent corrosion in metal-using industries.
Physical vapor deposition (PVD)
This type of metallic coating is a thin film production method that physically sublimates the surface of a source material (liquid or solid) by converting gaseous atoms, molecules or ions into ions under vacuum conditions. A film with a specific function is then deposited on the surface of the substrate using plasma or low-pressure gas.
The main technologies of physical vapor deposition are sputtering, ion plating, vacuum evaporation, arc plasma plating, etc. PVD coatings are characterized by rapid deposition, strong adhesion, excellent diffraction and a wide range of applications.
Plasma spray coating
This metal coating is a highly flexible and effective thermal spraying technique in which heat-softened or melted materials are sprayed onto the surface of a material to achieve the desired coating. It uses a powerful spray coating technology that allows the spraying of different materials such as ceramics, metal and cermet.
Plasma spray applications include protecting engines, restoring worn parts, and more. The plasma spraying process provides excellent resistance to wear, abrasion, electricity, heat and oxidation.
Advantages and Disadvantages of Metallic Siding
Surface coatings with metallic coatings offer many advantages that are of interest to many industries. The most common benefits of metal siding are:
- Increases the aesthetic appeal of the material used to manufacture a component.
- The various metallic coatings are compatible with an extensive list of materials.
- Helps protect components against wear and corrosion.
- Metallic plating is an economical finishing process.
- Increases the hardness and resistance of a material.
Although this post-processing technique offers a number of advantages to manufactured parts, it also has some disadvantages, including:
- In certain environments, the coating may chip and crack due to wear and tear.
- The metal plating process can be time-consuming and affect the specification of a component.
Metal coating applications
Different industries use different metal coatings to better meet their product specifications. These surfaces are the ideal choice for various industries. Here are some of its main uses:
Aerospace
In the aerospace industry, components are galvanized to obtain a sacrificial coating. In general, this increases component life by minimizing corrosion. Adding an additional layer of metal to parts can improve functionality. This is because aircraft components are typically exposed to significant temperature fluctuations and a variety of other environmental influences.
Auto Industry
Automakers often use electroplating to create custom parts for concept vehicles. Many vehicle customization and restoration companies use electroplating to apply nickel, chrome, and various other finishes to motorcycle and vehicle components. Additionally, vehicle manufacturers use black oxide coating as it is ideal for machined parts and can last longer.
Performance
The energy industry galvanizes solar components to improve their electrical conductivity. Manufacturers galvanize solar cell contacts and antennas. They also galvanize wires with silver, nickel and other metals.
Dentistry and medicine
In the medical field, metal coatings are often used to make the surfaces of medical and dental instrument components more robust and thus prevent metal deterioration. Manufacturers produce gold-coated dental inlays that are useful for various dental procedures.
Jewel
Electroplating is one of the most used techniques in jewelry. Manufacturers and designers often use this method to improve the aesthetics, durability and color of bracelets, pendants, rings and other accessories.
Factors to be considered in the surface finishing of metallic coatings
Properly executed metal finishes offer a variety of benefits, from durability to functionality and aesthetics. To achieve optimal metal coating results, here are some of the critical factors that determine how the metal is coated:
Conditions for pre-coated material
The material must be ready for coating before you can coat it. For example, if a substrate has scale, oxides, oil deposits and other heat treatment residues, the coating may not adhere to the surface of the substrate.
Therefore, it is necessary to remove these deposits using pre-treatment methods such as acid pickling, steam blasting, chemical descalers, deoxidizers, alkaline pre-soaking agents, etc. However, an effective method for preparing a galvanic surface is sandblasting.
Thickness Tolerance
Complications may occur during coating due to too high or too low coating thickness. Typically, the appropriate range of maximum and minimum desired thickness must be determined. However, here are some important factors to consider to ensure the scope of your metal siding is achievable and specific:
- In most cases, electroplating creates a uniform coating. Strict thickness tolerances therefore do not pose a problem.
- Mark the areas of a workpiece's surface that must be within a narrow thickness of metal plating. It is important to take into account depressions, corners and other geometric parameters.
- With electrolytic coating, the surfaces settle more in some areas of the coating surface than in others. For example, coating deposits will thin up to ¾ inch from a corner or recessed area. Therefore, it may not be advisable to use a tight tolerance on simple, flat shapes.
- It is important to create control points to establish coating tolerance requirements. Make sure you have these control points on surfaces where they are most appropriate.
Thread inclusion
Inspection of other thickness aspects of parts with machining threads is essential. Casing parts such as hydraulic fittings, screws, etc. they are typically about four times thicker than flat surfaces. Therefore, it would be useful to consider the structure of the desired coating process. This ensures that the threaded part meets essential specifications and fits perfectly.
WayKen metal cladding services for custom products
Concluding
The surface treatment of metal coatings is crucial to ensure that your products have excellent aesthetics, wear resistance, longer service life and high corrosion resistance. However, if you don't know what your products need, this can be a significant limitation. Therefore, you need to understand the needs of your project and find the ideal finishing option.
Common questions
Does gold plating disappear?
Metallic coatings, such as Some materials, such as gold coatings, can wear or tarnish over time and lose their shine. However, keep in mind that wear is a common reaction that occurs regardless of component quality.
Can metal siding prevent rust?
The coating technology permanently protects machines and various tools against rust and corrosion. This is because the thin layer deposited on the surface of these tools helps maintain their durability and corrosion resistance.
