Today’s aviation industry is worth many billions of dollars. Aside from the necessary safety precautions, manufacturing and purchasing aircraft costs millions of dollars. The harsh conditions threaten the integrity of the materials used in this application
One method for shielding aviation metals from these damaging elements is plating, which lengthens their lifespan and lowers the possibility of failure while in use.
The importance of aviation metal finishing, the two main types of metal finishing, and what to look for when choosing a metal finishing company will all be covered in this article.
If you need help, have an inquiry, or need a quote on your metal finishing project, you can reach out to us here, and we’d be happy to help.
What Is Aerospace Plating?
We’ll focus on titanium because it’s so prevalent in the aerospace industry, despite the fact that there are many different metal types that can be electroplated.
Due to the quick and vigorous formation of an oxide coating, titanium is a difficult metal to plate. The development of the plating-nickel titanium method was required because few other metals can bond with a titanium substrate.
If there is a nickel coating underneath the component, it is easier to weld other metals to it. Modern businesses have been attempting to optimize this process due to the increased use of titanium.
- High Phosphorus – Offers superior corrosion protection and improved resilience in extremely acidic situations.
- Medium Phosphorus – A good choice for enhancing the substrate’s aesthetic appeal.
- Low Phosphorus – Known to provide the best resistance to alkaline conditions and boost surface hardness and solderability.
Recently developed black electroless nickel coating makes it easier to absorb light and energy. This offers a more practical option for enduring harsh environments and circumstances while adding aesthetic applications when a black finish is required.
Importance Of Aerospace Plating
Higher Electrical Conductivity
It is possible to maintain the highest level of electrical conductivity. Corrosion and everyday wear and tear may ultimately affect their conductivity, which frequently negates their utility and purpose. By taking steps to protect the components of your project that rely on electrical conductivity, you can guarantee durability and top-notch performance.
Since each project has unique specifications and guidelines, we offer services like precision plating masking, pre-processing treatments, and more. Our experts can help you decide precisely what metal finishing you need for your upcoming project so that we can provide you with the best services possible.
Extends Parts And Components Lifespan
Due to the numerous advantages that increase the durability of your project, electroplating is a great way to improve protection. External factors that can lead to corrosion and other wear are easier to avoid, which ultimately lowers the cost of replacement in the long run.
Stronger Metal Substrate
Electroplating can significantly increase the strength of your product, depending on the substrate you choose. The most typical effects are increased hardness, corrosion resistance, heat resistance, and abrasion prevention, though every finish can produce different outcomes.
At Valence, we provide a variety of plating procedures and are open to the idea of investigating new materials in the future to use for the requirements of our clients.
Increased Resistance
The durability of the product is improved when metals are covered with a protective metal plate. The metal may corrode and deteriorate if not treated. Better durability and abrasion resistance are demonstrated by metal plating, which also shields the metal from wear, corrosion, and chemical damage. This is significant for drills, dies, and other tools that frequently have PVD coatings.
Improved Aesthetic Appeal
The original metal looks better after being polished and plated. The metal product’s surface is cleaned and polished during the polishing process, and any flaws, pits, scratches, and jagged edges are also removed. The product can also be further processed to a matte, glossy, or textured/brushed finish, as well as decorative accents like color application. An electroplate is put on top of a polished surface to further smooth out the surface for results that resemble mirrors.
Electroplating over matte and brushed finishes will maintain the texture characteristics of the surface while preventing corrosion. The effort is definitely worthwhile when you take into account that the advantages are anticipated to last for generations.
Types Of Plating
Electroplating
Positively charged metal ions are dissolved in a chemical solution during the electroplating process. On the negatively charged side of the circuit, the material that will be plated is drawn to the positively charged metal ions.
When the component or finished good is immersed in this solution, the dissolved metal particles are then drawn to the surface. Electroplating is a successful method for changing the surface of a substance because it gives the material a quick, even, smooth coating.
A few of the many stages and techniques that can be used in electroplating include cleaning, striking, electrochemical deposition, pulse electroplating, and brush electroplating.
Electroless Nickel Plating
Electroless Nickel Plating is a unique process that uses heat and a unique chemical bath to create the nickel without the use of any electrical current. Since electroless nickel finishing does not use electricity, the coating created by the process is very uniform across the entire surface of the part, even parts with complex geometry. Threads and close tolerance features can be plated precisely without edge build-up.
Because it works well in electroless plating, nickel is a common plating metal. For better ornamentation and wear resistance, household items like doorknobs, silverware, and shower fixtures are frequently nickel plated. Nickel, which frequently forms bonds with copper, aluminum, and a variety of other metals, is plated with chromium.
An alloy of nickel and phosphorus is used in electroless plating. The amount of phosphorus in the solution can range from 2 to 14%. Increased phosphorus concentrations improve hardness and corrosion resistance. Better magnetism and solderability are provided by lower phosphorus concentrations.
Anodizing
Anodizing is an electrochemical process that converts the metal surface into a decorative, durable, corrosion-resistant, anodic oxide finish. Although other nonferrous metals, such as magnesium and titanium, can also be anodized, aluminum is best suited for the process. The anodic oxide structure, made completely of aluminum oxide, comes from the aluminum substrate.
This aluminum oxide is totally integrated with the underlying metal substrate rather than being applied to the surface like paint or plating, making it resistant to chipping and peeling. In addition, its well-organized porous structure enables further procedures like coloring and sealing. Aluminum is anodized by dipping it into an acid electrolyte bath and then running an electric current through it.
The anodizing tank has a cathode mounted inside of it; aluminum serves as the anode, causing oxygen ions to be released from the electrolyte and combined with aluminum atoms on the surface of the component being anodized. Therefore, anodizing is the enhancement of a naturally occurring phenomenon through carefully controlled oxidation.
Metal Finish Vs. Surface Finish
Metal Finish
Metal Finishing is the process of adding a layer to the material in order to achieve a better appearance or improve its durability. The various metal finishes you should be aware of are as follows:
Painting: Like with any type of painting, finishing the surface with a coat of wet paint is a requirement for metal painting. Typically, fabricators will use pumps, sprays, or pressurized vessels to ensure that the paint is applied uniformly.
Powder Coating: Metal plating is a process that involves coating a substrate with a thin layer of metal. For instance, brass and woodwind musical instruments are often gold or silver-plated. The finish is achieved through electroplating and electroless plating. Electroplating requires an electric current, while electroless plating involves the use of autocatalytic chemicals.
Anodizing: Metal is electrolytically coated with a protective or aesthetic oxide during the anodizing procedure. Aluminum can be used to grow aluminum oxide by submerging it in an acid electrolyte bath and running electricity through it. The finished product is a strong, long-lasting coating that keeps the metal’s original luster and texture.
Plating: A thin layer of metal is applied to a substrate as part of the metal plating process. For instance, gold or silver plating is frequently used on brass and woodwind instruments. Electroplating and electroless plating are used to create the finish. While electroless plating uses autocatalytic chemicals, electroplating needs an electric current.
Surface Finish
Surface Finishing is the process of removing a layer from the material in order to achieve better functionality or improve its appearance. Industry-standard methods for surface finishing include the following:
Grinding: The surface of a metal can be smoothed out using grinding machines. To produce the desired finish, these machines use compression, attrition, and friction. A fabricator may select from a variety of grinding machines that vary in type and design depending on how smooth of a finish is desired.
Polishing and Buffing: In order to get a better finish and prepare the metal for buffing, polishing involves scraping off the surface material. Buffing creates a high luster, also known as a mirror finish, and smooths the surface.
Abrasive Blasting: You can easily combine cleaning and finishing into one process with abrasive blasting. To achieve the desired cleanliness and surface profile, abrasive particles are propelled against a metal surface using a high volume of pressure during abrasive blasting. In this process, abrasives like sand, glass, plastic, and aluminum oxide are used.
Milling: Fabricators will put the metal through a rolling mill, extrusion die, or drawing process to get a mill finish. This kind of finish typically feels rough to the touch and is dull in appearance.
How Does Plating Work?
The electroplating process uses an electric current to dissolve metal and deposit it onto a surface. The process works using four primary components:
Anode: The metal used for plating will be the anode, or positively charged electrode, in the circuit.
Cathode: The component that needs to be plated is the cathode in the electroplating circuit. Additionally known as the substrate. This component serves as the circuit’s negatively charged electrode.
Solution: In an electrolytic solution, the electrodepositing reaction occurs. For the purpose of facilitating the flow of electricity, this solution contains one or more metal salts, most frequently copper sulfate.
Power Source: Using a power source, the current is added to the circuit. The anode receives a current from this power source, which adds electricity to the system.
The power supply provides a direct current (DC) to the anode once the cathode and anode have been inserted into the solution and connected. The metal oxidizes as a result of this current, allowing metal atoms to dissolve as positive ions in the electrolyte solution. The metal ions are then moved by the current to the negatively charged substrate and deposit a thin layer of metal onto the object.
Applications Of Plating In Aerospace And Aviation
A wide range of aerospace components, such as airframes and engines, electronic housings, landing gear, turbine blades, actuators, bearing journals, bushing bores, flap tracks, and axles, can be selectively plated. Different deposits will be used for different applications depending on the component being plated.
Corrosion protection
The most frequent application of cadmium is as a sacrificial barrier on support lugs and landing gear. The need for post-baking is eliminated, and repairs can be made in a place with little to no disassembly.
Refurbishment
For dimensional restoration of inside or outside diameters on components like end bell housings and bushing bores, MRO applications use nickel or sulfamate nickel. With little masking or disassembly, parts that are out of tolerance from wear or improper machining can be plated to size in thicknesses ranging from.0002″ to.0300″ per side.
Cadmium replacements
Most importantly, for airlines looking for alternatives to cadmium deposits, selective plating, valence processes offer multiple solutions. While detailed studies show these alternatives do not perform well in either tank or thermal spray applications, they deliver excellent results via selective plating, offering superior sacrificial corrosion protection for steel by combining the barrier protection of tin with the galvanic protection of zinc.
Final Thoughts
Looking to talk to an expert on aerospace plating or finishing-related topics? Let Valence help you. Valence is the industry leader in quality for precision components in the aerospace, satellite, electronics, and medical device industries. With unique selective plating and precision masking techniques for critical plated components, we are the leader in satellite and UAV applications, including a proprietary process for the precision internal plating of waveguides.
We offer integrated honing and grinding capabilities to complement our cadmium and chrome plating. To get a quote on your next project, get in touch with us today, and we’ll discuss all of the aerospace plating questions you may have.
FAQ
What is the difference between plating and anodizing coating?
Anodizing transforms the substrate into the coating, whereas plating causes the metal in the solution to deposit directly onto the surface. The processes of plating and anodizing can be compared to painting a piece of wood black and charring it, respectively. Anodizing can be thought of as a particular kind of conversion coating.
If the stripper does not corrode the substrate, you can remove the coating from plating without changing the size of the substrate. If you remove the coating from a conversion coating, you will remove some base material and change the size of the original part. More material will be removed from the surface as the conversion coating becomes thicker because more of the base material was converted.
What does passivation do to stainless steel?
The primary purpose of passivation is to remove foreign metal components from stainless steel parts. Nitric acid reacts with stainless steel at the same time as passivation to form a very thin oxide film that shields the metal from further corrosion. In the presence of some ions that are typically referred to as “aggressive,” such as those that are thin (10 nm), it is difficult to establish and maintain this thin passivation film. The chloride ion is the one in this category that is most frequently found. Cotton gloves must be worn when handling passivated parts because of this.