When bonding, coating, painting, printing or sealing, most manufacturers eventually experience adhesion failure, corrosion protection issues, or structural weaknesses.
In industries such as automotive, aerospace, and electronics, ensuring a high-quality surface finish is crucial to avoid these issues.
Paint chipping, cracked seals, inconsistent coating, prints not sticking and bonds not holding are a few manufacturing problems that can be avoided with surface treatment.
In this article, we will explain what surface treatment is and describe its benefits for various applications. We will also guide you in choosing among today’s 10 most common surface treatment methods.
Table of Contents
Surface treatment refers to various methods used to modify the surface layer properties of materials (mostly metal parts and substrates) through physical, chemical or thermal techniques. These various types of surface treatments can improve a material’s adhesiveness, corrosion protection, durability or performance requirements.
Surface treatment can also be used to enhance conductivity and remove contaminants from metal surfacesfor subsequent processing, such as coating and bonding. For this reason, this manufacturing process is also called “surface preparation.”
Essentially, a surface treatment process helps ensure minimum scrap, waste, recalls and returns. It also helps prevent safety and public health issues.
In the automotive and aerospace industries, for example, the reliability and durability of materials are non-negotiable. Without proper surface preparation, those materials may suffer from oxidation, corrosion, contamination or weak adhesion in bonding applications.
For most industries, surface treatment has 5 main benefits:
Picking the right method depends on 4 key factors:
The chart below gives an overview of the main methods used, which will be detailed in the next section:
Here are the 10 most frequently used surface treatment techniques in manufacturing:
Laser cleaning is a highly precise, non-contact way of removing contaminants, rust, oxides, paint and coatings (e.g., powder coating, e-coating, phosphate coating) from metal surfaces without damaging the substrate.
This technique can also ensure optimal adhesive bonding before welding or assembly, as shown in this video:
Contrary to chemical and blast treatments, pulsed laser beams generate consistent results in removing contaminants even on thin or soft surfaces and require no consumables.
Laser texturing creates micro and nano-scale textures to modify the texture and roughness of metal parts.
This surface treatment method offers much control over the surface finish (linear, random, grid or circular), which can ensure optimal adhesive bonding or thermal spray coating.
Also called laser structuring, laser texturing is, in fact, a 3-in-1 method: It cleans the material’s surface, etches it to create the desired texture and roughness, and alters its chemical composition to increase adhesiveness.
Laser hardening (also called laser heat treatment) is used to enhance the wear resistance and mechanical properties (e.g., hardness, strength) of metal components.
It proceeds by directing a laser beam on the material to heat up localized areas of its surface layer, which then cools down rapidly. This alters the metal’s microstructure, resulting in a hardened surface layer.
Such treatment extends a metal part’s wear life, preventing any potential deformation or warping.
With laser cladding, we use a laser beam to deposit layers of material on a metal surface to improve wear and corrosion resistance or to repair damaged areas. The laser beam generates a melt pool (a superheated surface area) on the metal.
A nozzle feeds the stream of material above the substrate simultaneously, allowing the cladding to be achieved with high precision in the heated area. The deposited material typically consists of a metallic powder or wire.
With chemical etching, a chemical solution (e.g., ferric chloride) is applied to the surface and reacts with the material to achieve the desired effect. The surface is then rinsed or neutralized to stop the reaction.
This method is often used on microelectronics and medical devices. It is a versatile, cost-effective and precise way to enhance corrosion resistance and clean the surface of metals, ceramics and semiconductors with chemical reactions.
However, chemical etching requires tight control to avoid chemical contamination and variations in effectiveness. Since the process generates liquid waste, it can also pose safety hazards for operators and the environment.
The most common abrasive blasting technique is called sandblasting, which involves projecting sand at high speed onto a surface to remove contaminants or improve adhesiveness.
This inexpensive technique is best suited for large surfaces and materials like stainless steel and carbon steel.
However, there is a risk of sample recontamination with metallic particles. Abrasive blasting also uses consumables (e.g., sand) that need to be recycled.
High maintenance requirements also encourage a growing number of manufacturers to consider alternatives to sandblasting.
Plasma treatments can be applied to plastics, glass, composites, polymers and aluminum. This method heats a partially ionized gas (e.g., argon or oxygen) and bombards the material’s surface to improve adhesiveness.
This type of surface treatment may be more economical, but it doesn’t offer as much control as other methods, since plasma etching requires applying a mask to the surface to control the pattern. This method can also leave carbonized residues.
This method uses solvent vapors that emanate from a heated bath and enter a chamber where the material gets treated.
The solvent vapor eliminates contaminants on the material by condensing and dripping off its surface. Since the material doesn’t need to be dried, vapor degreasing is relatively time efficient.
Although the solvent can be reused, it must be changed regularly. Close monitoring is also required to avoid contamination.
Also called anodic oxidation, this method is best suited for light metals like titanium, aluminum, and magnesium. Thanks to electrolysis, this process allows the creation of an oxide coating layer on the metal, which enhances corrosion protection and appearance.
To increase durability, a thick ceramic coating layer can also be applied to the metal part’s surface through anodizing.
Anodizing requires a high initial investment and extra steps that make this process relatively time consuming.
E-coating is a common method in which conductive metal parts are submerged in a water-based electrolyte solution that also contains a primer or paint.
Similar to powder coating, this wet process relies on the opposite electrical charges of the part and the paint or primer, which enable the latter to attach to the metal’s surface.
The longer you leave the part in the e-coating bath, the higher the electrical charge’s voltage and the thicker the coating will be.
Electroplating uses a similar process involving an electrolyte solution bath. The key difference is its use of metal coatings (e.g., cadmium, copper, chromium, gold, nickel, silver, tin or zinc) to plate the metal part.
The result of e-coating and electroplating is improved wear and corrosion resistance and a smooth, durable finish.
On the other hand, they both require a considerable initial investment and large volumes of consumables besides generating wastewater.
Laser technology provides precise, efficient and environmentally friendly treatment solutions for various applications such as metal bonding, battery welding and thermal spray coating. It can reduce costs considerably and improve your operations’ speed and repeatability.
If you’re considering laser for your surface preparation and treatment needs, contact our experts today.
Catherine holds a bachelor’s degree in Engineering Physics and a master's degree in Physics. She completed her master’s in partnership with Laserax to develop industrial solutions for the laser texturing of metallic surfaces. She is now the Applications Lab Supervisor at Laserax, where she oversees the team that tests and optimizes laser processes for clients.
Removing surface contaminants is an essential step that directly impacts the performance and durability of materials and components. Understanding surface contamination helps compare standard decontamination methods and how laser technology differentiates from traditional approaches.
Laser surface treatments can be used on almost all types of metals, including carbon steel, cast iron, aluminum, molybdenum, and magnesium. They can remove contaminants and coatings (laser cleaning), modify the surface roughness (laser texturing), harden surfaces (laser hardening), and add materials to surfaces to improve surface properties (laser cladding).
Laser ablation occurs when a laser beam removes material from a localized area. Used in various industrial applications, this process can create permanent marks (laser marking), remove contaminants and coatings from surfaces (laser cleaning), modify a part’s roughness (laser texturing), cut through a surface (laser cutting) and much more.
