Electroplating & Surface Treatment FAQs – Groupe Altech
What is zinc plating?
Zinc plating is one of the most widely used corrosion protection processes in industry. At Groupe Altech, zinc is electrodeposited onto steel components to create a protective barrier that prevents rust formation.
Depending on the specification, zinc plating can be finished with clear, yellow, or black passivation to enhance corrosion resistance and appearance. In many applications, zinc coatings are also used as a base layer for painting or additional protection systems.
Zinc plating is commonly used in automotive, industrial hardware, fasteners, and general manufacturing applications where cost-effective corrosion resistance is required.
What is zinc nickel plating?
Zinc nickel plating is a high-performance corrosion-resistant alloy coating used primarily in automotive, aerospace, and heavy-duty industrial applications.
At Groupe Altech, zinc-nickel is typically co-deposited with a controlled nickel content, significantly improving corrosion resistance compared to standard zinc plating.
This coating is often specified where:
- High salt spray resistance is required
- Parts are exposed to harsh outdoor environments
- Aerospace or automotive Original Equipment Manufacturer (OEM) standards must be met
A key advantage of zinc nickel is its improved thermal stability and reduced risk of corrosion propagation, making it a strong alternative to cadmium in many applications.
What is the difference between zinc, zinc nickel, and nickel plating?
These coatings serve very different purposes:
- Zinc plating: Primarily sacrificial corrosion protection for steel
- Zinc nickel plating: High-performance corrosion protection for extreme environments
- Nickel plating: Hard, wear-resistant coating used for engineering, electrical, and decorative purposes
At Groupe Altech, we help clients select the correct system depending on whether the priority is corrosion resistance, conductivity, hardness, or appearance.
Is nickel plating the same as zinc plating?
No. Nickel and zinc are completely different materials with different functions.
Nickel plating is:
- Hard and wear resistant
- Often used for functional or decorative applications
- Not sacrificial in corrosion protection
Zinc plating is:
- Softer
- Sacrificial (protects the base metal even when damaged)
- Primarily used for corrosion resistance on steel parts
What is electroless nickel (EN)?
Electroless nickel is a chemical deposition process that does not require electrical current. At Groupe Altech, EN coatings are used to provide uniform protection even on complex geometries and internal surfaces.
Benefits include:
- Uniform thickness distribution
- Excellent corrosion resistance
- High hardness and wear resistance
- Ideal for precision components
EN is widely used in aerospace, oil & gas, and precision engineering applications.
What is electroplated nickel used for?
Electroplated nickel is typically used for:
- Wear resistance
- Decorative finishes
- Undercoating for chrome or other finishes
- Electrical conductivity applications
At Groupe Altech, nickel plating is used when durability, appearance, or conductivity is required in addition to moderate corrosion protection.
What is cadmium plating and is it still used?
Cadmium plating is a corrosion-resistant coating traditionally used in aerospace and military applications due to its excellent performance in salt environments and its anti-galling properties.
At Groupe Altech, cadmium is handled only where specifically required.
What is anodizing?
Anodizing is an electrochemical process applied to aluminum to increase surface hardness and corrosion resistance.
At Groupe Altech, anodizing also allows for:
- Decorative color finishes
- Improved wear resistance
- Enhanced paint adhesion
- Electrical insulation properties
It is widely used in aerospace, architectural, and industrial aluminum components.
What is black oxide?
Black oxide is a chemical conversion coating applied primarily to steel to improve appearance and provide mild corrosion resistance.
It is commonly used for:
- Fasteners
- Tools
- Mechanical parts
- Automotive components
At Groupe Altech, black oxide is often combined with oil sealing to enhance corrosion protection.
What is passivation?
Passivation is a chemical treatment applied to stainless steel to remove free iron and enhance corrosion resistance.
At Groupe Altech, passivation ensures:
- Improved resistance to rust and staining
- Clean, stable stainless steel surfaces
- Compliance with aerospace and industrial specifications
What is Iridite / Alodine?
Iridite (Alodine) is a chemical conversion coating applied to aluminum.
It provides:
- Corrosion resistance
- Electrical conductivity retention
- Improved paint adhesion
It is widely used in aerospace and electronic applications where conductivity must be preserved.
What is electro-polishing?
Electro-polishing is an electrochemical process that removes a thin layer of metal to improve surface finish.
Benefits include:
- Smoother surface finish
- Reduced friction and contamination
- Improved corrosion resistance
- Hygienic surface for medical and food applications
What is phosphate coating used for?
Phosphate coating is used primarily as a surface preparation layer.
It provides:
- Improved paint adhesion
- Mild corrosion protection
- Reduced friction in mechanical applications
It is commonly used in automotive and industrial manufacturing.
What is salt spray testing?
Salt spray testing is a controlled corrosion test used to evaluate the durability of coatings.
At Groupe Altech, this testing helps verify:
- Corrosion resistance performance
- Coating quality consistency
- Compliance with customer and industry specifications
What is hydrogen embrittlement relief (baking)?
Hydrogen embrittlement relief is a heat treatment process applied after plating high-strength steel parts.
At Groupe Altech, baking is used to:
- Remove trapped hydrogen
- Reduce risk of part failure
- Compliance with customer and industry specifications
Hydrogen embrittlement relief is typically performed following the plating process and after a stress-relief treatment to reduce the risk of hydrogen-induced cracking or snapping in high-strength materials.
Can aluminum, steel, and stainless steel all be plated?
Yes. At Groupe Altech:
- Aluminum typically requires anodizing or conversion coatings
- Steel can be zinc, nickel, cadmium, or black oxide plated
- Stainless steel is typically passivated or electro-polished
Each material requires a specific preparation and plating system.
How long does electroplating last?
Coating lifespan depends on:
- Type of plating
- Thickness
- Environmental exposure
- Maintenance and usage conditions
At Groupe Altech, coatings are engineered to meet customer-specific performance requirements, including high salt spray resistance when required.
Can you plate complex or precision parts?
Yes. Groupe Altech is equipped to process:
- Complex geometries
- Threaded parts
- Internal cavities
- Precision machined components
Our process controls ensure uniform coverage and consistent quality across all parts.