Clad metal is a composite of two or more dissimilar metals, metallurgically bonded together, to achieve improved functional characteristics, better than those available in a single metal or alloy. The bonding can be achieved by use of one of the various methods, including extruding the two metals, diffusion bonding, pressing or rolling sheets together under pressure and many more.
Clad metals allow combining of desirable characteristics and properties of individual metals and alloys into a material. The resulting component has superior qualities such as improved corrosion resistance, lower porosity and better formability than the individual metals or alloys.
Cladding provides a method of designing a composite material with specific characteristics not available from a single metal. Clad metals can take various forms as dictated by requirements, such as:
- Clad plate
- Clad rod
- Clad tube
- Clad sheet
- Clad wire
The form or shape determines the cladding processes, including:
- Diffusion bonding
- Heavy chemical deposition
- Heavy electroplating
A metal clad is classified according to the types of material and the bonding. Typical categories include inlay clad, overlay clad, solder clad, contact tape clad or any other combinations thereof.
Inlay clad metals are made by integrating precious materials such as gold, platinum, silver and palladium with cheaper materials such as copper, brass and stainless steel. The precious metals are placed at exact places where they are required. The final product is hard, exhibits better wear resistance and is denser with a highly consistent composition as compared to the selective plating process.
Overlay clads are made by a metallurgical technique that bonds together layers of dissimilar metals at high pressure and sometimes heat. This can produce single clad (two layers), double clad (three layers), or even up to seven layers. Overlay clads can also be customized for specific industrial requirements.
Advantages of clad metals include:
- Reduced material and fabrication cost
- Lower porosity
- Better formability
- Design flexibility
- Better thermal and electrical conductivity
- Outstanding corrosion resistance
- Better appearance and improved wear resistance
Clad metals are used in a wide range of applications such as:
- Power generation
- Oil & gas
- Chemical processing
- Structural systems
- Aircraft components
- Home appliances
- Air conditioning
- Metal production
- Aluminum smelting