Cladding is primarily done by bonding together dissimilar metals, often achieved through methods like extruding metals through a die or pressing or rolling sheets together under high pressure.
Understanding Metal Cladding
Cladding is a process used to combine different metals, creating a composite material that leverages the best properties of each component. Unlike welding, which involves melting and fusing metals, or gluing, which uses an adhesive, cladding creates a strong, permanent bond between the metal layers.
This technique is distinct because it relies on mechanical forces or controlled heating processes (like in extrusion) to forge a metallurgical bond without fully melting the base metals. This makes cladding valuable for applications requiring specific surface properties, such as corrosion resistance (from one metal) combined with structural strength or lower cost (from another metal).
Key Methods for Cladding
Based on common practices and the provided information, here are the primary ways cladding is performed:
- Extrusion: This method involves forcing two or more metals simultaneously through a shaped opening (a die) under high pressure and often elevated temperature. The intense pressure and heat (from friction and preheating) cause the metals to bond metallurgically as they are extruded.
- Pressing: This involves placing sheets or layers of different metals together and applying significant pressure, sometimes with heat, to create a solid-state bond. This pressure deforms the surfaces microscopically, bringing them into intimate contact and allowing atomic diffusion to occur across the interface, forming the bond.
- Rolling: Similar to pressing, rolling involves passing layered metal sheets through rollers under high pressure. This process reduces the thickness of the layers while simultaneously bonding them together. Heat can also be applied during rolling to facilitate the bonding process.
The method chosen depends on the specific metals being bonded, the desired thickness of the layers, and the final application of the cladded material. For example, cladding aluminum with stainless steel for cookware might use rolling or explosive bonding (another method not mentioned in the reference but common), while cladding pipes might use extrusion.
