Ovvg Borden

In materials engineering, cladding is the process of bonding one material (the clad) to another (the substrate) to combine their properties—like corrosion resistance on a strong core. Common methods include:

Methods: - Roll Bonding: Hot or cold rolling two or more sheets together under high pressure. - Explosive Bonding: Using controlled explosives to propel one plate onto another, creating a metallurgical bond at the interface. - Laser Cladding: Melting a powder or wire feedstock onto a substrate with a laser, common for repair or adding wear-resistant coatings. - Extrusion: Co-extruding two materials through a die.

Evaluation: The key is assessing the bond integrity and quality. 1. Non-Destructive Testing (NDT): Ultrasonic testing (UT) is primary—it detects delaminations or voids at the interface. Also, visual inspection, dye penetrant testing. 2. Mechanical Testing: Peel tests, shear tests, and tensile tests on specially prepared samples to measure bond strength. 3. Metallurgical Examination: Cut a cross-section, polish, and examine under a microscope (metallography). Look for a continuous, defect-free interface, diffusion zones, and the absence of cracks or oxides. 4. Corrosion Testing: Expose the clad material to corrosive environments to ensure the clad layer provides the intended protection without peeling.

The specific method and evaluation criteria depend entirely on the materials (e.g., titanium on steel, aluminum on aluminum) and the application (nuclear fuel rods, cookware, chemical tanks). Standards from ASTM or ISO provide detailed procedures.