galling
Galling can also damage two sliding metal surfaces and may completely lock them when they rub each other with great the pressure. It is known to most engineers in fasteners and bearings, or sliding components, because of the high load acting as a friction along both surfaces.

Key Features:

  • Material Transfer & Surface Damage: Contact pressures and frictions produce such high levels that microscopic welding of one metal surface against the other occurs. Severance of small metal particles proceeds with the motions on the surfaces, resulting in rough surfaces, scores, and seizure.
  • Preventive Methods: Minimize direct metal contact by lubrication or anti-seize. Use different material combinations to minimize the probability of bonding. Train surfaces like nitriding, coating, or hardening for better wear resistance. Design suitable smooth surface fasteners with defined tensile torque.
  • Common Applications & Industries: It is evident in the automotive, aerospace, and industrial machinery industries in the form of threaded fasteners, bearings, valves, or sliding parts. Galling has become a bother in the stainless steel and aluminum components since these metals tend to cold weld under considerable stresses.

Galling is a kind of wear. Wear reduces or even completely destroys components or assemblies made from metals. Therefore, damage-preventing strategies and durability development should include materials selection, lubrication, and effective surface treatments against wear in applications with high friction.