Regime 2 — Interfacial Detachment

Interfacial detachment removes coatings by fracturing the adhesive bond at the coating-substrate interface rather than ablating the coating bulk. A short nanosecond pulse creates a compressive stress wave that propagates through the coating and reflects as a tensile wave at the free surface (top of the coating) — when the tensile stress exceeds the coating's adhesion strength, delamination occurs. This mechanism is particularly effective for multilayer paint stacks, powder coatings, and anodize layers where the coating itself is not strongly absorbing at 1064 nm.

The substrate receives minimal thermal input because the energy converts to mechanical stress rather than heat. Paint removal from aerospace alloys often uses this mechanism — Ti-6Al-4V paint removal at 0.9–1.1 J/cm² achieves full coating detachment with substrate Ra unchanged within measurement tolerance.