Thermography assisted mechanical testing of Cold-Spray (AM) repair

Cold Spray Additive Manufacturing (CSAM) is a solid-state process increasingly used for structural repairs in aerospace and energy sectors. It enables the deposition of dense material at low temperatures by accelerating metal particles to supersonic velocities, thereby reducing thermal distortion. However, the structural integrity of CSAM repairs—particularly at the interface between the deposited layer and the substrate—remains a critical concern. Various post-treatments and characterisation methods have been explored to optimise performance. While X-Ray Computed Tomography (XCT) is effective for sub-surface inspection, it cannot be applied in-situ during mechanical testing. Digital Image Correlation (DIC), a surface-based method, also lacks sub-surface sensitivity. To address this, Infrared Thermography (IRT) was employed alongside DIC during tensile and fatigue testing of aluminium CSAM-repaired specimens. A cooled IRT camera operating at 200 FPS captured thermal data, with Lock-in processing subsequently applied in post-processing. IRT successfully detected early interfacial damage and enabled tracking of crack propagation, which was later confirmed through fracture surface analysis. This extended abstract presents findings from fatigue tests using IRT. Results from DIC and tensile tests will be discussed during the conference presentation.