Thermal Gradient Behaviour of TBCs Subjected to a Laser Gradient Test Rig: Simulating an Air-to-Air Combat Flight

A computer-controlled laser test rig (CO₂ laser) offers an interesting alternative in evaluating TBCs. The temperature gradient between the top and back surfaces of a TBC system can be controlled based on the laser power and a forced air back-face cooling system. Complete aircraft missions can be simulated. APS TBCs were tested. Based on experimental data available in the literature, the temperature gradients in TBCs (YSZ top coat and substrate back-face) and their respective frequencies during air combat air-to-air missions of fighter jets were replicated. The missions included (i) idle on the runway, (ii) take-off and climbing, (iii) cruise trajectory to rendezvous zone, (iv) air-to-air combat maneuvering, (v) cruise trajectory back to runway and (vi) idle after landing. The results show that the TBC thermal gradient experimental data in turbine engines can be replicated in the laser gradient rig, leading to an important tool to better engineer TBCs.