Thermal barrier coatings (TBCs) are widely used in the hot sections of gas turbine systems as they are remarkably efficient in insulating the underlying superalloys, leading to higher operating temperatures and therefore enhancing the performance of the engines. However, this benefit is only possible if the integrity of the TBC under aggressive thermo-mechanical environments is ensured. Delamination is a common but hard to detect failure mode. We present, in this work, supported by experimentation, the implementation of a modeling approach applying the Kubelka-Munk theory to provide numerical quantification of luminescence contrast and intensity due to top coat delamination in TBCs. The method relies on the drastic change in reflectivity when a delamination forms, exploiting it for high-contrast luminescence mapping. Two distinct TBC configurations containing an erbium-doped yttria-stabilized zirconia (YSZ:Er³⁺) layer for delamination sensing were used to validate this model. A delamination zone induced by Rockwell indentation was successfully tracked by measuring an increase of the intensity of the erbium emission line at 562 nm. Luminescence-based methods for delamination detection can provide a revolutionary non-invasive technique, with potential for both off-line and on-line engine monitoring.

热障涂层（TBC）广泛用于燃气轮机系统的高温区域，因为它们在隔离下面的高温合金方面非常有效，从而导致更高的工作温度并因此提高了发动机的性能。但是，只有确保在侵蚀性热机械环境下TBC的完整性，才能获得此好处。分层是一种常见的但很难检测到的故障模式。在实验的支持下，我们在这项工作中提出了一种应用Kubelka-Munk理论的建模方法的实现，以提供由于TBC中的面涂层分层而导致的发光对比度和强度的数值量化。该方法依赖于分层形成时反射率的急剧变化，并将其用于高对比度发光映射。用于分层传感的³⁺）层用于验证该模型。通过测量562 nm处的emission发射线强度的增加，成功跟踪了由洛克威尔压痕引起的分层。基于发光的分层检测方法可以提供一种革命性的非侵入性技术，具有离线和在线发动机监控的潜力。