To obtain high gas turbine efficiency, a film cooling hole is introduced to prevent the destruction of thermal barrier coating systems (TBCs) due to hot gases. Furthermore, environmental calcium-magnesium-aluminum-silicate (CMAS) particulates plug the film cooling hole and infiltrate the TBCs to form a CMAS-rich layer, which results in phase transformations and significant modifications in the thermomechanical properties that impact the TBCs during cooling. This study aimed to establish a three-dimensional thermo-fluid-solid coupling TBCs model with film cooling holes and CMAS infiltration to analyze the temperature and residual stress distribution via simulations. For the interfacial stress around the cooling hole at the TC/BC interface, the film cooling holes alleviated the interfacial residual stress by 60% due to the reduction in temperature by 40%. In addition, CMAS infiltration intensified the interfacial residual stress via phase transformation. As a result of the influence of larger penetration depths and expansion rates of phase transformation, a significant increase in residual stress was observed. At the beginning of CMAS infiltration, the interfacial stress would be more dominated by the effect of infiltration depth. In addition, the failure due to interfacial normal and tangential stresses was more likely to be found at the infiltration zone near the cooling hole.

In this work, the microstructural deformation and damage mechanisms of TRIP steel metal matrix composites (MMCs) reinforced with Magnesia Partially Stabilized Zirconia (Mg-PSZ) particles are investigated by employing in situ tensile testing within a scanning electron microscope chamber, complemented by digital image correlation and advanced image processing techniques. The study is carried out on samples with varied volume fractions (0%, 10%, and 20%) of zirconia particles and damage mechanisms in different samples under specified loading conditions. Through both qualitative and quantitative assessments of deformation, damage, and clustering, the investigation provides a comprehensive understanding of the distribution and damage initiation. The study findings reveal that, generally, the steel matrix exhibits high toughness, with minimal occurrences of microcracking at high strains that cause significant damage. In samples with increasing particle content, delamination at the matrix–particle interface and cracking of Mg-PSZ particles were found to be critical contributors to material failure and were quantitatively analyzed using computational analyses conducted with MATLAB. The work highlights the initiation and evolution of each damage mechanism in zirconia particle-reinforced TRIP steel MMCs to facilitate scientists and engineers in improving manufacturing and application decisions in industries such as automotive, aerospace, and heavy machinery, which demand materials with exceptional toughness and durability. Graphical Abstract

In this study, the effect of the energy release rate on the transformation-induced plasticity (TRIP) steel composite reinforced with 5 vol% ceramic particles is determined using the crystal plasticity simulation of the coupled brittle-ductile damage model and validated by experimental results. A miniature dog bone tensile sample is subjected to an interrupted in situ quasi-static tensile test up to a true strain of 20.3%. Using the commercial digital image correlation program VEDDAC and the image processing method in MATLAB, the test data are utilized to monitor the progress of local microstrain and damage. The impact of the energy release rate of ceramic particles is investigated by simulation using a coupled crystal plasticity-dislocation density model with ductile–brittle criteria for the corresponding phases. It can be shown that the local deformations predicted by the numerical simulation and the experimental data are qualitatively comparable. The damage pixel of the experiment, smaller E_cr (1.0 × 10⁸), and larger E_cr (1.2 × 10⁸) cases of energy release rates are 4.9%, 4.3%, and 5.1%, respectively. Furthermore, on a global strain of 20.3%, the relative error between simulation and experimental validation of smaller E_cr (1.0 × 10⁸) and larger E_cr (1.2 × 10⁸) cases is 12.2% and 4%, respectively.