Thermal barrier coatings (TBC) are advanced materials typically applied to metal surfaces subjected to extreme temperatures to protect them and increase their lifetime. Ceria stabilized zirconia ceramic layer (CSZ) is increasingly used as an alternative improved as replace for classical TBC system - yttria stabilized zirconia - thanks to superior properties, including mechanical and high resistance to thermal corrosion. The paper describes the thermal shock testing of two types of thermal barrier coatings used to protect a nickel super alloy. For the experimental procedure, it was used plate samples from nickel super alloy with a bond coat and a ceramic top coat. The top coat was different: on some samples, it was used YSZ and on others CSZ. Ni based super alloys have good corrosion resistance in reducing environments action, but poor in oxidizing conditions. Extreme environments can lead to loss of material by oxidation / corrosion, along with decreased mechanical properties of the substrate due to damaging elements which diffuses into the substrate at high temperatures. Using laboratory equipment, the TBC systems were exposed repeatedly to extreme high temperatures for a short time and then cooled. After the thermal shock tests, the samples were morph-structured characterized using electronic microscopy to analyze the changes. The experimental results were compared to rank the TBC systems in order of performance.

Airframe noise generated at wing trailing edges and high-lift devices, such as flaps, remains a major challenge during landing, with significant contributions in the low-frequency band of 500–1500 Hz. While solid surfaces reflect this acoustic energy, metallic porous materials can effectively absorb it through viscous and thermal dissipation within their internal pore structure. To address this, the present study examines the acoustic absorption characteristics of open-cell AlSi porous cylinders featuring controlled pore diameters between 0.3 mm and 2.25 mm. Measurements were conducted in an acoustic impedance tube according to the ISO 10534-2:2023 standard, using six cylindrical samples (28 mm diameter, 70 mm length). Two sets of measurements were performed for each sample (front and rear faces), and the average values were used. The findings indicate that the normal-incidence sound absorption coefficient α rises as pore size increases, reaching 0.93–0.97 at low frequencies of 500–700 Hz for the samples with the largest pores (1.8–2.25 mm). These results indicate that open-cell AlSi alloys offer strong low-frequencies sound absorption, positioning them as promising options for aeroacoustic noise mitigation, including applications such as porous trailing edge and hybrid flap designs.

This study focused on the development of a new concept for ablative thermal protection material, using a relatively new polymer matrix based on polysiloxane resin, which exhibits high-performance thermal properties. As a reinforcing element, graphite felt (GF/UHT) was selected. These new ablative materials were tested and characterized to evaluate their thermal properties through comparison with established/standard ablative materials based on phenolic resin and graphite felt (GF/Isophen). To evaluate them, two distinct types of thermal tests were performed. The first consisted of subjecting the ablative materials to a temperature of 1100 °C for a total duration of 10 min (with three different dwell times: 30 s, 120 s, and 300 s). A mass loss of 31% was recorded for the GF/UHT ablative material samples compared to the GF/Isophen material, where the mass loss reached approximately 68%. The second test consisted of exposure to an oxyacetylene flame at a temperature of 1600 °C. The GF/UHT samples had an improved behavior compared to the GF/Isophen samples, the latter being completely penetrated at the end of the test. Additionally, differential scanning calorimetry (DSC) tests were performed and characterized by FTIR spectroscopy and scanning electron microscopy.

This chapter discusses the importance of zirconium-based materials in the aerospace industry, highlighting their need for high-performance applications due to their properties, such as low weight, good resistance to high temperatures and corrosion. The basic aspects of zirconium and its compounds are analyzed and the crystal structure, physical and mechanical characteristics important for severe applications are highlighted. A detailed description is dedicated to specific applications, illustrating the use of zirconium-based materials in critical components of aircraft engines, thermal protection systems for space vehicles, high-performance sensors, and equipment for hostile environments. Potential emerging applications, such as lightweight structural elements and components for braking systems, are also explored. Finally, the chapter identifies current challenges related to cost, processability, and long-term reliability. Research and development directions aimed at improving performance and expanding the scope of applicability are presented, along with anticipated future trends in the use of advanced ceramic materials in the aerospace sector.

Glass-fiber-reinforced polymer composites are of interest for lightweight structural applications, including marine structures, where accidental low-velocity impact is an important design consideration. This study investigates the low-velocity impact response of polyester-matrix composites reinforced with 4 layers, 6 layers, and 8 layers of biaxial glass fabric. A progressive test program, designed according to the number of fabric layers, used increasing impact-energy levels to cover both an indentation-dominated non-perforating regime and complete perforation, with the transition toward complete perforation in each configuration guiding the energy range selected for the configuration with the next higher number of fabric layers. Instrumented drop-weight tests with a 16 mm hemispherical impactor were analyzed using force, displacement, velocity, and energy histories. At the highest fully non-perforating energy levels of 30 J, 60 J, and 100 J, maximum contact forces were 7.25 kN, 13.05 kN, and 17.45 kN, while absorbed energies were approximately 28.7 J, 54.1 J, and 95.3 J. At 40 J, 80 J, and 120 J, respectively, the composite series entered the transition regime, with complete perforation observed for some of the tested specimens. The investigated parameters showed different diagnostic values: some were sensitive to the impactor mass–velocity combination, whereas displacement, energy, and velocity histories more clearly reflected the change in impact regime. The progressive test campaign, extended up to complete perforation, provides a practical means of identifying the transition between impact regimes and establishing application-specific impact limits. For design purposes, components exposed to accidental impact should therefore incorporate an adequate margin below the experimentally identified transition energy range.