A Comparative Analysis of Fatigue Behavior between Superalloys and Ceramic Matrix Composites under Extreme Conditions

Dear Colleagues,

The operating conditions experienced by superalloys and CMCs in the hot sections of turbine engines are known to be complex and harsh. The cyclic high temperatures and high stresses impose significant challenges, leading to fatigue phenomena. Furthermore, these critical engine components are subjected to various external and internal surface damages, including corrosion, oxidation, crack formation, erosion, and foreign object interactions. The combination of these factors accelerates the rate of failure caused by fatigue loading on such components.

Traditionally, fault identification and failure investigations into these materials have relied on experimental interpretations, microscopic observations, and non-destructive evaluation (NDE) inspections. Although these methodologies have provided valuable insights, the need for advanced analytical modeling and reliable fatigue life prediction techniques has become increasingly evident. We seek to bridge this gap by exploring state-of-the-art approaches that complement experimental techniques, encompassing the anisotropic attributes of materials and, particularly in the case of single crystals, considering their orientation characteristics.

Additionally, ceramic matrix composites (CMCs) have received significant attention in aerospace applications due to their higher temperature endurance and lighter weight compared to superalloys. Their characteristics are typically different from those of superalloys. They endure relatively higher temperature environments, and they are much lighter. CMCs’ weight is one-third of the weight of nickel (Ni) superalloys and they can operate at temperatures up to 260 °C higher. However, the analytical modelling of engine components composed of CMCs requires complex test-verified progressive damage models capable of capturing all the stages of damage evolution and must consider material processing and manufacturing defects.

This Special Issue seeks contributions that address the comparative analysis of fatigue behavior between superalloys and CMCs under extreme conditions. We encourage original research articles, reviews, and case studies that encompass a wide range of topics, including, but not limited to, the following:

• Experimental investigations and observations of fatigue behavior in superalloys and CMCs;
• Analytical modeling and simulation techniques to assess fatigue life and predict failure probability;
• Anisotropic modeling approaches accounting for the orientation characteristics of single crystals;
• Progressive damage modeling for CMCs, considering material processing and manufacturing defects;
• Applications and case studies in aerospace, defense, automotive, energy and power, and electrical and electronics industries;
• Advanced non-destructive evaluation (NDE) techniques for fault identification and characterization;
• Comparative studies on the performance and durability of superalloys and CMCs under extreme conditions.

This Special Issue aims to provide valuable insights into the fatigue behavior of superalloys and CMCs, supporting a broader understanding of materials’ performance in extreme environments. Moreover, this collaborative effort will facilitate knowledge exchange, foster advancements in analytical modeling, and aid in the development of more reliable fatigue life prediction techniques.

We invite researchers, experts, and professionals to contribute to the comparative analysis of fatigue behavior between superalloys and ceramic matrix composites (CMCs) under extreme conditions. This Special Issue aims to provide comprehensive insights into the performance and durability of these materials in demanding environments, particularly in the context of aerospace and turbine engine applications.

Articles and reviews exploring the life prediction of superalloys, including CMCs, for different market applications, including downstream sponsors, such as manufacturers, vendors, and end users, are welcome. This Special Issue also welcomes studies on various types of superalloys and ceramic matrix composites that are used by end users, such as in the aerospace and defense, automotive, energy and power, electrical and electronic industries.

Dr. Ali Abdul-Aziz
Dr. Theodore E. Matikas
Guest Editors

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• superalloys
• turbine engine
• CMC
• composites
• fatigue
• NDE
• testing
• durability
• single crystal
• characterization
• material defects
• damage and fracture initiation
• material modeling