In-situ Investigation of Composition and Temperature Effects on Damage Evolution in Structural Engineering Alloys

Abstract

Structural engineering alloys used in high-performance applications, such as aerospace and automotive components, must withstand complex (thermo-)mechanical loading conditions across a range of service temperatures. Their mechanical reliability depends strongly on microstructural characteristics, which evolve during thermal exposure and mechanical loading. This talk addresses the influence of alloy composition and test temperature on damage initiation and progression in cast and AM structural alloys using in-situ synchrotron X-ray tomography. Emphasis is placed on the evolution of rigid microstructural networks - such as intermetallic or second-phase reinforcements - embedded in a ductile matrix and their role in mechanical performance. The experimental results demonstrate that variations in chemical composition significantly alter the morphology and connectivity of these networks, thereby affecting their load-bearing capability. In addition, temperature-dependent damage mechanisms were identified, showing increased degradation of the microstructural network with rising temperature. The use of high-resolution 4D imaging allowed for direct observation of crack nucleation and propagation in real time, revealing correlations between local network connectivity and mechanical integrity. These findings highlight the importance of composition-sensitive design and temperature-aware performance assessment in structural alloy development.