Microstructure- and plasticity-based fatigue and defect tolerance assessment of age-hardenable Al-Si cast alloys in LCF and HCF regime. (January 2023) - Tenkamp, Jochen
Highlights: Characterization and comparison of process-induced effects on quasi-static and cyclic stress–strain behavior of AlSi7Mg0.3. Correlation of deformation with fatigue behavior by means of (non-dimensional) S-N curves (Murakami approach). Understanding of the increased LCF damage tolerance and the similar HCF damage tolerance of sand compared to die castings. Analysis of phase-specific effects on the cyclic deformation behavior by means of local cyclic indentation testing. Abstract: Due to their excellent strength-to-weight ratio and near- net -shape manufacturing possibility, precipitation hardening Al-Si cast alloys are promising candidates for cost-efficient lightweight components in the automotive and railway industry. In this work, the microstructure and the fatigue properties of cast AlSi7Mg0.3-T6 (A356-T6) were analyzed, whereby the influence of a variation in solution annealing, hot isostatic pressing (HIP) densification, solidification rates as well as casting processes, i.e., gravity die and sand casting on the fatigue behavior and fatigue damage tolerance was investigated. Sand castings exhibit a decelerated fatigue crack initiation and enhanced LCF damage tolerance compared to die castings.