Dr. mont. Patrick Willenshofer’s recent publication, “Influence of alloy chemistry and overaging on mechanical properties and corrosion resistance in aluminium crossover alloys”, is a remarkable contribution to the rapidly evolving field of advanced aluminium alloy development.
This paper investigates the nuanced interplay between alloying elements and thermal history in novel AlMgZn-based crossover alloys enriched with copper and silver. Through a robust combination of tensile testing, hardness measurement, and advanced electrochemical analyses such as Potentiodynamic Polarisation (PDP) and Electrochemical Impedance Spectroscopy (EIS), Dr. Willenshofer elucidates how noble element additions, while beneficial for mechanical strength, detrimentally affect corrosion resistance, thus challenging the conventional trends known from new 5xxx and 7xxx crossover alloy systems.
What distinguishes this work is its depth of microstructural insight achieved through SEM and (S)TEM. The research links specific features – such as grain boundary precipitates, PFZs, and precipitate morphologies – to macroscopic behavior under corrosive environments. Particularly noteworthy is the finding that double-step overaging promotes precipitate coarsening, which in tandem with Cu and Ag addition, enhances strength at the expense of surface stability due to galvanic effects and oxide degradation.
Dr. Willenshofer’s doctoral research sets a benchmark in alloy design, offering critical perspectives for tailoring aluminium alloys in applications demanding both strength and corrosion resistance — such as in automotive and aerospace sectors.
This paper was possible due to a very nice collaboration Patrick got us with the University of Padova and the National Research Council of Italy, to whom I am very grateful and pleased!
Open access paper: P.D. Willenshofer et al. Influence of alloy chemistry and overaging on mechanical properties and corrosion resistance in aluminium crossover alloys. Materials & Design 254 (2025) 114046. https://doi.org/10.1016/j.matdes.2025.114046
Materials at Extremes 