Abstract
This study investigates the effect of micro-alloying elements (Ti, Zr and Sc) on the crack tip damage behaviour of cast Al-6Zn-2.1Mg-2Cu-X alloys to understand the effect of grain boundary interfaces, matrix, intermetallics and dispersoids on deformation and fracture behaviour. Notched tensile specimens were prepared and subjected to in-situ tensile deformation under FESEM to investigate the crack initiation, propagation, and eventual failure processes under uniaxial tensile loading. The experimental results reveal that fracture in the four Al-6Zn-2.1Mg-2Cu-X alloys is quasi-brittle due to strain accumulation and cleavage fracture mechanisms. The crack mainly initiates from the grain boundary lath S-Al2CuMg and η-MgZn2 intermetallic phases. Adding 0.25 % Sc forms small coherent Al3(Sc, Zr) dispersoids, increasing crack resistance. The ductility of the matrix is due to void nucleation, crack meandering, and crack tip-blunting phenomena. At high additions of microalloying elements (1 wt%), large Al3(Zr, Ti) intermetallics form and agglomerate, contributing to premature fracture. These findings from materials characterization and in-situ tensile testing indicate potential methods to enhance the fracture toughness of Al-6Zn-2.1Mg-2Cu alloys with additions of Zr, Ti, and Sc.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
