Precise control of iron-containing phases is key to developing high-performance cast-rolled aluminum alloy sheets. This study investigates the effects of Mn and Zr on these phases in 6061 alloy. Adding 0.4 wt.% Mn raises the formation temperature of the AlFeMnSi phase, promoting the transformation from α-AlFeSi to AlFeMnSi. This increases the AlFeMnSi mass fraction from 0.07 to 0.624% while reducing α-AlFeSi from 0.13 to 0.04%. The combined addition of 0.3 wt.% Zr further refines the iron-containing phases, reducing their average size from 4.8 to 0.4 μm. The mechanism involves Zr inhibiting Si diffusion. The adsorption energy of Al 3 Zr for Si (− 4.75 eV) is higher than that of the θ-AlFe phase (− 4.62 eV), reducing Si segregation in iron-containing phases and suppressing their continuous growth. Additionally, Al 3 Zr alters and inhibits the growth direction of AlFeMnSi, synergistically promoting refinement. Consequently, the synergistic microalloying of Mn and Zr yields the optimal mechanical properties: a yield strength of 109.3 MPa, a tensile strength of 227.4 MPa, and an elongation of 15.3%.
Tian et al. (Wed,) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: