This paper studies the plastic deformation of a rotating disk made of aluminum dispersion-hardened alloys using mechanical tensile tests and a structured study using optical microscopy methods. Alloys such as AA5056 and A356 with dispersed Al₃Er and TiB₂ particles are used as the initial materials. Tensile strength testing of the obtained alloys shows that the addition of Al₃Er particles in the AA5056 alloy composition leads to an increase in its ultimate stress limit (USL) and plasticity from 170 to 204 MPa and from 14.7 to 21%, respectively, although the modifying effect is not observed during crystallization. The addition of TiB₂ particles to the A356 alloy composition also leads to a simultaneous increase in the yield strength, USL, and plasticity from 102 to 145 MPa, from 204 to 263 MPa, and from 2.3 to 2.8%, respectively. The study of the stress-strain state of the disk was carried out in the framework of deformed solid mechanics. The equilibrium equations were integrated analytically, taking into account the hardening conditions obtained from the experimental investigations. This made it possible to write the analytical relations for the radial and circumferential stresses and to determine the conditions of plastic deformation and loss of strength. The plastic resistance of a disk depends on the ratio between its outer and inner radii. The plastic resistance decreases with increasing disk width at a constant inner radius, which is associated with a stronger effect from the centrifugal force field. At a higher rotational rate of narrow disks, the tangential stresses are high and can exceed the USL value. A356 and A356–TiB₂ alloys are more brittle than the AA5056 and AA5056–Al₃Er alloys. In the case of wide rotating disks, AA5056 and AA5056–Al₃Er alloys are preferable.

In this work, the impact of ErF₃ submicroparticles on the microstructure and mechanical properties of the A359 alloy was studied. ErF₃ particles provided a homogeneous structure in castings produced via the casting method. The modifying effect of ErF₃ particles on the structure of Al–Si alloys is realized through the mechanism of restraining the crystallization front and is achieved through the reduction in the formation of clusters of iron phases and eutectic lamellar silicon. It was found that the addition of 1 wt% ErF₃ to the A359 alloy leads to a decrease in the average grain size by 21% and an increase in the yield strength by 14%, in tensile strength by 16%, in the microhardness of Al₁₅(FeMn)₃Si₂ phase by 34% and in the Al₁₅(FeMnCr)₃Si₂ phase by 7%. The heat treatment of the A359 alloy with ErF₃ particles increased the yield strength by 36% and the tensile strength by 34%. The absence of an effect of ErF₃ particles on the hardness values of the A359 alloy, as well as on the fracture process of the A359 alloy, was observed. The negative influence of ErF₃ particle agglomerates and clusters on the strength characteristics of the investigated alloys was observed. Approaches for further exploring the potential of ErF₃ particles as a strengthening phase in cast aluminum alloys of the Al–Si system were proposed.