In this study, an Al-Zn-Mg-Cu alloy with Ni added as alloying element was synthesized via spray deposition. The element was present in the alloy in the form of spherical submicrometer Al₉Fe_0.7Ni_1.3 compound particles. The effects of the particles on the microstructure and mechanical properties of the alloy after a solution treatment were investigated by scanning electron microscopy (SEM) in conjunction with electron backscatter diffraction (EBSD), transmission electron microscopy (TEM) and tensile tests. We found that the Al₉Fe_0.7Ni_1.3 compound particles were mainly present near the grain boundaries, revealing a powerful recrystallization inhibition effect during the solution treatment. After the solid solution treatment, the alloy exhibited an ultimate tensile strength of 603 MPa and an elongation at break of 11.79%, and transgranular ductile fracture was identified as the main fracture mechanism. The results show that the presence of the spherical submicrometer Al₉Fe_0.7Ni_1.3 compound particles played a key role on the mechanical properties of the alloy, leading to grain refinement strengthening and Orowan strengthening, and was the main reason for the occurrence of transgranular ductile fracture.