The article presents research results performed on aluminum bronze CuAl10Fe5Ni5 (BA1055) castings used for marine propellers.

Metallographic studies were made on light microscope and a scanning electron microscope to assess quantitatively and qualitatively the

alloy microstructure. It has been shown that the shape, size and distribution of the iron-rich κ−phase precipitates in bronze microstructure

significantly affect its mechanical properties. With an increase in the number of small κ−phase precipitates increases the tensile strength of

castings, while the presence of large globular precipitates improves ductility. Fragmentation and shape of κ−phase precipitates depends on

many factors, particularly on the chemical composition of the alloy, Fe/Ni ratio, cooling rate and casting technology.