LAUSR

Inconel 718 modified by magnesium and calcium was investigated in order to improve the ductile fracture properties of the alloy. Three different types of Inconel 718 containing 50 ppm Mg, 40 ppm Ca, and no trace elements were prepared by vacuum induction melting processes, rolled, and heat-treated. Tension and impact properties were tested at the room temperature and in the longitudinal and transverse directions. Fractographic and microstructural analyses were done by FESEM examinations. Reduction in area and impact energy was improved by 10–50% in the transverse direction, whereas strength was not changed by adding Ca and Mg. Also, these properties did not show any significant variations in longitudinal specimens. MC-type carbide was formed in solidification and rearranged as stringer during the rolling process, significantly reducing the impact energy of Inconel 718 on transverse samples. Ductile anisotropy was modified as the carbide shape and size were refined in the as-cast microstructure of Mg and Ca alloys.