The effect of nickel on shaping the structure of Al-Cu-Mn alloys

Abstract

This study investigated the effect of nickel on shaping the structure of aluminum alloys of the Al-Cu-Mn type in the "as-cast" condition and after heat treatment according to the T6 procedure. The aluminum alloys of type Al-5%Cu-1%Mn, containing nickel in a range of up to 1.9%, were taken into consideration in this work. Experiments were carried out for thin-walled thickness casting (g = 5 mm) and for reference casting with a wall thickness of g = 35 mm. Metallographic investigations of both the macro-and micro-structure were conducted to estimate the secondary dendrite arm spacing (SDAS), average diameter (dav) of the primary α (Al) grains, and surface fraction of the interdendritic phases (f). Moreover, the degree of dissolution of these interdendritic phases during the solution treatment process was determined. An SEM-EDS analysis was conducted, from which it follows that the addition of nickel at the level of 0.5% changes the un-dissolved particles from a needle-like β-Fe shape to blocky and coagulated. Higher additions of nickel starting from 0.88%) give rise to as many as four phases with higher copper content, the deficit of which results in the smaller strengthening effect of α (Al) dendrites.

Archives of Metallurgy and Materials

“…Al-Cu-Mn alloys are high-strength materials that are widely used in the aerospace and automotive industries [1,2]. This is due to their favorable properties at both ambient and elevated temperatures [1][2][3]. Compared to other alloys, these are distinguished by considerable strength and lightness [1,3].…”

“…This is due to their favorable properties at both ambient and elevated temperatures [1][2][3]. Compared to other alloys, these are distinguished by considerable strength and lightness [1,3]. Highquality Al-Cu-Mn alloys have excellent mechanical properties after T6-type heat treatment.…”