Apparent Morphology and Structure of Iron-Rich Phase in Aluminum Alloy

Abstract

This work extracted the iron-rich phases in aluminium alloy containing the iron of 0.3%, 0.6%, 1%, 0.6%, 2% and 5% respectively, and studied the morphology and the structure of the iron-rich phases by using electrolytic extraction technology. The results showed that the iron-rich phase in aluminium alloy is a large number of alpha - Al3Fe and a small amount of lambda - Al13Fe4; the rich iron phases are distributed in aluminum alloy substrate in three-dimensional space, and its metallographic appearances in different sections present sheet, plate and needle-like structure. High resolution electron microscopy shows that lambda - Al13Fe4 and alpha - Al3Fe are tetrahedral structure, and when iron content is 0.3% - 1%, the iron-rich phase transition of lambda - Al13Fe4 to alpha - Al3Fe is influenced by iron content, and alpha - Al3Fe lattice constants a and c are bigger than that of standard value under 0.3% iron content, and alpha - Al3Fe lattice constant a changes little with the increase of iron content, and the lattice constant c becomes larger along with the increase of iron content, and when the iron content is up to 1%, the lattice constant a and c are gradually stabilized; lambda - Al13Fe4 lattice constant a and c are constant.