EFFECT OF INCLUSIONS ON THE SOFTENING MECHANISM OF Al 1235 ALLOY DURING THERMAL DEFORMATION

Abstract

The effect of inclusions on the softening mechanism of a pure aluminum alloy is studied with TEM, EDAX and SAED. Oxide inclusions and iron-rich second-phase particles are the main inclusions in Al 1235 alloy. The phase of iron-rich particles in the alloy is phase AlFe3 with a lattice constant of 5.79 and crystal band axis of Š 231Æ. During thermal deformation, coarser inclusions in the alloy are beneficial to the nucleation of dynamic recrystallization, but they have a great effect on the separation of the alloy matrix. Nucleation and growth of dynamic-recrystallization grains are restricted by finer inclusions, reducing the possibility of aluminum-matrix fracture. The preferred places for dynamic-recrystallization nucleation include boundaries at the intersection of three grains, the dislocation plug area, the surface of the coarse oxide inclusions or the coarse second-phase inclusions.