Formation Process of Intermetallic Compounds in Aluminum-Iron P/M Alloys Made by Mecanical Alloying

Abstract

We have recognized that A1-8wt%Fe P/M alloys made by mechanical alloying(MA) for 54ks had tensile Strength of 365MPa at 298K, 258Mpa at 523k. And Main reason is that very small Al-Fe intermetallic compound partickles are dispersed uniformally in the Alminum matrix, Therefore, we tried to clear on the formation process of Al-Fe intermetallic compounds in A1-8wt%Fe P/M alloys made by MA.
According to the XRD patterns of the dispersoids, the specimens of MA and non-annealed powder, MA and 673K annealed powder and MA, 673K annealed and 773K extruded alloy were deeply corroded by phenol at 433K in order to pick out from the aluminum matrix, the MA, non-annealed powder showed only Fe peaks, the MA, annealed powder showed some peaks like Al-Fe intermetallic compounds, and the MA, annealed and extruded alloy showed clearly A13Fe peaks.
On the other hand, according to DTA results of MA and non-annealed powder, two exothermic reactions were obserbed, the one appeared at about 5739, another appeared at about 673K.
From the results of shoves, on the production process of A1-8wt%Fe P/M alloys made by MA, only Fe particles were dispersed in the Aluminum matrix before heating treatments, and the time when the Fe particles began to change Al-Fe intermetallic compounds were in the heating treatment processes.