Abstract

We report the crystallization and magnetic properties of non-equilibrium Al_0.6(Fe_xCu_1-x)_0.4(x=0.25, 0.50, 0.75) alloy powders produced by rod-milling as well as by new chemical leaching. X-ray diffractometry, transmission electron microscopy, differential scanning calorimetry and vibrating sample magnetometry were used to characterize the as-milled and leached specimens. After 400 h or 500 h milling, only the broad peaks of nano bcc crystalline phases were detected in the XRD patterns. The crystallite size, the peak and the crystallization temperatures increased with increasing Fe. After being annealed at 600circC for 1 h for as-milled alloy powders, the peaks of bcc AlCu_4;and;Al_13Cu_4Fe_3;for;x=0.25,;bcc;AlCu_4;and;Al_5Fe_2;for;x=0.50,;and;Al_5Fe_2,;and;Al_0.5Fe_0.5;for;x=0.75 are observed. After being annealed at 500circ;and;600circCfor 1 h for leached specimens, these non-equi-librium phases transformed into fcc Cu and CuFe_2O_4phases for the x=0.25 specimen, and into bcc alpha-Fe,;fcc;Cu,;and;CuFe_2O_4 phases for both the x=0.50 and the x=0.75 specimens. The saturation magnetization decreased with increasing milling time for Al_0.6(Fe_xCu_1-x)_0.4 alloy powders. On cooling the leached specimens from 800~850°C,;the magnetization first sharply increase at about 491.4°C,;745°C,;and;750.0°C for x=0.25, x=0.50, and x=0.75 specimens, repectively.

• Keywords: Al(Fe-Cu) system;Rod mi]ling;Chemica] leaching;;