Mechanical and magnetic properties of the rapidly quenched Cu₂MnAl

Abstract

Rapidly solidified Cu₂MnAl ribbons were fabricated by the chill-block melt-spinning technique as a function of rotation speed of an iron roller. The rapidly quenched ribbons were relatively ductile, and the total strain at failure for the bend test increased with increasing rotation speed of the roller. The effect of rapid quenching on long-range ordering in Cu₂MnAl alloy was studied by X-ray diffraction. The decomposition characteristics during isothermal ageing at temperatures between 350 and 600° C were also examined by X-ray diffraction, magnetization and Vickers hardness measurements. The decomposition reaction at temperatures below 400° C was Cu₂MnAl→γ-Cu₉Al₄+T-Cu₃Mn₂Al+β-Mn. However, at temperatures between 500 and 600° C, Cu₂MnAl decomposed into a new L2₁ type Cu₂MnAl andβ-Mn, and further annealing caused the appearance ofγ-Cu₉Al₄. The decomposition rate of the rapidly quenched ribbons was faster than that of the water-quenched alloy.