Icosahedral phase formation in high silicon and manganese content AlMnSi alloys

Abstract

Single-phase icosahedral AlMnSi alloys containing up to 30 at.% Mn and 33 at.% Si have been prepared directly by quenching from the melt. Alloys of the series Al 70− x Mn x Si 30 (10⩽ x⩽30), Al 80−xMn 20Si x (6⩽ x⩽40) and Al 67−xMn xSi 33 (28⩽ x⩽32) were investigated. The regions of x for the formation of single-phase icosahedral alloys by direct quenching are x ≈ 26, x ⩽ 20 and x ≈ 29 for the three series respectively. These alloys have quasi-lattice constants in the range 0.437–0.461 nm. Details of the structural properties of these alloys as well as their thermal stability as a function of composition are discussed.