Preparation and mechanical behavior of Mg-based bulk metallic glasses and their matrix composite

Abstract

Mg_87−xCu _xDy₁₃(x=22,27,32) bulk metallic glasses (BGMs) with a diameter of 6–8 mm and in-situ Mg phase reinforced Mg₇₀Cu₁₇Dy₁₃ BMG matrix composite with a diameter of 3 mm have been prepared by copper mould casting. The glass forming ability (GFA) of Mg-Cu-Dy alloys have been investigated by differential scanning calorimetry (DSC) and X-Ray diffraction (XRD) and tne mechanical properties have been measured. Results show that Mg_87−xCu _xDy₁₃(x=22,27,32) alloys in the Mg-Cu-Dy alloy system exhibit excellent GFA, and Mg₆₀Cu₂₇Dy₁₃ alloy has the largest GFA among these alloys. And In-situ Mg phase reinforced Mg₇₀Cu₁₇Dy₁₃ BMG matrix composite exhibits some work hardening and a high fracture compressive strength of 702.38 MPa and some plastic strain of 0.81%. The improvement of the mechanical properties is attributed to the fact that the Mg phase distributed in the amorphous matrix of the alloy has some effective load bearing and plastic deformation ability to restrict the expanding of shear bands and cracks and produce its own plastic deformation.

Keywords

Mg-Cu-Dy alloys / glass forming ability / composites / mechanical properties

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