Production of Bulk Glassy Alloy Parts by a Levitation Melting-Forging Method

Abstract

A levitation melting-forging (LMF) method was developed to prepare glassy Zr₅₅Cu₃₀Ni₅Al₁₀, Ni₅₃Nb₂₀Ti₁₀Zr₈Co₆Cu₃, Ti₄₅Cu₂₅Ni₁₅Zr₅Sn₅Al₅ and Cu₅₅Zr₂₅Ti₁₅Ni₅ alloy parts with various shapes of coin, ring and dumbbell of 1 mm in thickness. The glassy alloy samples of 1 mm in thickness for tensile test were also produced by the LMF method. These samples were shaped directly from liquid without any intermediate process. The glassy structure in the samples examined by XRD and DSC is independent of sites. The results show the absence of partial crystallization in the glassy alloy coin prepared by LMF, however, a small quantity of crystallization is found in the glassy alloy coin prepared by copper mold casting. This may be due to the suppression of heterogeneous nucleation resulting from non-contact with container. The density of defects in the glassy alloys prepared by the LMF was decreased significantly because of the absence of spurt.