Compression Behavior of Mg-Cu-Gd Bulk Metallic Glasses with Various Specimen Height to Diameter Ratios

Abstract

The mechanical behavior of the Mg₆₅Cu₂₅Gd₁₀ bulk metallic glasses (BMGs) in term of compression testing is reported in this study. Room-temperature compression tests are conducted on specimens with various height to diameter ratios (h⁄d) from 2:1, 1:1, 1:2, to 1:4. The failure strength, deformation strain, and the fracture surface morphologies are seen to vary systematically in accordance with the specimen h⁄d ratio. For specimens with h⁄d of 2:1 or 1:1, the compression response is similar to those in most reports. In contrast, for specimens with lower h⁄d ratios, especially at h⁄d=1:4 (or 0.25), the shear band propagation appears to be constrained, resulting in the enhanced ductility. It suggests that different deformation mechanisms are operative for specimens with different h⁄d ratios. The possible deformation mechanisms in specimens of different geometries are discussed.