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.