Large Compressive Plasticity of Brittle La₆₉Co₁₇Al₁₄ Bulk Metallic Glass Under Constrained Compression

Abstract: Catastrophic brittle failure prevents the application of bulk metallic glasses (BMGs).The brittle La₆₉Co₁₇Al₁₄ BMG shows large compressive plasticity when compressed in constrained conditions. Here the compressive plasticity of this BMG was systematically studied by decreasing aspect ratio (height/diameter) of the samples in uniaxial compression and the brittle-ductile transition occurs at an aspect ratio of 0.36. With the increase of the plasticity (decrease of the aspect ratio), the hardness decreases firstly and then increases, however, the relaxation enthalpy indicating its structure increases monotonically. Our findings provide a powerful experimental support for the application of brittle La-based BMGs. Graphic Abstract : [Figure not available: see fulltext.].