Thermally-Activated Martensitic Transformation Behaviour Below Room Temperature in CuZr-Based Bulk Metallic Glass Composites

Abstract

During the thermally-activated martensitic transformation (MT) of CuZr-based bulk metallic glass (BMG) composites containing B2 CuZr crystals, the MT temperatures were reduced to 162.7 ± 2.5 K due to the constraint effect from glassy matrix, which is far lower than those of crystalline counterparts. In situ high-energy X-ray diffraction measurements demonstrate that the thermally-activated MT is governed by an extremely incomplete MT from B2 to B19' and B33 phases without the decomposition of B2 phase which appears in crystalline counterparts. Due to free stress states during the thermally-activated MT, B33 phase forms more easily during thermal process than deformation process.

Keywords: Bulk metallic glasses, Composites, Martensitic transformation, High-energy X-ray diffraction