Formation of bulk metallic glass in situ composites in Cu50Zr45Ti5 alloy

The structure and mechanical property of the Cu50Zr45Ti5 bulk metallic glass in situ composites prepared by copper mold casting are investigated. It was found that nanocrystals with the sizes ranging from 2 to 10 nm distributed homogeneously in the glassy matrix for the Cu50Zr45Ti5 rod with a diameter of 1.5 mm. The 2.5 mm Cu50Zr45Ti5 rod is a kind of gradient composite, consisting of crystalline phase in the central part and glassy phase in the outer part. The yield strength and elastic–plastic strain for the 1.5 mm Cu50Zr45Ti5 rod are 1680 MPa and 10.6%, respectively. For the 2.5 mm Cu50Zr45Ti5 rod, the yield strength and elastic–plastic strain are 1020 MPa and 18% coupled with evident work hardening behavior. The ZrCu phase precipitated from the Cu50Zr45Ti5 rod shows evident plastic deformation, which contributes to the high ductility of the Cu50Zr45Ti5 bulk metallic glass in situ composites.