Effects of Sn addition on phase formation and mechanical properties of TiCu-based bulk metallic glass composites

A unique combination of macroscopic properties including high strength, large plasticity and strong work-hardening behavior was realized in TiCu-based bulk metallic glass (BMG) composite with proper addition of Sn. It was found that proper addition of Sn induced formation of BMG composites consisting of a single B2-TiCu phase via suppressing precipitation of the brittle CuTi2 and ZrTiCu2 intermetallic compounds. With excessive Sn addition, however, glass forming ability of the resultant alloys was severely decreased due to formation of additional Zr5Sn3 phase. Moreover, desirable elastic mismatch (e.g., Young's modulus and hardness) between the reinforcing crystalline phase and amorphous matrix, resulted from the Sn addition, remarkably accommodated large plasticity and strong work-hardening capability of the current BMG composites.