New Cu-based bulk glassy alloys exhibiting a large supercooled liquid region and good mechanical properties were formed in Cu-Zr-Ti-M (M=Fe, Co or Ni) systems by copper mold casting. The maximum diameter for glass formation was up to 4 mm for the Cu-Zr-Ti-Ni alloys. The addition of Co or Ni element caused an extension of a supercooled liquid region (ΔTx = Tx - Tg) from 38K for Cu60Zr30Ti10 to 54 K for (Cu0.6Zr0.3Ti0.1)95Co5 and 60 K for (Cu0.6Zr0.3Ti0.1)95Ni5, accompanying the change in the crystallization mode from two stages to a single stage. The crystallization of the 5%Ni alloy occurs through the direct precipitation of a metastable (Cu,Ni)10(Zr,Ti)7 phase from the supercooled liquid. The compressive fracture strength (σc,f) and plastic strain (εp) are in the range of 1830 to 2030 MPa and 0.3 to 1.7%, respectively, for the 1 to 4%Fe alloys, 1900 to 1920 MPa and 1.0 to 1.2%, respectively, for the 1 to 5%Co alloys and 1900 to 1960 MPa and 0.6 to 1.9%, respectively, for the 1 to 6%Ni alloys. The best combination of σc,f and εp was 2030 MPa and 1.7%, respectively, for the 2.5%Fe alloy. These favorable properties of the Cu-Zr-Ti-M (M=Fe, Co or Ni) bulk glassy alloys are promising for future practical use as a high-strength engineering material.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering