Abstract
Bulk glassy alloys containing cubic phase particles with a size of 3 to 5 nm were formed in Cu60Zr30Ti10 and Cu 60Hf30Ti10 ternary systems by copper mold casting. The cubic phase had a lattice parameter of 0.45 nm for the former alloy and 0.51 nm for the latter alloy and was analyzed to have Cu-rich compositions as compared with their nominal compositions. The mixed phase bulk alloys exhibit good mechanical properties of 2000 to 2130 MPa for tensile fracture strength, 2060 to 2160 MPa for compressive fracture strength and 0.008 to 0.017 for compressive plastic strain. The temperature interval of the supercooled liquid region prior to crystallization is 37 K for the Cu 60Zr30Ti10 alloy and 67 K for the Cu 60Hf30Ti10 alloy. The primary crystallization occurred by the precipitation of a cubic CuZr phase with a lattice parameter of 0.35 nm in a diffusion-controlled growth mode of nuclei and an orthorhombic Cu8Hf3 phase in an interface diffusion-controlled growth mode of nuclei with decreasing nucleation rate, respectively. The difference in the precipitation modes is interpreted to be the origin for the difference in the supercooled liquid region. The formation of Cu-based alloys with high strength in the nanoscale mixed phase state is encouraging for future development as a new type of structural materials.
Original language | English |
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Pages (from-to) | 11-20 |
Number of pages | 10 |
Journal | Journal of Metastable and Nanocrystalline Materials |
Volume | 22 |
DOIs | |
Publication status | Published - 2004 |
Keywords
- Bulk Glassy Alloy
- Mechanical Property
- Microstructure
- Supercooled Liquid
- TEM
ASJC Scopus subject areas
- Materials Science (miscellaneous)
- Materials Science(all)
- Condensed Matter Physics
- Physical and Theoretical Chemistry