Portal de Periódicos da CAPES

Artigo Produção Nacional Revisado por pares

BIBTEX RIS

Phases formed during crystallization of Zr55Al10Ni5Cu30 metallic glass containing oxygen

2002; Elsevier BV; Volume: 304; Issue: 1-3 Linguagem: Inglês

10.1016/s0022-3093(02)01003-7

1873-4812

Marcelo Falção de Oliveira, Walter José Botta Filho, M.J. Kaufman, Cláudio Shyinti Kiminami,

Metallic Glasses and Amorphous Alloys

In the present work the Zr55Al10Ni5Cu30 alloy has been processed by melt spinning and die-casting into a chilled copper mold. The ribbon was fully amorphous (X-ray diffraction and transmission electron microscopy) and cast samples partially crystalline. The amorphous ribbon was crystallized and analyzed by differential scanning calorimetry, X-ray diffractometry and transmission electron microscopy. The smaller supercooled liquid range of the glassy ribbons (60 K) and partial crystallization of a larger cast sample during quenching indicate the presence of oxygen in both samples (∼0.8 at.%). Although the crystallization process of the glassy ribbon, a glass transition followed by a single crystallization peak, showed the same crystallization process as reported by the literature, the heat release and the phases formed differed. The main phases formed were Zr2Cu, a complex `big-cube' fcc Zr4Cu2O-type phase and a tetragonal phase, not reported before to our knowledge, containing a lattice parameter of 2.8 nm.