This paper presents a search for Ni-Nb-Zr amorphous alloys for application as glass lens molding die materials. To efficiently screen candidate materials, we employed the combinatorial method partially to evaluate thermal stability. First, compositionally spread Ni-Nb-Zr libraries were fabricated by combinatorial arc plasma deposition (CAPD). In order to evaluate the high thermal stability, Ni-Nb-Zr amorphous samples in the libraries were annealed at 723K, the molding temperature for glass lens, for various times in vacuum. Phases in the annealed samples were identified by X-ray diffraction. From XRD identification, candidate amorphous samples with high thermal stabilities were screened. Sputtered samples with the same compositions as the candidate amorphous samples were then fabricated. Other desired properties for glass lens molding die materials, such as mechanical strength, machinability and anti-sticking properties, were evaluated. These investigations revealed Ni36Nb39Zr25 to be a suitable material for a new glass lens molding die. This material exhibited a high fracture stress f of 1.3 GPa, good heat resistance, good machinability, and excellent anti-sticking properties to molten glass.
The researches of influence of alloying on thermal stability and process of senescence of amorphous alloys
