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This paper presents a microstructural study of laser micro-processed high-purity CuZrAl alloys prepared by arc melting and Cu-mould casting. Microprocessing of the CuZrAl alloy was performed using a Rofin DC-015 diffusion-cooled CO slab laser system with 10.6-μm wavelength. The laser was defocused to a spot size of 0.2 mm on the sample surface. The laser parameters were set to give 300- and 350-W peak power, 30% duty cycle and a 3000-Hz laser pulse repetition frequency (PRF). About 100-micrometer-wide channels were scribed on the surfaces of disk-shaped amorphous and partially crystalline samples at traverse speeds of 500 and 5000 mm/min. These channels were analysed using scanning electron microscopy (SEM) and 2D stylus profilometry. The metallographic study and profile of these processed regions are discussed in terms of the applied laser processing parameters. The SEM micrographs showed that striation marks developed at the edge and inside these regions as a result of the laser processing. The results from this work showed that microscale features can be produced on the surface of amorphous Cu-Zr-Al alloys by CO laser processing. [ABSTRACT FROM AUTHOR]

The oxidation of the bulk amorphous alloy Zr65Cu17.5Ni10Al7.5 in air in its amorphous and the supercooled liquid states was studied in the temperature range 573–663 K using X-ray photoelectron spectroscopy (XPS). The oxide film mainly consisted of the oxides of Zr (as ZrO2) and Al (as Al2O3). No Cu or Ni was found in the oxide film formed on the amorphous state of the alloy while significant Cu (as CuO) was present in the oxide film formed on the alloy in its supercooled liquid state. The role of the various alloying elements during oxidation at high temperatures in air is discussed in the paper. The XPS data from oxide film support the previously suggested mechanism for oxidation of this alloy, i.e. the rate controlling process during oxidation of the alloy at low temperatures (in the amorphous state) is the back-diffusion of Ni and Cu, while the oxidation at high temperatures (in the supercooled liquid state) is dominated by the inward diffusion of oxygen. [ABSTRACT FROM AUTHOR]

This paper describes original experimental results obtained in a study of the rheological behavior of amorphous bulk Vitralloy 1 (Zr41Ti14Cu12.5Ni10Be22.5), which shows linear viscous (Newtonian) flow over a certain range of deformation rates. These results were compared against results obtained for other superplastic alloys, and against results obtained for metal melts during the crystallization process. [ABSTRACT FROM AUTHOR]

Minor alloying addition or microalloying technology has already shown dramatic effects on glass formation and thermal stability of bulk metallic glasses (BMGs). This paper intends to provide a comprehensive review of recent developments of this technology in the field of BMGs. The beneficial effects of minor alloying additions on the glass formation and the thermal stability of BMGs will be summarized and analyzed. In addition, principles and guidelines for future application of this technology will also be proposed. [ABSTRACT FROM AUTHOR]