Effects of Additional Elements on the Glass Formation and Corrosion Behavior of Bulk Glassy Cu-Hf-Ti Alloys

Abstract

New bulk glassy (Cu 0:6 Hf 0:25 Ti 0:15 ) 98 M 2 (M = Mo, Ta and Nb) alloys with high thermal stability were synthesized and the effects of additional elements Mo, Ta and Nb on the glass formation and corrosion behavior were examined. The maximum diameter for glass formation of the 2 at%Mo, 2 at%Ta and 2 at%Nb alloys was 1.5 mm, 3.5 mm and 4.0 mm, respectively. The corrosion behavior of the Cu-Hf-Ti-(Mo, Ta and Nb) glassy alloys was examined by weight loss and electrochemical measurements. By substitution of 2 at%Mo, Ta or Nb for the Cu 60 Hf 25 Ti 15 alloy, the corrosion rates of the alloys decreased to 1=2 in 1 N HCl and two orders of magnitude in 3% NaCl solution. It was also found that substitution of elements Mo, Ta and Nb for the Cu 60 Hf 25 Ti 15 glassy alloy was effective on decreasing anodic passive current density in 3% NaCl solution.

Formation and Thermal Stability of Cu‐Hf‐Ti‐M Glassy Alloys

“…However, addition of Ti in both these binary systems greatly increased the glass forming ability (GFA), [5][6][7][8] with the critical diameter for fully amorphous rods being at least 4 mm for Cu 60 Zr 30 Ti 10 , Cu 60 Hf 20 Ti 20 and Cu 55 Hf 25 Ti 20 . On the other hand, it has been shown that small additions of B and Y [7] and of Nb, Ta and Mo [9] reduce the GFA for Cu-Hf-Ti alloys.One of the empirical rules for high GFA in a metallic alloy is that the heat of formation from the constituent elements is negative. Nevertheless, although addition of alloying elements with positive enthalpy of solution should reduce the GFA, there have been some reports that the addition of elements with positive heats of mixing enhances GFA, [10][11][12][13] though Xu et al [10] show that this occurs only when they decrease the melting temperature of the alloy.…”

“…However, addition of Ti in both these binary systems greatly increased the glass forming ability (GFA), [5][6][7][8] with the critical diameter for fully amorphous rods being at least 4 mm for Cu 60 Zr 30 Ti 10 , Cu 60 Hf 20 Ti 20 and Cu 55 Hf 25 Ti 20 . On the other hand, it has been shown that small additions of B and Y [7] and of Nb, Ta and Mo [9] reduce the GFA for Cu-Hf-Ti alloys.…”

Retraction:Effect of Carbon Nanotube Addition on the Compressive Fracture Characteristics of Zr-based Bulk Metallic Glass Composites

“…These materials show excellent properties, for example, high fracture strength, and excellent magnetic properties, strong resistance to corrosion, and so on. [1][2][3][4] Carbon nanotubes (CNTs) are also one of the most advanced materials developed recently. CNTs have high elastic modulus and are one of the most stiffness materials ever made.…”

Improvement of corrosion resistance of Cu-based bulk metallic glasses by the microalloying of Mo

“…Johnson group [1e3] first developed a Cu 47 Zr 11 Ti 34 Ni 8 BMG with a thickness of about 4 mm, opening the door to the fabrication of Cu-based bulk metallic glasses. Subsequently, Inoue group [4e8] prepared a series of new Cu-based BMGs in a CueZreTi ternary system, which has a critical size of 3 mm in diameter, and exhibited very high compressive/tensile yield strengths up to 1.9 GPa.…”