Effects of Nb microalloying on properties of Zr-Al-Fe-Cu glassy alloy

Abstract

The effects of Nb-microalloying on glass forming ability, thermal properties and mechanical properties of (Zr _0.6032 Cu _0.2256 Fe _0.0995 Al _0.0717 ) _100-x Nb _x (x = 0, 1, 2, 3, 4) alloys were investigated. The best glass former was obtained for (Zr _0.6032 Cu _0.2256 Fe _0.0995 Al _0.0717 ) _97 Nb _3 , which could be fabricated into full glass with diameter up to 6 mm at least. In addition, the origin of enhancing GFA of ZrAlFeCu amorphous alloy by means of the minor addition of Nb, Gd and Hf, was also discussed from the aspects of clusters and mixing entropy, which might provide a method of understanding the mechanism of enhancing glass-forming ability via microalloying, and choosing minor alloying element with an aim of enhancing glass-forming ability. It was found that the thermal stability reduced as the content of Nb increased along with the supercooled liquid region decreased. Nb-microalloying decease the fracture strength. However, moderate Nb microalloying could enhance the room temperature plastic strain.

Keywords

• bulk metallic glass
• microalloying
• Zr-based alloys
• amorphous alloys