Glassy and Quasicrystalline (Zr_(65)Al_(7.5)Cu_(27.5))_(100-x)Ti_x Alloys and Their Mechanical Properties

摘要

The glass-forming ability (GFA) and thermal stability of (Zr_(65)Al_(7.5)Cu_(27.5)_(100-x) (x velence 0 approx 15; in at percent) alloys have been investigated. It was revealed that a certain amount of Ti addition could improve the GFA of Zr_(65)Al_(7.5)Cu_(27.5) alloy effectively. The best bulk metallic glass (BMG) forming composition was found at (Zr_(65)Al_(7.5)Cu_(27.5))_93Ti_7. Bulk glassy samples with diameter of 7 mm were made by means of copper mold casting. Further Ti additions deteriorated GFA and led to the precipitation of icosahedral phase, and 3 mm quasicrystalline cylinder was obtained at (Zr_(65)Al_(7 5)Cu_(27.5))_(90)Ti_(10). Room temperature compression testing showed that the quasicrystalline alloy had a fracture strength of 1875 MP_a, being 300 MP_a larger than that of the (Zr_(65)Al_(7.5)Cu_(27.5))_(93)Ti_7 monolithic BMG.