Vitrification and determination of the crystallization time scales of the bulk-metallic-glass-forming liquid Zr58.5Nb2.8Cu15.6Ni12.8Al10.3

The crystallization kinetics of Zr58.5Nb2.8Cu15.6Ni12.8Al10.3 were studied in an electrostatic levitation (ESL) apparatus. The measured critical cooling rate is 1.75 K/s. Zr58.5Nb2.8Cu15.6Ni12.8Al10.3 is the first bulk-metallic-glass-forming liquid that does not contain beryllium to be vitrified by purely radiative cooling in the ESL. Furthermore, the sluggish crystallization kinetics enable the determination of the time-temperature-transformation (TTT) diagram between the liquidus and the glass transition temperatures. The shortest time to reach crystallization in an isothermal experiment; i.e., the nose of the TTT diagram is 32 s. The nose of the TTT diagram is at 900 K and positioned about 200 K below the liquidus temperature.

[1]  J. Schroers,et al.  Critical cooling rate and thermal stability of Zr–Ti–Cu–Ni–Be alloys , 2001 .

[2]  J. Schroers,et al.  Repeated crystallization in undercooled Zr41Ti14Cu12Ni10Be23 liquids , 2000 .

[3]  J. Schroers,et al.  Pronounced asymmetry in the crystallization behavior during constant heating and cooling of a bulk metallic glass-forming liquid , 1999 .

[4]  W. Johnson,et al.  Large supercooled liquid region and phase separation in the Zr–Ti–Ni–Cu–Be bulk metallic glasses , 1999 .

[5]  W. Johnson,et al.  Equilibrium viscosity of the Zr41.2Ti13.8Cu12.5Ni10Be22.5 bulk metallic glass-forming liquid and viscous flow during relaxation, phase separation, and primary crystallization , 1998 .

[6]  W. Johnson,et al.  Experimental determination of a time–temperature‐transformation diagram of the undercooled Zr41.2Ti13.8Cu12.5Ni10.0Be22.5 alloy using the containerless electrostatic levitation processing technique , 1996 .

[7]  W. Johnson,et al.  Formation of Ti–Zr–Cu–Ni bulk metallic glasses , 1995 .

[8]  W. Johnson,et al.  A highly processable metallic glass: Zr41.2Ti13.8Cu12.5Ni10.0Be22.5 , 1993 .

[9]  Won-Kyu Rhim,et al.  An electrostatic levitator for high-temperature containerless materials processing in 1-g , 1993 .

[10]  A. Inoue,et al.  Amorphous Zr–Al–TM (TM=Co, Ni, Cu) Alloys with Significant Supercooled Liquid Region of Over 100 K , 1991 .

[11]  D. Turnbull.  Under what conditions can a glass be formed , 1969 .