Evolution of temperature gradients during rolling of Cu54Ni6Zr22Ti18 bulk metallic glass in the super cooled liquid region

Bulk metallic glass (BMG) strips of Cu54Ni6Zr22Ti18 were produced by warm rolling of the amorphous powder canned with copper. Controlling of temperatures of the rolled sample and rolls was essential for the successive rolling process. Because improper controlling of the sample temperature gave rise to the crystallization of BMG leading to the catastrophic fracture of BMG strips, the temperature of rolls should be properly controlled for achieving successful powder rolling of BMG. The variations of the strain state and temperature in the roll gap was simulated by the finite element method (FEM) using various roll temperatures.