Effects of the process conditions on the micro-formability of Zr62Cu17Ni13Al8 bulk metallic glass

Micro-formability of U groove on Zr62Cu17Ni13Al8 (numbers indicate at.%) bulk metallic glass plate was investigated by varying the process parameters, such as time, load and temperature. Micro-stamping machine and Si micro-dies with U groove were employed for micro-forming test. Micro-formability was estimated by comparing Rf values (=Af/Ag), where Ag is cross-sectional area of U groove, and Af the filled area by micro-formed sample. The Rf values increased with increasing load, time and temperature in the supercooled liquid state of Zr62Cu17Ni13Al8 bulk metallic glass. Micro-formed U patterns showed smooth surface with no defects like surface crack. Maximum Rf value was about 0.5 for the specimen micro-formed at 420 °C, at 167 N load for 25 min. It was concluded that the patterns with aspect ratio = 1 can be micro-formed at the process condition given above.