Effects of the intensity and frequency of electromagnetic vibrations on glass-forming ability in Mg-Cu-Y bulk metallic glasses

The present authors reported that a new method for producing Mg-Cu-Y bulk metallic glasses by using electromagnetic vibrations is effective in forming the metallic glass phase, and disappearance or decrement of clusters by the electromagnetic vibrations applied to a liquid state is presumed to cause suppression of crystal nucleation [Nature Materials 4 (2005) 289]. This paper aims to investigate the effects of the intensity and frequency of electromagnetic vibrations on apparent glass-forming ability in the Mg-Cu-Y bulk metallic glasses. It was found that the apparent glass-forming ability Of Mg65Cu25Y10 alloys increases with increasing the frequency of electromagnetic vibrations up to 5000 Hz. The effects of frequency more than 5000 Hz could not be investigated because of alternating current power devices. Moreover, it was found that the apparent glass-forming ability Of Mg65Cu25Y10 alloys increases with increasing the intensity of electromagnetic vibrations by an electric current or a magnetic flux density. However, increasing excessively the electric current was found to weaken the enhancement of the apparent lass-forming ability by using the electromagnetic vibration process because the crystalline particles grow larger by the Joule heat.