Oxidation induced phase instability of Cu54Zr22Ti18Ni6 bulk metallic glass

Effects of isothermal oxidation on the chemical instability which triggers crystallization of Cu54Zr22Ti18Ni6 (numbers indicate at.%) bulk metallic glass were investigated. Comparing the isothermal heat flux of Cu54Zr22Ti18Ni6 bulk metallic glass within the supercooled liquid region in differential scanning calorimetry, it could be observed that the isothermal oxidation did decrease the incubation time for crystallization. What is further, this amorphous phase instability was enhanced with the decrease of particle size. Through this study, chemical instability due to preferential oxidation of alloying element and resulting deviation of chemical composition in intact metallic region needs to be considered in phase evolution of bulk metallic glass during material processing.