Decomposition of amorphous phase in Ni 70Mo 10B 20 alloy above glass transition temperature

Abstract

Phase transformation of amorphous Ni 70Mo 10B 20 alloy (numbers indicate at.%) upon heating above the glass transition temperature T g have been studied by X-ray diffraction, transmission and high resolution electron microscopy and differential scanning calorimetry. Decomposition of amorphous phase to the regions depleted and enriched in Mo and/or in B occurs at heating above T g. Each type of these regions has been found to crystallize independently of others by primary crystallization mechanism. The crystallization above glass transition temperature leads to nanocrystalline structure formation. The crystallization mechanism and specific feature of the crystallization above T g are discussed.