Study on Structural Transformation Behavior of a Ti-Based Bulk Metallic Glass by Thermal Expansion Method

Ti40Zr25Ni8Cu9Be18 bulk metallic glass rod with diameter of 3 mm was prepared by the arc melting and injection casting method. The structural transformation behavior of the Ti-based bulk metallic glass has been studied by continuous heating thermal expansion method with a pusher thermal expansion instrument. It is found that there are five distinct stages during continuous heating according to the thermal expansion curve. The five distinct stages are the relaxation preparation stage, the structural relaxation stage, the first crystallization stage, the second crystallization stage and the stage of grain growth. Nanocrystals with size of 20 nm are found after thermal expansion. The study has also found that the characteristic temperatures of the Ti-based metallic glass in the thermal expansion curve have a good consistency with that in the DSC curve.