Absence of ultrasonic-vibration-induced plasticity in metallic glacial glasses
摘要
Metallic glasses (MGs) have been found to exhibit unexpected ultrasonic-vibration-induced plasticity (UVIP), which provides a promising way to realize room temperature processing and molding of MGs. However, whether all MGs possessing UVIP remains a mystery. Here, we report that metallic glacial glasses (MGGs) which are a new glass state obtained through a liquid–liquid transition, show a different behavior without UVIP. While the as-cast La65Ni20Al15 MG exhibits UVIP, consistent with conventional MGs, the MGG counterpart obtained by heat treatment exhibits brittleness under ultrasonic vibration loading. The MGG possesses higher α-relaxation and β-relaxation peak temperatures and a weaker boson heat capacity peak, indicating that it is more stable than the as-cast MG, consistent with its ultrastable nature. A schematic energy landscape is established accordingly. This work may provide new insights into the understanding of the ultrasonic plasticity of MGs as well as the nature of the MGGs.
Graphical abstract