Elastic properties of Ca-based bulk metallic glasses studied by resonant ultrasound spectroscopy

We report measurements of the elastic properties and internal friction of Ca-based bulk metallic glasses (BMGs), Ca50Mg20Cu30, Ca55Mg18Zn11Cu16 and Ca65Mg15Zn20 (numbers indicate at.%), as a function of temperature between 5 and 400 K. Below the glass transition temperature, both Young's modulus and shear modulus decrease with increasing temperature, and the Poisson ratio increases with increasing temperature. Above the glass transition temperature, these trends reverse due to crystallization. At temperatures close to the glass transition temperature, we observe the onset of a peak in the internal friction Q−1, attributed to crystallization.