Mechanical properties and non-isothermal crystallization kinetics of novel Ti-based high-entropy bulk metallic glasses

Abstract

In this work, five novel Ti- and TiZr-based high entropy bulk metallic glasses (HE-BMGs) with good glass forming ability (GFA) were developed, among which the (Ti37.31Zr22.75Be26.39Al4.55Cu9)94Ni6 alloy possesses the largest critical diameter of 9 mm. All developed HE-BMGs exhibit high yield strength and good compressive plasticity at room temperature. Especially, the (Ti37.31Zr22.75Be26.39Al4.55Cu9)94Co6 alloy with large GFA has suitable density and high specific strength (3.90 × 105 N m/kg), showing great potential in the aerospace sector. Moreover, the activation energies at characteristic temperatures of three HE-BMGs were obtained using the Kissinger method. The local Avrami exponents were calculated to analyze the crystallization mechanism of these HE-BMGs, revealing that the first crystallization process is mostly dominated by diffusion-controlled three-dimensional growth of pre-existing nuclei. In addition, all three HE-BMGs can be classified as “intermediate glasses” according to their fragility index values.