Influence of thermal activation on changes of mechanical properties and tensile fracture morphology surface of Ni-base metallic glasses

Purpose: The paper presents a structural relaxation and crystallization process of Ni68.7Cr6.6Fe2.65Si7.8B14C0.25 metallic glasses. The Ni68.7Cr6.6Fe2.65Si7.8B14C0.25 metallic glasses were produced by the CBMS method for two different conditions of casting at different cooling rate. Design/methodology/approach: The relaxation and crystallization of Ni68.7Cr6.6Fe2.65Si7.8B14C0.25 metallic glasses by methods: mechanical tests, scanning electron microscopy (SEM) and internal friction (IF) were studied. Findings: The investigation showed that conditions of vitrification (different, but higher than critical cooling rate) influence on different course of elementary structural relaxation processes during thermal activation. Research limitations/implications: The differences in temperature of the beginning of elementary relaxation processes and crystallization processes of alloy, in relation to strip thickness were disclosed. Practical implications: The course of relaxation processes can be used for analysis of thermal stability of metallic glasses. Originality/value: The paper presents those conditions of vitrification influence on different course structural relaxation processes during thermal activation.