Dynamic mechanical behavior of (La0.7Ce0.3)65Al10Co25 bulk metallic glass: Influence of the physical aging and heat treatment

Highlights: • (La_0.7Ce_0.3)₆₅Al₁₀Co₂₅ MG exhibits a pronounced slow β relaxation. • Physical aging below Tg leads to a reduction of concentration of quasi-point defects. • Heat treatment induces MGs to access into a higher density state and decreases the local free volume available for atomic rearrangement. -- Abstract: Dynamic mechanical relaxation behavior of (La_0.7Ce_0.3)₆₅Al₁₀Co₂₅ bulk metallic glass was studied by using dynamic mechanical analysis (DMA). The experimental results demonstrated that (La_0.7Ce_0.3)₆₅Al₁₀Co₂₅ bulk metallic glass displays a pronounced slow β relaxation. Influence of the physical aging and heat treatment on the internal friction of the metallic glass were also analyzed. Physical aging below the glass transition temperature Tg and in-situ heat treatment introduce a decrease of the atomic mobility of metallic glasses, which is closely associated with the annihilation of defects (structural heterogeneity) of the metallic glasses.