Physical aging effects on the dynamic relaxation behavior and mechanical properties of Cu46Zr46Al8 metallic glass

• Published in: Journal of alloys and compounds 2017-12, Vol.726, p.195-200
• Main Authors: Qiao, J.C., Feng, S.D., Pelletier, J.M., Crespo, D., Pineda, E., Yao, Y.
• Format: Article
• Language: English
• Subjects: Aging; Aluminum; Amorphous materials; Computer simulation; Copper; Cristalls metàl·lics; Dynamic mechanical properties; Edge dislocations; Engineering Sciences; Física; Glass transition temperature; Impact analysis; Materials; Mechanical properties; Mechanical spectroscopy; Mechanical tests; Metal crystals; Metallic glasses; Molecular dynamics; Physical aging; Physical properties; Point defects; Shear bands; Storage modulus; Studies; Zirconium; Àrees temàtiques de la UPC
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2017.07.291

Mechanical relaxation of glassy materials is strongly influenced by their mechanical and physical properties. In the current study, dynamic mechanical relaxation of Cu46Zr46Al8 metallic glass has been investigated by mechanical spectroscopy and molecular dynamics simulations. Our results show that mechanical properties of metallic glasses are highly dependent on their thermal history. α relaxation in the frequency region of the Cu46Zr46Al8 metallic glass was described by Havriliak-Negami (HN) model. In the framework of the quasi-point defects theory, the correlated factor χ could be used to characterize the concentration of “defects” of glassy materials. By molecular dynamics simulations of dynamic mechanical tests at different temperatures and frequencies, it is noted that adjusting of defects is inversely correlated to storage modulus at the atomic level. On the other hand, physical aging below the glass transition temperature Tg reduces the concentration of defects and narrows down the width of shear bands, which corresponds to decreasing of the atomic mobility. •Dynamic relaxation in metallic glasses was studied by DMA and MD.•Main relaxation is of the metallic glass was described by HN model.•The correlated factor is linked to the concentration of “defects” of metallic glass.•Physical aging below the Tg reduces the concentration of defects.