On the spherical nanoindentation creep of metallic glassy thin films at room temperature

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:685

Article

Zhang, T. H.¹  Ye, J. H.¹  Feng, Y. H.²  Ma, Y.¹ 

[1] Zhejiang Univ Technol, Coll Mech Engn, Inst Micro Nanomech Testing Technol & Applicat, Hangzhou 310014, Zhejiang, Peoples R China

[2] Chinese Acad Sci, Inst Mech, LNM, State Key Lab Nonlinear Mech, Beijing 100190, Peoples R China

关键词: Nanoindentation;    Creep;    Metallic glassy film;    Strain rate sensitivity;    Shear transformation zone;   

DOI  :  10.1016/j.msea.2017.01.018

来源: Elsevier

【 摘 要 】

Metallic glassy thin films with eight kind of compositions were successfully prepared on Si substrate by magnetron sputtering. The room-temperature creep tests were performed at plastic regions for each sample relying on spherical nanoindetation. The creep deformations were studied by recording the total creep displacement and strain after 2000 s holding. More pronounced creep deformation was observed in the sample with lower glass transition temperature (T-g). Strain rate sensitivity (SRS) was then calculated from the steady-state creep and exhibited a negative correlation with increasing T-g. It is suggested that creep mechanism of the nano-sized metallic glass was T-g-dependent, according to the demarcation of SRS values. Based on the obtained SRS, shear transformation zone (STZ) size in each sample could be estimated. The results indicated that an STZ involves about 25-60 atoms for the employed eight samples and is strongly tied to T-g. The characteristic of STZ size in metallic glassy thin films was discussed in terms of applied method and deformation modes.

【 授权许可】

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