PAPERS & REPORTS

Introduce technical papers and reports of IIT (Instrumented Indentation Technology) and correlated fields.

 

Title

Instrumented indentation of a Pd-based bulk metallic glass: Constant

loading-rate test vs constant strain-rate test

Author

Byung-Gil Yooa, Kyung-Woo Leeb, Jae-il Janga,∗

a Division of Material Science & Engineering, Hanyang University, Seoul 133-791, Republic of Korea

b Department of Material Science & Engineering, Seoul National University, Seoul 151-742, Republic of Korea

Press and Date of publication

Article history:

Received 30 August 2007

Received in revised form 2 July 2008

Accepted 10 July 2008

Available online 6 December 2008

Abstract

Most of the previous nanoindentation experiments on bulk metallic glasses (BMGs) were made under a

constant ‘loading rate,’ although ‘strain rate’ is a more useful parameter than loading rate to analyze the inhomogeneous plasticity in the BMG according to the classic free-volume theory. Here, we explore the strain-rate dependency of plastic characteristics in a Pd-basedBMGthrough nanoindentation tests under a variety of constant strain rates (0.01–0.25 s−1). The results arecomparedwith those fromnanoindentations under various constant loading rates (0.05–5 mN/s) and discussed in terms of the influences of strain rate on the plastic flow characteristics in the BMG.

ⓒ 2008 Elsevier B.V. All rights reserved.

Keywords:

Metallic glasses; Nanoindentation; Strain rate; Hardness