Nanoindentation size effects of mechanical and creep performance in Ni-based superalloy

ABSTRACT

Nanoindentation technique was adopted to study indentation size effects of physical-mechanical and creep performance with various depths (200–2000 nm) in GH901 utilising sharp and spherical tip. Residual impressions of both indenters with pile-up patterns are discussed. Nanohardness, reduced modulus and elastic recovery rates curves versus maximum displacement of two tips are obtained and nanohardness size effects are discussed with different models for Berkovich tip. The data obtained with spherical indentation are analysed separately by establishing stress–strain diagram. The creep results using Berkovich tip indicate that creep strain rate declines while creep stress exponent first decreases and then increases with the increasing depth; the creep stress exponent (n) values, 2.39–7.35, imply the dominant creep deformation mechanism is dislocation control.

KEYWORDS:

• Nanoindentation
• indentation size effect
• physical and mechanical properties
• creep performance
• Ni-based superalloy

Disclosure statement

No potential conflict of interest was reported by the author(s).

Correction Statement

This article has been corrected with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

The authors would like to acknowledge the support from Research Initiation Project of Chengdu University [grant number 2081920045]; Natural Science Foundation of Sichuan Province [grant number 2023NSFSC0916]; National Natural Science Foundation of China [grant number 52205182].