Role of stacking fault on mechanical properties of a DS alloy

Abstract

In the present study, a novel strengthening mechanism that does not impair the plasticity has been ascertained in a directionally solidified nickel-based superalloy (DS alloy) during monotonic and cyclic deformations. The alloy exhibited excellent mechanical properties at 750°C. Sub-structural examinations revealed that the activation of the stacking fault-induced micro-twinning mechanism is responsible for the improved fatigue performance at 750°C. This work may lead us to design advanced nickel-based superalloys having good synergy of strength and plasticity for turbine blade applications.

KEYWORDS:

• Ni-base superalloy
• micro-twin
• stacking fault
• low cycle fatigue
• TEM

Acknowledgements

The author acknowledges Dr JK Sahu, CSIR-National Metallurgical Laboratory, Jamshedpur, India, and Mrs N. Paulose, GTRE Bangalore, India, for their valuable discussions during this work.

Disclosure statement

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