BÁRTKOVÁ Denisa Brno University of Technology

Spoluautoři VLAŠIC František, MAZAL Pavel, DVOŘÁČEK Ondřej

This study presents results of high-cycle fatigue measurements of cast polycrystalline nickel superalloy Inconel 713LC and the analysis of acoustic emission response of this material. Inconel 713LC is usually used for gas turbines in aerospace and power industry. Fatigue is one of the most significant degradation mechanisms occurred in this application. Acoustic emission (AE) technique is an effective non-destructive method of detecting active structural defects or defects which could grow during service. It is also an adequate tool for monitoring a fatigue process. The particular aim of this study is to propose a methodology for evaluation of the early manifestations of fatigue damage and to describe the evolution of fatigue crack by AE parameters then. Smooth cylindrical specimens were subjected to alternating bending fatigue loading at room temperature. Two AE sensors were attached on the face of each specimen. Measured fatigue data were represented in a form of S-N curves. An examination of crack initiation sites and microstructure has been also performed. Four stages in the fatigue life of specimen were distinguishable in measured acoustic emission signal energy. It was found that for first stage of fatigue life is typical signal with highest energy.