| This thesis is a part of an investigation that is being conducted by the Institute for Aerospace Research (IAR) to look into the possibilities of extending the useable lives of Canadian Forces gas turbine engine components through a damage tolerance based life cycle management approach or component rejuvenation.;A direct current potential drop (DCPD) technique has been calibrated for use with a double edge notch (DEN) specimen for crack initiation, short and Paris region FCP at elevated temperatures. The sensitivity of the DCPD technique for initiation was 50 ;The effects of the conventional and an IAR developed damage tolerant heat treatment on the microstructure and elevated temperature mechanical properties of Inconel 718 wrought bar and service exposed J85-CAN15 turbine discs have been investigated. These mechanical properties include tensile, creep, fatigue crack initiation and short and long fatigue crack propagation (FCP) behaviour. |
