Service Life Predictions for Machined Components of Nickel-based Superalloys

Nowadays in aerospace industry, the main concern is to reach an optimum, reliable, and reproducible manufacturing process with a high predictability of the components service life and the lowest production cost. Machining is one of the main manufacturing processes for industrial parts which can change the surface characteristics of materials. The main aspects of these alterations are metallurgical, topographical, mechanical, and thermal which could affect microstructure, roughness, and residual stresses at the surface and near the surface of machined components, respectively. Since the fatigue behaviour of materials is sensitive to the local changes at their surface, developing a predictive model for fatigue life of machined components influenced by these surface characteristics is necessary to quantify their correlation. In this project different aspects of machining-induced surface integrity and their effect on fatigue behaviour of a Nickel-based superalloy used by Pratt & Whitney Canada in turning process will be investigated. For some applications testing real parts up to targeted fatigue life, sometimes over millions of cycles, is too expensive and time-consuming to be practical. The present project will also develop a predictive model for the functional performance of machined components by monitoring short crack propagations in the vicinity of machining affected layer.

Faculty Supervisor:

Philippe Bocher

Student:

Hamid Javadi

Partner:

Pratt & Whitney Canada

Discipline:

Engineering - mechanical

Sector:

Aerospace and defense

University:

Program: