ABSTRACT
Aero-Engines ....................................................................... 63 2.3 Overview of the Quantitative Characterization of the Fracture
Toughness for Hard Coatings .........................................................................65 2.3.1 Toughness Evaluation from Radial Cracks......................................... 67 2.3.2 Toughness Evaluation from Circumferential Cracking and
Spallation ............................................................................................ 71 2.3.2.1 Methodology of the Toughness Evaluation from
Circumferential Cracking and Spallation ............................ 71 2.3.2.2 Debates About the Extraction of the Irreversible
Work Wirr .......................................................................... 71 2.3.2.3 Argument on the Methodology of Circumferential
Cracking and Spallation for the Fracture Toughness of Thin Hard Coatings .............................................................77
