Morphological Aspects of Fatigue Crack Formation and Growth

A very important tool given to designer is the post mortem examination of service failed pieces. On the fracture surface it is written the complete story of its destiny. What is actually needed is the key to decode and interpreter the characteristic features that have been left on the fracture surfaces, some of which can be seen at naked eye while others need an optical or a scanning electron microscope. From the pioneer effort of Ewing and Humphrey already in 1903 fractography has become a mature science capable of providing complete information on fracture mode, stress, number of cycles etc. this chapter is aiming at providing some useful knowledge and an essential background for the study of fatigue from what can be seen or unveiled on the fracture surface.