ABSTRACT
Sliding is one of the most common contact congurations for materials used in engineering applications. It occurs wherever contacting parts are in relative motion, for example, in rotors, stators, pistons, and other wear parts of both large-and smallscale engines (i.e., microelectromechanical systems, MEMS). Moreover, sliding contacts may appear when third bodies impact a material at low angle, for example, slurry pump impellers. In sliding contacts, the friction between the contacting bodies creates relatively complex stress elds due to the presence of tangential forces in addition to normal forces. This, in turn, results in a wider range of possible failure
9.1 Introduction .................................................................................................. 529 9.2 Scratch Test ................................................................................................... 530
9.2.1 Experimental Method ....................................................................... 533 9.2.2 Focused Ion Beam Microscopy for Observation of Subsurface
Fracture in Coated Systems .............................................................. 536 9.3 Fracture Modes on Scratching of Brittle Layers .......................................... 539
9.3.1 Stress Field Originated by a Sliding Contact ....................................540 9.3.1.1 Bulk Material .....................................................................540 9.3.1.2 Coated System ...................................................................544
