Graded materials for resistance to contact deformation and damage

The mechanical response of materials with spatial gradients in composition and structure is of considerable interest in disciplines as diverse as tribology, geology, optoelectronics, biomechanics, fracture mechanics, and nanotechnology. The damage and failure resistance of surfaces to normal and sliding contact or impact can be changed substantially through such gradients. This review assess the current understanding of the resistance of graded materials to contact deformation and damage, and outlines future research direction sand possible applications for graded materials.