Scratch resistance

In general, high hardness materials have a high scratch resistance to objects made of materials of lower hardness. An exception are soft materials with elastic properties, which have a high scratch resistance because they reset elastically after deformation by objects of greater hardness. The scratch resistance of surfaces of inelastic materials can be increased by giving them scratch-resistant coats by means of a plasma process. An established application is the coating of spectacle lenses and CDs/DVDs made of polycarbonate.