The Determination of Surface Plastic and Elastic Properties by Ultra Micro-indentation

Abstract

An ultra micro-indentation system for investigating the elastic and plastic properties of surface coatings and near-surface materials is described. The instrument produces minute indentations by the application of loads to geometrically accurate pointed or spherical diamond indenters. Material properties are derived from records of the load and depth of penetration. Depth of penetration is measured with a resolution less than 1 nm. The force at initial contact can be substantially less than 0,1 mN. The instrument has a wide range of research and quality control applications which include the determination of the depth distribution of hardness and elastic modulus of hard and soft materials – TiN, gold and polymer films and coatings, for example. It also has applications in the determination of the workhardening index, in fracture mechanics and in exploring the material properties of small areas of individual phases in polyphased materials.