High Resolution Study of Local Stress in Spherical Alumina

Contact mechanics is a subject dealing with deformation of solids that touch each other at one or more points. The physical and mechanical formulation of this subject is built upon property of materials and theory of elasticity. The applications of contact mechanics bring impacts to our daily life, e.g. in architecture, machine design, engineering, automobile industry, and recently in microelectromechanical systems (MEMs) and biomechanics, etc. Since most surfaces possess roughness (protrusions) down to micro- or nanometer ranges, micromechanical contact becomes the most ubiquitous interaction in the solid world. The stress around micromechanical contacts can easily rise up to such an extreme level that it is the prelude for almost any macroscopic behavior of the materials, e.g. deformation and indentation, friction and attrition, fracture and failure, and so on. This book studies contact mechanics in alumina microspheres. Using confocal laser scanning microscopy, ~ 1 µm spatial resolution is achieved. Static and dynamic stress evolution and plasto-elastic properties of the material under extreme stresses are investigated.