Development of continuous stiffness measurement technique for composite magnetic tapes

Abstract

Studying mechanical properties of materials on the nanoscale has received much attention in recent years as the properties are size dependent. Continuous measurements of mechanical properties of these materials during indentation are greatly needed. A continuous stiffness measurement (CSM) technique allows the contact stiffness to be measured at any point along the loading curve and not just at the point of unloading. In the present investigation, an analytical methodology of CSM technique used for characterizing nonuniform materials is developed and applied to nanocomposite magnetic tapes. The contact stiffness, elastic modulus and hardness of fused silica, polytetrafluoroethylene (PTFE) and metal-particle (MP) tapes were measured as a function of indentation depth using the CSM technique. For the first time, the graded material characteristics of MP tapes are reported.