Micro-Impact Testing: A New Technique for Investigating Thin Film Toughness, Adhesion, Erosive Wear Resistance, and Dynamic Hardness

Abstract

A small scale probe testing method has been developed for investigating the behaviour of thin films under dynamic loading conditions. The primary objective of the development was to produce quantifiable techniques that closely simulate the conditions that thin films experience in service. Variations of the technique allow measurements related to: impact wear and adhesion failure, erosive wear resistance, fracture toughness, work hardening, and dynamic hardness. The common element in each variant is the acceleration of a test probe (usually diamond) towards the specimen surface and the monitoring its instantaneous position before and after collision. The impact energy can be controlled and either single impacts or multiple impacts can be produced. For single impacts, the energy delivered to the contact point can be quantified, allowing calculation of a dynamic hardness number.