Development of a high cycle fatigue testing system and its application to thin aluminum film

The principal goal of this investigation was to develop a feedback controlled high cycle fatigue testing system and to demonstrate its usefulness by acquiring a preliminary stress-life curve of an aluminum film in a very short period of time. A high cycle fatigue testing system having 2.5 N load capacities was constructed and proved reliable, stable and useful in doing long-run fatigue tests. A set of stress-life curves was collected under a mean stress level with 1.16 μm thick aluminum films under closed-loop load control. The system is compact enough to set it up on subsidiary equipment like an optical microscope. A white light interferometric microscope was utilized to observe a specimen’s surface morphology change with fatigue cycles in-situ. The surface roughness was decreased or remained constant in the beginning but started to increase in the later stage.