Developing Pulse Phase Thermography as a Characterisation Tool for Grossly Sculpted Surfaces

摘要

This paper presents the capabilities of a novel direct-writing electron-beam (EB) process and describes some initial work to develop pulse phase thermography (PPT) as a surface characterisation tool for geometrical features sculpted by this process. A concise review of existing rough surface characterisation techniques found no commonly accepted surface characterisation method for such grossly textured surfaces. Consequently, the potential of existing thermal technology and in particular PPT is explored in the context of developing a methodology to characterise the EB sculpted surface features. Initial tests using PPT on blind holes with various depths to simulate gross surface features are reported and used to determine the feasibility of this method for surface feature recognition and measurement. The paper also outlines proposals to extend PPT for protrusions and pits of different heights and depths measurements as a novel step forward to develop a sophisticated quality assessment (QA) tool. Scanning electron microscopy (SEM) and micro computed tomography (CT) are used as a reference to assess the accuracy of the three-dimensional surface topographical results obtained by PPT.