Flexible optical fiber probe for surface roughness evaluation of internal channels in additively manufactured components

Abstract

Recent developments in Additive Manufacturing (AM) has revolutionized the production capabilities of multitudes of aerospace components. However, being a stochastic process, there is minimal control over the surface quality and thus require adequate quality checks before implementation. In this context, this paper investigates a flexible optical fiber probe and speckle correlation measurements to quantitatively estimate the average surface roughness, Ra, of areas within internal channels. Details on probe design and preliminary measurement results on a comparator plate with Ra values varying between 6.3 μm and 25 μm are presented. The measurements are compared and validated using the Keyence optical tester (VR-3000).