TRACEABLE GEOMETRIC QUALIFICATION OF ADDITIVELY MANUFACTURED LATTICE STRUCTURES

Abstract

The manufacture of lattice geometries via Additive Manufacturing (AM) has the potential to impact the production of low-volume, high cost, complex components. However, the qualification of lattice geometries provides several challenges for traditional metrological techniques, limiting the use of these structures within industry. While recent studies in AM part qualification have improved its practice, the measurement of lattice structures unique to additive manufacturing is not well understood and methods to support traceability have yet to be developed. In this dissertation, a methodology to determine measurement uncertainty in the measurement of AM lattice components is developed. A refined sampling registration approach for lattice geometry based on spatially-dependent subsampling is derived and is shown to statistically decrease variation between measurement sources. The importance of sampling location in tactile measurements of components produced using additive manufacturing is investigated and recommends that definition of inspection locations/methods be integrated into the design cycle of AM parts. The substitution method is investigated to determine uncertainty in the measurement of AM lattice structures using X-ray Computed Tomography (XCT). A measurement artifact is developed and measured using the substitution method. The use of reporting measurement uncertainty using uncorrected bias is explored for strut diameter measurements. Components identical to the measurement artifact are manufactured using AM and measured to determine manufacturing variation. The uncertainty in XCT measurement of these AM components is determined using the substitution method and methods to report uncorrected bias. This study provides a methodology to design inspection routines for the qualification of a lattice component, furthers the scientific understanding XCT measurements of AM components, and lays the groundwork for further implementation of the presented method.