VISCOSITY MEASUREMENTS FOR INTERLAYER STRENGTH AND FAILURE IN ADDITIVELY MANUFACTURED PARTS

Abstract

Additive manufacturing (AM) holds considerable potential in the fabrication of multifunctional composites as well as printing components with optimized three-dimensional (3D) complex geometries layer by layer. However, the mechanical and thermal properties are not optimal for high precision and high performance applications. As the AM methods are transitioning from prototyping to fabrication, the interfaces between the precursor material properties, process parameters, structural resistance, and interlayer characteristics of 3D-printed parts are to be established. For AM applications using powder-based mixtures, it is necessary to understand the rheological properties of these non-Newtonian materials and their effects on deformation, stress, and viscosity, typically measured using a capillary rheometer. This research is focused on the viscosity of non-Newtonian heterogeneous polymer and powder mixtures used for direct-write AM using capillary rheometry and a custom measurement system for small-scale testing. This will help us understand the effects of deformation, stress, and viscosity to improve printed part properties such as interlayer strength.