Methodology for determining design rules for helical channels in glass components produced via selective laser sintering

The accuracy of geometric features is one of the main hurdles in advancing the use of additive manufacturing for the production of functional parts. Much research has gone into quantifying the dimensional accuracy and design limitations of various types of additive manufacturing utilizing a wide variety of materials and manufacturing techniques. Design rules can be found for parts produced using selective laser sintering for polymers with features such as thin walls and through-holes. However, these rules have not been studied for more complex features such as helical channels produced from glass or ceramic materials. In this study, we propose a methodology for predicting the success and failure in accurately reproducing internal helical channels produced via selective laser sintering. Parameters that define these geometries include the channel diameter and length and the helix diameter and pitch. The methodology is experimentally validated for parts created via indirect selective laser sintering from mixtures of glass and nylon powders. Feature resolution is quantified for successful production of both green parts as well as the final parts after debinding and sintering. This methodology is demonstrated for the production of glass components that are designed to manipulate light via the addition of orbital angular momentum in order to add an optical degree of freedom to the system.