Methodology For Determining Design Rules For Helical Channels In Glass Components Produced By Selective Laser Sintering

The ability to accurately produce geometric features is one of the main hurdles in advancing additive manufacturing for the production of functional parts. Design rules can be found for parts produced using selective laser sintering for polymers with simple 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, feature resolution for helical channels is quantified for successful production of both green and final parts after debinding and sintering. We found the ability to clear loose powder was a major factor in determining whether a particular channel/part geometry could be produced. Our experiments suggest a linear relationship between the scaled diameter and tortuosity for successful clearing of channels. Using this, we propose a design rule that can predict success and failure in accurately forming internal helical channels. The proposed methodology was experimentally validated for parts created via indirect selective laser sintering from mixtures of glass and nylon powders.