Effect of In-Plane Voiding on the Fracture Behavior of Laser Sintered Polyamide

Laser Sintering, a method of additive manufacturing, is used in the production of concept models, functional prototypes, and end-use production parts. As the technology has transitioned from a product development tool to an accepted production technique, functional qualities have become increasingly important. Tensile properties reported for popular polyamide sintering materials are comparable to the molded properties with the exception of elongation. Reported strains for laser sintered polyamide are in the 15–30% range with 200–400% strains reported for injection molding. The primary contributors to poor mechanical properties in polyamide materials used during Selective Laser Sintering® are studied. Of primary interest are Ultimate Tensile Strength (UTS) and Elongation at Break (EOB) of tensile specimens fabricated under conditions that produce varying degrees of ductile and brittle fracture.