In laser powder bed fusion factors such as residual stresses within the part, lead to deformations and cracks which impact the quality of the final product. Although residual stress and deformations have been thoroughly studied research and development of in-situ online monitoring requires a specimen that cracks in a predictable manner. This paper aims to show which sample geometry can be used to replicate cracks. The Ti6Al4V sample was designed based on known residual stress phenomena from literature of rapid heating and cooling cycles inducing compressive and tensile stresses during L-PBF. The sample was developed with the aid of computer aided design and simulation software using the inherent strain method. For the purpose of consistency, two identical samples were built simultaneously, and for the purpose of repeatability, two different builds were conducted. It was shown that the sample failed as predicted by the simulations due to the effective plastic strain and equivalent stress exceeding that of the mechanical properties. The sample developed can be used to test if cracks that form during the L-PBF build process can be predicted and detected.

In Laser Powder Bed Fusion there are certain considerations that need to be accounted for when designing for thin-walled or complex shapes. Much is known of how parameters such as build orientation and scanning strategy can affect the resultant tensile properties. The tensile property results are also influenced by factors such as the shape of the specimen. The specimens’ cross-sectional geometry and length ratio are carefully considered to obtain accurate and reliable tensile properties. Eighteen different tensile geometries were manufactured using an EOS P110 and PA12 powder. These different geometries were chosen to evaluate different influencing factors such as width, gauge length, specimen geometry and scanning strategy. This knowledge is used in conventional standards when determining specimen geometries. This work aims to combine conventional tensile specimen shape and L-PBF factors to best represent the actual tensile properties of different polymer geometries.