Effect of Aluminum Particles on the Fracture Toughness of Polyamide-based Parts Obtained by Selective Laser Sintering (SLS)

Abstract

Numerous additive manufacturing technologies are currently used in industry and research: selective laser sintering, selective laser melting, electron beam melting, fused deposition modelling, laminated object manufacturing and stereolithography. Independently on the type of technology, a set of technological parameters have to be controlled in order to obtain good quality parts that also possesses acceptable mechanical properties. Selective laser sintering (SLS) is a multipurpose additive manufacturing technology that allows fabrication of good resolution parts with adequate mechanical properties. The versatility of the process refers to the limitless geometrical shapes that can be achieved and also to a variety of powders and mixtures that can be used.The uncontrollable process variables occurring along the sinterization process (heat transfer, humidity), together with the multitude of controllable technological factors, including raw materials, lead to inconsistencies in shape, size and mechanical properties of the parts. These inconsistencies appear not only in SLS but in all additive manufacturing technologies.The study proposes to underline the influence of the aluminum mixed polyamide on the fracture toughness and geometrical characteristics of parts manufactured using the same energy density but different orientations in the building environment. The findings can be used for part design and parameter setup, in order to prevent both mechanical and geometrical failures.