Post-treatment to enhance the mechanical performance of printed Onyx

Moises Jimenez-Martinez^1*Julio Varela-Soriano¹Rafael Carrera-Espinoza²Juan Manuel Coca Gonzalez¹

• ¹Tecnologico de Monterrey, Monterrey, Mexico
• ²Universidad de las Americas Puebla, Cholula, Mexico

Additive manufacturing has a high potential to achieve a low carbon footprint because it offers the possibility of fabricating components without using manufacturing tooling. However, the mechanical properties of printed compo-nents need improvement. The flexibility of the designs generated by controlling the input of the material during filament extrusion in additive manufacturing allows the fabrication of components without tools; however, crystallisation oc-curs because of the temperature gradient in the printed layers and the layers added during printing. Temperature governs the polymer crystallization kinetic. Since material extrusion process is non-isothermal process at welding interface, polymer crystallization kinetics and degree of crystallization are determined by the thermal history developed during manufacturing process. Crystallisation worsens the mechanical properties since internal forces are concentrated because of the residual stresses present during cooling. There is a wide range of literature and research on the effect of post-heat treatment on improving mechanical properties in metals. To the best knowledge of the authors, studies on the post-processing of 3D-printed polymers are limited. This research proposes post-processing to homogenise the structure of the printed component through thermal treatment to improve the ultimate tensile strength of Onyx. Anneal-ing and normalising treatments almost doubled the mechanical strength of raw printed Onyx.