Mechanical properties enhancement for additive manufactured short fiber composites with salt remelting post-processing

Fused Filament Fabrication (FFF) stands out in several areas as the most used additive manufacturing (AM) process. FFF initially started as a rapid prototyping technology, known as 3D printing, but now has gained throughout the years the potential to produce functional parts straight from a 3D model with less required equipment compared to traditional manufacture. The idea of producing functional end-products through FFF has stood in the mind of researchers for the past years, encouraging significant research on this technology and expanding the FFF technology to the capabilities of composite materials with short and continuous fiber reinforcements. Moreover, this technique provides attractive economic and design opportunities. However, a notorious gap in traditional composites manufacture and FFF shows the many flaws in the mechanical properties of this AM technology, such as poor interface bonding, high roughness, and concentration of voids within the structure. This research evaluates a recently implemented salt remelting heat treatment for FFF on short carbon fiber reinforced polylactic acid. These experiments show an increase in the tensile elastic properties by 135% and the elastic region for parts likely to fail for delamination, using non-pulverized sea salt for cooking applications, tested through the ASTM 3039D norm for tensile testing composite materials.