Micro-FDM Process Capability and post-processing effects on mechanical properties

The mechanical behaviour of specimens fabricated using FDM machine has been thoroughly studied and several works have been presented. However, they are focused on few materials, in particular ABS, while very few papers analysed the mechanical properties of FDM samples made by PLA filament. Even though ABS is well known for its superior mechanical properties, some applications might require materials with other properties, such as PLA. Therefore, a deeper investigation of the effect of the process on its properties is needed. In this study, at first, the influence of the main FDM process parameters, such as raster angle, extrusion width, air gap and extrusion temperature, on mechanical performance of PLA samples has been evaluated. The mechanical tests have been carried out on miniaturized tensile specimens focusing on the tensile test main properties: ultimate tensile stress, Young modulus and elongation at break. Moreover, an experimental campaign has been carried out on the effect of a thermal post-processing, in order to evaluate the effects of the treatment and its relation with the process parameters on the mechanical properties of the specimens.