Thermal analysis for improvement of mechanical properties in fused filament fabricated parts.

Additive manufacturing techniques are widely used in the present manufacturing era because of their ability to manufacture intricate products. Fused filament fabrication (FFF) is one of the most commonly adopted additive manufacturing technology, which involves the extrusion of the semi-solid polymer through the nozzle to be deposited in layers to form the part. In FFF, the polymer melt being deposited, forms the bonds with the neighboring pre-deposited melt during the part fabrication. The pre-deposited melt is at the low temperature compared to the polymer melt extruding out of the nozzle; hence the heat transfer occurs due to temperature gradient by the mode of conduction and convection. The commercialization of the FFF technology in a wide range of industrial applications still seems to be constrained due to several drawbacks such as insufficient mechanical properties, poor surface quality, and low dimensional accuracy. The grade of FFF-produced products is affected by various process parameters, for example, layer thickness, build orientation, raster width, or print speed. In FFF, process parameters are optimized to improve the quality of the final printed part. The cost of post-processing is also reduced as a result of parameter optimization. In this study, the influence of the convection coefficient on bond formation was investigated, and a model for predicting bond size in terms of convection coefficient is discussed for a given set of parameters. This work also aims to study the effects of thermal properties on neck formation and the effects of neck formation on strength, surface finish, and dimensional accuracy of the printed parts. In addition, this study reveals the problems and difficulties found in previous works, potential future scope in this area has been analyzed, and new research approaches are suggested. [ABSTRACT FROM AUTHOR]