Toward the understanding of temperature effect on bonding strength, dimensions and geometry of 3D-printed parts

Abstract

Fused filament fabrication (FFF), which is an additive manufacturing technique, opens alternative possibilities for complex geometries fabrication. However, its use in functional products is limited due to anisotropic strength issues. Indeed, the strength of FFF fabricated parts across successive layers in the build direction (Z direction) can be significantly lower than the strength in X-Y directions. This strength weakness has been attributed to poor bonding between printed layers. This bonding depends on the temperature of the current layer being deposited-at melting temperature (T m)-and the temperature of the previously deposited layer. It is assumed that depositing a layer at T m on a layer at temperature around crystallization temperature (T c) would enable higher material crystallinity and thus better bonding between previous and present layers. On the contrary, if the previous layer temperature is below T c , material crystallinity will be low and bonding strength weak. This paper aims at studying the significant effect of temperature difference (DT) between previous and current deposited layers temperatures on (1) inter-layers bonding strength improvement and (2) part dimensions, geometry and structure stability. A 23% increase in the inter-layers bonding strength for previous layer temperature slightly higher than T c reported here confirms the above assumption and offers a first solution toward the increase in inter-layers bonding strength in FFF.

Multi-scale damage analysis and fatigue behavior of PLA manufactured by fused deposition modeling (FDM)

“…Three-dimensional-printed structures fabricated by FDM process possessed entirely different mechanical properties from those manufactured by other methods. It is widely mentioned that the mechanical properties of plastic parts are extensively influenced by the mechanism of layer-by-layer deposition (Vanaei et al , 2020b). This particularly exists in FDM that offers a wide range of process parameters affecting the mechanical behavior of manufactured parts (Vanaei et al , 2020c).…”

In-Process Monitoring of Temperature Evolution during Fused Filament Fabrication: A Journey from Numerical to Experimental Approaches

“…On the other hand, the adhesion of layers for the FFF parts is thermally driven. Their temperature history should be considered as a critical variable in characterizing the mechanical characteristics of the final parts [22][23][24][25].…”

Experimental study of PLA thermal behavior during fused filament fabrication

“…Given the above, the evolution of the temperature profile of the filaments during deposition is a key parameter affecting the bonding quality. 12 Both experimental and theoretical approaches have been proposed to obtain data on the temperature profile of a printed structure. 13 Generally, temperature measurements are limited to a single location.…”