Interlayer thermal history modification for interface strength in fused filament fabricated parts

Fused filament fabrication (FFF) technology has been a cost-effective option in the additive manufacturing industry. It, however, still faces drawbacks in terms of tolerance, accuracy, surface finish and material property anisotropy that prevent it from applications in engineering production environment. To address the issue of material property anisotropy, authors had reported an in-process laser local pre-deposition heating (LLPH) method to increase the inter-layer interface temperature during FFF printing. As a result, interpenetrating inter-layer diffusion is achieved to a larger extent, and thereby higher part strength in the build direction is achieved. In the current work, a detailed analysis of the temperature history of the inter-layer interface with and without LLPH method has been presented. The effect of increase in the thermal bonding potential due to the use of LLPH method on the interlayer bond toughness and the peak flexural strength of the components has been presented. A 77% increase in the interlayer bond toughness has been demonstrated.