Hybrid deposition additive manufacturing: novel volume distribution, thermo-mechanical characterization, and image analysis

Abstract

The structural integrity of additive manufacturing structures is a pronounced challenge considering the voids and weak layer-to-layer adhesion. One of the potential ways is hybrid deposition manufacturing (HDM) that includes fused filament fabrication (FFF) with the conventional filling process, also known as “HDM composites". HDM is a potential technique for improving structural stability by replacing the thermoplastic void structure with a voidless epoxy. However, the literature lacks investigation of FFF/epoxy HDM-based composites regarding optimal volume distribution, effects of brittle and ductile FFF materials, and fractographic analysis. This research presents the effects of range of volume distributions (10–90%) between FFF and epoxy system for tensile, flexure, and compressive characterization. Volume distribution in tensile and flexure samples is achieved using printable wall thickness, slot width, and maximum width. For compression, the printable wall thickness, slot diameter, and external diameter are considered. Polylactic acid and acrylonitrile butadiene styrene are used to analyze the brittle and ductile FFF structures. The research reports novel application of image analysis during mechanical characterization using high-quality camera and fractographic analysis using scanning electron microscopy (SEM). The results present surprising high tensile strain (0.038 mm/mm) and compressive strength (64.5 MPa) for lower FDM-percentages (10%, 20%) that are explained using in situ image analysis, SEM, stress–strain simulations, and dynamic mechanical analysis (DMA). In this regard, the proposed work holds novelty to apply DMA for HDM. The optimal volume distributions of 70% and 80% alongside fractographic mechanisms for lower percentages (10%, 20%) can potentially contribute to structural applications and future material-based innovations for HDM.

Analyzing the Impact of FDM Parameters on Compression Strength and Dimensional Accuracy in 3D printed PLA Parts

“…For instance, a specimen with 100% infill density exhibits a compression strength of 56.5 MPa, approximately ten times higher than that of a specimen with 20% infill density (4 MPa). However, it's worth noting that the expected maximum compressive strength based on reference [34] is 44.64 MPa for the specimen, whereas the strength at 100% is equal to the 65.9 MPa claimed in literature [17]. The increase in infill density is associated with increased material usage.…”

“…Results show that 190°C and 40 mm/min are most effective, but 80 mm/min speed may be considered for higher FDM productivity. Harris et al [17] explored the impact of volume distributions (10-90%) on the tensile, flexure, and compressive characterization of FFF and epoxy systems. It uses scanning electron microscopy (SEM) and a high-quality camera for mechanical characterization.…”

Enhanced structural integrity of Laser Powder Bed Fusion based AlSi10Mg parts by attaining defect free melt pool formations

“…The parametric influence analysis is based on the analysis of variance where the significance of individual parameters and their interactions are determined 26 , 27 . The significance of the parameters is categorized with respect to confidence interval of 90% and 95%.…”

Ironing process optimization for enhanced properties in material extrusion technology using Box–Behnken Design

“…Material extrusion (MEX), which is also recognized as Fused Filament Fabrication (FFF) or as Fused Deposition Modeling (FDM) 1 , 2 , is an additive manufacturing (AM) process that employs a heated extruding nozzle to deposit a continuous filament of thermoplastic or polymer material layer by layer to create 3D parts 3 , 4 . MEX technology has several advantages over other AM technologies, including the diverse choice of filaments (such as acrylonitrile butadiene styrene (ABS), polylactic acid (PLA), acrylonitrile styrene acrylate (ASA), polyether ether ketone (PEEK), Polypropylene (PP) 5 , and polyethene terephthalate glycol (PETG) 6 , etc.…”