Experimental investigations into abrasive flow machining (AFM) of 3D printed ABS and PLA parts

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Nitin Dixit ◽  
Varun Sharma ◽  
Pradeep Kumar

Purpose The surface roughness of additively manufactured parts is usually found to be high. This limits their use in industrial and biomedical applications. Therefore, these parts required post-processing to improve their surface quality. The purpose of this study is to finish three-dimensional (3D) printed acrylonitrile butadiene styrene (ABS) and polylactic acid (PLA) parts using abrasive flow machining (AFM). Design/methodology/approach A hydrogel-based abrasive media has been developed to finish 3D printed parts. The developed abrasive media has been characterized for its rheology and thermal stability using sweep tests, thermogravimetric analysis (TGA) and differential thermal analysis (DTA). The ABS and PLA cylindrical parts have been prepared using fused deposition modeling (FDM) and finished using AFM. The experiments were designed using Taguchi (L9 OA) method. The effect of process parameters such as extrusion pressure (EP), layer thickness (LT) and abrasive concentration (AC) was investigated on the amount of material removed (MR) and percentage improvement in surface roughness (%ΔRa). Findings The developed abrasive media was found to be effective for finishing FDM printed parts using AFM. The microscope images of unfinished and finished showed a significant improvement in surface topography of additively manufactures parts after AFM. The results reveal that AC is the most significant parameter during the finishing of ABS parts. However, EP and AC are the most significant parameters for MR and %ΔRa, respectively, during the finishing of PLA parts. Practical implications The FDM technology has applications in the biomedical, electronics, aeronautics and defense sectors. PLA has good biodegradable and biocompatible properties, so widely used in biomedical applications. The ventilator splitters fabricated using FDM have a profile similar to the shape used in the present study. Research limitations/implications The present study is focused on finishing FDM printed cylindrical parts using AFM. Future research may be done on the AFM of complex shapes and freeform surfaces printed using different additive manufacturing (AM) techniques. Originality/value An abrasive media consists of xanthan gum, locust bean gum and fumed silica has been developed and characterized. An experimental study has been performed by combining printing parameters of FDM and finishing parameters of AFM. A comparative analysis in MR and %ΔRa has been reported between 3D printed ABS and PLA parts.

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2601
Author(s):  
Yue Ba ◽  
Yu Wen ◽  
Shibin Wu

Recent innovations in 3D printing technologies and processes have influenced how landscape products are designed, built, and developed. In landscape architecture, reduced-size models are 3D-printed to replicate full-size structures. However, high surface roughness usually occurs on the surfaces of such 3D-printed components, which requires additional post-treatment. In this work, we develop a new type of landscape design structure based on the fused deposition modeling (FDM) technique and present a laser polishing method for FDM-fabricated polylactic acid (PLA) mechanical components, whereby the surface roughness of the laser-polished surfaces is reduced from over Ra 15 µm to less than 0.25 µm. The detailed results of thermodynamics and microstructure evolution are further analyzed during laser polishing. The stability and accuracy of the results are evaluated based on the standard deviation. Additionally, the superior tensile and flexural properties are examined in the laser-polished layer, in which the ultimate tensile strength (UTS) is increased by up to 46.6% and the flexural strength is increased by up to 74.5% compared with the as-fabricated components. Finally, a real polished landscape model is simulated and optimized using a series of scales.


MRS Advances ◽  
2018 ◽  
Vol 3 (40) ◽  
pp. 2373-2378 ◽  
Author(s):  
Sandra E. Nájera ◽  
Monica Michel ◽  
Nam-Soo Kim

ABSTRACTPolymer composites of Polylactic acid (PLA) and poly-ε-caprolactone (PCL), containing small amounts of titanium oxide (TiO2) were developed for biomedical applications. These composite materials were prepared, and then printed using Fused Deposition Modeling (FDM). 3D printed structures were characterized to determine their mechanical properties and biocompatibility. DSC analysis yielded useful information regarding the immiscibility of the different polymers, and it was observed that the particles of TiO2 improved the stability of the polymers. The ultimate tensile strength and the fracture strain increased by adding TiO2 as a filler, resulting in values of approximately 45 MPa and 5.5 % elongation. The printed composites show excellent in vitro biocompatibility including cell proliferation and adhesion, and are therefore promising candidates to be used in the biomedical field for bone replacement procedures, due to their properties similar to those of cancellous bone.


2015 ◽  
Vol 21 (3) ◽  
pp. 250-261 ◽  
Author(s):  
Brian N. Turner ◽  
Scott A Gold

Purpose – The purpose of this paper is to critically review the literature related to dimensional accuracy and surface roughness for fused deposition modeling and similar extrusion-based additive manufacturing or rapid prototyping processes. Design/methodology/approach – A systematic review of the literature was carried out by focusing on the relationship between process and product design parameters and the dimensional and surface properties of finished parts. Methods for evaluating these performance parameters are also reviewed. Findings – Fused deposition modeling® and related processes are the most widely used polymer rapid prototyping processes. For many applications, resolution, dimensional accuracy and surface roughness are among the most important properties in final parts. The influence of feedstock properties and system design on dimensional accuracy and resolution is reviewed. Thermal warping and shrinkage are often major sources of dimensional error in finished parts. This phenomenon is explored along with various approaches for evaluating dimensional accuracy. Product design parameters, in particular, slice height, strongly impact surface roughness. A geometric model for surface roughness is also reviewed. Originality/value – This represents the first review of extrusion AM processes focusing on dimensional accuracy and surface roughness. Understanding and improving relationships between materials, design parameters and the ultimate properties of finished parts will be key to improving extrusion AM processes and expanding their applications.


Author(s):  
John Cote ◽  
John Haggstrom ◽  
Ranuga Vivkanandan ◽  
Kristin Ann Coté ◽  
Daniel Real ◽  
...  

Abstract Background Powered air-purifying respirators are in short supply and can break down with extended use. Replacement parts can become hard to acquire. The aim of this study was to create an innovative quality improvement proof of concept using rapid prototyping. Methods Here we report three cases of 3D printed powered air-purifying respirator parts. 3D printing was performed on all parts using fused deposition modeling with standard polylactic acid, in the same way that presurgical models would be created. Measurements using an electronic caliper as well as CT scans were used to compare an original part to its corresponding 3D printed parts for accuracy. Results Electronic caliper and computed tomography measurements both showed accuracy consistant with current published norms. Conclusions Ultimately, there will be questions surrounding intellectual property, effectiveness and potential long-term safety for these types of 3D printed parts. Future research should look into the addition of specific nanoparticles from the position of cost, efficacy, safety and improved accuracy.


2018 ◽  
Vol 178 ◽  
pp. 02008
Author(s):  
Dragoş-Florin Chitariu ◽  
Adriana Munteanu

Fixtures are used for orientation, positioning and tightening of the workpiece during machining, control and assembly. The main fixture requirements are: orientation, positioning and tightening precision in accordance with the machining requirements. The materials used for fixture components, especially, supports and clamping mechanism are, usually, alloy steel with HRC hardness up to 55-60 HRC. These components are machined to high level of precision thus assuring the overall precision of the fixture. In order to achieve high stiffness and a good dampening capacity the fixture become, usually, very heavy. In the case of manually operated fixtures light weight is an advantage; also there are operations such as inspection, assembly where the operating forces are low. In this case lightweight materials can be used for fixture construction. In this paper the FDM (Fused Deposition Modeling) 3D printing technology is used. Support buttons and v-block fixture components were selected and 3D printed. The effect of printing orientation of active surfaces of support was analysed. The dimensional accuracy and surface roughness on the active surface were measured. Experimental results indicate that surface roughness is dependent on the orientation of the printed workpiece.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Vivek Kumar Tiwary ◽  
Arunkumar P. ◽  
Vinayak R. Malik

Purpose Three-dimensional (3D) printing, one of the important technological pillars of Industry 4.0, is changing the landscape of future manufacturing. However, the limited build volume of a commercially available 3D printer is one inherent constraint, which holds its acceptability by the manufacturing business leaders. This paper aims to address the issue by presenting a novel classification of the possible ways by which 3D-printed parts can be joined or welded to achieve a bigger-sized component. Design/methodology/approach A two-step literature review is performed. The first section deals with the past and present research studies related to adhesive bonding, mechanical interlocking, fastening and big area additive manufacturing of 3D printed thermoplastics. In the second section, the literature searches were focused on retrieving details related to the welding of 3D printed parts, specifically related to friction stir welding, friction (spin) welding, microwave and ultrasonic welding. Findings The key findings of this review study comprise the present up-to-date research developments, pros, cons, critical challenges and the future research directions related to each of the joining/welding techniques. After reading this study, a better understanding of how and which joining/welding technique to be applied to obtain a bigger volume 3D printed component will be acquired. Practical implications The study provides a realistic approach for the joining of 3D printed parts made by the fused deposition modeling (FDM) technique. Originality/value This is the first literature review related to joining or welding of FDM-3D printed parts helping the 3D printing fraternity and researchers, thus increasing the acceptability of low-cost FDM printers by the manufacturing business leaders.


2018 ◽  
Vol 7 (1) ◽  
pp. 44 ◽  
Author(s):  
Mohammad Alsoufi ◽  
Abdulrhman Elsayed

Fused deposition modeling or FDM technology is an additive manufacturing (AM) technology commonly used for prototyping applications which suffer seriously from low levels of fluctuated surface finish quality, demanding some hand finishing tool for even the necessary levels of 3D printed parts. This paper, therefore, aims at giving close attention to the variation in the surface roughness profile between the inner and the outer faces of FDM 3D printed parts based on advanced polylactic acid (PLA+) thermoplastic filament material. The surface roughness is quantitatively analyzed using a contact-type test-rig with a 90° angle measurement on each face along with each zone and sub-zone. The obtained results revealed that the surface finish of the inner faces is rougher than those of the outer faces as regards nozzle temperature, nozzle diameter, infill density and layer height is 220°C, 0.5 mm, 0% and 0.3 mm, respectively. The personal FDM 3D printer is thus confirmed to be an excellent platform, flexible, straightforward and cost-effective. 


2014 ◽  
Vol 20 (3) ◽  
pp. 236-244 ◽  
Author(s):  
David Espalin ◽  
Jorge Alberto Ramirez ◽  
Francisco Medina ◽  
Ryan Wicker

Purpose – The purpose of this paper is to investigate a build process variation for fused deposition modeling (FDM) in which contours and rasters (also referred to as internal fill patterns) are built using different layer thicknesses and road widths. In particular, the paper examines the effect of the build process variation on surface roughness, production times and mechanical properties. Additionally, a unique FDM process was developed that enabled the deposition of discrete multiple materials at different layers and regions within layers. Design/methodology/approach – A multi-material, multi-technology FDM system was developed and constructed to enable the production of parts using either discrete multi-materials or the build process variation (variable layer thickness and road width). Two legacy FDM machines were modified and installed onto a single manufacturing system to allow the strategic, spatially controlled thermoplastic deposition with multiple extrusion nozzles of multiple materials during the same build. This automated process was enabled by the use of a build platform attached to a pneumatic slide that moved the platform between the two FDM systems, an overall control system, a central PC and a custom-made program (FDMotion) and graphic user interface. The term multi-technology FDM system used here implies the two FDM systems and the integration of these systems into a single manufacturing environment using the movable platform and associated hardware and software. Future work will integrate additional technologies within this system. Parts produced using the build process variation utilized internal roads with 1,524 μm road width and 508 μm layer height, while the contours used 254 μm road width and 127 μm layer height. Measurements were performed and compared to standard FDM parts that included surface roughness of planes at different inclinations, tensile testing and fabrication times. Findings – Results showed that when compared to the standard FDM process, the parts produced using the build process variation exhibited the same tensile properties as determined by a student's t-test (p-values > 0.05, μ1-μ2 = 0, n = 5). Surface roughness measurements revealed that the process variation resulted in surface roughness (Ra) improvements of 55, 43, 44 and 38 per cent for respective planes inclined at 10, 15, 30 and 45° from vertical. In addition, for a 50.8 × 50.8 mm square section (25.4 mm tall), the build process variation required a minimum of 2.8 hours to build, while the standard FDM process required 6.0 hours constituting a 53 per cent reduction in build time. Finally, several manufacturing demonstrations were performed including the fabrication of a discrete PC-ABS sandwich structure containing tetragonal truss core elements. Originality/value – This paper demonstrates a build strategy that varies contour and raster widths and layer thicknesses for FDM that can be used to improve surface roughness – a characteristic that has historically been in need of improvement – and reduce fabrication time while retaining mechanical properties.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mojtaba Zeraatkar ◽  
Marco Donato de Tullio ◽  
Alessio Pricci ◽  
Francesco Pignatelli ◽  
Gianluca Percoco

Purpose The purpose of this study is to introduce an alternative construction for microfluidic micromixers, where the effect of the extruded filaments in the fused deposition modeling (FDM) technique is used to enhance mixing performance identified as a challenge in microfluidic micromixers. Design/methodology/approach A simple Y-shaped micromixer was designed and printed using FDM technique. Experimental and numerical studies were conducted to investigate the effect of the extruded filaments on the flow behavior. The effects of the extruded width (LW), distance between adjacent filaments (b) and filament height (h1) are investigated on the mixing performance and enhancing mixing in the fabricated devices. The performance of fabricated devices in mixing two solutions was tested at flow rates of 5, 10, 20, 40, 80 and 150 µL/min. Findings The experimental results showed that the presence of geometrical features on microchannels, because of the nature of the FDM process, can act as ridges and generate a lateral transform through the transverse movement of fluids along the groove. The results showed the effect of increasing ridge height on the transverse movement of the fluids and, therefore, chaotic mixing over the ridges. In contrast, in the shallow ridge, diffusion is the only mechanism for mixing, which confirms the numerical results. Originality/value The study presents an exciting aspect of FDM for fabrication of micromixers and enhance mixing process. In comparison to other methods, no complexity was added in fabrication process and the ridges are an inherent property of the FDM process.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ali Alperen Bakır ◽  
Resul Atik ◽  
Sezer Özerinç

Purpose This paper aims to provide an overview of the recent findings of the mechanical properties of parts manufactured by fused deposition modeling (FDM). FDM has become a widely used technique for the manufacturing of thermoplastic parts. The mechanical performance of these parts under service conditions is difficult to predict due to the large number of process parameters involved. The review summarizes the current knowledge about the process-property relationships for FDM-based three-dimensional printing. Design/methodology/approach The review first discusses the effect of material selection, including pure thermoplastics and polymer-matrix composites. Second, process parameters such as nozzle temperature, raster orientation and infill ratio are discussed. Mechanisms that these parameters affect the specimen morphology are explained, and the effect of each parameter on the strength of printed parts are systematically presented. Findings Mechanical properties of FDM-produced parts strongly depend on process parameters and are usually lower than injection-molded counterparts. There is a need to understand the effect of each parameter and any synergistic effects involved better. Practical implications Through the optimization of process parameters, FDM has the potential to produce parts with strength values matching those produced by conventional methods. Further work in the field will make the FDM process more suitable for the manufacturing of load-bearing components. Originality/value This paper presents a critical assessment of the current knowledge about the mechanical properties of FDM-produced parts and suggests future research directions.


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