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3D printing, specifically fused deposition modeling (FDM) of poly-ether-ether-ketone (PEEK), is one of the most powerful and efficient state-of-the-art manufacturing techniques. However, FDM of PEEK is challenging. Indeed, it is critical to consider specific 3D printing parameters and filament feedstock quality to achieve optimum mechanical properties in the 3D-printed PEEK parts. In this paper, we investigate the effect of specific 3D printing parameters such as nozzle and chamber temperature, print speed, and layer height on the mechanical properties of 3D-printed PEEK. Moreover, we explore the effect of filament quality on the structures' mechanical properties. In that regard, we developed PEEK filaments using a customized extruder setup in-house and used those laboratory-developed filaments (LD) to 3D print PEEK structures suitable for mechanical testing (tensile, compression, and flexural testing) and compared them to the mechanical properties of 3D-printed parts that were developed using commercially available (CA) filaments. Results indicate that an optimum combination of a nozzle and chamber temperature, print speed, and layer height is appropriate to achieve 3D-printed parts with optimum mechanical properties. Notably, results confirmed no significant differences between the specimen groups developed using LD and CA filaments, highlighting that the LD filaments were of comparable quality to the CA ones. The highest mean strengths recorded for the parts printed with the LD filaments were 106.45 MPa (compressive), 85.43 MPa (tensile), and 102.63 MPa (flexural). This paper confirms that high-quality PEEK-based filaments can be developed in-house to yield 3D-printed PEEK parts with optimum mechanical properties. [ABSTRACT FROM AUTHOR]

The spread of 3D printing in many different fields has become eminent. This paper aims to improve the mechanical properties of parts printed by fused deposition modeling technique. Acrylonitrile butadiene styrene (ABS) specimens are printed with custom printing parameters. These parameters give a tensile strength that is 86% of the injection- molded ABS strength, and give one of the best recorded results for 100% infill printed ABS tensile specimens. Furthermore, a post filling technique has been studied. Specimens are printed with inner voids and different densities using slicing software. Void shape is precisely selected to conform to the filling process. High-strength, low-cost thermoset resin is injected through specimens to fill those voids. A tensile test has been performed after the full curing of the resin. A morphology analysis is done. Using this technique strength to printed weight ratio is improved by 151% and the cost is reduced by 51%. [ABSTRACT FROM AUTHOR]

In recent years, 3D printing technology has played an essential role in fabricating customized products at a low cost and faster in numerous industrial sectors. Fused deposition modeling (FDM) is one of the most efficient and economical 3D printing techniques. Various materials have been developed and studied, and their properties, such as mechanical, thermal, and electrical, have been reported. Numerous attempts to improve FDM products' properties for applications in various sectors have also been reported. Still, their applications are limited due to the materials' availability and properties compared to traditional fabrication methods. In 3D printing, the process parameters are crucial factors for improving the product's properties and reducing the machining time and cost. Researchers have recently investigated many approaches for expanding the range of materials and optimizing the FDM process parameters to extend the FDM process's possibility into various industrial sectors. This paper reviews and explains various techniques used in 3D printing and the various polymers and polymer composites used in the FDM process. The list of mechanical investigations carried out for different materials, process parameters, properties, and the FDM process's potential application was discussed. This review is expected to indicate the materials and their optimized parameters to achieve enhanced properties and applications. Also, the article is highly anticipated to provide the research gaps to sustenance future research in the area of FDM technologies. [ABSTRACT FROM AUTHOR]

Laser powder deposition (LPD), as one of the most widely used additive manufacturing methods for metals, is an important rapid prototype manufacturing and repairing method for large components. However, great challenges exist in LPD of aluminum alloy due to the high reflectivity to laser, the poor fluidity of the powder, the high porosity in the printed component, and the crack sensitivity, which blocks the performance of the printed structure and limits its application. Recently, various researchers have focused on LPD of aluminum alloys and explored its potential mechanism. This paper reports on the recent advances in this area and highlights the key topics requiring attention, presenting the knowledge gaps in this industry. Our work aims to develop a comprehensive understanding of the interrelation among the various aspects of the subject suggesting directions for improvement in producing aluminum alloy structure with LPD. [ABSTRACT FROM AUTHOR]

Additive manufacturing (AM) technology is capable of efficiently building complex shapes when compared with traditional manufacturing methods. Fused deposition modeling (FDM) is one of the AM processes, and it produces a great variety of polymeric parts. Therefore, it is essential to determine the relationship that exists among its process parameters, productivity and sustainability, quality of the final piece, and its structural performance. This paper presents an experimental study centered on optimizing five responses associated with FDM: energy consumption of the 3D printer, processing time, part's dimensional accuracy, the quantity of material used to print the pieces, and mechanical strength of the specimens. The model material employed was acrylonitrile styrene acrylate. The effects of five key process parameters on the responses were studied using the Taguchi methodology and analysis of variance (ANOVA). These parameters were layer thickness, filling pattern, orientation angle, printing plane, and position of the piece on the build platform. A desirability analysis was employed to determine the set of process parameters that provided the best trade-off among all the considered variables. The results showed that the approach presented in this work allowed for simultaneous optimization of all the observed variables for the 3D printing process. [ABSTRACT FROM AUTHOR]

Additive manufacturing (AM) has various independent parameters that affect the mechanical properties and quality of the produced parts that are not linearly the function of each other. Process parameters in metal AM are very hard to control, analyse and optimise because they affect each other even though they can be independently changed. Changing process parameters in a wide range is not possible due to the formation of problems such as cracks, balling, unmelted powders, porosity and distortion. In this paper, a numerical model to predict the value of tensile strength of selective laser melting (SLM) Ti-6Al-4V parts and analyse the effect of process parameters on the results has been proposed. Taguchi L25 Design of Experiment (DOE) across 125 samples to create a comprehensive and general overview of influential parameters on the build process was investigated. Specifically, parameters included laser power, scan speed, hatch spacing, laser pattern angle and heat treatment (HT). To evaluate and analyse the build process according to established statistical variances, a minimum of five samples based on ASTM standard (for tensile test) were prepared. Heat treatment was added to the DOE to analyse the combined process and post-process effects. Results were compared (cross-validated) against existing values found in the literature and were found to effectively predict and explain the behaviour of tensile strength when changing process parameters. [ABSTRACT FROM AUTHOR]

The aim of this study is to evaluate the effect of printing parameters and their interactions on the mechanical properties of ABS-based specimen, 3D printed by fused deposition modeling (FDM), using the response surface method. The manufacturing direction (X, Y, or Z) and the deposition angle (0°, 30°, or 45°) are analyzed as input factors. The Young modulus, the yield stress, the tensile strength, and the deformation at fracture in tension are considered as responses. An empirical model for each response is built in terms of factors and their interactions. The predicted results are in good coherence with experimental ones. The original contribution of this paper consists in the evaluation of the optimal combination of manufacturing parameters thanks to the MINITAB software. [ABSTRACT FROM AUTHOR]

Additive manufacturing (AM) started as a rapid prototyping (RP) technology to aid in visualizing and validating designs in the design process. However, with the recent improvements in metal AM parts, functional parts can be manufactured using laser-based AM. Currently, metal AM parts have comparable mechanical properties to traditional manufacturing parts. 15-5PH stainless steel and Inconel 718 are two of the most commonly used metals in laser-based AM, and they have a high modulus of elasticity and tensile strength and can be precipitate hardened to increase their strength and hardness by heat treatment. These properties make 15-5PH stainless steel and Inconel 718 suitable for many industrial applications such as aerospace and automotive. However, due to the nature of AM, AM parts usually suffer from anisotropy. In this paper, the mechanical properties such as tensile strength, modulus of elasticity, yield strength, and ductility are investigated at various elevated temperatures up to 350 °C and compared with the mechanical properties at room temperature using specimens printed in three different orientations to capture the effect on the anisotropy. In addition to that, the microstructure of the specimens is studied to investigate the influence of elevated temperature on the specimens. [ABSTRACT FROM AUTHOR]

In this paper, the effect of additive particles on the mechanical properties of ultraviolet (UV)-cured resin was evaluated based on tensile strength and shear strength. The experimental results showed that the tensile strength was improved with proper particle addition, but the shear strength was always decreased. Moreover, the effects of additive particles on the holding force of diamond abrasive, critical exposure energy, and penetration depth of UV-cured resin were elucidated. The holding force of resin with 15 wt.% Al2O3 addition was found to be higher than that of pure UV resin. Based on the experimentally determined critical UV exposure energy and penetration depth, UV-cured resins with and without additive particles were used to fabricate grinding wheels using additive manufacturing technology. Grinding experiment demonstrated the performance of UV resinoid grinding wheels was significantly improved with the addition of 15 wt.% Al2O3 particles. [ABSTRACT FROM AUTHOR]

In recent years, additive manufacturing (AM) has been developed for industrial applications due to its superior performance, such as in building complex parts, which are especially difficult to build when using traditional methods. However, the surface quality, and dimensional and geometric accuracies of AM parts do not exceed conventionally machined parts, which hinders the AM applications. To overcome these limitations, hybrid manufacturing (HM) technology, which combines AM and subtractive manufacturing (SM) technologies in a single workstation has received a great deal of attention in academic and industrial circles to enhance material utilization, part complexity and quality control when producing functional parts. In this paper, we present research achievements using ANSI 316L stainless steel parts via the HM process and analysis of its surface morphology and microstructural characteristics, densification behaviour and mechanical properties. Specimens before and after heat treatment were analysed and compared. The study also dealt with material characterization via the Archimedes method, scanning electron microscopy (SEM), X-ray polycrystalline diffractometer (XRD) and tensile measurements. This study provides a valuable guide to determining the effectiveness of the HM process and its use when producing engineering parts. [ABSTRACT FROM AUTHOR]

Electron beam melting (EBM) has been recognized as an emerging additive manufacturing technology, which allows the production of fully dense parts from various metals. The technique builds parts using an electron beam to melt metal powder, layer by layer, in a powder bed. Thus, complex parts, including internal structures, can be made directly from 3D CAD models without special fixtures and cutting tools. Much research is conducted to study the microstructure and mechanical properties of EBM-built parts or to investigate the effects of EBM process parameters on the quality of parts. However, using EBM for building new features on an existing part has received little attention from the research community. Due to its performance, EBM seems able to transform an end-of-life (EoL) part/existing part into a new part without returning to the level of raw material. The aim of this study is to validate such principle. In this paper, an EBM machine was used to produce new Ti-6Al-4V features on a Ti-6Al-4V plate, which was considered as a useful core retrieved from an EoL product. The built samples, including EBM-built features and Ti-6Al-4V plate, were investigated in terms of their microstructure and mechanical properties. The results showed that EBM technique allows new features with a suitable microstructure and controlled mechanical properties to be built on an existing part. Moreover, the EBM-built features have a strong bond with the existing part leading to the same mechanical characteristics as original part. These demonstrate that the EBM technology has a promising potential for producing new parts from EoL parts/existing parts. [ABSTRACT FROM AUTHOR]