Search

Most of the research on Binder Jetting 3D Printing of AISI316L stainless steel has focused on optimizing the sintering cycle, with less emphasis on the effect of printing parameters on the properties in the sintered state. This study aims to investigate the influence of printing parameters on density, mechanical properties in both the green and sintered states. A Taguchi model was employed to experimentally study four parameters (printhead speed, dark body, powder applicator speed, and shell thickness) at three levels using an L9 orthogonal array. The results showed that green density ranged from 51.3% ± 0.9%–57.0% ± 0.9%, while a sintered density of 98.6% ± 0.08% was achieved. Mechanical testing revealed green strengths between 1.8 ± 0.1 MPa and 6.1 ± 0.8 MPa, while tensile tests provided yield strength of 175.1 ± 3.5 MPa, ultimate tensile strength (UTS) of 532 ± 9.7 MPa, and elongation at break of 87.7% ± 7.5%.ANOVA analysis indicated a statistically significant effect of the dark body (binder saturation) on density and mechanical properties. In the green state, increasing binder saturation enhances green density and bending strength. However, in the sintered state, higher binder saturation results in lower densification and UTS. Powder applicator speed also demonstrated statistical relevance for green density, where lower speeds produced higher density. Conversely, shell thickness and printhead speed had negligible effects on the properties investigated. These findings highlight the most significant printing parameters and their impact of target properties. Additionally, linear models were developed as a tool for optimizing printing parameters based on the desire density and mechanical outcomes.

Improving the printing accuracy and stability of shrimp surimi and finding appropriate printing parameters and suitable thermal processing method can help to develop high value-added 3D printing products of shrimp surimi. It was found that in order to make the 3D printing products of shrimp surimi have higher printing adaptability (printing accuracy and printing stability reach more than 97%), by choosing nozzle diameter of 1.20 mm and setting the printing height of the nozzle to 2.00 mm, the layers of the printed products were better fused with each other, and the printing accuracy of the products could be greatly improved; there was no uneven discharge and filament breakage when the nozzle moved at the speed of 30 mm/s; and the products were internally compact and had good stability when the printing filling rate was 80%. In addition, the deformation rates of steamed, boiled and deep-fried shrimp surimi products were significantly higher than those of oven-baked and microwaved shrimp surimi products (P

This study investigates the impact of printing parameters on the adhesion strength of ink-jet films, focusing on indium tin oxide (ITO) and indium oxide (In2O3) films deposited on ceramic substrates with varying printing speed and stack layers. The surface morphology of films with different printing parameters is characterized, and microscratch tests are conducted to calculate the adhesion energy of the films. The relationships between printing parameters, microstructures, and adhesion strength are emphasized, which could provide innovative insights into the mechanical properties of ink-jet printing films dependent on printing parameters. The results are also contributed to a new perspective on the design and repair of ink-jet printed indium tin oxide films.

As one of the light materials with superior biocompatible properties, magnesium has drawn more attention in recent years. More industries, such as the automotive, aerospace, and medical, are adopting new strategies to employ this material. Mg-based batteries with potential advantages over Li-based batteries are also predicted to be used in electric vehicles shortly. However, significant problems in the production of Mg, such as its low ductility at ambient temperature and high oxidation and flammability at high operating temperatures, have limited its application. Therefore, selecting an appropriate manufacturing method can lessen or resolve Mg's drawbacks. Castings, different traditional forming and Severe Plastic Deformation (SPD) methods, and alloying of Mg with other elements are among the most popular fabrication and processing techniques to improve Mg properties and expand its application. However, as an innovative Additive Manufacturing (AM) method, the Selective Laser Melting (SLM) is considered a more reliable way of producing Mg-based products, especially for applications with complex geometry design, the least amount of waste, and no need for molds and accessories. Of course, SLM also has its challenges, such as the strong dependence of the properties on printing parameters and the raw material; however, apparent horizons can be imagined for SLM of Mg according to recent developments and research. This paper summarizes the SLM of Mg by introducing the SLM parameters, properties, defects, and applications of SLMed Mg alloys and discussing the challenges and solutions of this method. The impact of the SLM parameters and initial Mg powder characteristics as the primary inputs of this method on the resultant properties of the SLMed Mg components and the potential defects are thoroughly discussed. The thermal zones produced in the SLM process of Mg are divided into four categories, which are strongly influenced by the printing parameters and, on the other hand, affect the quality of the final product so that a high relative density of 99% and the much better mechanical and microstructural properties than those produced via other conventional methods, such as casting are achieved by adjusting the printing parameters. The characterization of the primary powder is divided into two categories: morphology and particle size, along with chemical composition. Morphology and chemical composition play an essential role in the final part by affecting the alloy's flowability, oxidation, and ignition. Characterization of properties is also reviewed in three general densifications, mechanical properties, and microstructure of SLMed samples and their dependence on parameters and input materials. Finally, the defects and challenges are briefly discussed, and the applications of Mg alloys in two widely used areas, including automotive and medicine, are presented.

Resource recovery and better use of food processing wastes are topics of significant attention. Fruit wastes in particular are perishable yet contain a wealth of unrealized advantages. This study presents the 3D printability of banana peel (BP) powder with the addition of guar gum (GG). The particle characteristics of BP powder were analyzed. The microscopic morphology of the BP powder was found to be erratic and clumped. The printability of extruded material supply was optimized after the characterization of BP and BP + GG material supplies. When 6 bar pressure was used and the motor speed was 150 rpm, it was found that the BP + GG material supply could be printed utilizing a 1.2 mm nozzle diameter. Printing speed and printing rate was optimal at 500 mm/min and 0.186 ± 0.002 g/min, respectively. A nozzle height of 0.8 mm was found to be optimal for printing. Thus, non-printable BP was made printable and the concept can be applied to the development of unique and customized food packaging casings. The results of this study shed light on how various agri-food wastes can be used to create biodegradable 3D-printed structures.

Goal: Material extrusion additive manufacturing, is a relatively inexpensive and popular manufacturing technique that can be used to fabricate complex 3D geometries at low cost. However, parts produced by this process are often characterised by poor quality, particularly with regards to dimensional and geometrical accuracy. This review provides a comprehensive analysis of experimental studies conducted over the past 25 years that have aimed to improve these quality variables via printing parameter optimisation. Methods: An initial non systematic scoping study coupled with a subsequent scientific systematic literature review protocol to identify experimental studies on dimensional quality in material extrusion additive manufacturing was conducted. 127 individual studies are identified and analysed. Results: The authors critically analysed the relevant and salient studies (127) by evaluating which machines; materials; sample sizes; artefact designs; and most importantly what printing parameters have been used in the experimental investigations. A total of (79) machine variations were used; ABS and PLA made up (43%) and (36%) of materials investigated respectively; (84%) of studies had sample sizes of less than (40); and artefact dimensions ranged from (10–270 mm) (1–240 mm), and (3.5–220 mm) in the X, Y, and Z axes respectively. In many cases, the relationships between printing parameters (independent variables) and dimensional qualities (dependent variables) were found to be uncertain or even contradictory between studies. Conclusions: A wide range of studies have sought to optimise parameters (e.g., Nozzle gap height, print head velocity, filament volumetric velocity) to address dimensional quality issues in ME AM. However, the authors have demonstrated that a lack of agreement among studies limits the generalisability of these parameter optimisation findings. More recent studies have considered the local dimensional variance of deposited single strands. This offers greater potential to understand the underlying causes of component defects and inaccuracy.

Direct-Ink-Writing (or robocasting) is a subset of extrusion-based additive manufacturing techniques that has grown significantly in recent years to design simple to complex ceramic structures. Robocasting, relies on the use of high-concentration powder pastes, also known as inks. A successful optimization of ink rheology and formulation constitutes the major key factor to ensure printability for the fabrication of self-supporting ceramic structures with a very precise dimensional resolution. However, to date achieving a real balance between a comprehensive optimization of ink rheology and the determination of a relevant protocol to predict the printing parameters for a given ink is still relatively scarce and has been not yet standardized in the literature.The current review reports, in its first part, a detailed survey of recent studies on how ink constituents and composition affect the direct-ink-writing of ceramic parts, taking into account innovative ceramic-based-inks formulations and processing techniques. Precisely, the review elaborates the major factors influencing on ink rheology and printability, specifically binder type, particle physical features (size, morphology and density) and ceramic feedstock content.In the second part, this review suggests a standardized guideline to effectively adapt a suitable setting of the printing parameters, such as printing speed and pressure, printing substrate, strut spacing, layer height, nozzle diameter in function of ink intrinsic rheology.

Binder jetting (BJ) is an additive manufacturing process in which powder materials are selectively joined by a binder. BJ is plagued by its high sensitivity to both powder properties and process parameters which critically affect the quality of powder beds and final products. Alumina powder was used as a model material processed using different routes to obtain granules with various characteristics. Granule properties (particle size, morphology, flowability), characteristics of powder bed (roughness, packing density) and process parameters (binder saturation, layer thickness) were highly optimized in order to achieve the highest printed parts quality in terms of compressive strength and volume density. Optimized values reach 102.2 ± 11.1 MPa and 64.2 ± 1.9% T.D respectively which are close to expectations for this process. The paper serves as an aid in understanding the influence of powder properties and processing parameters and provides general guidelines to rapidly develop ceramic powders for conventional binder jetting process.

3D-printed composites have promising potential for applications as structural or functional parts in different engineering fields. However, due to the presence of pores and weak interface interactions, 3D-printed parts have weaker mechanical performance than traditional processed ones. In recent years, polypropylene (PP) emerged as a new 3D printing material with enormous potential. In this work, two PP-based composites (PP/EPR(ethylene-propylene-rubber) and PP/EPDM(ethylene-propylene-diene-monomer)/talc) were chosen to study the effects of extrusion temperature and layer thickness on the quasi-static and dynamic behavior of 3D-printed PP-based composites. The results obtained in this study indicated that the processing induced voids have a significant impact on the mechanical properties of printed specimens as they could cause stress concentration and trigger crack propagation. A smaller layer thickness and a moderate printing temperature could reduce pore size and porosity in the printed parts and consequently increase their mechanical properties. Compared to the response under quasi-static loading, the apparent strength and modulus for both materials under dynamic compression were much higher. Under impact loading, polypropylene-based composites exhibited different rupture characteristics caused by the different reinforcement.

In this study, a comprehensive experimental investigation is performed to observe the influence of printing process parameters on the interfacial fracture toughness of bi-material additively manufactured composites. A single leg bending (SLB) specimen made of Polylactic acid (PLA) and Nylon is loaded under the quasi-static three-point bending condition to initiate the fracture between the PLA/Nylon interface. Six different process parameters (bed temperature, printing temperature, printing speed, printing orientation, layer height, and thickness ratio) are considered to investigate the fracture toughness. It is observed that process parameters have a significant impact on the bi-material interfacial fracture toughness. Due to the increase of crystallinity of the polymer, the fracture toughness decreases by about 40% when the bed temperature increases from 60 °C to 100 °C. However, with improved molecular diffusion, the fracture toughness is enhanced by 95% with the increase of the printing temperature. Although printing speed has not any significant impact on fracture toughness, thinner layers provide a better bond strength and polymer wetting, resulting in a higher fracture initiation toughness compared to thicker layers. Due to the presence of extra voids and anisotropic behavior, the specimens of 0o/90o raster-orientation demonstrate about 75% lower fracture toughness compared to those of +45o/-45o orientated specimens.

Objective: To review the elements of the vat-polymerization workflow, including the 3D printing parameters, support structures, slicing, and post-processing procedures, as well as how these elements affect the characteristics of the manufactured dental devices., Data: Collection of published articles related to vat-polymerization technologies including manufacturing workflow description, and printing parameters definition and evaluation of its influence on the mechanical properties of vat-polymerized dental devices was performed., Sources: Three search engines were selected namely Medline/PubMed, EBSCO, and Cochrane. A manual search was also conducted., Study Selection: The selection of the optimal printing and supporting parameters, slicing, and post-processing procedures based on dental application is in continuous improvement. As well as their influence on the characteristics of the additively manufactured (AM) devices such as surface roughness, printing accuracy, and mechanical properties of the dental device., Results: The accuracy and properties of the AM dental devices are influenced by the technology, printer, and material selected. The printing parameters, printing structures, slicing methods, and the post-processing techniques significantly influence on the surface roughness, printing accuracy, and mechanical properties of the manufactured dental device; yet, the optimization of each one may vary depending on the clinical application of the additively manufactured device., Conclusions: The printing parameters, supporting structures, slicing, and post-processing procedures have been identified, but additional studies are needed to establish the optimal manufacturing protocol and enhance the properties of the AM polymer dental devices., Clinical Significance: The understanding of the factors involved in the additive manufacturing workflow leads to a printing success and better outcome of the additively manufactured dental device., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Scaffold micro-topological structure plays an important role in the regulation of cell behavior in bone tissue engineering. This paper investigated the effect of 3D printing parameters on the scaffold micro-topological structure and its subsequent cell behaviors. By setting of different 3D printing parameters, i.e., the 3D printing laser power, the scanning interval and the thickness of sliced layers, the highest resolution up to 20 μm can be precisely fabricated. Scaffolds' characterization results indicated that the laser power affected the forming quality of melt tracks, the scanning interval distance determined the size of regularly arranged pores, and the thickness of sliced layers affected the morphological and structural characteristics. By regulating of these printing parameters, customized porous Ti6Al4V scaffold with varied hierarchical micro-topological structure can be obtained. In vitro cell culturing results showed that the regular porous micro-topological structure of scaffolds with the aperture close to cell size was more suitable for cell proliferation and adhesion. The overall distribution of cells on regular porous scaffolds was similar to the orderly arrangement of cultivated crops in the field. The findings suggested that customization of the scaffold provided an effective way to regulate cellular behavior and biological properties., (Copyright © 2020 Elsevier B.V. All rights reserved.)