Metal additive manufacturing (AM) has received a lot of attention since its introduction, owing to its cost efficiency and freedom in design. For a successful and repeatable AM process, metal powders conform to strict chemical and physical properties requirements. There are numerous factors affecting these characteristics in both virgin and used powders. This article presents a comprehensive overview

The material extrusion (ME) process, which is an additive manufacturing technology applicable to a wide range of polymers, has a drawback in that the inherent bonding between the deposited layers is vulnerable. To this end, we present an efficient strengthening method for the ME process by introducing bidirectional in situ infrared (IR) heating during the polymer melt deposition in the 3D-printing

Graphene–polyamide-6 composite (GC) filament was 3D-printed via melt extrusion (ME). The influence of specimen thickness and internal geometric designs on electromagnetic interference shielding effectiveness (EMI SE) and dielectric properties in the X-band frequency range (8.2–12.4 GHz) was investigated. Increasing specimen thickness from 1 to 5 mm did not improve EMI SE due to impedance matching and

Dimensional and geometrical precision of parts produced by binder jetting is a crucial issue to be considered aiming at promoting the transition to industrial production. The influence of both the printing and the sintering processes has to be evaluated, and the high shrinkage has to be considered. The task is further complicated by the anisotropy of dimensional change on sintering. The aim of this

Additive manufacturing has advantages of cutting the time from design to making new parts but it suffers from metallurgical defects such as porosity. For example, wired arc additive manufacturing(WAAM) of new alloys such as Al–Li alloys is very challenging due to the fact that the porosity level is so high as to degrade not only fatigue life but also the static mechanical properties. In this study

The tensile response of chiral auxetic cellular structures was experimentally and computationally studied. The auxetic cellular structures with two different chiral geometries (tetrachiral and hexachiral) were fabricated using laser powder bed fusion (LPBF) technology from two different materials (aluminium alloy AlSi10Mg and stainless steel AISI 316 L). The specimen's microstructure, porosity and

In this work, the influence of milled and chopped carbon and glass fibers on the curing behavior and accuracy of the acrylic-based photopolymer LOCTITE 3D 3860 was investigated. The analysis was performed using working curves and optical methods. A comparison between the two fiber types showed that using glass fibers leads to increased volume efficiency, which improved even more with increasing fiber

Assessing the material stiffness of fiber reinforced polymer composites deposited in Large Area Additive Manufacturing (LAAM) is needed to define the process-structure-property mapping for the LAAM technology. While the screw-extrusion-based LAAM systems yield a distribution of fiber aspect ratio (i.e., length to diameter ratio for cylindrical inclusions) within deposited beads, most composite micromechanical

Solidification or hot cracks are commonly observed defects in a number of metal alloys and may lead to deterioration of additively manufactured parts quality. In this study, ultra-high-speed x-ray radiography experiments enable the observation and characterization of bundles of hot-cracks that form in monobloc AA6061 substrate. The crack bundles are related to meltpool characteristics and pore formation

The ability to align ex-situ inspection data of an additively manufactured (AM) part to its build geometry can be helpful, for example, to correlate observed in-situ monitoring events or features to measured discontinuities, such as pores and cracks, in ex-situ inspection. In some cases, the original part design does not lend itself to such an alignment due to the absence of datum surfaces. In this

Laser Powder Bed Fusion (LPBF) is an additive manufacturing process where laser power is applied to fuse the spread powder and fabricate industrial parts in a layer by layer fashion. Despite its great promise in fabrication flexibility, print quality has long been a major barrier for its widespread implementation. Traditional offline post-manufacturing inspections to detect the defects in finished

In Direct Energy Deposition, manufacturers require a simple and economical technique to simulate a given powder flux. This study proposes a novel analytical method based on a straightforward measurement technique to reverse engineer the powder flow distribution of a coaxial annular nozzle up to its focus position. Different axial profiles of powder concentration were obtained by blowing powder over

Wire and Arc Additive Manufacturing (WAAM) is a direct-energy deposition technique (unlike SLM or EBM) that builds up a part in a layer-by-layer fashion, each layer being constituted of interlaced weld beads. It is the best suited Additive Manufacturing (AM) technique for large structures thanks to its high deposition rate (5 kg/h). The resulting material shows a rough surface, strong residual stress

Scan pattern dependent (multi-track) residual stress buildup over multiple layers in the powder bed fusion process is governed by coupled thermo-mechanics. The high computational cost associated with these simulations has resulted in the general adoption of approximate computational methods. The numerical or thermo-mechanical accuracy of assumptions made in these computational methods is not fully

The ever growing demand for reducing costs and decreasing the time to market in today’s plastics industry makes rapid tooling and rapid prototyping a highly researched area. 3D printed injection mould inserts make it possible to produce prototype parts in small series fast and cost-effectively. The mechanical strength and therefore the life expectancy of 3D printed polymeric injection mould inserts

Although additive manufacturing offers numerous potential advantages for fabricating functional, complex geometry zirconia parts with efficiency, industrial interest in practical applications is currently lacking. This potentially stems from the need for a more comprehensive investigation into the performance of additively manufactured zirconia components, which is essential for promoting and initializing

The elastic response of homogeneous isotropic materials is most commonly represented by their Young's modulus (E), but geometric variability associated with additive manufacturing results in materials that are neither homogeneous nor isotropic. Here we investigated methods to estimate the effective elastic modulus (Eeff) of samples fabricated by fused filament fabrication. We conducted finite element

Currently, applying 3D concrete printing to compressed structural systems with low tensile/shear stresses is a feasible and alternative route to promote this advanced technology into engineering practice because of the lack of an effective structural reinforcing method. Modular manufacturing of segmental components and fabricated construction of large-scale structures are promising for overcoming the

For hard tissue engineering applications, biodegradable composite scaffolds have been extensively investigated because of their satisfactory mechanical properties and biocompatibility. Recently, 3D printing processes have received substantial attention in the tissue engineering field because of their ability to be customized for tissues that have suffered different types of loss or damage for each

In this work, the mechanism of melt pool oxidation and reduction during the powder bed fusion was studied. To elucidate the mechanism, the effect of process parameters such as laser power, scan speed and shield gas flow speed on the variation on oxygen, nitrogen and carbon content in the printed material was investigated. In 316L stainless steel, melt pool reduction and oxidation occurred simultaneously

Wire Arc Additive Manufacturing is a near-net-shape processing technology which allows cost-effective manufacturing of large and customized metal parts. Processing of aluminium in Wire Arc Additive Manufacturing is quite challenging, especially in terms of porosity. In the present work, pore behaviour in Wire Arc Additive Manufacturing of AW4043/AlSi5(wt.%) was investigated and a post-process monitoring

Fused filament fabrication (FFF) continues to be among the most widespread additive manufacturing process for making polymeric functional prototypes, and in several cases end-use parts. There is a large installed base of serial-link industrial robots, some of which could be potentially retrofitted with an extruder head as an end-effector to serve as FFF systems with as many as six degrees of freedom

In the process of arc welding additive manufacturing, real-time monitoring weld reinforcement of the deposited layer could provide additional information for the researcher to understand the layer by layer mechanics. In this paper, a molten pool vision sensor system is utilized to collect the welding pool image at the first 1 ms of the short circuit phase. A locating system is applied to detect the

Powder Bed Fusion Additive Manufacturing (PBFAM) processes have emerged as important industrial processes that are capable of manufacturing complicated part features, such as hollow designs, lattice structure and other unique design structures. The current state of computing technology requires significant time to predict the part distortion formed during the PBFAM build process. In this paper, a novel

While the relationships between processing, structure, and properties of solid titanium alloys produced by additive manufacturing have been established, these relationships are less understood for porous materials, particularly those with rough surfaces inherent to L-PBF. For orthopedics applications, porous architecture and surface roughness are desirable for bone growth, and thus optimization of

Grain-scale microstructure evolution during additive manufacturing is a complex physical process. As with traditional solidification methods of material processing (e.g. casting and welding), microstructural properties are highly dependent on the solidification conditions involved. Additive manufacturing processes however, incorporate additional complexity such as remelting, and solid-state evolution

Metamaterials are defined as artificially designed micro-architectures with unusual physical properties, including optical, electromagnetic, mechanical, and thermal properties. This study proposes a thermal metamaterial that provides an efficient thermal cycle with two conflicting objectives: (i) high thermal resistance as a thermal insulator and (ii) high cooling capability as a heat exchanger. To

Part defects and irregularities that influence the part quality is an especially large problem in additive manufacturing (AM) processes such as selective laser sintering (SLS). Destructive and non-destructive testing procedures are currently mostly used for quality control and defect detection of AM parts after production. In this context, machine learning (ML) algorithms are increasingly being used

Material extrusion, a filament-based three-dimensional (3D) bioprinting technique, is commonly adopted to fabricate many complex constructs for its high efficiency, compatibility with a variety of biomaterials, and easy realization. During extrusion bioprinting, the morphology (including the shape and size) of extruded filaments is of great interest since the filaments are the basic building blocks

Adding fiber filler is a classic strategy for plastic reinforcement, which is well worth applying to Digital Light Processing (DLP) 3D printing technology. Herein, this study evaluated the application of micro-size poly(p-benzoyl-p-phenylenediamine) (Kevlar) fiber in resin for stereolithography. The mixture of Kevlar fiber and resin has an acceptable viscosity. In the mentioned process, the resin was

The unique capability of additive manufacturing (AM) to deal with complex geometries drives the traditional topological optimization and lightweight design to a new paradigm. However, AM constraints are still hard to integrate into the optimization procedure, and the multiple conflict design objectives are difficult to handle when making decisions. In addition, the computation cost is usually high

This work investigated the phase formation, thermal stability, and mechanical behavior of a metastable quasicrystal-forming Al95Fe2Cr2Ti1 alloy prepared by selective laser melting (SLM). The powder of this alloy was obtained by gas atomization using recycled material (Al cans) which brings several economic and social advantages. It showed chemical composition, particle size distribution, flowability

16MnCr5 steel parts were additively manufactured by laser powder bed fusion in order to investigate the effect of microstructure on electromagnetic properties. As process parameters have a direct impact on the obtained microstructure, different conditions were used to manufacture samples on which magnetic and electrical tests were conducted. The obtained results were presented and discussed in terms

Laser Powder Bed Fusion (LPBF) enables complex structures to be manufactured, which is attractive to industries where augmented service performance can be achieved. However, the build time of LPBF can be slower than traditional manufacturing processes, especially for higher volumes of parts. Multi-laser machines have the potential to significantly reduce process time, but there is little understanding

Laser powder bed fusion (LPBF) is an additive manufacturing (AM) process widely adopted in multiple industries for various purposes. When LPBF is used for part fabrication, determining the manufacturability of a specific design is a challenge. Therefore, this study aimed to identify a printable design using a novel approach to predict the potential printing failures of a given design via the LPBF process

This research reveals the effect of building direction on the microstructure, mechanical properties and the deformation behaviour of additively manufactured maraging steels. 18Ni-300 maraging steel samples were manufactured throughout the laser powder bed fusion (LPBF) process in horizontal and vertical directions. Uniaxial tensile tests were then conducted for as-built and heat-treated specimens to