To develop low-cost additive manufacturing for metal parts, a methodology, namely, pneumatic extruding direct-writing deposition (PEDWD), is investigated in this paper. The deposition system mainly consists of a pressure and valve controller, temperature controller, three degree-of-freedom motion platform and computer system. By adopting the pressure of compressed nitrogen, molten metal was extruded

Material extrusionbased additive manufacturing (ME-AM) has been recently adopted by the pharmaceutical field as a potential method for decentralised small-batch manufacturing of personalised solid dosage forms. The unique advantage of ME-AM is the ability to implement a wide range of micro-scale internal structures within a dosage form that can be used to manipulate the drug release kinetics. However

3D printing materializes physical objects through sequentially depositing thin layers. The layer-by-layer stacking involves controlling 3D printing parameters (e.g., fan speed, nozzle temperature, printing bed temperature, and filament extrusion rate) to ensure conformity to a CAD (Computer-aided Design) model. Attackers target the parameters during a printing process to sabotage the printing object

Additive manufacturing (AM) process parameters highly affect the mechanical and fracture properties of additively manufactured carbon fiber reinforced polymer (CFRP) composites. In this work, we study the effect of two process parameters, including three build orientations (XYZ, XZY, and ZXY) and two raster patterns (±45º and 0º/90º), on the fracture behavior of the CFRP composites fabricated by fused

In this study, the effects of bentonite, diatomite, and metakaolin on the rheological behavior of 3D printed magnesium potassium phosphate cement composites (3D printed MKPCs) were investigated through characterization of the material properties, including yield stress, plastic viscosity, thixotropy, and creep. The thixotropy was studied by assessing the hysteresis area and thixotropic parameters under

The aligned bond interfaces resulting from the layer-by-layer nature of material extrusion-based additive manufacturing (MEAM) leads to anisotropic properties in printed parts. This study examines the anisotropy in electrical impedance and its variation with print parameters. Samples consisting of a stack of filaments are used to study the interfaces, which are the fundamental building block of MEAM

High mix, low volume processes such as additive manufacturing (AM) offer tremendous promise for increasing the customization in manufacturing but are hindered by the lack of efficient methods for identifying process parameters for complex new geometries exhibiting the desired performance. The search over the process space can be automated with analysis tools that can be applied in a time and resource

Additive manufacturing is a technology that enables mass customization of products owing to its flexibility and is one of the key technologies used in Internet-of-Things-based manufacturing systems. In recent years, industrial applications of additive manufacturing have been increasing, and expanding into space manufacturing. However, the controllability of gravitational acceleration has not been well

Laser powder bed fusion (LPBF), an important additive manufacturing (AM) technique, has received a great deal of research attention and industrial application. The capability to fabricate complicated shapes and structures enables this technique to be applied for the manufacturing of rapid prototypes and complex parts. In operation, the constant melting and cooling of metal powders in a layer-by-layer

Porous biomaterials are often used to treat large bony defects or fractured vertebras. Most of such biomaterials are made of metals and their alloys and have a pre-defined, fixed shape. Due to their predefined fixed shape, however, they are not suitable for implantation through minimally invasive surgical procedures. To overcome this problem, we designed three different deployable non-assembly mechanisms

In additive manufacturing (AM), low geometrical tolerances, high-quality material properties, and low surface roughness are challenges. To increase the process capabilities, a promising concept is to tailor process parameters for the fabrication of a part. Instead of selecting identical process parameters to the geometry of the whole part, different sets of process parameters are assigned to different

This study deals with additive manufacturing (AM) products. Employing AM technology, complex-shaped, and lightweight parts can be fabricated using the aluminum alloy, AlSi10Mg. Typically, AM of this alloy is performed by laser powder bed fusion (LPBF). The mechanical properties of LPBF products are crucial for many engineering applications. Therefore, there have been efforts to measure the dynamic

The effects of laser power on the formation, texture evolution, and mechanical properties of 316 L stainless steel fabricated by laser-arc hybrid additive manufacturing were studied. The results showed that the surface accuracy was first improved and then degraded with increasing laser power, because the stability of the molten pool first rose and then fell with the rising laser power. Additionally

Cementitious composites blended with high Belite sulfoaluminate cement and medium-heat Portland cements were optimized to achieve both favorable 3D printability and durability performance. The influence of the hybrid cement ratio on the rheology and the hardened properties, such as mechanical properties, drying shrinkage, and carbonization resistance, was systematically investigated. The results revealed

This paper aims to develop a high-efficient finite element (FE) model by combining the equivalent boundary condition method (EBCM) and dynamic mesh method (DMM) for accelerating the thermo-mechanical simulation of additive manufacturing by powder bed fusion (PBF). EBCM and DMM take advantage of the strong non-linear phenomenon in the thermo-mechanical affected zone (TMAZ) by simplifying the temperature

Additive manufacturing (AM) of metallic alloys for structural and functional applications has attracted significant interest in the last two decades as it brings a step change in the philosophy of design and manufacturing. The ability to design and fabricate complex geometries not amenable to conventional manufacturing, and the potential to reduce component weight without compromising performance,

Considering the long-term development of digital construction, a cost-effective and environmental printing material was designed with blast furnace slag as main cementitious material and sodium desulfurization ash as activator. However, weak alkaline environment lead to the insufficient 3D printability (e.g. yield stress, viscosity). Ethylene/vinyl acetate copolymer (EVA) was used to make up this defect

Nickel-based superalloys show severe cracking tendency during laser powder bed fusion (LPBF), which hinders their widespread applications in aerospace. A two-step heat treatment, including hot isostatic pressing (HIP) and solid solution heat treatment (SSHT), was proposed to obtain crack-free LPBF nickel-based superalloy components with a supersaturated solid solution of alloying elements for desirable

Titanium/Titanium Carbide (Ti/TiC) composites with 20, 40 and 60 vol% of TiC powders were deposited on Ti-6Al-4V substrates using a laser-directed energy deposition method. The bulk relative densities exceeding 99% were achieved in the deposits. The evolution of microstructures and local chemical compositions in the deposits under rapid melting and solidification were analyzed using X-ray diffraction

This paper presents computational fluid dynamics simulations of the deposition flow during printing of multiple layers in material extrusion additive manufacturing. The developed model predicts the morphology of the deposited layers and captures the layer deformations during the printing of viscoplastic materials. The physics is governed by the continuity and momentum equations with the Bingham constitutive

In this work, a novel alloy design of a stainless steel with a ferritic-austenitic microstructure is derived for PBF-LB/M (powder bed fusion-laser beam/metal). The alloy was developed based on X2CrNiMo17-12-2 steel, for which an austenite volume content of approx. 54 vol% in the PBF-LB/M state was achieved using a reduced Ni equivalent. Partial substitution of Ni by Mn increases the N solubility of

The inconsistent interfacial bonding of 3D-printed materials is accompanied by increasing scattering of the measured fracture toughness in delamination tests. This article focuses on the analysis of the delamination tests using theories developed for conventional composites. To this end, nylon 3D-printed specimens reinforced with carbon fibers are subjected to the mode I Double Cantilever Beam (DCB)

In this study, the conversion of plastic work to heat, also known as the Taylor-Quinney coefficient (β), of Inconel 718 (IN718) is investigated. Three material conditions are examined, specifically wrought IN718 and laser powder bed fusion (LPBF manufactured IN718 in the as-built condition and one that has been recrystallized through a solutionizing heat treatment. Adiabatic deformation conditions

During the L-PBF process stresses are developed due to the large temperature gradients induced by the laser beam and the fast cooling rates which occur while the part is being built. In this study, the development of forces induced layer by layer from the cycles of thermal gradient during L-PBF are measured in-situ using a Force Transducer Device (FTD) for several processing parameters, including laser

In the current study, the microstructural consistency in a laser powder bed fusion (L-PBF) AlSi10Mg material is investigated. A rectangular sample with a height of 40 mm is fabricated through the L-PBF technique. The main aim of the study is to analyze the effect of the repeated thermal cycles on the hierarchical characteristics of the microstructure in solid state. While the top of the sample represents

Additive manufacturing (AM) has changed the entire manufacturing enterprise by offering unique features for the fabrication of complex-shapes with superior mechanical properties. In the last decades, through an exponential advancement, AM has been promoted from a prototyping to a series and mass production platform. Like all conventional techniques, quality assurance procedures/tools are of the utmost

Coupling additive manufacturing (AM) with interlayer peening introduces bulk anisotropic properties within a build across several centimeters. Current methods to map high resolution anisotropy and heterogeneity are either destructive or have a limited penetration depth using a non-destructive method. An alternative pseudo-nondestructive method to map high resolution anisotropy and heterogeneity is

17–4 PH (precipitation hardening) stainless steel is commonly used for the fabrication of complicated molds with conformal cooling channels using laser powder bed fusion process (L-PBF). However, their microstructure in the as-printed condition varies notably with the chemical composition of the feedstock powder, resulting in different age-hardening behavior. In the present investigation, 17–4 PH stainless

In selective laser melting (SLM) heat diffusing from the melt pool promotes the growth of surface oxide layers on powder particles surrounding the built part, and material ejected from the melt pool oxidises rapidly before landing on the powder bed, creating local variability in the oxygen content of any used powder. Although large particles are removed when recycling, smaller oxidised particles (the

Additive manufacturing and 3D printing technology using thermoplastics and metals have found mainstream use and acceptance. Nevertheless, these methods are not suitable for several industrially important materials, such as silicones and epoxies that are formed by mixing two or more reactive components and chemically inducing crosslinking. The reaction increases the viscosity of the material significantly

As additive manufacturing (AM) increases in popularity, many companies seek to identify which parts can be produced via AM. This has led to new areas of research known as “part filtering”, “part selection”, or “part identification” for AM. Numerous methods have been proposed to quantify the suitability of a design to be made with AM, and each has its own benefits and drawbacks. This paper reviews 13

Metal Big Area Additive Manufacturing is an additive manufacturing technique based on Gas Metal Arc Welding (GMAW) with the option to use many shielding gases, and materials. The system is equipped with a dual torch design allowing for printing different materials; in our study, AISI 410 stainless steel and AWS ER70S-6 mild steel are both printed in the same component. Different print strategies were

The effect of a spot melt strategy on the solidification texture, variant selection, phase fraction, and their variations along the build height was investigated in comparison to a conventional linear melt strategy. Ti-6Al-4V alloy samples were manufactured by an electron-beam powder bed fusion process using two different melt strategies and characterized using high-energy synchrotron x-ray diffraction

Material Extrusion (ME) is the most prevalent Additive Manufacturing (AM) technology due to the broad range of materials and equipment available, generally attainable at a fraction of the cost of other AM processes. While ME has gradually found niche applications outside of the casual user, including implementations in the automotive and aerospace sectors, the slow print speed of the process represents

The combination of shape memory polymer composites and 3D printing technology provides novel opportunities for customized manufacturing and intelligentization of products. Here, we developed magneto-responsive shape memory polymer composites with well-balanced strengths and toughness by adding Fe3O4 and cellulose nanofibers (CNFs) to a poly-hydroxybutyrate/poly(ε-caprolactone) blend as functional particles

In this study, the effects of inter-layer temperature variation on the microstructure, crystallographic orientation, and corrosion performance of a multilayer single-pass wall-shaped 420 stainless steel part fabricated using wire arc additive manufacturing (WAAM) were investigated. The microstructural evolution and texture formation after fabrication were analyzed using scanning electron microscopy

When tungsten is processed by laser powder bed fusion additive manufacturing, the combination of high residual stresses and tungsten’s inherent ductile-to-brittle transition leads to a network of microcracks. While preheating is widely accepted as the most efficient way to reduce residual stresses in additively manufactured parts, thus far it has proven ineffective in completely eliminating microcracking

Additive manufacturing, also known as 3D printing, overcomes many design and manufacturing constraints to allow almost direct production of metals into complicated geometries. However, coarse columnar grain structures, up to the millimeter-scale, are commonly produced in titanium and its alloys through the layer-by-layer process and this causes significant anisotropy in mechanical properties. Here

Understanding the thermal history of a metal part during additive manufacturing (AM) is essential for process design and microstructural control. In this study, detailed thermal history simulation was carried out for laser metal deposition (LMD) of Ti-6Al-4V (wt%) using the Directed Energy Deposition (DED) module in Simufact Welding. The simulation identified necessary LMD conditions for in-situ decomposition

The characteristic sub-grain cellular structures widely observed in additively manufactured metals and alloys play an important role during plastic deformation. In the present study, the influence of cell boundaries on the mechanical response of a directed energy deposited 316 L stainless steel was investigated using site-specific micro-compression tests of single and bi-crystal micro-pillars with

During laser-based powder bed fusion, the non-equilibrium solidification conditions promote local elemental segregation, leading to a characteristic microstructure composed of cellular walls. These walls can display either low carbon BCC martensite or FCC retained austenite crystal structures, thus affecting the subsequent isochronal or isothermal martensite to austenite phase transformation mechanisms

A novel approach to fabricate magnetic elements made from nanocomposite materials by material extrusion is proposed. Flexibility in the shape and dimensions of this technology leads to the possibility to overcome the restrictions in the design and manufacturing of complex-shaped bulk magnets. The nanocomposites discussed here were fabricated by the addition of magnetite (Fe3O4) nanoparticles into a

Down-facing surfaces are one of the most challenging features in metal parts produced by laser powder bed fusion (LPBF). A combination of reasons, primary of which are residual stresses and overheating cause these features to have the worst surface finish and dimensional accuracy of all LPBF surfaces. In order to examine this phenomenon, a Design of Experiments (DoE) study is conducted for three different