Additive Manufacturing Methods Research Articles

INFLUENCE OF ADDITIVE MANUFACTURING TECHNOLOGY OF TOPOLOGICALLY OPTIMIZED PRODUCTS FROM PHOTOPOLYMER RESINS ON THE ANISOTROPY OF THEIR MECHANICAL PROPERTIES

This article discusses the problem of ensuring strength and minimum mass in the design of products manufactured using additive technologies. The authors investigated the possibility of using topological optimization in computer-aided design systems to create an optimized model with the necessary strength at a minimum weight. As part of the work, the topological optimization of the bracket, the production of its samples by additive manufacturing methods and strength tests were carried out. The optimal values were found via finite element analysis using the SolidWorks and ANSYS software. The calculation results show that the optimized model retains about 20% of the original mass and has the necessary mechanical characteristics. In particular, the excess safety margin is reduced by 2.5 times, which is acceptable for this bracket. The subsequent verification of the models is carried out through destruction tests of the products manufactured using additive technologies, i.e. the method of filament deposition and stereolithography. To account for the anisotropy of the material, a series of samples oriented at different angles to the direction of construction was made. The tests were carried out on a test bench for simultaneous biaxial stretching, which corresponds to the design loads on the bracket. An increase in the tensile load on the sample was carried out before its destruction. In the course of the work, the presence of anisotropy of mechanical properties was revealed, and optimization results in various software packages were studied. The results of strength tests allow us to draw two conclusions. Firstly, due to the anisotropy of the material, the strength properties significantly depend on the orientation of the bracket during additive manufacturing. Secondly, the bracket, optimized by means of the SolidWorks software package, generally showed the best strength properties for various orientations during manufacturing. Also, which is quite expected, the samples obtained by stereolithography showed less anisotropy than the samples obtained by the method of filament deposition. In conclusion, it is noted that the use of additive technologies to create optimized forms requires considering printing technologies and anisotropy of properties, as well as the choice of appropriate software.

Microstructure, Recovery Stress and Mechanical Property of Direct Energy Deposition Welded Fe-Mn-Si Based Shape Memory Alloy

Direct Energy Deposition (DED) is one of the main methods of additive manufacturing in which a feedstock material in the form of powder or wire is delivered to a substrate while an energy source, such as laser beam or electron beam, is simultaneously applied to melt the feedstock. In addition to fabricating complex three-dimensional shapes using computer aided design, the DED laser welding process can be employed to fill complex shaped gaps between two objects. In this study, 3 mm thick Fe-based shape memory alloy plates with a 45° groove were welded by DED using high manganese steel powder filler. The process parameters including scan speed, hatch spacing, and layer thickness were fixed at values of 840 mm/min, 0.3 mm, 0.15 mm, respectively and laser power was varied during the welding process from 150 W to 300 W. Microstructures of the welds showed different shapes and quantities of defects such as cracks, pores and a lack of fusion depending on the laser power used. Laser power of 150 W showed crack-free weldment with the highest mechanical properties. The tensile strength and recovery stress of the welded sample were higher than the base metal, demonstrating the potential high performance of welding Fe-Mn-Si shape memory alloy components using the L-DED.

On the Hydrodynamic and Structural Performance of Thermoplastic Composite Ship Propellers Produced by Additive Manufacturing Method

In the marine industry, the search for sustainable methods, materials, and processes, from the product’s design to its end-of-life stages, is a necessity for combating the negative consequences of climate change. In this context, the lightening of products is essential in reducing their environmental impact throughout their life. In addition to lightening through design, lightweight materials, especially plastic-based composites, will need to be used in new and creative ways. The material extrusion technique, one of the additive manufacturing methods, is becoming more widespread day by day, especially in the production of objects with complex forms. This prevalence has not yet been reflected in the marine industry. In this study, the performances of plastic composite propellers produced by the material extrusion technique is investigated and discussed comparatively with the help of both hydrodynamic and structural tests carried out in a cavitation tunnel and mechanical laboratory. The cavitation tunnel test and numerical simulations were conducted at a range of advance coefficients (J) from 0.3 to 0.9. The shaft rate was kept at 16 rps. The thrust and torque data were obtained using the tunnel dynamometer. Digital pictures were taken to obtain structural deformation and cavitation dynamics. The structural performance of the propellers shows that an aluminum propeller is the most rigid, while a short carbon fiber composite propeller is the most flexible. Continuous carbon fiber composite has high strength and stiffness, while continuous glass fiber composite is more cost-effective. In terms of the hydrodynamic performance of the propellers, flexibility reduces the loading on the blade, which can result in thrust and torque reduction. Overall, the efficiency of the composite propellers was similar and less than that of the rigid aluminum propeller. In terms of weight, the composite carbon propeller containing continuous fiber, which is half the weight of the metal propeller, is considered as an alternative to metal in production. These propellers were produced from a unique composite consisting of polyamide, one of the thermoplastics that is a sustainable composite material,, and glass and carbon fiber as reinforcements. The findings showed that the manufacturing method and the new composites can be highly successful for producing ship components.

Prototyping sutureless shape memory valve stent via integrated 3D printing

Abstract Transcatheter aortic valve replacement (TAVR) has increasingly emerged as a forefront option for treating aortic valve diseases. However, the currently prevalent valve prostheses used in TAVR typically involve stitching biologic leaflets onto metallic stents, which introduces challenges in the durability of leaflets and the biocompatibility of metallic stents. This work proposes an integrated additive manufacturing method for prototyping sutureless prosthetic aortic valves that combine shape memory polymer (SMP) stents and hydrogel valve leaflets. The SMP stent exhibits sufficient toughness to maintain structural integrity upon shape memory programming, while the Fe3+-treated hydrogel leaflets possess sufficient swelling resistance to ensure dimensional stability. Finally, the proof-of-concept valve stent is successfully fabricated by integrated 3D printing and validated via an in vitro hemodynamic experiment. Overall, our approach holds promise for prototyping sutureless polymeric valve stents for future generations.

Drop-on-Demand 3D Printing of Programable Magnetic Composites for Soft Robotics

Soft robotics have become increasingly popular as a versatile alternative to traditional robotics. Magnetic composite materials, which respond to external magnetic fields, have attracted significant interest in this field due to their programmable two-way actuation and shape-morphing capabilities. Additive manufacturing (AM), also known as 3D printing, allows for the incorporation of different functional composite materials to create active components for soft robotic systems. However, current AM methods have limitations, especially when it comes to printing smart composite materials with high functional material content. This is a key requirement for enhancing responsiveness to external stimuli. Commonly used AM methods for smart magnetic composites, such as direct ink writing (DIW), confront challenges in achieving discontinuous printing, and enabling multi-material control at the voxel level, while some AM techniques are not suitable for producing composite materials. To address these limitations, we employed high-viscosity drop-on-demand (DoD) jetting and developed versatile programmable magnetic composites filled with micron-sized hard magnetic particles. This method bridges the gap between conventional ink-jetting and DIW, which require inks with viscosities at opposite ends of the spectrum. This high-viscosity DoD jetting enables continuous, discontinuous, and non-contact printing, making it a versatile and effective method for printing functional magnetic composites even with micron-sized fillers. Furthermore, we demonstrated stable magnetic domain programming and two-way shape-morphing actuations of printed structures for soft robotics. In summary, our work highlights high-viscosity DoD jetting as a promising method for printing functional magnetic composites and other similar materials for a wide range of applications.

Fabrication of Hierarchically-Porous Diatomite Scaffolds for Dye Adsorption by a Dual-templating Approach

Compared to single-scale porous structures, multi-scale porous materials are distinguished by their unique hierarchical architecture composed of macro-, meso-, and micro-pores. These materials are widely adapted in nature and endowed with high surface area, improved transport efficiency, and reduced weight due to their structural design. Such characteristics lead to various applications, especially in filtration and adsorption. In this study, a dual-templating method integrating freeze casting and 3D-printing sacrificial templating techniques was employed to develop multi-scale porous scaffolds with pore sizes distributed across three distinct length scales. Gyroid, a type of triply periodic minimal surface (TPMS) structure, was selected for the millimeter-scale channel design because of their high permeability, non-tortuous fluid pathways, and interconnected pores. Moreover, periodic gyroid structures can be described by mathematical equations, allowing for the systematic designs of 3D models. By varying the volume fractions of the 3D-printed gyroid templates and the cooling rates during the freeze casting process, pore sizes at both millimeter and micrometer scales can be tuned to achieve desired structures. Furthermore, the smallest pores were provided by diatomites, the fossilized silica-based algae with inherent nanoscale pores, offering extremely high surface area and porosity. Permeability experiments were conducted to further explore the influence of multi-scale pores on fluid transportation properties. Results showed that scaffolds with three scales of pore sizes (millimeter, micrometer, and nanometer) exhibited up to 58 times increase in permeability compared to those with two scales of pore sizes (micrometer and nanometer). Additionally, by leveraging the inherent functional groups on diatomites, multi-scale porous scaffolds were used in methylene blue dye adsorption experiments, revealing a dye removal efficiency of 63%. In conclusion, this study integrated freeze casting and additive manufacturing methods for multi-scale porous ceramics with tunable structural features and functionalities, which can be applied in wastewater treatment, ultra-lightweight structural materials and other engineering fields.

3D printing of biomimetic hierarchical surface textures using L-PBF for improving tribological performance of Ti6Al4V alloy

Energy and material losses due to friction and wear during the use of materials bring about very serious costs in every sector. In order to minimize friction and wear losses of materials, different surface engineering applications are used, especially surface coatings, thermal, mechanical and thermochemical processes. On the other hand, it has been shown in recent years that the tribological properties of materials can be controlled by creating different types of biomimetic hierarchical patterns on the surface of materials. Therefore, this study investigates both the individual and the synergetic effects of both biomimetic surface textures and thermal oxidation process on the tribological performance of Ti6Al4 V alloy. For this purpose, hierarchical models were produced using the laser powder bed fusion (L-PBF) technique, which is one of the additive manufacturing methods. Snake skin, shark skin and tree frog models were used as biomimetic hierarchical models. Additionally, flat and random snake skin models were used to examine the effect of texture orientation. Moreover, thermal oxidation was carried out at 700 ⁰C for 2 h and 4 h and the wear tests were carried out using a reciprocation-type tribo-tester under dry and simulated body fluid (SBF) conditions. As the oxidation time increased, the hardness and surface roughness of the material increased. A significant improvement in the wear rate of biomimetic models was observed compared to the non-textured sample. Lower tribological performance was observed in the tree frog model (hexagonal geometry) compared to other biomimetic models due to the presence of sharp corners. In particular, the snakeskin model provided the best wear rate because it trapped wear residue and provided additional hydrodynamic pressure. The highest tribological performances for all samples were observed in the samples oxidized at 700 ⁰C for 4h.

Experimental study on compression response of additively manufactured lattice structures

The intricate nature of lattice structures poses challenges for conventional manufacturing approaches, necessitating the adoption of Additive Manufacturing (AM) methods. This work presents design of three novel biomimetic lattice structures namely Modified Schwarz Primitive (MSP), Tetrahedral (TLS) and Octagonal prism with square hole (OPL). Digital Light Processing (DLP) based AM technology was utilized for fabrication and the compressive strength and porosity was evaluated. The results shown that the MSP have the highest porosity of 68.6 % whereas the OPL exhibited the highest compressive strength of 9.63 MPa.

Multi‐Material Gradient Printing Using Meniscus‐enabled Projection Stereolithography (MAPS)

AbstractLight‐based additive manufacturing methods are widely used to print high‐resolution 3D structures for applications in tissue engineering, soft robotics, photonics, and microfluidics, among others. Despite this progress, multi‐material printing with these methods remains challenging due to constraints associated with hardware modifications, control systems, cross‐contamination, waste, and resin properties. Here, a new printing platform coined Meniscus‐enabled Projection Stereolithography (MAPS) is reported, a vat‐free method that relies on generating and maintaining a resin meniscus between a crosslinked structure and bottom window to print lateral, vertical, discrete, or gradient multi‐material 3D structures with no waste and user‐defined mixing between layers. MAPS is compatible with a wide range of resins shown and can print complex multi‐material 3D structures without requiring specialized hardware, software, or complex washing protocols. MAPS's ability to print structures with microscale variations in mechanical stiffness, opacity, surface energy, cell densities, and magnetic properties provides a generic method to make advanced materials for a broad range of applications.

Selective Deposition and Fusion of AISI 316L: An Additive Manufacturing Process for Space Environments via Direct Ink Writing and Laser Processing

Abstract Unlocking the potential of additive manufacturing (AM) for space exploration hinges on overcoming key challenges, notably the ability to manufacture or repair parts on-site during exploration missions with consideration of quality, feedstock utilization, and challenges involved in microgravity environments. While there are multiple efforts to investigate the use of existing metal AM processes such as powder bed fusion (PBF), directed energy deposition (DED), and filament-based material extrusion, each process comes with a different set of challenges in space environments. Here, we introduce a new AM method that integrates the benefits of Direct Ink Writing (DIW) to selectively deposit metallic pastes with laser-based processing to locally de-bind and subsequently melt and fuse metal powder, layer by layer, enabling the manufacturing of AISI 316L samples with densities exceeding 99.0%. The impact of process parameters on single-track dimensions, surface morphology, and porosity was characterized. The efficacy of laser de-binding was assessed via secondary-ion mass spectrometry, permitting the carbon content to be estimated at 0.0152%, which is safely below the acceptable limit (0.03 wt%) for AISI 316L.

Geometric and Flow Characterization of Additively Manufactured Turbine Blades With Drilled Film Cooling Holes

Abstract As designers investigate new cooling technologies to advance future gas turbine engines, manufacturing methods that are fast and accurate are needed. Additive manufacturing facilitates the rapid prototyping of parts at a cost lower than conventional casting but is challenged in accurately reproducing small features such as turbulators, pin fins, and film cooling holes. This study explores the potential application of additive manufacturing and advanced hole drill methods as tools to investigate cooling technologies for future turbine blade designs. Data from computed tomography scans are used to nondestructively evaluate each of the cooling features in the blade. The resulting flow performance of these parts is further related to the manufacturing through benchtop flow testing. Results show that while total blade flow is consistent for all additively manufactured cooled blades, flow through smaller regions of the blades shows variations. Shaped film cooling holes manufactured using a high-speed electrical discharge machining method are within tolerance in the metering section but do not expand at the specified angle in the diffuser even though design tolerances are met. In contrast to high-speed EDM, conventional EDM holes are undersized throughout the length of the hole. Due to the additive manufacturing process, the surface roughness was higher on the additively manufactured parts in the current study than has been previously reported for surface roughness of commonly used cast components. The roughness results show high levels on thin walls, particularly at the trailing edge as well as on downskin surfaces. Internal surface roughness is higher than external roughness at most locations on the blade. The results of this study confirm that additive manufacturing along with advanced hole drilling techniques offers faster development of blade cooling designs.

Integrating Deep Learning with Generative Design and Topology Optimization for Efficient Additive Manufacturing

Abstract. Additive manufacturing (AM) through generative design and topology optimisation creates complex, lightweight structures with exceptional material efficiency and structural integrity. When coupled with deep learning functionality, generative design and topology optimisation can explore broader design spaces and optimise more efficiently, creating novel AM structures that utilise material more efficiently and have better strength and performance than their counterparts created through conventional AM methods. The study tackles how deep learning models such as convolutional neural networks (CNNs) can be integrated into generative design and topology optimisation and how these integration help optimise material usage, production time and performance. Case studies from the aerospace, automotive, and healthcare industries exemplify how these synergies resulted in more resilient, cost-effective designs that would not have been possible through conventional AM approaches. The study focuses on material usage efficiency, reduction in production time and performance improvement to showcase how deep learning integrations enhance the process from design conceptualisation, through iterations, to final production.

Chain-based lattice printing for efficient robotically-assembled structures

Due to the nature of their implementation, nearly all low-level fabrication processes produce solidly filled structures. However, lattice structures are significantly stronger for the same amount of material, resulting in structures that are much lighter and more materially efficient. Here we propose an approach for fabricating lattice structures that echoes 3D printing techniques. In it, a modular chain of specially designed links is “extruded” onto a substrate to produce various lattices configurations depending on the chosen assembly algorithm, ranging from rigid regular lattices with nodal connectivity of 12, octet-truss, to significantly less dense configurations. Compared to conventional additive manufacturing methods, our approach allows for efficient use of nearly any material or combination of materials to construct lattices with programmed arrangements. We experimentally demonstrate that a 3x3x2 lattice structure (287 total links) is fabricated in 27 minutes via a modified robotic arm and can support approximately 1000 N in compression testing.

Investigation of formation, microstructure and hardness of Ti-6Al-4V single tracks via Joule-fused filament additive manufacturing

Purpose This paper aims to investigate a novel additive manufacturing (AM) method for titanium alloy using Joule heat as the single heat source to melt TC4 wire, which intends to provide a new low-power, low-cost solution for the processing of titanium alloys. Design/methodology/approach When current flows through the wire and the substrate, Joule heat will be generated to melt the wire and join the wire with the substrate. By stacking the wire layer by layer, finally a part can be formed. The cross-sectional morphology, microstructure and hardness of TC4 single track deposits formed by Joule heat melting wire AM were investigated by various characterization methods. Findings The melting width and melting penetration decreased with the increase of printing speeds. There is no obvious change in single track morphology with the change of printing pressures. The melting width and melting penetration increased with the increase of printing currents. The observation of the internal microstructure of a single track reveals a decrease in grain size as printing speeds increase. The average hardness of the single track was about 363 HV, which is comparable to the hardness of the parts fabricated by selective laser melting process. The printing power is less than 300 W, which is lower than other AM processes. Originality/value This paper provides a novel solution for the processing of titanium alloy parts. Compared with other expensive energy sources, this work only uses an ordinary DC power supply as the energy source. The printing process is simple and the cost is low. The power is much lower than other AM processes.

Molten Metal Jetting for Repairing Aluminum Components

Molten metal jetting (MMJ) is an additive manufacturing (AM) method where droplets of molten metal are used to build parts. Like most AM technologies, MMJ is typically used to build stand-alone parts rather than add onto existing parts. However, the droplet-wise deposition method of MMJ is inherently compatible with the ability to build on existing parts. Here, we utilize MMJ to “repair” machined damage on cast aluminum parts. A commercial MMJ system was used to fill in varied but defined groove geometries to find optimal shapes amenable to repair with MMJ. Subsequently, grooves were cut into tensile specimens and back-filled (repaired) using MMJ. Tensile tests indicate that MMJ repair restores significant strength to samples despite the distinct microstructure and void structures present in the repaired section. Repaired samples demonstrated tensile strengths ∼72% of the as-received material, compared to UTS of ∼33% for damaged samples. These results indicate that MMJ is a viable method to repair parts where other repair methods may be impractical.

The Torsional Characterization of 3D‐Printed Polylactic Acid Parts With Alternating Additive Manufacturing Parameters

ABSTRACTThree‐dimensional (3D) printed polymer parts can be subjected to torsional loads in accordance with the conditions of use. Understanding the torsional properties of 3D printed polymers depending on the printing parameters is a significant research topic in fused deposition modeling (FDM) additive manufacturing processes to be used as machine parts operating under torsional load, such as polymer parts manufactured by extrusion method. Some studies have shown that raster angle and printing speed affect the mechanical properties of 3D‐printed polymers. However, tensile tests were used in most of those studies. In this study, the torsional behavior of 3D printed Polylactic acid (PLA) materials was investigated by static torsion tests, finite element analyses, and theoretical and failure analyses with respect to the printing speed and raster angle parameters. Torsion test specimens were manufactured at five different raster angles (0°, 30°, 45°, 60°, and 90°) and two different printing speeds (20 and 80 mm/s) from PLA material using the FDM additive manufacturing method. The results showed that raster angle and printing speed parameters affected the torsional load‐carrying capacity of FDM‐3D printed PLA parts. The best load‐carrying capacity was achieved at 30° and 60° raster angles, while the lowest was measured at 0° raster angle. The torsional load‐carrying capacity was significantly enhanced by 85% for specimens manufactured at the printing speed of 80 mm/s.

On the printability of high-density polyethylene (HDPE) reinforced with long glass and short carbon fibres

Purpose This research is about the possibilities of using high-density polyethylene (HDPE)-based composites consisting of long glass and short carbon fibres because HDPE is one of the more preferred thermoplastics day by day due to its sustainability, cost-effectiveness and availability in the relevant markets. HDPE has become an increasingly preferred material in the marine industry in recent years due to its high resistance to marine environmental conditions (high resistance to UV, surface-fouling marine organisms and corrosive effects of salty and low-pH water). In the highly competitive boat building industry, additive manufacturing offers new opportunities such as rapid prototyping and design freedom. This study aims to investigate the possibilities of using a material suitable for the marine environment and an additive manufacturing (AM) method offering new possibilities, especially for small craft with complex forms. Design/methodology/approach A total of six new HDPE-based composites consisting of long glass and short carbon fibres at 10, 15 and 20% by weight have been proposed for the first time in this study for the use in boat building industry, proposing the application of these new composite materials with AM method, which the industry is not yet fully adopted, is also an innovative aspect of the study. The performances of the materials in AM’s material extrusion (MEX) method were evaluated using the results obtained from mechanical (tensile, compression, shear and impact) and thermal (melt flow index [MFI], thermogravimetric analysis [TGA] and thermomechanical analysis [TMA]) tests. In addition, the structure of the composites was examined with scanning electron microscopy and micro computed tomography visually, and the rheological properties of the composites were also determined by the related tests. As an industrial case study, a ship propeller was manufactured from the composites produced with CF15, which was thought to give the best performance in marine use, and this propeller was tested under water flow. Findings It is evaluated that the composites proposed in this study can be used in marine industry in line with the analyses and test results. The performance of the propeller produced as a case application also confirms this view. The printability of HDPE-based composites, reinforced by both glass and carbon fibre, is much better than that of pure HDPE, and the composites are suitable for use AM’s MEX method in boat building industry. As the fibre contents in the proposed composites increase, the strength values increase and the impact resistance and hardness decrease. The CF15 composite, which meets each of those mechanical and physical values at an average level, is a recommended option for marine applications. Originality/value This study has two basic originalities: (1) On the basis of HDPE, which is widely used in the marine industry, to produce composites that will overcome the deficiencies of this material in practice and to present them to relevant industry by improving their properties; (2) at the same time, to discuss for the first time the use of new HDPE-based materials in AM, whose printability has also been improved through composite, to help dissemination of AM technologies in marine industry in general and in the boat building industry in particular.

Improving the Fatigue Performance of Binder Jet Manufactured 316L by Severe Shot Peening Surface Modification

Binder jetting is a rapidly evolving additive manufacturing technique, challenging the dominance of laser powder bed fusion in metal fabrication. This study focuses on the material properties of austenitic stainless steel 316L produced via binder jet technology. Porosity remains a significant challenge across additive manufacturing methods, adversely affecting material properties and fatigue life. To address this issue, we propose a novel approach employing severe shot peening as a post-processing treatment to enhance the material's characteristics. Microstructural analysis, including electron backscatter diffraction (EBSD), coupled with tensile testing, was conducted to evaluate the mechanical properties. Additionally, fatigue behavior was investigated under both axial and flexural bending loading conditions. The results revealed a substantial increase in material strength achievable through the post-treatment. Notably, the fatigue limit of the material in bending fatigue was elevated from 120 MPa to 190 MPa, indicating a significant enhancement in fatigue performance. This study contributes new insights into the enhancement of fatigue resistance in binder jet-manufactured 316L stainless steel through surface modification techniques. The findings underscore the potential of severe shot peening as an effective strategy to improve material properties and expand the applicability of binder jet printing in demanding industrial applications.

Intensify the hindrance to gas entrapment on the construction of Al 5356 thin-walled structure by tuning the WAAM process parameters

Abstract Compared to other metallic additive manufacturing methods, Wire Arc Additive Manufacturing (WAAM) has a number of advantages, such as less equipment capital required and more material composition flexibility. However, uneven welding and feed rates, as well as inadequate gas flow, can result in flaws such oxidation, gas entrapment, and humping. This study aims to reduce gas entrapment, maximize tensile strength, and reduced elastic modulus of the WAAM Al5356 wall by optimizing gas flow rate (13, 16 and 19 l min−1) in conjunction with welding and feed rates. The study highlighted gas flow rate as the most important component in pore formation and used the Entropy approach in conjunction with the COmplex PRoportional ASsessment (COPRAS) tool to identify ideal settings. The reduction in gas entrapment to 0.02%, as shown in the confirmation studies, resulted in a 33.9% rise in tensile strength and a 64.7% rise in elastic modulus. To verify these ideal parameters, elastic modulus mapping was done on the printed WAAM Al5356 wall. Moreover, the damage processes connected to gas entrapment and humping development were examined using fractography. Consequently, the research determined the ideal conditions to generate a multi-layer structure free of defects, improving its practicality in aerospace and automotive sectors.

Detecting and evaluating surface defects in additive manufacturing composite materials via image processing technique

Purpose This study aims to offer an image-based robust edge detection system that can estimate, identify, locate and label surface flaws during manufacturing for real-time surface issue diagnostics. Of great concern, this methodology extrapolates surface defect information from scanning electron microscopy (SEM) images of composite fracture surfaces. This study predicts changes in topological intensity of composite fracture surfaces and display them as real-time surface intensity values for the first time. Design/methodology/approach This work, however, introduces a novel robust edge detection method – based image processing – as it is shown to be effective in locating defects, as measured by SEM images of composite fracture surfaces created using additive manufacturing (AM). SEM images, obtained in this study, are related to previous study considering the fracture surfaces of reinforced thermoset composites created via the AM method. These SEM images are of two types: fracture surface of AM of carbon fiber reinforced thermoset composites and fracture surface of AM of syntactic foam reinforced thermoset composites. Initially, MATLAB environment is used for analyzing the SEM images; the technique used, as well as the validity are explained more in the methodology section. Findings The robust surface defect inspection approach used herein is found to be capable of predicting, identifying, localizing and labeling surface defects during production, allowing for real-time surface issue diagnosis. Further, this work makes it possible to use image processing and analysis of these surfaces to anticipate fluctuations in the topological intensity of the fracture surfaces of composites and represent them as values of surface intensity in real time. Originality/value Rising worldwide company rivalry requires a fast, accurate component failure diagnostic method. To create an efficient feature set, a surface defect inspection system must identify product flaws in real time. Thus, this study proposed an image-based robust edge detection system – based on MATLAB environment – that is capable of estimating, identifying, locating and labeling surface faults during production. This paves the way for an extensive set of high-quality tools for dealing with a wide range of problems associated with digital image processing in composites. As a result, the ability to define methodologies and rapidly prototype prospective solutions typically minimizes the cost and time required to implement a successful system during the design phase of an image processing system.