Online Detection and Prediction of Fused Deposition Modelled Parts Using Artificial Intelligence

Fused deposition modelling (FDM) is a technology used for filament deposition of heated plastic filaments by a given pattern by the melted extrusion process. Delamination is a critical issue of FDM's incredibly complex parts. In this chapter, the artificial intelligence (machine learning) model is used for online detections and prediction of FDM parts. The proposed machine learning and convolutional neural network model is capable of online detect delamination of FDM parts. The proposed model can also be applied for different types of additive manufacturing materials with less human interaction.

Design, simulation and optimisation of lattice structures for remote control aeroplane

PurposeThus, in this work the goal is to design, simulate and optimise a holder of a brushless motor in lattice structure to get the best performance in terms of mechanical strength, vibration absorption and lightness.Design/methodology/approachNowadays, most manufacturers and designers' goal are to sell efficient products in mass to keep up or outrun competition. Medical, aeronautical, automobile and civil engineering sectors produce complex parts and products that encompasses multiple properties such as lightweight, energy absorbance, vibration reduction and stress resistant. Studies found that lattice structures are more and more useful in these fields since their characteristics satisfy complex behaviour.FindingsThe study's outcome suggests that the use of lattice structure reduces 60% of the actual motor holder mass while keeping the strength of the material, meeting initial specifications.Research limitations/implicationsThe Ram capacity of the PC.Practical implicationsLight materials for aerospace engineering elongate the range of the unmanned aerial vehicle (UAV) to an extra range of flight.Social implicationsSituation awareness of the country border using surveillance drone and minimising the consumption of fuel.Originality/valueThe research allowed reducing 60% the actual holder mass.

Laser Welding of AISI 316L Stainless Steel Produced by Additive Manufacturing or by Conventional Processes

Among all the additive manufacturing techniques, Laser Powder Bed Fusion (LBPF), also called Selective Laser Melting (SLM), is the most common technique due to its high capability of building complex parts with generally improved mechanical properties. One of the main drawbacks of this technique is the sample size limitation, which depends on elaborating chamber dimensions. In this study, we investigate the viability of obtaining large parts with the laser welding of additive manufactured plates. A comparison of the microstructure and the tensile mechanical properties of SLM-welded plates and cold-rolled welded plates was performed. This paper shows the possibility of obtaining defect-free parts. Even if welding has a low impact on the microstructure of the SLM samples, fractures are located on the fusion zone, and a decrease in ductility of around 30% compared to the base metal is observed.

STUDY OF DEFORMATION PROPERTIES OF COMPOSITES WITH A HYBRID MATRIX BY THE METHOD OF DYNAMIC AND MECHANICAL ANALYSIS

Polymer and composite materials (PCMs) are widely used in various industries for production of small but complex parts and large-sized body parts subjected to significant loads. The production of more critical parts from PCM has led to the need to develop new compositions, structures and technologies for molding composites. The manufacturing technology of PCMs with a hybrid matrix is presented, one of the components of which retains its "liquid" state after the molding of the products, and the second is completely solid. In the resulting composite, the “liquid” components form an independent phase and together with the main binder material, the PCMs represent a hybrid matrix. The results of dynamic mechanical analysis (DMA) of basalt plastics with hybrid matrices, in which the composition of the “liquid” component are anaerobic technical wax and organosilicon polymer materials, are presented. DMA is performed on samples of two types: № 1 - samples with a low content of "liquid" components in the matrix and № 2 - samples with a high content of "liquid" components in the matrix. According to the results of the tests carried out, the best characteristics among PCMs with various types of hybrid matrices are possessed by samples with an organosilicon polymer material in the matrix

Powder bed selective laser process (sintering/melting) applied to tailored calcium phosphate-based powders

This paper focuses on the tailoring of calcium phosphate powders for their use as powder bed selective laser process feedstock. Hydroxyapatite and chlorapatite were used as starting powders for the preparation of different blends through the addition of graphite as a laser absorptance additive. A methodical study was conducted to compare the processing windows of the blends containing different amounts of graphite through the laser patterning of circular samples. It was found that the addition of graphite increases the process window of the powder blends being the powder without additive non processable. Hydroxyapatite showed a clear phase transition (decreased when using higher volumetric energy density) into other calcium phosphate phases while chlorapatite was demonstrated to be thermally stable during the whole process (examined through X-ray diffraction and vibrational spectroscopies). In parallel, the study evaluating the powder blend composed of hydroxyapatite and graphite for the production of solid and complex parts was carried out although it required long printing times. The productivity of the process was improved by modification of printing parameters. Then, a series of solid samples were produced for the analysis of the microstructure and mechanical properties. High interconnected porosity was observed in the samples which could improve the bioactivity of the bioceramic scaffolds. A post-treatment of the parts increased their proportion in the hydroxyapatite phase and their mechanical properties. These results are expected to contribute to the application of powder bed selective laser processing of calcium phosphates powders toward bone tissue engineering.

Opportunities and challenges in additive manufacturing used in space sector:a comprehensive review

Purpose The purpose of this study is to compile the successful implementation of three-dimensional (3D) printing in the space for the manufacturing of complex parts. 3D printing is an additive manufacturing (AM) technique that uses metallic powder, ceramic, or polymers to build simple/complex parts. The parts produced possess good strength, low weight, excellent mechanical properties and are cost-effective. This saves a considerable amount of both time and carrying cost. Thereof the challenges and opportunities that the space sector holds for AM is worth reviewing to provide a better insight into further developments and prospects for this technology. Design/methodology/approach The potentiality of 3D printing for the manufacturing of various components under space conditions has been explained. Here, the authors have reviewed the details of manufactured parts used for zero gravity missions, subjected to onboard International Space Station conditions and with those manufactured on earth. Followed by the major opportunities in 3D printing in space which include component repair, material characterization, process improvement and process development along with the new designs. The challenges such as space conditions, availability of power in space, the infrastructure requirements and the quality control or testing of the items that are being built in space are explained along with their possible mitigation strategies. Findings These components are well comparable with those prepared on earth which enables a massive cost saving. Other than the onboard manufacturing process, numerous other components and a complete robot/satellite for outer space applications were manufactured by AM. Moreover, these components can be recycled on board to produce feedstock for the next materials. The parts produced in space are bought back and compared with those built on earth. There is a difference in their nature i.e. the flight specimen showed a brittle nature and the ground specimen showed a denser nature. Originality/value The review discusses the advancements of 3D printing in space and provides numerous examples of the applications of 3D printing in space and space applications. The paper is solely dedicated to 3D printing in space. It provides a breakthrough in the literature as a limited amount of literature is available on this topic. The paper aims at highlighting all the challenges that AM faces in the space sector and also the future opportunities that await development.

Review of Aluminum Alloy Development for Wire Arc Additive Manufacturing

Processing of aluminum alloys by wire arc additive manufacturing (WAAM) gained significant attention from industry and academia in the last decade. With the possibility to create large and relatively complex parts at low investment and operational expenses, WAAM is well-suited for implementation in a range of industries. The process nature involves fusion melting of a feedstock wire by an electric arc where metal droplets are strategically deposited in a layer-by-layer fashion to create the final shape. The inherent fusion and solidification characteristics in WAAM are governing several aspects of the final material, herein process-related defects such as porosity and cracking, microstructure, properties, and performance. Coupled to all mentioned aspects is the alloy composition, which at present is highly restricted for WAAM of aluminum but received considerable attention in later years. This review article describes common quality issues related to WAAM of aluminum, i.e., porosity, residual stresses, and cracking. Measures to combat these challenges are further outlined, with special attention to the alloy composition. The state-of-the-art of aluminum alloy selection and measures to further enhance the performance of aluminum WAAM materials are presented. Strategies for further development of new alloys are discussed, with attention on the importance of reducing crack susceptibility and grain refinement.

Wetting and Spreading of AgCuTi on Selective Laser-Melted Ti-6Al-4V

Selective laser melting (SLM) can be used to manufacture complex parts, however, it is difficult to make large parts due to the size limitation of the SLM equipment. In application, smaller selective laser-melted (SLMed) Ti-6Al-4V (TC4) parts can be brazed or welded to form larger components. In the brazing, AgCuTi is often used to braze TC4. However, the wettability of AgCuTi on the SLMed TC4 should be evaluated before joining the SLMed TC4 parts. As a result, wetting and spreading tests and brazing experiments should be undertaken to successfully join the SLMed TC4 parts. In this study, a LINKAM TS 1500 high-temperature hot stage was used to test the brazability of the AgCuTi on the surface of SLMed TC4. Different temperatures and dwell times were used: (i) 850 °C 900 °C and 950 °C, holding for 120 s, were used to study the temperature effects; (ii) 20 s, 120 s and 200 s were used at 850 °C to study the dwell time effects. The R~t model was used to describe the wetting and spreading process. The results of this study can provide basic data for the joining of SLMed TC4 in industry.

SUPPORT-FREE METAL ADDITIVE MANUFACTURING: A STRUCTURED REVIEW ON THE STATE OF THE ART IN ACADEMIA AND INDUSTRY

Especially in the Laser Powder Bed Fusion (L-PBF) technology for metals, current manufacturing systems require the use of support structure to withstand recoater forces and lower thermal induced stresses. These support structures set limitations on the design freedom and affect the surface quality, part cost and lead-time in an undesirable manner. Complex parts, which were not possible with conventional manufacturing methods, can be produced without these limitations. While some companies claim to print parts with horizontal overhangs without the use of support structure, academic research seems to deal with these limitations by defining design guidelines rather than eliminating them. In order to highlight the discrepancies between academia and industry, a structured review is presented. As result, severe differences in knowledge were discovered, which might emerge from the use of unconstrained cutting-edge systems in industry. Eventually support-free L-PBF is not yet fully developed, but the use of support structure can be drastically reduced by optimizing the build process.