Article
Engineering, Manufacturing
P. Navarrete-Segado, C. Frances, M. Tourbin, C. Tenailleau, B. Duployer, D. Grossin
Summary: This paper focuses on the tailoring of calcium phosphate powders for their use in powder bed selective laser process feedstock. Through the addition of graphite as a laser absorptance additive, the processing window of the powder blends containing different amounts of graphite was increased, making the powder without additive non-processable. The study also showed the phase transition of hydroxyapatite while chlorapatite remained thermally stable during the whole process. Another study evaluated the production of solid and complex parts using a powder blend of hydroxyapatite and graphite. The microstructure and mechanical properties of the samples were analyzed, and the bioactivity of the bioceramic scaffolds was improved through a post-treatment process. These findings are expected to contribute to bone tissue engineering using powder bed selective laser processing of calcium phosphate powders.
ADDITIVE MANUFACTURING
(2022)
Article
Engineering, Manufacturing
Yusuke Sugiura, Ryo Koike
Summary: This study developed a high-gravitational powder bed fusion system that improves the surface quality, density, and hardness of fabricated parts by applying high gravitational acceleration. Experimental evaluations demonstrate that a high gravitational field enhances the quality of the parts produced.
ADDITIVE MANUFACTURING
(2021)
Article
Engineering, Manufacturing
Changgong Kim, Houshang Yin, Andrii Shmatok, Barton C. Prorok, Xiaoyuan Lou, Kathryn H. Matlack
Summary: Additive manufacturing (AM) has the potential to revolutionize manufacturing by fabricating complex geometries, but faces challenges in quality assessment. This study demonstrates the use of ultrasonic phase velocity measurements to evaluate defects and microstructural differences in AM stainless steel 316L parts, showing sensitivity to pore geometry and texture. The research suggests that the measured ultrasonic phase velocity is sensitive to changes in anisotropic elastic constants in AM materials.
ADDITIVE MANUFACTURING
(2021)
Article
Engineering, Manufacturing
Marvin A. Spurek, Adriaan B. Spierings, Marc Lany, Bernard Revaz, Gilles Santi, Jonatan Wicht, Konrad Wegener
Summary: Powder bed fusion of metals (PBF-LB/M) is a commonly used additive manufacturing process, but the lack of effective sensing technologies has led to inconsistent quality in manufactured parts. This study investigates the potential of eddy current testing (ECT) as an in-situ process monitoring technology for PBF-LB/M. The results show that ECT can effectively monitor the relative part density, paving the way for deploying ECT for in-situ nondestructive testing (NDT) of PBF-LB/M-manufactured parts.
ADDITIVE MANUFACTURING
(2022)
Article
Engineering, Manufacturing
Tao Liu, Edward C. Kinzel, Ming C. Leu
Summary: This paper introduces an in-situ measurement method utilizing active lock-in infrared thermography (LIT) to determine the thermal diffusivity and thickness of the powder layer. The proposed method exhibits great potential for accurate powder property and thickness measurements and real-time process monitoring. The findings highlight the potential of the lock-in thermographic technique for rapid in-situ inspection of the new powder layer in laser powder bed fusion (LPBF) processes.
ADDITIVE MANUFACTURING
(2023)
Article
Chemistry, Analytical
Leigh Stanger, Thomas Rockett, Alistair Lyle, Matthew Davies, Magnus Anderson, Iain Todd, Hector Basoalto, Jon R. Willmott
Summary: This article emphasizes the importance of considering the inherent spatial transfer function of a thermographic instrument when measuring thermal fields. A validated methodology was used to correct spatial transfer function errors, resulting in significant changes to signal levels and effective temperature, which in turn affected the accuracy of validation data for process and microstructure modeling. These corrections demonstrate the necessity of considering image blur when quantifying thermal fields in laser-based powder bed fusion.
Article
Materials Science, Multidisciplinary
Kai Gutknecht, Michael Cloots, Ryan Sommerhuber, Konrad Wegener
Summary: This paper compares three distinctive sensors for laser powder bed fusion metal additive manufacturing process monitoring, including a microphone, an on-axis two-colour pyrometer, and an off-axis thermographic camera. The study finds that the microphone has higher sensitivity but is more susceptible to interference, while the pyrometer provides sensitive signals and is robust against different sensing distances.
MATERIALS & DESIGN
(2021)
Article
Engineering, Manufacturing
Tao Liu, Cody S. Lough, Hossein Sehhat, Yi Ming Ren, Panagiotis D. Christofides, Edward C. Kinzel, Ming C. Leu
Summary: This paper investigates the in-situ characterization of the powder layer using thermographic inspection and proposes a method to predict part distortion and prevent damage to the recoater system and powder layer abrasion.
ADDITIVE MANUFACTURING
(2022)
Article
Materials Science, Multidisciplinary
Tian Yang, Zhijian Feng, Yating Qiu, Wei Han, Lingbao Kong
Summary: This paper explores the benefits and possibilities of using irregular shaped powder in selective laser melting (SLM) of glass. Through a series of experiments, it is demonstrated that irregularly-shaped glass powder can be successfully used in the SLM process and that process parameter changes can yield builds with comparable porosity levels to builds using typical spherical powder.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Engineering, Manufacturing
Ju Wang, Dengzhi Yao, Meng Li, Xizhong An, Shujun Li, Wentao Hou, Xing Zhang, Guangyu Yang, Jian Wang, Lin Wang
Summary: In this study, the PBF-EB additive manufacturing of pure tungsten component is numerically reproduced using a validated DEM-CFD model. The effects of different process parameters on the characteristics of the powder bed are comprehensively analyzed, revealing the correlation between the stable state of powder layer accumulation and the packing density, surface roughness, and deposited layer height. The study also uncovers the different motion behaviors and forces experienced by particles located at the top and bottom regions of a new powder layer.
ADDITIVE MANUFACTURING
(2022)
Article
Computer Science, Artificial Intelligence
Paromita Nath, Sankaran Mahadevan
Summary: This work presents a Bayesian methodology for layer-by-layer predictive quality control of an additively manufactured part by integrating physics-based simulation with online monitoring data. The proposed method infers porosity in the printed layers using a porosity inference model constructed by reducing the dimension of thermal images obtained from an infra-red thermal camera. The model also predicts porosity in future layers and adjusts process parameters if the predicted porosity exceeds a desired threshold. To improve speed and accuracy, a surrogate model is used instead of a finite element model, and a discrepancy term is calibrated using experimental data. The method is demonstrated for controlling porosity in laser powder bed fusion by changing process parameters.
JOURNAL OF INTELLIGENT MANUFACTURING
(2023)
Review
Chemistry, Physical
Zhuo-Jun Hou, Qing Wang, Chen-Guang Zhao, Jun Zheng, Ju-Mei Tian, Xiao-Hong Ge, Yuan-Gang Liu
Summary: This paper presents the current status and future trends of online monitoring technology for the metal powder bed fusion (PBF) process. By combining powder recoating monitoring, powder bed inspection, building process monitoring, and melt layer detection, the quality and reliability of PBF parts can be improved.
Article
Materials Science, Multidisciplinary
Farhang Honarvar, Sagar Patel, Mihaela Vlasea, Hossein Amini, Ahmad Varvani-Farahani
Summary: The study demonstrates the use of high-frequency phased array ultrasonic testing (PAUT) for nondestructive evaluation of a cubic AlSi10Mg sample manufactured by the LPBF process, showing successful identification of defects as small as 0.75 mm with good agreement between PAUT and XCT results.
JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE
(2021)
Article
Engineering, Manufacturing
Zijun Yuan, Xiangdong Chen
Summary: Fabricating overhanging structures in Selective laser melting is challenging. Temporary supports are currently required, but they generate additional waste. This study proposes a new method by using a defocused laser to print a new structure layer directly on the powder bed, eliminating the need for traditional supports. Experimental results demonstrate that this approach can greatly reduce waste caused by conventional supports.
JOURNAL OF MANUFACTURING PROCESSES
(2023)
Article
Materials Science, Multidisciplinary
Moritz Gruenewald, Kevin Popp, Johannes Rudloff, Marieluise Lang, Alexander Sommereyns, Michael Schmidt, Shoya Mohseni-Mo, Claas Bierwisch
Summary: This study investigates the impact of material properties on product quality in powder bed fusion through experiments and numerical simulations, proposing a method to calculate dimensionless energy input. The results show good correlation between experimental data and numerical simulation results.
MATERIALS & DESIGN
(2021)
Article
Materials Science, Multidisciplinary
Rui F. Sampaio, Joao P. M. Pragana, Ivo M. F. Braganca, Carlos M. A. Silva, Paulo A. F. Martins
Summary: This paper focuses on hybrid busbars made from aluminum and copper and analyzes the influence of temperature on the electric performance of the joints. Through the fabrication of various types of unit cells for hybrid busbar joints, development of a special purpose laboratory apparatus, and numerical simulation, the paper provides insights into the variation of electrical resistance of hybrid busbars with temperature.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART L-JOURNAL OF MATERIALS-DESIGN AND APPLICATIONS
(2023)
Article
Green & Sustainable Science & Technology
Joao P. M. Pragana, Ivo M. F. Braganca, Carlos M. A. Silva, Paulo A. F. Martins
Summary: This study investigates the feasibility of combining wire-arc additive manufacturing with metal forming to create conformal cooling channels. Plastic deformation is utilized to create overhangs connecting the inner and outer tubular elements, enabling the fabrication of the cooling channels. The results show that this hybridization technique provides a more flexible method for designing and manufacturing conformal channels.
INTERNATIONAL JOURNAL OF PRECISION ENGINEERING AND MANUFACTURING-GREEN TECHNOLOGY
(2023)
Article
Chemistry, Analytical
Pedro P. Garcia, Telmo G. Santos, Miguel A. Machado, Nuno Mendes
Summary: The current human-robot collaboration solutions have the drawback of relying on the human's state or specific gestures, leading to increased task time and slower human labor. This study introduces a different concept of an HRC system that manages assembly processes executed by both humans and robots. It uses deep learning models and RGB camera data to predict collaborative workspace and human action, enabling effective management of the assembly process. The HRC framework was tested with an industrial demonstrator, achieving a mean average performance of 72.26% and successfully completing all assembly tasks within the desired time frame.
Article
Metallurgy & Metallurgical Engineering
Guilherme Gadelha de Sousa Figueiredo, Igor Jordao Marques, Lucas Oliveira Siqueira, Jiajia Shen, Joao Pedro Oliveira, Tiago Felipe de Abreu Santos
Summary: Friction stir welding improves mechanical resistance and maintains optimal phase fraction for duplex stainless steel joints. Numerical models are practical tools for assessing the welding condition of these joints. This study developed a complete coupled numerical model for friction stir welding of UNS S32205 plates and found that strain rate has a greater effect on microstructure development compared to welding peak temperatures.
WELDING IN THE WORLD
(2023)
Article
Nanoscience & Nanotechnology
J. G. Lopes, Priyanka Agrawal, Jiajia Shen, N. Schell, Rajiv S. Mishra, J. P. Oliveira
Summary: In recent years, high entropy alloys (HEAs) have been explored as potential alternatives to traditional engineering alloys. Efforts have been made to improve their mechanical properties and discover new HEAs due to the multitude of compositions allowed by these materials. The processability of HEAs, particularly in welding, is an important topic that needs to be studied. This research examines the microstructure and mechanical behavior of defect-free joints in a Fe50Mn30Co10Cr10 HEA achieved through Gas Tungsten Arc Welding (GTAW). The resulting joints exhibit excellent mechanical performance, making them viable for real-life applications.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Nanoscience & Nanotechnology
Jiajia Shen, J. G. Lopes, Zhi Zeng, Yeon Taek Choi, E. Maawad, N. Schell, Hyoung Seop Kim, Rajiv S. Mishra, J. P. Oliveira
Summary: High energy synchrotron X-ray diffraction was utilized to investigate the deformation behavior of an as-cast eutectic AlCoCrFeNi2.1 high entropy alloy during tensile testing. The study determined the volume fractions of different phases and elucidated their roles in the alloy's mechanical response. The findings showed that stress partitioning between the soft disordered FCC and hard ordered B2 BCC phases could modulate the material's deformation behavior. Additionally, analysis of dislocation density and lattice strain demonstrated the preferential deformation of certain lattice planes and the significance of the B2 BCC phase in strengthening the alloy.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Chemistry, Analytical
David Santos, Miguel A. Machado, Joao Monteiro, Jose P. Sousa, Carla S. Proenca, Fernando S. Crivellaro, Luis S. Rosado, Telmo G. Santos
Summary: This paper presents an automated Non-Destructive Testing (NDT) system for inspecting orbital welds at temperatures up to 200°C. The system combines ultrasounds and Eddy current techniques to detect both volumetric defects and surface/sub-surface cracks. The results show that the system is effective at compensating for temperature effects and has minimal influence at temperatures up to 300°C.
Article
Materials Science, Multidisciplinary
V. Chakkravarthy, J. P. Oliveira, Anisa Mahomed, Nan Yu, P. Manojkumar, M. Lakshmanan, Long Zhang, V. Raja, S. Jerome, T. Ram Prabhu, R. L. Narayan
Summary: Hot corrosion studies were conducted on pristine and abrasive water jet peened (AWJP) Ti-6Al-4V surfaces. Both surfaces developed oxide scales when coated with NaCl and exposed to 600 degrees C for 100 h, but the oxide scale on the AWJ peened surface had lower thickness and roughness. The hot corrosion rate on the pristine surface was 2.5 times higher compared to the AWJ peened surface. The improved hot corrosion resistance of the latter can be attributed to compressive residual stresses on the surface, which hinder chloride diffusion in the material.
Review
Materials Science, Multidisciplinary
Douglas S. M. Serrati, Miguel A. Machado, J. P. Oliveira, Telmo G. Santos
Summary: The wire and arc additive manufacturing (WAAM) process combines the fusion and solidification of metal wire with electric arc to create and repair complex structures. However, the high number of depositions increases the likelihood of defects, and high temperatures and surface irregularity make inspection difficult. Recent studies have shown that non-destructive testing (NDT) based on different physical phenomena can significantly reduce the rejection rate, allowing for in-line repair and waste reduction.
Review
Materials Science, Multidisciplinary
Francisco B. Ferreira, Igor Felice, Isaque Brito, Joao Pedro Oliveira, Telmo Santos
Summary: Friction stir welding is widely used in various industries, and its variant, orbital friction stir welding, is particularly important in fundamental industries like oil and gas and aerospace. The development of new process parameters, tools, and ancillary mechanisms is necessary to ensure high-quality joints. This review assesses the current state of orbital friction stir welding and discusses key aspects of this technology.
Article
Engineering, Manufacturing
Henrique V. Silva, Nuno P. Catapirra, Marta S. Carvalho, Telmo G. Santos, Miguel A. Machado
Summary: This study evaluates the performance and detects defects of polymer matrix composite (PMC) materials using four nondestructive testing (NDT) techniques. PMC samples with different reinforcement fibers are 3D printed with artificial defects. The results show that different techniques have different advantages, and using a combination of techniques can improve the reliability of defect detection.
3D PRINTING AND ADDITIVE MANUFACTURING
(2023)
Article
Engineering, Manufacturing
Liwei Wang, Tao Wu, Dianlong Wang, Zhimin Liang, Xiao Yang, Zhenzhen Peng, Ying Liu, Yongmei Liang, Zhi Zeng, J. P. Oliveira
Summary: A novel heterogeneous multi-wire indirect arc directed energy deposition (DED) technique was developed to decouple mass transfer and heat transfer for the synthesis of Al-Zn-Mg-Cu alloy components. The process parameters significantly affected the multi-wire indirect arc DED process, and the resulting indirect arc had a 'heart' shape. The deposited Al-Zn-Mg-Cu alloy exhibited composition, phases, and microstructure comparable to the 7xxx series aluminum alloys, with improved mechanical properties compared to the as-cast 7050 aluminum alloy. The novel multi-wire indirect arc DED technique shows great potential for the in-situ synthesis of high-performance alloys.
ADDITIVE MANUFACTURING
(2023)
Article
Engineering, Manufacturing
Rui F. V. Sampaio, Joao P. M. Pragana, Ivo M. F. Braganca, Carlos M. A. Silva, Chris V. Nielsen, Paulo A. F. Martins
Summary: This paper introduces a new formability test based on double-action radial extrusion to characterize material formability in the three-dimensional to plane-stress material flow transitions that are found in bulk metal-formed parts. The new test method utilizes a multidirectional tool, experimental strain determination, fractography, and finite element analysis. Results show that the new test method is capable of characterizing the failure limits of very ductile materials and facilitating the identification of cracking and corresponding fracture strains.
JOURNAL OF MANUFACTURING AND MATERIALS PROCESSING
(2023)
Article
Materials Science, Multidisciplinary
G. G. Ribamar, G. Miyamoto, T. Furuhara, J. D. Escobar, J. A. Avila, E. Maawad, N. Schell, J. P. Oliveira, H. Goldenstein
Summary: The evolution of retained austenite in a high-carbon high-silicon bearing steel during fast tempering was explored using high energy X-ray diffraction. The study revealed that the stability of retained austenite and the degree of phase decomposition can be controlled by adjusting the tempering temperature. The research also found that stress relief can reduce the lattice anisotropy of retained austenite.
METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE
(2023)
Article
Engineering, Manufacturing
Wenchao Ke, Wentao Yan, J. P. Oliveira, Bowen Pang, Long Chen, Yiming Wu, F. B. Teshome, Jiajia Shen, Liwei Wang, Caiwang Tan, Bei Peng, Xiaoguo Song, Zhi Zeng
Summary: In this study, the impact of droplet transfer on the molten pool during DED-Arc process was investigated by coupling the CFDc model and CFDi model. The metal transfer phenomena in liquid bridge transfer and free droplet transfer modes were compared, showing that the liquid bridge transfer mode is more stable and results in a better molten pool quality.
ADDITIVE MANUFACTURING
(2023)