Article
Chemistry, Multidisciplinary
Wenjia Wang, Jinqiang Ning, Steven Y. Liang
Summary: A complete analytical approach was proposed to predict the occurrence of defects in laser powder bed fusion, taking into account factors such as boundary heat loss and powder bed porosity. The predicted thresholds of these defects under various process conditions showed good agreement with experimental results. The proposed analytical methods show higher computational efficiency than finite element methods, making them a useful tool for optimizing process conditions in laser powder bed fusion.
APPLIED SCIENCES-BASEL
(2021)
Article
Engineering, Manufacturing
Satyajit Mojumder, Zhengtao Gan, Yangfan Li, Abdullah Al Amin, Wing Kam Liu
Summary: In this study, a physics-based thermo-fluid model is used to predict the lack-of-fusion (LOF) porosity in the laser powder bed fusion (L-PBF) process. An active learning framework and symbolic regression are adopted to find the mechanistic relationship between process parameters and LOF porosity. The results show that this relationship is predictive for a wide range of processing conditions and can effectively explore the high-dimensional process design space.
ADDITIVE MANUFACTURING
(2023)
Article
Materials Science, Multidisciplinary
Pramod R. Zagade, B. P. Gautham, Amitava De, Tarasankar DebRoy
Summary: A novel functional relation is proposed for rapid estimation of lack-of-fusion porosity fraction in laser powder bed fusion (LPBF). The estimated values are in good agreement with experimental results for five commonly used alloys and a wide range of process conditions. The functional relation is further used to construct process maps for avoiding lack-of-fusion porosity on the shop floor.
SCIENCE AND TECHNOLOGY OF WELDING AND JOINING
(2023)
Article
Crystallography
Wenjia Wang, Steven Y. Liang
Summary: This study proposed an analytical modeling strategy to calculate product porosity in laser powder bed fusion, taking into account various factors and utilizing a range of methods and models for computation and prediction.
Article
Engineering, Manufacturing
Alistair Speidel, Leonidas Gargalis, Jianchao Ye, Manyalibo J. Matthews, Adriaan Spierings, Richard Hague, Adam T. Clare, James W. Murray
Summary: This study demonstrates a new method to chemically reprocess spent LPBF metal powder under ambient conditions. The results show that surface oxide layers on spent powder can be effectively reset after rapid reprocessing. Chemically etched spent powder eliminates extensive porosity and produces track density comparable to virgin powder.
ADDITIVE MANUFACTURING
(2022)
Article
Automation & Control Systems
Wenjia Wang, Jinqiang Ning, Steven Y. Liang
Summary: This study develops an analytical modeling method with closed-form solutions to predict keyhole-induced porosity in LPBF. The model shows good agreement with experimental data, indicating acceptable predictive accuracy. The proposed model is computationally efficient and can help researchers rapidly predict porosity and understand its physics.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2022)
Article
Automation & Control Systems
Wenjia Wang, Steven Y. Liang
Summary: This study proposes a three-dimensional analytical modeling method for predicting keyhole porosity in laser powder bed fusion metal additive manufacturing. The method includes a physics-based thermal model for keyhole melting mode and a pore formation model. The predictions of keyhole porosity are compared with experimental data and show good agreement.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2022)
Article
Engineering, Manufacturing
P. Zagade, B. P. Gautham, A. De, T. DebRoy
Summary: A novel three-dimensional analytical heat transfer model is proposed to simulate the laser powder bed fusion process efficiently and accurately. The computed results show good agreement with experimental data and process maps are provided for estimating desired fusion zone dimensions.
ADDITIVE MANUFACTURING
(2021)
Article
Thermodynamics
Zhi-Jian Li, Hong-Liang Dai, Jian Xu, Zheng-Wei Huang
Summary: In this paper, a semi-analytical model is established to predict the three-dimensional transient temperature field distributions during laser additive manufacturing process. The model considers heat losses caused by conduction, convection, and radiation. The effect of process parameters and heat source model on peak temperature, temperature gradient, molten pool dimensions, and heat losses is analyzed. It is found that the volumetric heat source model results in higher average temperature and lower heat losses, and heat losses increase with increasing laser power, energy absorptivity, and effective radius of the laser beam.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Engineering, Industrial
Patcharapit Promoppatum, Raghavan Srinivasan, Siu Sin Quek, Sabeur Msolli, Shashwat Shukla, Nur Syafiqah Johan, Sjoerd van der Veen, Mark Hyunpong Jhon, Rajiv Mishra
Summary: This study compares three common strategies to measure porosity in additively manufactured metals, highlighting the differences between the Archimedes method and the micrograph-based approach. It is found that the Archimedes method measures total porosity while the micrograph method measures effective porosity, leading to divergent predictions at higher void fractions. Additionally, a geometric model for porosity prediction is implemented and proven to show good agreement with numerical simulations and experimental measurements.
JOURNAL OF MATERIALS PROCESSING TECHNOLOGY
(2022)
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
Danilo de Camargo Branco, Eshan Ganju, Licong An, Nikhilesh Chawla, Gary J. Cheng
Summary: The Powder Bed Fusion (PBF) additive manufacturing technique is widely used in the industry but has issues of porosity and lack of fusion. This study focuses on controlling the transient temperature field by shaping the laser pulse to improve build quality and reduce defects.
ADDITIVE MANUFACTURING
(2023)
Article
Engineering, Manufacturing
Xing He, Decheng Kong, Yiqi Zhou, Li Wang, Xiaoqing Ni, Liang Zhang, Wenheng Wu, Ruixue Li, Xiaogang Li, Chaofang Dong
Summary: This study compares and analyzes the impact of different powders on the mechanical properties of Hastelloy X alloys and reveals the evolution of printed defects. The findings highlight the increase in particle size and oxygen content of recycled powder, leading to some issues in the manufacturing process. However, the difference in grain size is minimal. Furthermore, it is shown that large-sized printed defects significantly affect crack initiation and propagation.
ADDITIVE MANUFACTURING
(2022)
Article
Engineering, Manufacturing
Corey L. Smithson, Taylor Davis, Tracy W. Nelson, Nathan B. Crane
Summary: Additive manufacturing (AM) provides design freedom but also introduces defects. This study examines porosity in 316 SS samples manufactured with LPBF at different depths from the surface. Results show that surface porosity is often higher than bulk porosity, especially at larger build angles and close support spacing values. These findings highlight the importance of considering near surface porosity in selecting build conditions and finishing requirements for PBF parts.
JOURNAL OF MANUFACTURING PROCESSES
(2023)
Article
Engineering, Manufacturing
M. Amiri, E. J. Payton
Summary: Accurately modeling the physics of laser-powder interaction is crucial for predicting performance-limiting defects in parts manufactured through laser powder bed fusion. This paper introduces an analytical model for rapid prediction of denudation width in this additive manufacturing process, taking into account factors like laser power, scan speed, and powder particle characteristics. The study also presents a criterion for the onset of denudation, showing that denudation width increases with decreasing laser speed for a given laser power.
ADDITIVE MANUFACTURING
(2021)
Article
Green & Sustainable Science & Technology
Jinqiang Ning, Daniel E. Sievers, Hamid Garmestani, Steven Y. Liang
INTERNATIONAL JOURNAL OF PRECISION ENGINEERING AND MANUFACTURING-GREEN TECHNOLOGY
(2020)
Article
Automation & Control Systems
Jinqiang Ning, Maxwell Praniewicz, Wenjia Wang, James R. Dobbs, Steven Y. Liang
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2020)
Article
Optics
Xia Ji, Elham Mirkoohi, Jinqiang Ning, Steven Y. Liang
OPTICS AND LASERS IN ENGINEERING
(2020)
Article
Engineering, Mechanical
Jinqiang Ning, Daniel E. Sievers, Hamid Garmestani, Steven Y. Liang
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2020)
Article
Chemistry, Physical
Jinqiang Ning, Wenjia Wang, Xuan Ning, Daniel E. Sievers, Hamid Garmestani, Steven Y. Liang
Article
Robotics
David W. Collinson, Hannah M. Emnett, Jinqiang Ning, Mitra J. Z. Hartmann, Lynda Catherine Brinson
Summary: Many mammals rely on their vibrissae (whiskers) to explore their environment tactually. Research has shown that tapered vibrissae can accurately determine the three-dimensional location of contact with an object. Creating biomimetic tapered whiskers has been challenging, but a new study has developed artificial whiskers that outperform previous non-tapered filaments in predicting contact points.
Article
Chemistry, Physical
Yuanzhe Dong, Jinqiang Ning, Peng Dong, Yujian Ren, Shengdun Zhao
Article
Automation & Control Systems
Wenjia Wang, Jinqiang Ning, Steven Y. Liang
Summary: This study develops an analytical modeling method with closed-form solutions to predict keyhole-induced porosity in LPBF. The model shows good agreement with experimental data, indicating acceptable predictive accuracy. The proposed model is computationally efficient and can help researchers rapidly predict porosity and understand its physics.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2022)
Article
Chemistry, Multidisciplinary
Wenjia Wang, Jinqiang Ning, Steven Y. Liang
Summary: A complete analytical approach was proposed to predict the occurrence of defects in laser powder bed fusion, taking into account factors such as boundary heat loss and powder bed porosity. The predicted thresholds of these defects under various process conditions showed good agreement with experimental results. The proposed analytical methods show higher computational efficiency than finite element methods, making them a useful tool for optimizing process conditions in laser powder bed fusion.
APPLIED SCIENCES-BASEL
(2021)
Article
Chemistry, Multidisciplinary
Wenjia Wang, Jinqiang Ning, Hamid Garmestani, Steven Y. Liang
Summary: This research proposes an analytical method for predicting the molten pool size in laser-based powder bed fusion (LPBF) additive manufacturing by taking into account the process conditions-dependent absorptivity. The method uses an empirical model of absorptivity to calculate the laser absorptivity under different process conditions, and an analytical point-moving heat source model to calculate the temperature distribution of the build-in LPBF. The predicted molten pool widths and depths were found to be close to the experimental measurements, and the computational time of the model was shown to be efficient.
APPLIED SCIENCES-BASEL
(2022)
Article
Engineering, Manufacturing
Wenjia Wang, Jinqiang Ning, Steven Y. Liang
Summary: The paper introduces an analytical modeling method to predict the in-situ distortion in laser cladding process without using iteration-based numerical calculations. The effects of build edges and geometry on thermal convection and radiation are considered, demonstrating good predictive accuracy and low computational cost for studying full-field temperature and distortion of geometrically complex parts.
INTERNATIONAL JOURNAL OF PRECISION ENGINEERING AND MANUFACTURING
(2021)