Comparison and analysis of hyperspectral temperature data in directed energy deposition

Article Engineering, Industrial

Calibrated closed-loop control to reduce the effect of geometry on mechanical behaviour in directed energy deposition

F. Freeman et al.

Summary: Directed energy deposition (DED) is a promising technology for repairing aerospace components, but concerns about variation in microstructure and mechanical properties have limited its adoption. In this study, we developed an industrially-suitable control algorithm using a low-cost coaxial camera and statistical process control techniques to identify representative melt pool images. Testing on long builds confirmed that the control algorithm successfully eliminated component-scale trends in melt pool size and achieved improved mechanical homogeneity.

JOURNAL OF MATERIALS PROCESSING TECHNOLOGY (2023)

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Article Optics

Continuous online flaws detection with photodiode signal and melt pool temperature based on deep learning in laser powder bed fusion

Zhuangzhuang Mao et al.

Summary: In this work, a continuous online flaws detection method in Laser Powder Bed Fusion (LPBF) is proposed, combining the photodiode signal and melt pool temperature based on deep learning algorithms. By establishing a correlation model between the photodiode signal and average melt pool temperature, continuous online flaws detection can be achieved using only the photodiode signal.

OPTICS AND LASER TECHNOLOGY (2023)

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Article Materials Science, Multidisciplinary

Closed-loop control of meltpool temperature in directed energy deposition

Ziyad Smoqi et al.

Summary: The objective of this study is to reduce flaw formation in powder and laser-based additive manufacturing process by controlling the meltpool temperature through closed-loop control. The results demonstrate that parts built under closed-loop control have reduced porosity variation and consistent microstructure compared to parts built under open-loop conditions.

MATERIALS & DESIGN (2022)

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Article Materials Science, Multidisciplinary

Toward defect-free components in laser metal deposition with coaxial wire feeding through closed-loop control of the melt pool temperature

Christian Bernauer et al.

Summary: Laser metal deposition is an additive manufacturing process used for the manufacturing, modification, and repair of metal components. The use of wire as feedstock offers advantages over powder. The melt pool temperature is an important input parameter that affects the resulting geometry and material properties.

JOURNAL OF LASER APPLICATIONS (2022)

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Article Optics

The influence of key process parameters on melt pool geometry in direct energy deposition additive manufacturing systems

Robert Sampson et al.

Summary: Measuring melt pool width is critical in additive manufacturing for developing advanced control systems and defect detection algorithms. Parametric studies are crucial in identifying optimal settings, requiring in-depth process/material knowledge. Understanding parametric interaction and melt pool mechanics is essential for developing state of the art additive manufacturing components.

OPTICS AND LASER TECHNOLOGY (2021)

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Article Engineering, Multidisciplinary

Improved monochromatic pyrometry for synchronous measurement of full-field temperature and deformation

JinSong Zhang et al.

Summary: A method for synchronous temperature and deformation measurement at high temperatures, including monochromatic pyrometry and high-temperature digital image correlation, was proposed. Experimental results showed that the proposed method can reduce errors caused by camera channel crosstalk and is applicable for simultaneous measurement of temperature and deformation.

SCIENCE CHINA-TECHNOLOGICAL SCIENCES (2021)

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Article Thermodynamics