Residual Stress Reduction Technology in Heterogeneous Metal Additive Manufacturing
1
Mechanical components and Materials R&D Group, Korea Institute of Industrial Technology, Daegu 711-883, Korea
2
Graduate School, Kyungpook National University, Daegu 41566, Korea
3
School of Mechanical Engineering, Kyungpook National University, Daegu 41566, Korea
*
Author to whom correspondence should be addressed.
Materials 2020, 13(23), 5516; https://doi.org/10.3390/ma13235516
Received: 2 November 2020
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Revised: 30 November 2020
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Accepted: 1 December 2020
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Published: 3 December 2020
(This article belongs to the Special Issue Additive Manufactured Metals, Polymers and Hybrid Materials for Engineering Applications)
Metal additive manufacturing (AM) is a low-cost, high-efficiency functional mold manufacturing technology. However, when the functional section of the mold or part is not a partial area, and large-area additive processing of high-hardness metal is required, cracks occur frequently in AM and substrate materials owing to thermal stress and the accumulation of residual stresses. Hence, research on residual stress reduction technologies is required. In this study, we investigated the effect of reducing residual stress due to thermal deviation reduction using a real-time heating device as well as changes in laser power in the AM process for both high-hardness cold and hot work mold steel. The residual stress was measured using an X-ray stress diffraction device before and after AM. Compared to the AM processing conditions at room temperature (25 °C), residual stress decreased by 57% when the thermal deviation was reduced. The microstructures and mechanical properties of AM specimens manufactured under room-temperature and real-time preheating and heating conditions were analyzed using an optical microscope. Qualitative evaluation of the effect of reducing residual stress, which was quantitatively verified in a small specimen, confirmed that the residual stress decreased for a large-area curved specimen in which concentrated stress was generated during AM processing.
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Keywords:
additive manufacturing; residual stress; mold steel; functional metal powder; direct energy deposition
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MDPI and ACS Style
Hong, M.-P.; Kim, Y.-S. Residual Stress Reduction Technology in Heterogeneous Metal Additive Manufacturing. Materials 2020, 13, 5516. https://doi.org/10.3390/ma13235516
AMA Style
Hong M-P, Kim Y-S. Residual Stress Reduction Technology in Heterogeneous Metal Additive Manufacturing. Materials. 2020; 13(23):5516. https://doi.org/10.3390/ma13235516
Chicago/Turabian StyleHong, Myoung-Pyo, and Young-Suk Kim. 2020. "Residual Stress Reduction Technology in Heterogeneous Metal Additive Manufacturing" Materials 13, no. 23: 5516. https://doi.org/10.3390/ma13235516
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