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Description:

Microdefects sometimes form in workpieces fabricated by selective laser melting (SLM). It is difficult to understand the mechanism of generation of microdefects because the occurrence time during processing cannot be easily identified by conventional monitoring methods. We have therefore developed a convenient method for real-time monitoring of microdefects generation during SLM by using proprietary battery-powered equipment capable of continuous recording and wireless transmission of acoustic emission (AE) waveforms. To clarify the detection capabilities of the proposed method and to evaluate the factors that cause microcrack generation, AE monitoring was conducted for single-layer modeling tests with single-track or multi-track. We could successfully detect AE signals during the tests. The times of occurrence and locations of AE events were identified, and the results were compared with observations of the specimen cross-sections by the X-ray computed tomography (CT). At first in single-track tests, burst type AE events were detected during processing and their origin was confirmed to be pores and microcracks in the specimen. Then in multi-track tests, defects slightly after laser irradiation and defects due to the turning back of the irradiation were detected. The effectiveness and potential of our novel AE monitoring technique for the SLM process have been demonstrated.

Rights:

• Creative Commons BY Attribution 4.0 International
  

Keyword: Selective laser melting, Crack detection, Acoustic emission, Wireless monitoring, Real-time monitoring

Date published: 2021-02-18

Publisher: Elsevier

Journal:

• Additive Manufacturing (ISSN: 22148604) vol. 40 p. 101915-101915

Funding:

• JST (本研究は，内閣府総合科学技術・イノベーション会議の戦略的イノベーション創造プログラム（SIP)「統合型材料開発システムによるマテリアル革命」（管理法人：JST）によって実施されました。)

Manuscript type: Publisher's version (Version of record)

MDR DOI:

First published URL: https://doi.org/10.1016/j.addma.2021.101915

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Updated at: 2024-01-05 22:11:37 +0900

Published on MDR: 2023-04-24 15:08:17 +0900