Targeted rework of powder bed fusion additive manufacturing

Dryburgh, Paul; Patel, Rikesh; Catchpole-Smith, Sam; Hirsch, Matthias; Parry, Luke; Smith, Richard J.; Clark, Matt; Ashcroft, Ian A.; Clare, Adam T

Abstract

There is a clear industrial pull to fabricate high value components using premium high temperature aerospace materials by additive manufacturing. Inconveniently, the same materials’ properties which allow them to perform well in service render them difficult to process via powder bed fusion. Current build systems are characterised by high defect rates and erratic microstructure, leading to components with inferior mechanical properties. Given the high specific costs in powder bed fusion manufacture there is a real and apparent need to minimise component scrappage due to these defects. Here a method is proposed to make good the defects that will inevitably be produced in current class laser processing of metallic powders. This study investigates the use of spatially resolved acoustic spectroscopy (SRAS) scan data to inform repair strategies within a commercial selective laser melting machine. Using the common aerospace nickel superalloys, Inconel 718 and CM247-LC, localised remelting was shown to consistently reduce the depth of defect. A 50 % reduction in defect depth was observed for both materials using different rework strategies. No appreciable variation was seen with the single-shot strategy, due inaccurate realignment.

Citation

Dryburgh, P., Patel, R., Catchpole-Smith, S., Hirsch, M., Parry, L., Smith, R. J., …Clare, A. T. (2018). Targeted rework of powder bed fusion additive manufacturing. In Proceedings of LPM2018 - the 19th International Symposium on Laser Precision Microfabrication (#18/030)

• Conference Name: 19th International Symposium on Laser Precision Microfabrication
• Start Date: Jun 25, 2018
• End Date: Jun 27, 2018
• Acceptance Date: Jul 17, 2018
• Publication Date: Jun 25, 2018
• Deposit Date: Oct 25, 2018
• Publicly Available Date: Oct 26, 2018
• Pages: #18/030
• Book Title: Proceedings of LPM2018 - the 19th International Symposium on Laser Precision Microfabrication
• Chapter Number: 30
• ISBN: n/a
• Public URL: https://nottingham-repository.worktribe.com/output/1190715
• Publisher URL: http://www.jlps.gr.jp/en/proc/lpm/18/
• Contract Date: Oct 25, 2018