Revealing internal flow behaviour in arc welding and additive manufacturing of metals.
journal contributionposted on 2019-04-05, 09:03 authored by L Aucott, H Dong, W Mirihanage, R Atwood, A Kidess, S Gao, S Wen, J Marsden, S Feng, M Tong, T Connolley, M Drakopoulos, CR Kleijn, IM Richardson, DJ Browne, RH Mathiesen, HV Atkinson
Internal flow behaviour during melt-pool-based metal manufacturing remains unclear and hinders progression to process optimisation. In this contribution, we present direct time-resolved imaging of melt pool flow dynamics from a high-energy synchrotron radiation experiment. We track internal flow streams during arc welding of steel and measure instantaneous flow velocities ranging from 0.1 m s-1 to 0.5 m s-1. When the temperature-dependent surface tension coefficient is negative, bulk turbulence is the main flow mechanism and the critical velocity for surface turbulence is below the limits identified in previous theoretical studies. When the alloy exhibits a positive temperature-dependent surface tension coefficient, surface turbulence occurs and derisory oxides can be entrapped within the subsequent solid as result of higher flow velocities. The widely used arc welding and the emerging arc additive manufacturing routes can be optimised by controlling internal melt flow through adjusting surface active elements.
This research work was supported by the European Commission as part of the FP7 programme, as the project, Modelling of Interface Evolution in Advanced Welding, Contract No. NMP3-SL-2009-229108. We thank Diamond Light Source for access to X-ray beamtime on Beamline I12 (visits EE8218, EE7855).
CitationNature Communications, 2018, 9, Article number: 5414
Author affiliation/Organisation/COLLEGE OF SCIENCE AND ENGINEERING/Department of Engineering
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