TY - GEN

T1 - Resonant pulsed electromagnetic stirring of melt for effective grain fragmentation

AU - Köppen, D.

AU - Baake, E.

AU - Gerstein, G.

AU - Mrówka-Nowotnik, G.

AU - Jarczyk, G.

N1 - Funding information: This work was partially supported by the Ministry of education and science of Russian Federation (Russian President Grant). Authors are grateful to the Helmholtz-Alliance LIMTECH (Liquid Metal Technology) for financial support of the experiments in PSI and to the colleagues from Paul Scherrer Institute for their help during experiments.

PY - 2018/10/13

Y1 - 2018/10/13

N2 - The paper describes the results of an experimental research, demonstrating and explaining the effect of grain fragmentation, caused by pulsed resonant electromagnetic stirring. In the experiments, 6082 aluminium alloy melt was directionally solidified under the influence of continuous (AMF) and pulsed application (PMF) of an alternating magnetic field. The frequency of applied PMF was in accordance to the low-frequency circulation of the melt, causing the resonant increase of a pulsed component of the melt velocity. The structure of electromagnetically stirred specimens was compared to those, solidified without a magnetic field. A strong fragmentation effect (decrease of an average grain size on 51%, comparing with the solidification in natural conditions) for the case of resonant EM stirring was stated. Further, to analyse the influence of the flow, appearing due to the resonant stirring, we observed the formation of solid/liquid interface and a macro-crystalloid structure during solidification of continuously and pulsed stirred melt by applying the novel method of neutron radiography. The results confirmed the strong influence of the pulsed component of velocity on thermal conditions during solidification and, consequently, the metal structure.

AB - The paper describes the results of an experimental research, demonstrating and explaining the effect of grain fragmentation, caused by pulsed resonant electromagnetic stirring. In the experiments, 6082 aluminium alloy melt was directionally solidified under the influence of continuous (AMF) and pulsed application (PMF) of an alternating magnetic field. The frequency of applied PMF was in accordance to the low-frequency circulation of the melt, causing the resonant increase of a pulsed component of the melt velocity. The structure of electromagnetically stirred specimens was compared to those, solidified without a magnetic field. A strong fragmentation effect (decrease of an average grain size on 51%, comparing with the solidification in natural conditions) for the case of resonant EM stirring was stated. Further, to analyse the influence of the flow, appearing due to the resonant stirring, we observed the formation of solid/liquid interface and a macro-crystalloid structure during solidification of continuously and pulsed stirred melt by applying the novel method of neutron radiography. The results confirmed the strong influence of the pulsed component of velocity on thermal conditions during solidification and, consequently, the metal structure.

KW - electromagnetic stirring

KW - grain fragmentation

KW - neutron radiography

KW - process imaging

KW - solidification

UR - http://www.scopus.com/inward/record.url?scp=85056512622&partnerID=8YFLogxK

U2 - 10.1088/1757-899X/424/1/012036

DO - 10.1088/1757-899X/424/1/012036

M3 - Conference contribution

AN - SCOPUS:85056512622

VL - 424

T3 - IOP Conference Series: Materials Science and Engineering

BT - 9th International Symposium on Electromagnetic Processing of Materials (EPM2018)14–18 October 2018, Hyogo, Japan

PB - IOP Publishing Ltd.

T2 - 9th International Symposium on Electromagnetic Processing of Materials, EPM 2018

Y2 - 14 October 2018 through 18 October 2018

ER -