In-situ fabrication of graded material with the application of a horizontal magnetic field during directional solidification

Journal Article · Sun Jul 15 04:00:00 EDT 2018 · Materials Characterization

DOI:https://doi.org/10.1016/J.MATCHAR.2018.05.007· OSTI ID:22805062

Du, Dafan ^[1]; Fautrelle, Yves ^[2]; Dong, Anping; Shu, Da; Zhu, Guoliang; Sun, Baode ^[1]; Nguyen-Thi, Henri ^[3]; Ren, Zhongming; Li, Xi ^[2]

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1. Shanghai Key Lab of Advanced High-temperature Materials and Precision Forming, Shanghai Jiao Tong University, Shanghai 200240 (China)
2. SIMAP-EPM-Madylam/G-INP/CNRS, PHELMA, BP 75, 38402 St Martin d'Heres Cedex (France)
3. Aix Marseille University, CNRS, IM2NP UMR 7334, Campus Saint-Jerome, case 142, 13397 Marseille (France)

Highlights: • The horizontal magnetic field caused the migration of primary grains and the formation of graded material. • TEMF play a major effect on the formation of graded material. • The magnitude of TEMF increases with the increase of magnetic field intensity. • This work initiates a new method to prepare the “graded material” via an applied horizontal magnetic field. - Abstract: The present paper proposes a method of graded materials preparation under a low horizontal magnetic field during directional solidification. The external horizontal magnetic field was applied to the mushy zone of the directionally solidified Al-10 wt% Cu and Al-18 wt% Si samples, which was perpendicular to the growth direction. Experimental results demonstrate that the applied horizontal magnetic field produces a gradient size distribution of the primary α(Al) grains in Al-10 wt% Cu alloys and a gradient fraction distribution of primary Si particles in Al-18 wt% Si alloys. 3D numerical simulations indicate that the formation of graded structure should be attributed to the migration of primary phase driven by the thermoelectric magnetic force (TEMF). The formation of segregation channel should be attributed to the TEM convection (TEMC) in the mushy zone. Further, in situ synchrotron X-ray radiography observations of the initial transient of directional solidification show that the primary α(Al) phases were migrated approximately along the direction perpendicular to the magnetic field. These results suggest that the TEM effects can greatly change the growth of primary grains and the solidification structure, and the application of an external horizontal magnetic field would be beneficial to fabricate the graded material during directional solidification.

• OSTI ID: 22805062
• Journal Information: Materials Characterization, Journal Name: Materials Characterization Vol. 141; ISSN 1044-5803; ISSN MACHEX
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM COMPOUNDS
BINARY ALLOY SYSTEMS
COMPUTERIZED SIMULATION
DISTRIBUTION
MAGNETIC FIELDS
SEGREGATION
SILICON COMPOUNDS
SOLIDIFICATION
SYNCHROTRON RADIATION
TRANSMISSION ELECTRON MICROSCOPY
X-RAY RADIOGRAPHY